1800s mixed crops – lessons from the Agrostographia

The 1800s, especially the first three quarters of it, was a period of notable invention and experiment, building on the gains from the first phase of Improvement that began a century earlier. Mixtures of crops, of grass and of crops and grass together are repeatedly referenced in the various books and manuals published throughout the period.

Several of these mixtures are examined here, as possible pointers and templates for modern attempts to re-diversify agriculture. The main sources are those published by the Lawsons, seed merchants based in Edinburgh, notably their Agrostographia [1, 2], which appeared in various forms from 1833 to 1877. For example –

  • barley-sainfoin (cereal-legume) mixture, the barley sown as a ‘nurse’, sainfoin drilled at right angles to the barley (a line intercrop?)
  • barley-oat-weld, the first two harvested after the first season, the weld yielding the next year.
  • within-species field bean varietal mixtures.
  • legume-legume, for example, field bean and vetch/tare.
  • barley, oat or any corn sown with grass as a nurse to protect the more valuable grass-legume sward.

As in other articles on this web site about our cool-climate mixtures, all crops were sown as seed mixes rather than line or row intercrops (with the possible exception of barley-sainfoin).

[Note – article in progress and…]

Barley-sainfoin gridded at drilling

When considering which dicot forages to recommend, Agrostographia suggested that sainfoin Onobrychis sativa could be grown in several parts of Scotland, though it was primarily grown in more southern climates. It likes a ‘dry’ and well drained soil, and was also recommended as an addition to their perennial pasture mix on calcareous soil.

Barley and sainfoin are sown together, drilled at right angles, the barley growing quickly, ‘nursing’ the other, then harvested in late summer for grain or fodder. Sainfoin overwinters in the barley stubble, then grows into a full forage crop the next year, when it is cut for fodder. It regrows and is repeatedly cut for several years. Original drawings by K Owen.

As a sole forage, it sometimes suffered in the first year. Therefore to aid establishment, the Lawsons pointed out the practice of sowing a nurse crop, such as barley, first. Then in those situations where that crop was drilled, the sanfoin was drilled at right angles to it, in effect forming a grid, rows of sainfoin crossing rows of barley. The barley was harvested in the first year, as cereal grain or forage crop, leaving the sainfoin to over-winter as a small plant, then extend and flower the next year. It would have been cut one or more times in the summer of the second year, after which it became a perennial forage.

This practice presumably prevented the second drilling (that of the sainfoin) from interfering too much with the first. It might have created an interesting pattern if the drills were reasonably wide apart.

Unlike many mixed crops, the aim of this one was to encourage the legume to establish. Barley would have been sown at a smaller seed weight per acre than when sown for a sole crop, so as to form enough cover to protect the sainfoin without completely denying it light and nutrients. It is unclear whether any particular advantage came to the barley, since it would grow much faster than sainfoin in the first year. No information is available from that time on nodulation in the legume and whether it released any fixed nitrogen when the barley needed it.

Field bean variety mixtures

In their Agriculturists’ Manual (1836) and the later Synopsis (1852), the Lawsons’ list varieties of Vicia faba of which the main one grown at that time was named Common Scottish or Horse Bean. They write: “Beans enter the rotation of cropping in the early districts of Scotland, and are very successfully cultivated on all strong soils, forming an excellent preparation for wheat. The straw or haulm forms nutritious food for horses during the winter and spring months.”

This comment – on the successful cultivation of beans – contrasts with the decline in area of this crop, along with many other arable crops, during the economic depression after 1880 when agriculture made one of its shifts to grass, on this occasion because of low global grain prices.

Page from the Lawsons’ Synopsis of 1852 showing the description for Common Scottish or Horse bean, the 295th entry (after the cereals but before the forages and fruits).

The point of interest here is the comment of what appear to be crop variety mixtures, identified by the range of flower colour. The wording in the above is little different from that given in the earlier 1836 Agriculturist’s Manual, and extract of which is given below.

