A baseline for Scotland’s lowland arable-grass

James Hutton Institute, Dundee, UK: Geoff Squire, Cathy Hawes, Gillian Banks, Linda Ford, Tracy Valentine, Mark Young, Contact: geoff.squire@hutton.ac.uk

Featured case study: Knock Farm, Roger Polson

[Under editing – subject to minor changes -18 July 2018]

Towards an Atlantic regional hub for sustainability R&D

An update on aims and progress with examples to coincide with the Royal Northern Agricultural Society’s EcoAgriTech event at Knock Farm near Huntly.

Introduction

The sustainability of food production systems and landscapes is a global priority. The lowland arable-grass agriculture of Scotland’s Atlantic coast presents a significant regional study, unique in its diversity, high yield potential and landscape complexity. The James Hutton Institute has been developing the arable-grass as an Atlantic regional R&D hub to stimulate and enable collaboration with expertise in Boreal, Mediterranean, Continental and Balkan regions across Europe.

The aims are to establish a sound baseline through a wide range of biophysical and economic indicators, define sustainable states, assess the current direction of change and where necessary initiate remedial action.  An essential part of the effort and expertise is contributed by farmers who allow access to their fields and landscapes for monitoring and experiment. Here, we summarise data collection on soils and seedbanks as a case study for Knock Farm near Huntly.

Methods

The region has been sampled and analysed since a first field survey in 2007. The structure of fields and their locality, the crops and weeds, the agronomy, invertebrates and the vegetation of field margins were examined in over 100 fields from the Black Isle to the Borders.  Soil was taken and assessed for biophysical quality, including particle size, carbon (C) and nitrogen (N) content, C:N ratio, water holding capacity, bulk density, penetrability, pH and pore space. The samples were processed to assess the buried weed seedbank – a useful indicator of field biodiversity and farming intensity. Return visits were made to selected sites to assess change over time. Methods are described in Publications.

Soil and seedbank indicators

Of the biophysical attributes measured in the surveys, those defining soil quality and seedbank diversity are among the most instructive. Soil indicators differ greatly among sites. To demonstrate the range, the data for each attribute are summarised in the form of frequency histograms, presented for two soil variables in Fig. 1. The horizontal axis gives the range of values divided into intervals (the upper limit of each is labelled), while the vertical axis shows the percentage of sites in each interval. 

Taking soil carbon (C, % by weight) for example, the highest proportion of sites occurs between 1.5 and 2.5%, but there are some very low values and a long higher tail of a few sites stretching to more than 6%. The spread shows that many soils, such as those around 2.5% are in moderately good health, but some soils have a low content below 1.5% and are in danger of erosion and loss of function, including capacity to yield. The other histogram shows water holding capacity (field capacity), higher values indicating a soil can hold more water when fully wetted and allowed to drain. During drought, crops in those fields at the lower end of the range will suffer water stress more quickly.

Fig. 1 Frequency histograms for all sites of soil % carbon and field (water holding) capacity. The arrows indicate values for fields sampled at Knock Farm. 

The seedbank of buried ‘weed’ seeds has a dual role in cropland ecology.  Too many injurious weeds are damaging to yield. Too few of the beneficial weeds limit the cropland’s ability to sustain food webs that in turn mediate essential processes such as breakdown of organic matter, nitrogen transformations, pest regulation and pollination. Arable seedbanks are generally manageable if they contain 3,000 to 9,000 seeds per square metre (of field surface to a depth of 20 cm). Below 2,000 and they tend to hold too few beneficial species. Above 9,000 and their weed burden becomes difficult to control. These numbers might sound high, but they were much higher, typically 10,000 to 100,000 per square metre, in the first half of the 20th century.

Seedbanks are usually dominated by a few species but contain others at low density.  Seedbanks that can sustain a diverse in-field food web typically contain 15-25 species, ideally in an equitable balance. 

Fig. 2 Frequency histograms for all sites of the number of plant species in seedbank samples and the number of seeds per unit field area. The arrows indicate values for fields A and B sampled at Knock Farm. Text box below gives explanation.

Case study: Knock Farm, Huntly (Roger Polson)

Two fields were sampled at Knock Farm. They were very similar in terms of soil attributes. In Fig. 1, the location of the fields on each histogram is shown by the single arrow. Fields were well above average in soil carbon and near the top of the range in field capacity. The fields also came out near the top in most other soil quality variables, including bulk density and porosity (air space). 

The fields differed in their seedbank, probably indicating either a difference in previous management or local conditions. Seed numbers of all species combined (10 to 15) in Field A were in the range 9000-12,000 per square metre and the seedbank was dominated by one species at very high density, chickweed (Stellaria media). The other, Field, B, was far less dominated: it had fewer seeds and more species, almost an ideal combination. 

Each year, weeds emerge from a seedbank but hardly ever in direct proportion to the species present. Here, Field A also had a higher density of emerged weeds in 2007, but the dominant species was annual meadow grass (Poa annua). On a subsequent sample in 2014, both Poa annua and Stellaria media were still the commonest weeds, but other species, bringing diversity to the food web, were hemp-nettles (Galeopsis species) and redshank (Persicaria maculosa). 

Conclusions and progress to date
  • Field surveys in eastern, lowland Scotland are providing baseline data to characterise an Atlantic zone hub in sustainability R&D.
  • Time trends are being assessed by measuring factors in the same locations in different years.
  • Information collected at field and farm scales is being aligned with national inventories and mapping of soil, climate and land use.
  • The baseline can be used to rate and rank fields and practices on individual holdings, as shown here for Knock Farm, near Huntly.
 Acknowledgements

The original survey in 2007 was managed jointly by TJHI and SRUC in a major project funded by Scottish Government as part of the Sustainable Crop Systems Programme 2006-2011. Soil and seedbank attributes were measured at TJHI’s laboratories. Subsequent sampling up to 2015 was also funded by Scottish Government.

Publications

Hawes C, Squire GR, Hallett PD, Watson C, Young M. 2010. Arable plant communities as indicators of farming practice. Agriculture Ecosystems and Environment 138:17–26.

Squire G R. 2017. Defining sustainable limits during and after intensification in a maritime agricultural ecosystem. Ecosystem Health and Sustainability 3; doi.org/10.1080/20964129. 2017.1368873.

Squire G R, Hawes C, Valentine T A, Young M W. 2015. Degradation rate of soil function depends on trajectory of agricultural intensification. Agriculture Ecosystems and Environment 202:160–167.

Valentine TA, Hallett PD, Binnie K, Young MW, Squire GR, Hawes C, Bengough AG. 2012 Soil strength and macropore volume limit root elongation rates in many UK agricultural soils.  Annals of Botany 110:259-270. 

Young M W, Mullins E, Squire G R. 2017. Environmental risk assessment of blight resistant potato: use of a crop model to quantify nitrogen cycling at scales of the field and cropping system. Environmental Science and Pollution Research 24:21434–21444.

Greening with decision trees

Analysis of the Report of the Scottish Government CAP Greening Group 2017. Interpretation through DEXi decision trees. Their potential in planning and implementation.

During 2017, a group of farmers, NGO representatives and scientists were asked to consider the current status and utility of Greening measures and options for an improved future system. This article is an interpretation of the group’s report [1] augmented with related discussion, including a much wider examination of CAP Greening by a team from The James Hutton Institute [2].

Concepts and ideas discussed  in the Greening group are summarised as a ‘tree’ built in a programme called DEXi, devised by Marko Bohanec at the Josef Stefan Institute, Slovenia [3]. The tree shows two main branches – one in blue in Fig. 1, covering the methods of a future CAP replacement, and one in orange showing the things that the replacement should try to improve, such as the rural economy, biodiversity and appreciation of the countryside.

 

Fig. 1 Division of the tree: the upper branch, blue, defines how to achieve a future ‘CAP’; the lower, orange, sets out the required economic, biophysical and societal status of a sustainable system.

DEXi trees such as this can be made ‘active’ and ‘worked’ to quantify, compare and rank different schemes .

The structure of the tree, explained below, is not one that the author thinks is final or complete – its aim is to summarise the report and discussion of the Greening group. The author’s preference for a more expansive and integral ‘greening’ will be argued in subsequent articles.

The main branches

The tree begins or ends, because it can work both ways, with an overall appraisal of the reform, named here ‘future sustainable’ [4]. To achieve this state, the methods of future-CAP (branch 1, its aims and incentives) and the desired states of the ecosystem that the methods are designed to achieve (branch 2, the outputs and services) both need to be satisfied (Fig. 2). There is little point in having a great system that encourages farming to achieve a desired state, but that state itself is unsustainable, and vice versa.

Each main branch sub-divides in this case into three (but it could be two or four). Branch 1 needs an overall strategy and design, then a set of assessment and advisory tools and finally a means to make it work. Branch 2 is here expressed through environmental, economic and societal features of the ecosystem. There is no unique merit in this division – branch 2 could be split into the four main ecosystem services or several Sustainable Development Goals or any other overarching frame. In fact, these sub-divisions are simply what the author felt best covered the recommendations of the CAP Greening group – but they could easily be altered.

Fig. 2 Primary branches of the tree into aims & incentives and outputs & ecosystem services, each of which then subdivides into three. Each group of three ‘leaves’ determine the value of a ‘node’ through  a utility function.

Each ‘box’ on the tree – named an attribute in decision tree terminology – can be defined by its contribution to an overall sustainable state. In practice, attributes tend to be rated on a three- to five-point scale, e.g. high, medium or low.  As the tree is worked rightwards, each box is seen to depend on several other boxes. For example, outputs-services depends on environment, production and societal attributes, and if all these three are rated high, then the branch is also rated high. But what happens if environment is high but societal low. The result is then decided by a utility function. The rules governing each utility function are set by the operators or group of people working the tree.

This working of the utility function is the core of DEXi decision trees. In practice, the function can be changed during a round-table meeting and the result compared. How to do this will be covered in another article. This one will set out the main structure of the tree.

Aims and incentives – how to achieve the desired ecosystem state

The part of the overall tree in blue in Fig. 1 and named as branch 1 in Fig. 2 consists of three main boxes split into further boxes, shown here as a set of hierarchical levels (Fig. 3). Altogether 5 levels are shown from left to right.

 

Fig. 3 Branch of the decision tree covering aims and incentives of a ‘future CAP’.

One of the sub-branches is described for illustration – the central one ‘strategic / design’. Discussion emphasised the need to have a broad but defined framework in which future-CAP would operate and the need for it to be holistic, i.e. covering a wide range of land management outcomes and their interactions, and inclusive, allowing a range of people both managing and affected by the system to have a say. The framework should be ‘enabling’, which means letting managers decide how to achieve the best result, and both flexible and sensible, allowing managers to vary decisions depending on the season and locality.

Other needs that recurred in the discussion were for greater professional training for farmers and advisers and a set of new metrics by which the achievements were judged. The Result-based approach to agri-environment schemes offers one way to devise such new metrics [5].

As before, utility functions determine the value of an attribute from its dependents. If two proposed schemes are being compared, for example, each would be ranked as to how well they satisfied all the attributes in the boxes. For ‘Advice and training’ to rate high, both ‘enhanced extension services’ and ‘professional development’ would need to rate high (and so on).

Features of a sustainable system

The lower branch in Fig. 1 – branch 2, outputs / services – defines features of a sustainable system. ‘Outputs’ refers to the economic and other products supported by the system while (ecosystem) ‘services’ refers to the functions of storage and cycling of solar energy, water and nutrients among different parts of the system. Generally on this web site, economic products will be regarded as another flow of energy and materials, no different in principle from the main element cycles, but here they are distinguished.

The central sub-branch of 2 is about agricultural production. It is of course highly simplified but shows some of the main topics discussed. Central to the whole debate is the balance between how much comes off the farm and what farming gets for it. The general opinion was that other stages in the quality chain from yield to consumer get more of the benefits than accrue to the farmer. So there is little point in having a profitable crop if the balance is unfair, and to achieve fairness will need buy-in from people and government.

 

Fig. 4 The branch of outputs-services dealing with agricultural production.

Another sub-branch is named ‘environment’ (Fig. 5), which again shows some of the main topics  examined. For example, ‘landscape complexity’ would be ranked according to how well the landscape supported a diversity of plants and animals. Connectivity, including managing across types of landscape, featured highly in discussion. For landscape complexity to rank high, several landscape types, here illustrated by upland high-nature-value farmland and lowland farmland, would each have to each rank high, but then the connectivity between them would also have to be high.

Under ‘reduce adverse impacts’, losses & pollution would need to include all the various processes that lead to a low carbon footprint and therefore high sustainability, while ‘soil & food webs’ would be broken down into many compartments, not just the general one indicated.

Fig. 5 The branch of outputs-services dealing with ‘environment’.

The final branch under 2 deals with ‘societal health & wellbeing’ in terms of food and nutrition, landscape, a sense of place and employment in the countryside (Fig. 6). Taking one of these for illustration, food and nutrition divides into diet and also local production – the latter to capture those aspects of locality and provenance that are considered increasingly important by many people. For ‘food and nutrition’ to rate high, therefore, it will not be enough that the food is nutritious, but it must also be produced with regard for and least damage to nature, and from a short quality chain, rather than one that goes round the world and back.

Fig. 6 The branch of outputs-services dealing with societal health and wellbeing.

The operation of a decision tree

The first task in designing a decision tree is to set out the main variables – the ‘attributes’ in decision tree terminology and the relations between them. The structure of the tree and its attributes shown in Fig. 2 to 6 are based on topics that emerged in the Greening report and related discussion [1]. The author finds that doing this in itself helps appreciation of the range of issues that need to be considered.

For the tree to operate as a decision-aid, each box has to be quantified on a scale, typically 1 to 5  or 1 to 3, or high-medium-low, which defines the degree to which the attribute contributes to a sustainable state. Then the utility functions (see Fig. 2, 3) have to be set that determine the value given to an attribute depending on the value of the two or more that that feed into it. This might sound a little complicated, but in DEXi software, a simple tree such as this, once built, can be worked in an hour of round-table discussion.

DEXi decision trees are mainly used for comparison, so it would now be time to compare schemes, such as two proposed alternatives for future CAP greening. (Before doing that, the author needs to do further checks to consider whether the structure is ‘right’ for the purpose.)

In the meantime, the full branch 2 is laid out in Fig. 7. Even in simplified form, it involves a lot of attributes – but this reflects the complexities of managing land for many outputs and ecosystem services.

Fig. 7 Branch 2 combining Fig. 4, 5, 6 and showing the utility functions (ovals) that need to be in place to make the tree operational.

Putting numbers on the attributes

As stated, each box or attribute has to be defined on a scale indicating its contribution to a sustainable production system. Decision trees much larger than this have been constructed for comparing integrated pest management schemes (DEXiPM) and production ecosystems. One developed by the author and collaborators is named DEXiES – DEXi for Ecosystem Services. It has hundreds of attributes, most well quantified through years of research in the landscapes of eastern Scotland.

DEXiES has been used to compare high- and low-input cropping and is being extended to HNV grazing. Ratings applied to each attribute are mostly taken from hard quantitative data. For example, in lowland cropped agriculture, soil carbon below 1.5% might be classed as ‘low’ for sustainability, 1.5-3% as medium, 3-4% as medium-high and above as 4% high.

While each of the attributes in the DEXi tree shown here could in principle by quantified in a similar way on a three or five point scale, many of them will not have been thought about in this way – ‘beauty of nature’ for example. Yet experience has shown that a group of people, of diverse backgrounds and interests, could after some debate, rate and rank a greening support scheme in terms of its contribution to sustainability.

Sources, links

[1] Report by the CAP Greening Group available on the Scottish Government web site at CAP Greening Group: Discussion paper.

[2] A major, detailed review of CAP Greening was undertaken by The James Hutton Institute. Findings are detailed in summary and multi-part report available to download from the Scottish Government web site at CAP Greening Review.