The authors could not be certain that the fields they referred to were intentionally sown mixtures. Many of them would have been landraces, maintained by farm-saved seed, or seed impurities or even ‘volunteers’ (which arise from seeds shed by a previous crop and emerging in the current crop). Certainly, faba bean today readily gives rise to short-lived volunteer populations on waysides and in fields of other broadleaf crops..

This note from the Lawsons’ experience shows that despite the seedsman’s quest for purity in seed stocks, diversity was hard to eradicate.

Barley-oat-weld – grain and dyestuff

[in progress]

Barley, oat and weld sown as a mixture in spring, the two cereals growing more quickly and harvested during the first summer for grain or fodder, weld much slower and lower. Weld over-winters as a ‘rosette’ then extends the next spring into a flowering plant, harvested green for dyestuff. Original drawings by K Owen.

Sources, references, links

[1] Agrostographia; a treatise on the cultivated grasses and other herbage and forage plants. Authors: The Lawson Seed and Nursery Company. Successors to Peter Lawson and Son. Date: 1877 (6th Edition, by David Syme, Manager). Publisher: William Blackwood & Sons, Edinburgh and London. Online through sources such as the Biodiversity Heritage Library. Information in the Agrostographia was first published in 1833, though not under that name, and then as part of The Agriculturist’s Manual in 1836 [3].

[2} Agrostographia as a title is of much older origin, being that of a major compendium on grasses written in Latin, by or edited by, Johannes Scheuchzer (1684-1738), published 1719, edition of 1775 viewed. Scheuchzer is credited with being a founder of the science of Agrostology – the study of grasses.

[3] The Lawsons’ Agriculturist’s Manual (1836) and Synopsis (1852), the latter an expanded version of the Manual, are invaluable sources for 1800s crops and their varieties, both available online, e.g. through the Biodiversity Heritage Library. Details:

The Agriculturist’s Manual. Peter Lawson and Son 1836. Edinburgh, London and Dublin. Being a familiar description of the Agricultural Plants Cultivated in Europe including practical observations respecting those suited to the Climate of Great Britain; and forming A Report of Lawson’s Agricultural Museum in Edinburgh (Seedsmen and Nurserymen to the Highland and Agricultural Society of Scotland).

Synopsis of the vegetable products of Scotland. Peter Lawson and Son. 1852. Private Press of Peter Lawson and Son. Prepared for the Great Exhibition and dedicated to William Jackson Hooker, Director of the Royal Botanic Gardens of Kew.  

[4] Sainfoin was grown in the Living Field garden at the James Hutton Institute, Dundee, for several years. It grew slowly in the first year but overwintered successfully and then flowered in the second and subsequent years.

Non-serious depiction of a barley-sainfoin mixture to show the practice of drilling barley in one direction then drilling sainfoin at right angles. Described in Agrostographia 1877. Images from plants grown in the Living Field Garden, Dundee.

form line, form square? … naargh just mix it!

Formal and informal mixed cropping. Mixed corn and mashlum (oats, beans) preferred historically in Scotland, seed mixed not sown in lines or squares. By mid-1900s, covering very small areas of cereal land. Dredge corn from SW Britain.  Unintended mixed grain from volunteer weeds. Mixes grown as a safeguard. Lessons from history.

Archaeological evidence from many landscapes across the globe shows agricultural land divided into geometric shapes. Linear features may have been constructed as drove-ways to move stock from one piece of land to another; or for cultivation by teams of animals dragging a plough that was difficult to turn. Squares or or other shapes with conserved side-length, are preferred when something has to be contained, such as stock animals or valuable crops that can be surrounded by a wall or fence.

Similar features occur when more than one species of crop is grown in a field. Such intercropping or mixed cropping is widely practiced in many agricultural regions. Smallholder gardens will often consist of small blocks, sometimes even single plants, grown close to each other, sometimes under the shade of a tree-crop. Perhaps the most widely observed configuration is that of lines or rows. One species might occupy one or more adjacent lines, then another species then back to the first species, as in the example below of an intercrop of chickpea and sunflower [1]. 

Chickpea field in which lines of sunflower have been sown, Burma (Myanmar), image by curvedflatlands.