[3] Decision trees, multi-attribute modelling and DEXi software at Marko Bohanec’s web site DEXI: a programme for Multi-Attribute Decision Making.

[4] The definition of what is meant by sustainable will be examined in detail elsewhere. Growing cereals and tending stock have been  practiced here for 5000+ years and there is no reason in principle why they should not continue for this period into the future. Within the bounds of arguments around CAP greening,  ‘sustainable’ means any practice that contributes to such a continuation, which relies on healthy soil and an ecologically well functioning landscape.

[5] For an introduction to Result-based approaches, see Regenerative agriculture : short supply chains.

Author/contact: geoff.squire@hutton.ac.uk


Acknowledgements

The author (G R Squire) was funded by The James Hutton Institute to take part in discussions of the CAP Greening group [1]. The contribution of a chapter by G R Squire & C Hawes to the Hutton Greening report [2] was funded from the Hutton’s Ecological Sciences group budget.

Again, thanks are to Marko Bohanec for devising DEXi and making it available free of charge.

Posts, articles and blogs on this curvedflatlands web site (including this one) are prepared in the author’s own time.

 

 

Regenerative agriculture : short supply chains

Comment on the meeting Farmers and Nature, SNH, 18 May 2018. Inspiring examples: holistic, diverse, innovative. Current support unfitting. Long supply chains need disrupting. Result-based payment a way forward. B for A and A for B.

Inspiring examples were heard today of a commitment to farming and wider land management by five different people and enterprises [1]. The aim of this SNH-sponsored meeting – Farmers and Nature: promoting success and looking forward, 18 May 2018 – was to get people to share their experiences of managing land for the long term and for a range of economic and environmental outputs. All five speakers agreed that just taking from the land was not feasible, but that ecological regeneration and maintenance were essential for a future. There was little prosaic description of what not to do. Rather, the day was a set of inspired personal accounts by people operating outside the expected norms of agricultural management and long food supply chains.

Fig. 1 Contrasting lowland landscapes, fields mapped in colour: greens representing various types of grass, orange cereals. Prepared by Nora Quesada and Graham Begg for the Living Field web site.

Diversity of landscape and land use (Fig. 1) means that no one set of prescriptions can be applied to gain environmental benefit in farmland. Flexibility is needed to allow local adaptation to solve local problems, as was heard.

Speakers were: David Aglen, Balbirnie Home Farms [2], specialising in combinable crops, veg and potatoes, grass for suckler cows and forestry; Bryce Cunningham, Mossgiel Farm [3] producing ‘non-homogenised milk, by Ayrshire cows grazing the historical pastures of Robert Burns’ and in doing so disrupting the established the long and convoluted supply chain for milk processing and marketing; Lynn Cassels, Lynbreck Croft [4] producing hens, pigs, cattle and bees and also planting trees, in what many would class as difficult land and climate; Roger Polson, Knock Farm, Hunty [5] running a mixed organic enterprise with suckler cows, breeding ewes, livery horses and spring crops; and Teyl de Bordes, Whitmuir Estate, near Selkirk [6], creating opportunities and support for a wide range of plants and animals in mixed farmland. Links to their work and presentations on the day via YouTube can be found near the bottom of the page [2 to 6].

The speakers saw themselves as far from the mainstream. It was not just that they thought themselves on the fringes, but that their neighbours and peers thought they were. Yet to me their philosophy and practices are examples of what will be central to a sustainable future. They are innovators, not complying with what is expected of farmers and crofters in the early 21st century. It was encouraging also to see some disruption of the long supply chains that force farm profits down and the decouple land from the consumer. 

Fig. 2 Some of the topics at the meeting, from general characteristics of a managed ecosystem, through products, methods and biodiversity, to criteria for support, payment and targeting. A for B is Agriculture for Biodiversity and B for A is Biodiversity for Agriculture (not presented in this form but highly relevant, see text below).

Common threads

Several general threads recurred among these examples, brought out both in the talks and in discussion (Fig. 2). One was the need to manage land holistically and over time and space rather than concentrate on one product that satisfies immediate economic demands. Most of the farms and crofts managed a range of saleable products and all farmed for the long term, despite having to overcome physical and sometimes economic hardships in the short term. ‘Work with nature not against it’ was the recurrent message: a hackneyed phrase some may think, yet true nevertheless. In the concepts discussed in these web pages, ‘working with nature’ implies managing multiple channels for the balanced flow of natural resources to soil, plants and animals [7].

Another was innovation – re-thinking how to do things. Farming did this in a big way during the Improvements era in the 1700s and in the Agricultural Expansion Programme in the late 1940s. In both instances, change was needed to overcome stagnation and reverse decline. Examples presented here included sowing tramlines to hinder surface wash after rain, and so  slowing the erosion of soil and loss of fertiliser as pollutant, and encouraging nitrogen-fixing legumes back into grass swards. 

Hardly innovations, you might think. But just look at the areas of compacted mush around most farm gates, and next time you see a mud-on-road sign, imagine where the mud came from; and then look at the imports of nitrogen and plant-protein to Europe due much to the cumulative loss over the last 150 years of home-grown legume pulses and forages. You can imagine also that some of the practices would have been seriously debated at  farmer-scientist meeting in the 1750s – running sheep on winter wheat when grass offered poor pasture was one, with little stated detrimental effect on the wheat (Balbirnie).

Support and conditions for agri-environment schemes formed a third thread (Fig. 2, lower box). Schemes were too inflexible, too prescriptive, for example in terms of dates that things should be done by,  and schemes rarely confirmed that a desired result had been achieved. Payment for result, specified in terms of populations and other ecological states was preferred and would ensure that public money led to a demonstrable, beneficial change.

And a fourth was the need to disrupt or bypass existing, mostly long, supply chains whose complexity determines, often obscurely and perhaps from thousands of miles away, what must happen on the farm, while the grower and manager has limited reward and control. The solution is to replace the long chain with a much shorter one from field and farm to consumer in one or two intermediate steps that involve retaining the production and marketing processes within the enterprise (Fig. 3). The experiences of Mossgiel Farm are a lesson. 

Fig. 3 Diagram of production and quality chains: production is buffered by operating across several different enterprises (F1, F2, etc.) that are interconnected in terms of the flow and sharing of resources over seasons and landscape; the short quality- or supply chain keeps processing and sometime sales within the enterprise (upper large box), adding value to the product and control to the grower, after bypassing an existing long chain. Design of supply chains is a main part of the EU project TRUE [9].

Result-based payment for agri-environment works

Teyl de Bordes introduced some examples of Result-based schemes in Europe in which farming is paid for delivering specified environmental benefits. Kirsten Brewster, from SNH, who organised the meeting and Teyl de Bordes since wrote a summary of six Results-based pilots. Here is an extract from their introduction. 

Result Based Agri-environment Payment Scheme (RBAPS) pilots “Results-based” is a term used to refer to agri-environment type schemes where farmers and land managers are paid for delivering an environmental result or outcome, e.g. number of breeding birds, or number of plant species in grasslands, with the flexibility to choose the management required to achieve the desired result. 

All agri-environment schemes are of course designed to deliver environmental results. However, what distinguishes a ‘pure’ results-based scheme, is that payments are only made where a result is achieved, making a direct link between the payment and the achievement of defined biodiversity outcomes (or other environmental results) on the ground. Focusing payments on achieving results encourages farmers to use their knowledge and experience to decide how to manage the land in a way that benefits biodiversity alongside farming operations. In so doing, results-based payment schemes may lead to an enhanced awareness of the importance of biodiversity conservation and protecting environmental resources as part of the agriculture system. http://ec.europa.eu/environment/nature/rbaps/articles/1_en.htm

The report by Brewster and de Bordes gives descriptions and links for each of 6 pilot studies and is downloadable as a PDF [8].

A for B and B for A

A distinction not discussed specifically at the meeting but one that is highly relevant to the design of future support, joins Agriculture (A) and Biodiversity (B) in two directions [10]. A for B is where agriculture, either inherently or by alignment, fits its methods and management to support certain life forms such as rare plants, invertebrates or birds. B for A is where essential life forms have to be maintained in a good functioning state for agriculture to continue sustainably. Examples of B for A include microbial transformations in the soil and the broadleaf weed (= wild plant) flora supporting predatory organisms that suppress pests.

Most existing schemes and support operate A for B, but in doing so almost exclusively, they do little to encourage the sustainability of agriculture.  A topical example is the argument around legumes such as peas in CAP Greening. Peas bolster a wide range of ecological processes – N-fixation, allowing a diverse dicot weed flora and enriching the habitat mosaic – yet the main and possibly only purpose of pea crops in greening measures is to be in the ground at a certain date in summer.

Whatever weighting is given to A for B and B for A, most of the ecological processes operate at scales well beyond the field. Such is the diversity of land use in the lowlands (e.g. Fig. 1) that landscapes of only a few km diameter may need specific measures. Flexibility therefore and payment for results, not blanket prescriptions, should be the basis of future support.

References, links

[1] Farmers and nature: promoting success and looking forward. Click the following links for Agenda and Speakers and the Presentations.

[2] David Aglen, Balbirnie Home Farm. Web: http://www.balbirnie.com/people. YouTube video of presentation:  Regenerative agriculture at Balbirnie. 

[3] Bryce Cunningham, Mossgield Farm. Web: mossgielfarm.co.uk Presentation on Youtube: The challenges of breaking the mould. 

[4] Lynne Cassels, Lynbreck Croft, south of Grantown-on-Spey. Web: https://www.lynbreckcroft.co.uk. Presentation on YouTube: A croft for the future

[5] Roger Polson, Knock Farm Presentation on YoTube: Managing Knock, a holistic approach. 

[6] Teyle de Bordes, Whitmuir Estate: Twitter: https://twitter.com/whitmuir1?lang=en. Presentation on YouTube: Recording nature on the farm. 

[7] Crops, grass and management open or restrict channels through which energy and nutrients flow to sustain a managed ecosystem’s various parts. See Crop Diversification at the Living Field, also [9]. Diversity of practice is the key – maintaining  to the soil and the wider food web of both invisible and visible biodiversity. Narrow the diversity and a single product might prevail, but the system fragments.

[8] Result Based Agri-environment Payment Scheme (RBAPS) pilots: K Brewster and T de Bordes, 31 May 2018. Click to download PDF BrewsterdeBordes-resultsbasedagrienvtrials.

[9] The EU H2020 TRUE project is actively developing short supply chains for legume-related crops and products. the project has much in common with many of the the sentiments of this meeting. More on TRUE on these web pages at Transitions to a legume-based food and agriculture where there are also links to the TRUE web site.

[10] The concept A for B and B for A (A = Agriculture, B – Biodiversity) which draws a workable distinction that could be introduced to future support, has been widely promoted by the agroecologist Paolo Barberi from the University of Pisa.

Acknowledgements

Scottish Natural Heritage organised the meeting. Contact: Kirsten Brewster, Kirsten.Brewster@snh.gov.uk. Kirsten Brewster and Teyl de Bordes provided access to their article on Result-based schemes, with thanks.

This article is an offshoot of work on crop diversification and food quality chains in the EU H2020 TRUE project based at the James Hutton Institute, Dundee. Views are those of the author, Geoff Squire: geoff.squire@hutton.ac.uk.

Crop diversification at the Living Field

The Living Field project will be exploring in 2018 the history, methods and value of diversifying crops and cropland. An Introduction is given on the Living Field’s web site at Crop diversification which explains why diversification matters, what it does for the sustainability of an ecosystem, its general decline in cropland and possibilities of restoring it. The Living Field articles will run in parallel to accounts of diversification on the Hutton Institute’s farms.

A wide range of crops and other useful domesticated and wild plants have been grown in the Living Field garden over the past 15 years. Starting with the cereals, for example, the Garden has grown emmer wheat, one of the first crops to be domesticated in the fertile crescent, and also spelt and bread wheats.

Cereal or corn crops also include barley, both old landraces and modern varieties, oat, rye and maize. Rice and millet were tried but did not appreciate the temperature. Cereals are shown to the left on the collage below, reproduced from the Living Field web site.

Other main groups include grain and forage legumes, medicinals and herbs, dye plants, tubers and vegetables. Micro-habitats have also been created and maintained – wet ditch and small pond, hedges and trees, meadow. Each supports a specific  flora.

Because of limits to space, not everything can be grown in all years, but in any summer, typically 200 plant species can be found. The garden is profiled on the Living Field’s web site at garden/living-exhibits.

 

Transitions to a legume-based food and agriculture

A summary with diagrams and photographs of an invited talk at the recent Conference on Advances in Legume Science and Practice organised by the Association of Applied Biologists in Glasgow 21-22 March 2018. Topics at the meeting covered a wide range of experience and disciplines from crop physiology, nutrition, molecular and traditional breeding, symbioses, landscape processes and food security.

Background – summary

Our invited presentation on Transitions to a legume based food and agriculture [1] introduced the aims and approach of the EU TRUE project, notably its central matrix consisting, first, of the quality chain from production through to markets and consumption, and second, sustainability, assessed through  economic, societal and environmental indicators.

The argument runs as follows. (A) Crops and their management alter the flows of energy and matter to various functions in the managed ecosystem. (B) Legume crops and forages have unique roles in channelling energy and matter to crucial functions related to soil quality, the nitrogen economy, pollinators and the production of plant protein. (C) To achieve a balanced and sustainable system, different types of crop, including legumes, need to be grown in planned configurations, whether within fields as mixtures, in  sequences or rotations and in spatial mosaics in the landscape. Practical designs need to consider those configurations that achieve the desired combination of functions.


Fig. 1 Faba beans Vicia faba: young crop, plant in flower, pods and fresh beans, and (small squares l to r) dried beans, flour, shelled split beans and bran.

Increasing legume production and output can be designed and managed in three stages. First, the area grown with existing legume crops such as field bean (Fig. 1)  can be increased with no change to the existing system. Second, the existing system can be modified – but not fundamentally changed – through (for example) mixed cropping of legumes and cereals, rhizobial inoculation of legume seed and  new legume products. Third, the system can be changed completely, with new crops, biotechnology and methods and untried configurations.

The presentation concentrated on  stage 1, but related work in Agroecology at the Hutton is already advancing in stage 2 though experimentation with crop mixtures, rhizobia and new products such as bread, beer and tofu made from beans [2].

Diversifying agriculture using grain and forage legumes

The flows of energy in production systems are investigated through a chain of effect linking interventions, such as agronomic management and choice of crop, through biota, including crops, to ecological processes which in combination satisfy (or not) desired higher level outputs [3].

The main crops in temperate Europe today are managed so that most of the energy is channelled to grain, oilseed or tuber yield (Fig. 2). In consequence,  other channels have been closed, or at least severely restricted, leading to long term declines in farmland wildlife and soil quality. Ultimately, such losses will feed back to limit economic output itself.

Fig. 2 The flow of energy in a winter cereal is concentrated into resource capture by the crop, then formation of yield and product, at the expense of trophic functions and soil.

The solution is to diversify the production systems of the region, in effect opening and regulating channels to other functions.  The diagram in Fig. 3 offers a highly simplified depiction of the wider balance of flows that should be realised in a forage legume.

Fig. 3 The flow of energy in a legume forage is distributed across a range of functions, notably N-fixation and trophic activity, e.g. through invertebrates.

The scope for diversification is being examined in this way for the case study of lowland Scotland. Grain legumes, mainly peas Pisum sativum and beans Vicia faba have been present from the neolithic and bronze periods and a wide range of forage species have been tried and grown over the millennia. Grains and forages are therefore being quantified as to their effect on flows such as represented in Fig. 2 and Fig. 3. Species are then modelling alone and in various spatial and temporal combinations to find optimum states.