Not all mixed crops are grown in formal configurations. Seeds can be mixed in the bag or mechanical sower and broadcast on the land. Two or more species then emerge together to form a mixed stand.

Also, unintended mixtures can occur when seed dropped on the soil by previous crops emerges in a later one (see below). Whether unintended or planned, simple mixtures have been recorded in agriculture since records began.

A new dawn for mixed cropping in Atlantic Europe?

Three factors need to be assessed when considering the (re)introduction or expansion of mixed cropping. One is whether a biological advantage results from growing the species in a mixture: if there is, the grower gets more from the land or resources than they would if the crops were grown alone over the same area. A second is whether the mixture provides a convenience: even without a biological advantage, it might simply be easier for sowing and harvesting to grow two or more crops in a particular configuration, especially if the grower wanted a varied output (e.g. cereals, legumes, fruit, vegetables) from a small plot of land. The third is whether the mix provides a safeguard or security against unexpected events: here, a biological advantage and ease of management may combine to ensure something is produced.  

The type of mixture used in previous times may also be a practical guide to what might still be feasible. In Scotland, and elsewhere in Britain, the most common sown mixtures from the 1700s to the early 1900s were intended for hay and grazing. They were rarely ‘grass only’, but comprised grasses, legumes and other broadleaf species in proportions varying with the intended use [2]. The legumes in the mix, the most abundant being white and red clover, fixed much of the nitrogen used by subsequent grain crops.

Also references are repeatedly made to assorted mixes of corn and grass, where barley or the landrace bere was sown as a ‘nurse’ for the more valuable and longer lasting hay or grazing mixture [3].

Mixed arable crops (no grass) were also mentioned in sources from the 1700s and 1800s, mainly as sown seed mixtures, very rarely if ever as line intercrops. But by the time formal agricultural census began in the later 1800s, sown crop mixtures such as mixed corn and mashlum were grown over a very small area. 

Mixed corn, dredge corn and mashlum

The two most widely grown crop mixtures in the north of Britain go under the names mixed corn or mixed grain and mashlum. Mixed corn consists of two or more cereals, barley and oats for example, while mashlum consists of a cereal and a grain legume, typically oats and beans (Vicia faba). Mashlum reached its 20th century peak during WW2 (Fig. 1). The subsequent fall but continued usage of mashlum was documented on the Living Field web site [4].

Mixed corn or mixed grain appeared as a separate entry among grain crops in the Agricultural Census of 1929 [5]. Its area expanded and contracted over the next 50 years but generally remained less than 0.05% of the combined cereal area (Fig. 1). There is little information of why mixed corn was grown and also why its area was so small. Oat dominated the cereals in the earlier part of the period shown, then gave way to barley and wheat. 

Fig. 1. The areas sown with mixed corn and mashlum in the Agricultural Census for Scotland [5]: mixed corn not identified from other cereals before 1929 and after 1978; mashlum grouped with other forages before 1944 and after 1960. Over the period shown, mixed corn comprised less than 0.05% of the combined cereal area.

Cereal mixtures grown elsewhere in the UK offer some explanation. A mixture of barley and oats named Dredge Corn was a feature of arable in the south west, mainly in Cornwall [6]. Its area was uncertain due the fact it was returned as ‘barley’ before 1919. As the quote at the top of the page implies, it was used as a safeguard, to ensure a reasonable yield under most conditions. It had a place in the crop rotation, sometimes replacing oats, sometimes barley, and was used in particular for a whole crop feed when the soil or the year was not capable of producing a pure crop of quality to sell as grain.  The proportions varied but were typically two parts oats to one barley. Wheat was added in some cases, making a three-part mixed grain.

While it was certainly grown as a safeguard, it was also attributed biological benefits [6]. It was stated to produce more grain than barley alone and generally more than oats alone, oats being deeper rooted and thereby accessing more resource. In dry years, barley grew to fill the ‘gaps’ left by dying oat tillers. The straw was of higher feeding value than the individual crops, due to better overall structure. But perhaps most relevant to the Atlantic climate, the mix was better able than barley or oat alone to withstand the forces of wind and rain to flatten the crop.  Similarly, one source reported that another variant – a mix of white and black oats – gave a greater yield (of straw) than either alone – the stronger stemmed white supporting the finer stemmed black. 