Much can be learned from the way legumes and other crops have been grow in in the past, including in-field mixtures, often broadcast from a single ‘bag’ of mixed seed, such as mashlum, and temporal sequences, in some of which the legume and non-legume overlap (Fig. 4). Fields and sequences then combine to give additional properties at the scale of the landscape.

Fig. 4 Examples of crop diversification used traditionally in the region: B is a legume and A another crop (e.g. a cereal, root, oilseed, grass); C is an in-field mixture, such as mashlum, D a blocked, in-field mixture where the crops are separated, Ea a sequence or rotation, Eb a sequence in which some crops overlap in time (e.g. nurse crops and undersowings) and F a spatial configuration in a landscape.

The main problem facing the study was uncertainty in the locations within the region in which legumes appeared historically. However, crop census data, beginning in the mid-1800s is being examined to get the missing information.

First census of the mid-1800s

Legumes became integral to both crop sequences and forage mixtures in the Improvements era after 1700, but while some records suggest legumes occurred  1 in 4 years [4], there is little hard data on the areas grown with them compared with cereals such as oat and barley.

The 1700s and 1800s witnessed a phase of innovation and trialling of both grain and forage legumes, but for reasons that will be explored elsewhere on these pages, most forage legumes dropped out of mainstream usage with the exceptions of clovers and vetches, while grain legumes were reduced to various forms of pea Pisum sativum and bean Vicia faba.

The census of crops and grass in 1854 carried out by the Highland Society, covered most of Scotland and initiated a period of regular crop censuses which have proved invaluable in charting the phasing in and out of different crops. Data on the main crops [5], summarised for each of the old counties of Scotland (current up to to 1890), were transcribed from the 1854 records. Data were available for peas, beans and vetches: as an example, that for vetches is shown in Fig. 5, where the area of the circles, each representing an old county, indicate the relative area occupied by each crop. The circle out to the north-east represents Orkney and Shetland.

Fig. 5 Distribution of the vetches crop in 1854, sown areas represented by circles centred on the old counties of Scotland, superimposed on current administrative areas.

Beans occupied the largest area, followed by vetches and peas which covered similar areas. Most of the crops would have been grown for animal feed. Their combined areas were small, about 5% of that grown with cereals. Other sources specify that mixed forages, such as red clover, ryegrass and plantain, were also grown extensively, but no records are available of their composition and coverage. One of the recurring deficiencies of agricultural census is the classification of mixed forages as ‘grass’.

The distributions of vetches (Fig. 5) and peas were similar, both concentrated in the east and today’s central belt, but extending both south-west and north to Orkney and Shetland. That of beans was more concentrated in the east and centre.

Various crop census after the 1880s continued to show a similar distribution. When peas and beans were distinguished as to whether they were intended for human and animal consumption, those for human occupied a more restricted area in the east of centre.

Grain legume coverage today

Going forward 160 years, IACS data – from the EU’s Integrated Administration and Control System [6] – allows more precise definition of the current area grown with grain legumes.  There is still no data for grass-legume forages which must all classified under one or other of the forms of ‘grass’. Four types of grain legume are reported,  in decreasing order of area – beans for animal consumption, peas for human and for animal consumption, and least, beans for human consumption.

The total areas grown today are even smaller than the combined area of legumes in the 1850s. Maps of legume distribution after 2000 are in preparation. Examples  can be seen at the Living Field post Can we grow more vegetables? and further analysis of changes over time will be given later in these pages. However, the combined areas of the four legume types recorded tend to remain <2% and in some years near 1% of the total cereal acreage.

Low inclusion of legumes in a dynamic production ecosystem

The main conclusion so far is that grain legumes (pulses) were minor components of agriculture in the mid-1800s and have remained minor. Yet many aspects of the the crop and grass production systems in the region have been far from stable. For example, ‘root’ crops, mainly swede and turnip, covered large expanses in the late 1800s, but are relatively minor now, while of the cereals, oat was dominant in the 1800s and early 1900s but  supplanted by barley and now occupies less than 10% of the cereal area.

Recently, other crops have risen to much greater coverage than the legumes, notably winter wheat and oilseed rape in the later part of the 1900s. During all these changes, grain legume areas remained small or decreased.

One of the questions being examined is why legumes have occupied such low acreage in the region and whether and where they could be increased. Investigations of the phenomenon are continuing but one reported contribution is a greater reliance historically on clover and other legume forages for soil fertility.

There seems no particular reason, however, due to limitations of soil or climate, for the restricted area grown with legumes today within the eastern and central ranges shown in Fig. 5. Nor should it be assumed that increases will come only from existing crops. In response to CAP Greening measures, small fields of assorted legumes have appeared in the region.

That in Fig. 6 comprised three species of clover, the well know red Trifolium pratense and white Trifolium repens species, but also an unusual one, crimson clover Trifolium incarnatum which was once tried as a forage at these latitudes. A few plants of sainfoin were seen near the edge of the field, but it was not certain they were sown as part of the mixture.

Fig. 6 Legume forage, mainly of white, red and crimson clover: (top l c’wise) the field, young and older flowering head of crimson clover, sainfoin (image from plant in the Living Field garden) and  plants in an approx 0.5 m width of field (images by curvedflatlands).

Assessment by multi-attribute decision modelling

Opportunities for expanding the area of existing grain legumes are now being examined. It should also be possible to quantify potential savings of mineral nitrogen fertiliser and pesticide as the legume area is increased. The IACS data again provides the wherewithal, allowing us to assess not only which fields contained grain legumes in any year, but also which other crops were grown in the same fields in years before and after the legume. With knowledge of the crops grown in each field, nominal attributes can be assigned based on the pesticide and fertiliser applied to each crop as quantified from national surveys.

Each field can then be given a nominal agronomic ‘intensity’.  The reduction of intensity due to the substitution of an existing crop with a grain legume can then be calculated, as can the trade offs in the areas and output of other crops and products such cereal grain. The four current grain legumes offer plenty of scope for substitution, since some are grown with high-input crops, mainly winter wheat and potato, while others are grown with short-term grass and spring cereals.

Placing a value on each system, and then comparing systems, is facilitated by multi-attribute decision models (MADM) built in DEXi software [7]. A  part of the ‘tree’ structure of the current MADM is shown in Fig. 7. The interventions are shown to the right. They affect in turn the biota and ecosystem processes that determine a higher-level attribute, in this case the N loss in water leaving a field. The full MADM will include the wide range of attributes determining the economic, environmental and societal contributions of production systems.

Fig. 7 Part of a decision tree or multi-attrbute decision model built in DEXi software showing the way interventions combine in effect to influence field-scale attributes, in this case loss of nitrogen (N) in water.

Sites for expansion of legumes are therefore being selected on the basis that (a) they lie within an area, soil and climate in which grain legumes are or have been grown, and (b) they have a balance of crops very close to those fields that already include legumes in the crop sequence.

The aim is to quantify the benefits of legume expansion for the purpose of informing government policy and encouraging food and agriculture to use and grow more legumes. While concentrating on the grains at this stage, there is no reason why the approach cannot be extended to forages such as those in Fig. 8. More widely, the results will form a comprehensive study in the EU TRUE project of an approach to define long term trajectories of legume-based production systems and to extend those trajectories across Europe and farther afield.

Fig. 8 Legume species historically trialled in the region as forages: (top l, c’wise) sainfoin, milk vetch, kidney vetch, tufted vetch and white melilot,all grown in the Living Field garden (images by www.livingfield.co.uk)

Acknowledgement of funding

The main work summarised here and presented at Glasgow was funded as part of the EU TRUE project.  Background knowledge of the maritime production system of lowland Scotland was acquired with funding from Scottish Government (Rural and Environment Science and Analytical Services Division). The authors are based at The James Hutton Institute, Dundee UK.

Sources, references

[1] Squire GR, Iannetta PPM. 2018. Transition paths to sustainable legume production. Aspects of Applied Biology 138, 121-130.  Squire GR, Quesada N, Begg G, Iannetta P. 2018. Transition paths to sustainable legume production. Invited presentation at Advances in Legume Science and Practice, Association of Applied Biologists Glasgow UK, 21-22 March 2018.

[2] Links to bean beer on the Hutton website – Feed the world, help the environment and make great beer. Link to ‘tofu’ make from beans on the Living Field web site – Scofu: the quest for an indigenous Scottish tofu. See also Feel the Pulse.

[3] Squire GR 2017. Defining sustainable limits before and after intensification in a maritime agricultural ecosystem. Ecosystem Health and Sustainability, 3:8, DOI: 10.1080/20964129.2017.1368873

[4] Wight, A. 1778-1784. Present State of Husbandry in Scotland. Extracted from Reports made to the Commissioners of the Annexed Estates, and published by their authority. Edinburgh: William Creesh. Vol I, Vol II, Vol III Part I, Vol III Part II, Vol IV part I, Volume IV Part II. All available online via Google Books. Note from GS: Wight’s journals of his travels through the agricultural regions of Scotland present an unrivalled account by a farmer of the state of agriculture in the Improvements era.

[5] The agricultural census of the Highland Society, 1854, summarised by:  Thorburn T 1855. Diagrams, Agricultural Statistics of Scotland for 1854. London: Effingham Wilson. The Living Field web site has more on Thorburn  at Thorburn’s Diagrams.

[6] Integrated Administration and Control System, IACS on the EU web site.

[7] Decision trees, multi-attribute modelling and DEXi software at Marko Bohanec’s web site DEXI: a programme for Multi-Attribute Decision Making.

Contact: geoff.squire@hutton.ac.uk

 

 

Dundee sweltering in tropical heat

Early 2018 and Dundee’s waterfront is shaping well. The various cafes, restaurants and bars are gearing up for the opening of the V&A museum later in the year and locals will be dusting off their sun hats in readiness for long evenings dining by the waterside. Yet now in March that seems improbable. The winter 2017-18 has been colder than usual, temperature persistently below and around zero for months.

But which Dundee can we see here in these photographs? Not quite the Dundee as we know it – the one 7 miles from the Living Field garden [1], even with the tall ship and strange looking building by the waterfront … and the heavy cloud about to drop its load of water.

No. This place is somewhere warmer. A full-grown palm tree gives it away, and then the dark, flat line of a mangrove forest, half in the water. Mangroves couldn’t grow by the Tay, not before some serious warming. This is not cold, wet Dundee at 57N but a warm and monsoonal Queensland at 17S.

Looking back to Cairns waterfront (top), a line of mangrove forest (lower left) and palm

We were out from Cairns,  looking back towards the waterfront from a boat  to Fitzroy Island, named by Captain Cook after a member of the nobility, not Robert Fitzroy, the eminent meteorologist who captained the HMS Beagle that took Darwin on his voyage round the world [2].

Fitzroy Island

Fitzroy Island lies in the inner Great Barrier Reef, a small island, surrounded by warm water that supports vibrant corals and fish within easy snorkelling distance from the beach. The corals and sea life were astounding, and one of our party even swam with a wild turtle.

The island rises from the shore to a rocky peak over a couple of miles, forming a gradient of soil depth and exposure over which the land plants  varied according to their needs and capacity to survive. Pandans and casuarina fringed the  beaches, the dense forest behind merging into dry woodland and scrub on the higher land in the centre of the island.

Fire had blackened much of the vegetation on this higher land, yet adaptation to periodic burning was evident in the form of leafy shoots emerging from singed turf and dead-looking stems.

From Fitzroy to the mainland, large ‘cricket’ and shoots emerging from fire damaged trunk

The Great Barrier Reef is under threat, notably through bleaching of the coral [3]. Plastic also has its insidious effect here as in many places. The seas round the island looked fairly clear of it. The wind and tides brought a few pieces of waste onto the beaches, but they were being picked up and binned by visitors.

Even here

The problem here is not so much the large mass of waste being washed up on the beaches, as happens in parts of the West Highlands of Scotland for example. The reef is habitat to six of the world’s seven marine turtles.  If a single piece of plastic is ingested by a turtle, it is unable to function and floats on the surface, where unless rescued, it weakens and dies.

Turtles  can live for many decades but the Green  Turtle, for examples does not breed before 45 years [4]. Its populations – though showing no evidence of decline – are said to be  imbalanced towards females, a change attributed to increasing temperature in the nest.

A turtle sanctuary and rehabilitation centre on the island and on the mainland at Cairns looks after damaged animals, removing the plastic by feeding them until the stuck piece passes through and then nursing them until they are strong enough to be released [4]. To be rescued, a floating turtle has to be seen by a passing boat, and one sympathetic to its plight. For every one rescued, many others are likely to die.

The Great Barrier Reef and Scotland’s coasts therefore share more than primal beauty and a claim to wildness. The millions of bite-sized plastic pieces on the Scottish beaches referred to in the Living Field article Colours of Silverweed [5] are of a size to be swallowed by a turtle. It’s almost a relief that the plastic bits managed to find their way to our coasts, and settle themselves for a while among the shingle.

Neither place can do much to stop the plastic. The origins of most of it are many thousands of miles away. Even if the entry of new waste into the seas was reduced on a global scale, which is unlikely to happen for decades, the plastic already there will still circulate, get washed up or be eaten. Despite some complacency that the problem is soon solvable [6], all that can be done at the point of receipt is to continue limiting its damaging effects.

A long period of habitation

There is geological evidence that Fitzroy Island and other similar islands were once connected to a mainland until rising sea levels towards the end of the last Ice Age cut them off. This is another north-south connexion since the effects of the melting of ice covering northern Europe were to raise sea levels  here and around the world [7].

People had been living in Queensland for tens of thousands of years before that time. The mainland and the island would have been part of the same land mass. Improbable as it may seem to us in Europe, there is evidence that the people have kept alive the memory of the rising sea level through their spoken traditions [8].

Dead coral washed up on a beach, Fitzroy Island
Sources and further information

[1] The Living Field Garden is located at the James Hutton Institute, near Dundee, and is a place to study the crops and wild plants, past and present,  of lowland Scotland: www.livingfield.co.uk. The new V&A museum is sited by the Tay estuary in the centre of Dundee.

[2] The island had aboriginal names before James Cook named it FitzRoy in 1770. Naturalists and meteorologists are likely to know another FitzRoy – Robert Fitzroy (1805-1865) – as the captain of the ship HMS Beagle that took Charles Darwin on his voyage round the world. Robert FitzRoy was also a pioneering meteorologist, whose name replaced Finisterre in the Shipping Forecast in 2002. (Met geeks will have stayed awake to hear the first ‘Fitzroy’!) For general information on the island, try the Queensland Government web site on Fitzroy Island National Park.

[3] Great Barrier Reef: for background and research, see ARC Centre of Excellence for Coral Reef Studies, and a YaleEnvironment 360 article published 2017 A close-up look at the catastrophic bleaching of the Great Barrier Reef. The ARC web pages described other harmful effects of plastic on the Reef’s ecology.

[4] Information on the Green Turtle is given at the GBR Marine Park Authority’s web site. The Cairns Turtle Rehabilitation Centre describes the many ways that turtles can be damaged by human-made objects, including getting tangled in nets and being hit by boats, as well as by ingesting plastic and other waste.

[5] Colours of Silverweed [link available soon] is a Living Field article, describing the truly astounding amount plastic pieces accumulating on some of Scotland’s finest beaches, coves and inlets; and also what people are trying to do to remove it.

[6] Several newspaper articles and posts towards the end of 2017 implied that if action is taken now by governments across the world then the problem of plastic waste would disappear. One such was a leader in The Times newspaper of October 6 2017 with the title Rubbish Dumped and the strapline “The world’s oceans are being choked by plastic, but they will recover quickly if governments work together to stop it reaching the open sea”. Here, ‘recover’ and ‘quickly’ need to be reconsidered. There is no short term solution.

[7] Current predictions of sea level rise in the 21st century are compared with the much greater disturbances towards the end of the last Ice Age in an information piece by the Great Barrier Reef Marine Park Authority at Impacts of Sea Level Rise on the Reef. There is also a link on their web site to further information on ‘Marine Debris’.