Despite such reports from farmers, there is little hard information on the yield advantage given by mixtures sown on the fringes of Atlantic Europe. They might have given the 1.1. to 1.3 times advantage widely recorded for intercrops, but without the experimental data from the 1920s or earlier, there is no way of knowing. 

Sown as a seed mix in April, no fertliser or pesticide: (left to right, 1 to 4) the bere barley grew quickly (1), then oat pushed through (2), bere matured first (3) and finally oat (4).

The widespread occurrence of unintended mixtures

It is the nature of small-grained cereals – oats, barley, wheat – to drop seed before or at harvest. The seed remains in the soil and, depending on conditions, emerges in a later crop. Today, such crop-weeds are commonly termed ‘volunteers’ [7]. The sown species and the volunteers in effect form a mixed crop (image below for wheat in barley). Other crops also generate volunteers. Those of oilseed rape are the most visible, but potato and field bean (Vicia faba) often produce mixed crops with cereals, though these broadleaf species may be really controlled by selective herbicides today. 

Unintended mixed crops have been a feature of cereal lands probably since domestication. If the intended product was whole-crop cereals to be fed to stock, then they would have been seen as a benefit – free seed. However, they may also create a problem. They are an unwanted nuisance when they have to be separated from the crop, for example when a pure seed-harvest is needed, and they could harbour and carry over disease. Volunteer cereals are not a recent problem: records from the 1500s [8] on oats relate “that they grow amongst wheat and barley without being sowen, as an evil and unprofitable thing ..”.

Maturing barley crop, golden brown, in which volunteer wheat (upright heads, dark grey-green) has established; younger, still green plants growing in the wheel lines.

Conclusions

Mixed corn, and mixtures of corn and grain legumes, have been recorded for centuries in Scotland, and more generally in Atlantic Europe, but their benefits have not been adequately quantified. Where they were grown, it was as broadcast seed mixtures rather than line intercrops. By the early 1900s, they were minor crops. After the 1940s, agriculture was aiming for the high yields promised by intensification: mixtures almost disappeared. 

Current reappraisal of crop mixtures might perhaps examine why in the early 1900s they never became major crops and why they were rarely grown as line intercrops.

Sources

[1] Photograph of chickpea-sunflower intercrop taken in Burma (Myanmar). Details on curvedflatlands at Mixed cropping in Burma.

[2] Seed mixtures for hay or grazing from the 1700s to the early 1900s are described in a related article on curvedflatlands: Grass mix diversity a century past.

[3] Crop mixtures are frequently referred to by Andrew Wight in the Present state of husbandry in Scotland (1778-84. Volumes 1 to 6), where one of the components (usually bere or barley)  is most commonly a ‘nurse’ crop, protecting the others, which are usually grass mixes (grasses, legumes and other broadleaf species) to be used for hay or grazing. 

[4] Mashlum, Scotland’s cereal-legume seed mix, still occasionally grown, is described on the Living Field web pages at Mashlum – a traditional mix of oats and beans  and Mashlum no more! Not yet.

[5] Data in Fig. 1 are taken from the online Agricultural Statistics in Scotland one of the Historical Agriculture Publications on the Scottish Government web site. Based on the 1965 census, Coppock created an atlas in which the small area sown with mixed corn was noted with the comment that it was ‘not grown in the great majority of parishes’. Ref: Coppock, JT. 1976. An agricultural atlas of Scotland. John Donald, Edinburgh.

[6] Borlase, W. 1925. Dredge corn. In: Farm Crops, Vol 1, pages 265-269.

[7] Volunteer weeds, derived from crops, and presently common in Scotland  are described at the Living Field web pages on Crop-weeds.

[8] Quote on oat from L’Agriculture et Maison Rustique by Estienne and Liebault, 1593 edition. Further details and origin on the Living Field web pages at: Ready, steady mundify (your barley) and  The Library of Innerpeffray.

 

 

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.