[8] For example, see the following article in the online journal The Conversation Ancient Aboriginal stories preserve history of a rise in sea level.

[9] Views on the origins and distinctness of some of the peoples of the Queensland rainforest are highly contentious. See the article by Peter McAllister in The Weekend Australian, January 2011 – The ‘short mob’ goes back a long way. The 2002 article by Keith Windschuttle and Tim Gillin can be viewed with footnotes and references at The Sydney Line.

 

New EU TRUE project holds first meeting

Fantastic news that one of our new EU-funded H2020 project is getting underway. The inaugural meeting was held in Edinburgh, 19-21 April 2017. Around 50 people attended from all EU partners.

The project is coordinated by Pete Iannetta from Agroecology at the Hutton. The aims and methods of the various Workpackages were aired and discussed during two full days. A great feeling among partners of delight that the project would be funded and of looking forward to several years of intense collaborative effort ahead.

Here is the first group photograph.

Project description to follow …..

root art

Jean Duncan’s been working with Paula Pongrac, Lionel Dupuy and colleagues to capture cross sections of roots in the form of etchings and especially etchings on paper that she makes herself from plant fibre.

Jean has also been preserving seedlings with their seed-leaves, young root system and shoots on plant-paper. The central image in the panel below is of a young brassica plant, impressed on plant-fibre-paper. It looks a bit like a fossil.

The other images are etchings of cross sections through the fine roots of various plants, including brassicas and maize. She expresses all this developing structure in the fine roots etched or pressed into various surfaces. The image lower right shows a very young root system, about 10 cm long, also of a brassica.

How Jean makes these prints is a mystery. Alchemical.

Structures like these form in all roots in all land plants all over the world. The roots take up water to allow the plants to fix carbon dioxide from the air into products that form their carbon-rich structures. The roots take up mineral elements from the soil, which the plant then makes into vitamins and other life-sustaining compounds.

Animals that live on land, including us, eat the carbon, vitamins and minerals both as plants directly or second-hand as meat. Without these microscopic, sliced orbs that Jean captures in her art and paper-making, there would be no life on land as we know it.

Roots have a hard time …. even when they are set to work for us – big machines over-tilling and compacting the ground, the roots trying to grow through hard or slaked soil. Where’s the fun in being a cropland root.

Do they envy those tree-roots growing down 10 metres in a deep African red soil, or even an annual millet reaching 3 m in a sub-Saharan soil (seeking water just to survive), or the stumpy mangrove roots able to cope with being submerged in briny mud, or even the marram grass ‘roots’ of our coastlines extending out metres through hot dry sand, or a legume (bean, pea, clover) seeking to form that productive union with soil-living bacterial rhizobia.

No, there’s little joy being a cropland root today. (But there could be.)

Sources and links

The collection of root images above was prepared by GS from image files provided by Jean Duncan. The panel first appeared on the Living Field web site at The Beauty of Roots.

An exhibition by the same name will be held at the Dalhousie Building, University of Dundee, 17-30 March 2017. Notes and images of the exhibition can be seen at Jean’s page on the Living Field web site.

Jean also worked with plant microscopist Robert Baker, Department of Botany, University of Wyoming http://www.robertlbaker.org and http://www.macromicroscopic.com. Examples on the Living Field web site (e.g. below) can be viewed at Sectioned II.

final yield estimates – Bronze Age Clava

Apologies straight away to those who might be looking for Bronze Age cereal yields … but visits on the same day, the last in the calendar year, to the Bronze Age Clava Cairns and the government web site on the Final estimate of the cereal and oilseed rape harvest 2016 conspired to get the mind to bridge 4000 or more years.

About this time, farming societies then and now had made their calculations and decided what would be needed to last out the winter. Then, of course, in the Bronze Age, cereal farming was well established. It took the lead from the first settlers in the neolithic. It had expanded and organised, but was still reliant on good summers to yield enough grain for beast and human.

Now it’s more a matter of trying to work out whether cereal yields have gone up or down a few percent in relation to the flatlining after the 1990s. The yield per unit area and the total grain output appear to be becoming more sensitive to unusual weather. The wet winter of 2012 caused (what for these regions is) a large drop in yield, and the high rainfall and extensive flooding of last winter might have done something similar.

The Bronze Age, settled, farming societies who lived here and built their monuments, but left little else, had serious strategic issues of life and death at this time of year. There were no ‘root’ crops then, no turnips or potatoes to lie in the frozen ground, but to remain fresh to eat into the spring. Life depended on grain already harvested and stored, and the health and fatness of the stock of cattle and sheep. Life and death depending on barley and wheat.

Today, food security is assured by imports of most of the consumed cereal carbohydrate except oats. The state of the autumn harvest is irrelevant to most people. To farming though, a poor harvest will cut already meagre profits from growing grain, since fertiliser will have been applied to fields well before any threat of bad weather over the summer. And it looks as if bad weather during the summer periods of bulking and maturing of crops and harvest has become commoner in the past two decades.

What’s different?

The annual rainfall has changed over the last 100 years, through the 1900s (Fig. 1). There were several peaks over 1200 mm (1.2 metres) annual rainfall in the period up to the 1950s, then a dry period that lasted to the mid-1990s, but since 1998 there have been 10 years with rainfall above 12oo mm.

Fig. 1 Annual rainfall 1910 to 2016 in the region Eastern Scotland (source: Met Office UK).

There’s nothing new about wet weather. They would have been soaked at Bronze Age Clava and all places and ages before and since. The significance now is that wet years are reversing some of the advances in yield made during the phase of arable crop intensification from the 1950s to the 1990s.

The problem is shown by the relative yields after 2000 for three grain crops: wheat, mainly winter varieties, spring barley and oilseed rape. Annual yields are shown as a percentage of the average over the period. The yields drop in 2002 in two of the crops, then remain steady and above average until 2011, drop sharply in 2012, recover to well above the average in 2014 and 2015 then fall to around the average in 2016 (Fig. 2).

There is no relation between the annual total rainfall and the yield. Several >1200 mm years occurred during the steady, above-average period in the central part of Fig. 2. The rainfall in 2002 and 2012 was  less than the rainfall in several other years. The factor that caused the drop in 2012 and carried over into 2013 was the timing – there was greater than average rainfall in the late summer and early autumn.

Fig. 2. Grain yield 2000-2016 as a percentage of the average for wheat  (red), spring barley (green) and oilseed rape (blue). Source: Scottish Government statistics.

This unseasonal rainfall had four main effects.

Late summer rainfall

The associated cloud reduced the solar income during the summer months when crops are bulking most rapidly: it reduced the actual mass of crop.

The rain kept the crop plants moist in late summer, by physically wetting them and by preventing evaporation and grain drying due to the associated humid air: the grain was slow to mature or became diseased on the plant.

It weakened the soil structure during a time of high field-traffic at harvest: grain was lost or spoiled at harvest and the ground was slaked and compacted.

And it interfered with ground preparation and seedling establishment of the winter crops that are normally sown from late August to October: the same bout of wet weather in autumn 2012 slowed development and canopy expansion of the crops, thereby limiting the next harvest, 2013, which was also well below the average.

[in progress …. month by month comparison, the recovery of 2016, compensation by shifting between crop types]

Sources

Clava Cairns

Historic Environment Scotland gives a brief introduction to Clava Cairns; for detail, the Canmore web portal describes separately the South-west, Centre and North-east cairns.

Barclay GJ. 1990 The clearing and partial excavation of the cairns at Balnuaran of Clava, Inverness-shire, by Miss Kathleen Kennedy, 1930-31. Proc Soc Antiq Scot 120, 17-32. [detail, maps, old photographs]

Rainfall

Rainfall since 1910 for UK and regions. Annual and monthly totals are available from 1910 at the Met Office pages for UK and Regional Series. For example, to view data behind Fig. 1: at the Download site for UK and regional datasets scroll down to ‘Year ordered statistics’ and click the download link for ‘Scotland E – Rainfall’.

Winter rainfall 2015/2016. The following Met Office web article gives a summary, with maps, videos and data, of the very wet November to January: Further rainfall and flooding across north of the UK. http://www.metoffice.gov.uk/climate/uk/interesting/december2015_further Jan 27 2016

Cereal yields

Scottish Government. Final estimate of cereal and oilseed rape harvest 2016. Downloads are available for pdf and excel files. In the excel download, Tables 2 and 3 give cereal and oilseed rape areas, yield per hectare and total production  from 1997 to 2016.

[in progress]

 

mixed cropping in Burma

Growing crops as mixtures of different species in the same field was commonplace in Britain during the Improvements era but gradually fell out of favour in the 19oos as single crops became easier to manage and could command a high value on the grain market. ‘Grass seeds’ in the 1700s often meant not just one or more grass species, but a mix of a grass, a clover or several legumes and another species such as ribwort plantain. A cereal (corn) and a nitrogen fixing legume (pea) were also broadcast over the same field, as were mixtures of different cereals.

Mixed cropping is now being reconsidered in northern Europe as a possible means to producing the same with less input of fertiliser and pesticide. In our most recent outing, at the December 2016 meeting of the British Ecological Society, Pete Iannetta talked about the benefits of a barley-pea intercrop grown at the Institute (links at Latest). But for inspiration we can look to other places.

Mixed cropping is still widespread in the tropics, but the reasons for planting different species close together, sometimes in strict spatial patterns, are not always obvious. The scientific tendency is usually to look for a biophysical mechanism behind the pattern. Perhaps the two or more species take resource from different parts of the environment or use the resource more efficiently. Mixed cropping works – the two species together tend to produce 1.1 to 1.3 (110 to 130%) times the equivalent yield of the crops grown alone.

This is a useful but not a great advantage, and it may well be that the plants are grown in mixtures for other reasons also. Sometimes the arrangement might arise simply out of convenience or as a means of lowering the risk of not putting all your eggs (i.e. the few seed of one crop) into one basket (i.e. a small area of soil).

This mixed cropping, named intercropping when the plants are in rows, was frequently observed on a self-funded trip to Burma (Myanmar) during the dry season of 2014. Our interpreter, knowledgeable about local farming, was still not always able to explain what was behind the crop configurations.

Planned intercrops

The biophysical basis of the intercrop was best appreciated for perennial plants such as the pigeon pea Cajanus cajan grown at Bagan with cotton, probably one of the shrubby species, and another plant that had shrivelled to unrecognition in the dryness. The pigeon pea would have fixed and released nitrogen to the soil for the cotton to take up. In some fields, the pea had recently been cut back to stop it using water, whereas the cotton, most likely deep rooting, was in full flower and fruit and using the water and nutrients stored in the ample soil-space between cotton rows.

On the banks of the Irrawaddy, highly regimented rows of groundnut Arachis hypogaea had maize Zea mays sown within every 5th row (image below). The land would have been awash as the river rose in the wet season, when presumably the silty soil, and any nitrogen fixed previously by a legume, would have been picked up in the current and deposited somewhere else.

The crops were therefore growing on nutrient-rich alluvium and soil-stored water. The maize was starting to flower but the groundnut was still in leaf only. It was unlikely that this year’s N fixation by the groundnut would have ‘leaked out’ so early in its growth. Rather, the maize was taking advantage of additional resources, sunlight above ground and residual soil nitrogen from the bordering rows.

Elsewhere, a field of the nitrogen-fixing chickpea Cicer arietinum had been planted with widely spaced rows of sunflower Helianthus annuus.  The sunflower would have benefitted as the maize in the previous example, but it was difficult to see the advantage to the chickpea. Possibly, the farmers wanted some sunflower seed or oil and grew a few plants in what was otherwise a chickpea field.

But why plant in rows …? Rows are generally easier to establish with animal-drawn implements than are small blocks of crop. Intercrop rows also make it more difficult for a farmer to lose a large proportion of one or other species. Repeatedly, patches of a few square metres occurred in the intercropped fields where the crops were stunted or dead, probably due to poor soil or disease. Planting in rows allows both crops to experience the whole field, its good and bad parts.

Unplanned(?) intercrops

In a further set of configurations, the growers appeared not to have planned the mixture. Rather, they took advantage of a situation in which other species emerged with the sown crop.

One such was a small plot of groundnut in which plants of the Chenopodium genus (probably C. album) were growing in a random configuration. Someone nearby, who knew the practice, said that Chenopodium appeared whenever groundnut was grown. It probably emerged from the soil seedbank, stimulated by conditions peculiar to groundnut cultivation. It was encouraged – the ‘weed’ is widely used as a salad vegetable, as it was once in Britain.

Another example was a field of groundnut again, but one that appeared invaded by two or three other species. Chenopodium was there again but also maize and sunflower, and each was located irregularly, not in rows. The groundnut had been sown but the others, including the two crops, had emerged from the soil seedbank. They were ‘volunteer’ weeds, and had been left, not weeded out.

Multiple crops

In Shan agriculture, a mixed crop new to my experience was one of taro Colocasia esculenta, ginger (Zingiberaceae, species uncertain) and chillie, species of Capsicum. It was easy to walk past the field, because the chillies had been harvested and the taro tubers and ginger were mostly invisible underground.  This was an intentional mixed crop. There would have been biological interactions between the three, but perhaps the main advantage was one of getting three crops from the same bit of land in one year – the chillies first, finally the taro.

Repeatedly, crops were seen growing in intended and apparently random configurations. Fruit trees were grown in small orchards, where they usually had an understorey of legumes or mustards. Fruit trees were also dotted around the landscape, enjoying the benefit of nearby fixers and fumigants.

Palms were common, often grown in lines or groves within the general mix of annual cropping. On the high land, fruit and beverage trees were commonly grown in planned (tea and oranges) or semi-random configurations.

Comment

This brief experience, over only a few weeks, introduced the sheer diversity of crops and farming methods here, the ubiquity of legumes, the widespread use of ‘wild’ plants, and the frequent desegregation of the sown and the wild.

Perhaps the lasting impression is one of nitrogen-fixing legumes being among the commonest crops, essential to the mix, whereas in north-west Europe, they have been reduced to minor status.

In some areas, the people had a very advanced understanding of how plants complement each other and together provide human dietary needs, an understanding that has almost lapsed in mainstream farming in north west Europe.

Subsequent pages will deal in more detail with (2) perennial pigeon pea-cotton at Bagan, (3) groundnut-maize by the Irrawaddy and chickpea-sunflower near Mandalay and (4) assorted mixtures which may or may not have any biological advantage.

Sisal plants in the foreground, grown for the fibres in their leaves. The small trees just behind them have been pruned, with one ‘lung’ (a leafy branch) remaining.
Author’s note and further reading

We visited Burma, not in any official capacity, but as ‘tourists’. I had intentionally not read any of the reports from international development agencies before going there, wanting instead to get a first-hand (even if fleeting and random) feel for the soil, people, plants and agriculture. Many of the reports read since have seemed to me to be a bit impersonal, not fully accepting and promoting the great ingenuity and knowledge of the people who live and farm there.

We were more than fortunate to be guided during a crucial part of the visit by Ei Ei Lin (or Lin Latt). Her farming background and natural curiosity introduced us to many hidden wonders of (plant) life in the dry season.

For factual and largely non-judgemental information, the following report offers much on the conditions in Burma’s dry zone:

Improving water management in Myanmar’s Dry zone – for food security, livelihoods and health. 2015. International Water Management Institute (IWMI) 52 pages. doi:10.5337/2015.213. Based on 3 reports published in 2013. http://www.iwmi.cgiar.org/Publications/Other/Reports/PDF/improving-water-management-in-myanmars-dry-zone-for-food-security-livelihoods-and-health.pdf?

Books read during the visit included (and both freely available in bookshops there):

Aung San Suu Kyi. 2010. Letters from Burma. Penguin.

Emma Larkin. 2006. Finding George Orwell in Burma. Penguin Random House.