This field lab looked at how farmers can use intercropping to provide more efficient resource use, reducing pest and disease pressure and provide better weed competition in their arable systems.
The group explored opportunities for intercropping and companion cropping in arable systems, aiming to identify beneficial combinations and their impact on key indicators identified by farmers e.g – yield, soil and plant health, weed burden and pest / disease – in different contexts.
They were also interested in the practical considerations – including crop competition, establishment, machinery, harvest, separation and finding markets.
This field lab built on the DIVERSify project, which stems from EU Horizon 2020 funding, to optimise the performance of crop species mixtures or ‘plant teams’ to improve yield stability, reduce pest and disease damage, and enhance stress resilience in agricultural systems.
Intercropping is a method of growing more than one crop in the same piece of land during the same crop season. Interest in the practice has been growing amongst conventional and organic farmers for some time.
Intercropping can provide multiple benefits including:
Small trial plots were set up on each farm, and each farmer chose the crop combinations they wanted to grow.
Small trial plots have also been set up at the University of Reading Crops Research Unit and The Organic Research Centre also have wheat and bean, and wheat and lupin intercropping trials at this site.
The following metric were measured:
In 2019 three trials are being established on two farms. The two field lab farmers have developed plant team trials to test a certain objective of their choice.
T1: Test the effectiveness of oats in reducing linseed loss during establishment via reduction of pest and disease pressure.
T2 (A): Test the effectiveness of oats in reducing spring oil seed rape (SOSR) losses (in a crop which is also intercropped with peas) via reduction in pest and disease pressure.
T2 (B): Test the effectiveness of SOSR in supporting the pea crop and reducing lodging.
T3: Test whether intercropping beans with wheat reduces the weed burden in the bean crop and increases the protein content in wheat.
Plant teams will be drilled in winter/spring and harvested in summer 2019. Each trial has different data collection priorities to address the objective, as determined by the farmers, but yield will be collected from all field-scale strips by farmers using their combine monitors and separating a subsample to determine crop ratios. Quadrat sampling will be primarily undertaken by the farmers with support from ORC/LEAF researchers. Farmers will collect data such as crop establishment and yield data, whilst weed burden, pest and disease pressure and degree of lodging will be analysed by the researchers.
We are definitely doing this again next year, we’d be stupid not to! In fact, we’ve already ordered our seed.”
“The beans were our main crop so any wheat we got was a bonus. We actually saw slightly lower bean yields where we intercropped but this was more than made up for by the wheat. Crucially, we saw 64% less weed biomass in the intercropped plots. With far fewer weeds, we should have a much cleaner field next year."
“This is our first foray into intercropping and we are convinced it was worthwhile. Having the extra biomass in the form of a wheat crop - rather than weeds - is hugely beneficial. Next year, we’ll probably drop the wheat rate to around a third to try and boost our bean yield while still suppressing the weeds.”
• Will try to drop the wheat rate to 1/3 of normal rate and increase beans
• Overall happy with the intercrop, especially useful biomass vs weeds
Key learnings & Economics
A number of group members were successfully funded for the 2018 DIVERSify Intercropping trials looking at a range of plant teams. Plant teams include: Wheat and beans, Carlin peas and triticale, beans and Spring OSR, peas and barley.
Each farmer will be trialling as follows:
Farmer A - Spring barley with crimson & berseem clover (2.5 ha) vs Spring barley monoculture (2.8 ha)
Farmer B – Spring beans with Spring wheat (2.8) vs Spring beans (2 varieties) (2.8 ha)
Farmer C – Winter wheat with white clover, aslike clover & trefoil (7.5 ha) vs Winter wheat monoculture (0.5-1 ha)
Farmer D – Winter beans & Spring wheat (1 ha) vs Winter beans monoculture (1 ha)
Farmer E – Peas & barley with vetch & grass (5 ha) vs Pea and barley (2 ha)
Farmer F – Spring beans with Spring OSR (4 ha) vs Spring beans (2 ha)
Farmer G 1 – Carlin peas with Spring triticale (4 ha) vs Carlin peas (1.8 ha)
Farmer G 2 – Fodder beat with buckwheat (3 ha) vs Fodder beat (0.23 ha)
Farmer H – Rye with beans (4 ha) vs rye monoculture (1.4 ha) and bean monoculture (1.4 ha)
Small trial plots have also been set up at the University of Reading Crops Research Unit. Four reps of x 6 treatments: Pea, Bean, OSR, Pea/OSR, Bean/OSR and an OSR/legume intercrop (to fill the 6th plot in the block) in 5m x 2m plots. There will also be 3 reps x 3 treatments of OSR, OSR/Barley and OSR/legume in 5m x 4m plots to look at the effect of intercropping on fleabeetle damage.
The Organic Research Centre also have wheat and bean, and wheat and lupin intercropping trials at this site.
This meeting identified the past experiences working with plant teams (complementary crops) within the group.
Example plant teams tried and effectiveness are as follows:
- Spring Wheat and Tundra Beans,
- Spring Barley and Peas (Unsuccessful),
- Peas and Oil Seed Rape (OSR),
- Chickpeas and Linseed (Unsuccessful),
- Clover and OSR alongside direct drilling.
Plant teams of interest for further trials were selected and discussed. It was noted that the type of plant team will depend on the farm environment e.g. soil type and weed burden. Plant team success will likely be measured at a single farm scale but the group will consider options for cross-farm comparisons of different crop combination 'working groups' e.g. cereal and legumes.
The group discussed what they would like to get out of the plant teams and why they are interested in trialling certain combinations. The first ideas are as follows:
- Clover undersown / companion cropped with a cash crop (to supress weeds, improve soil health, improve yield, improve water infiltration and soil structure).
- Beans and OSR (to increase yield, the two crops are easy to separate and have similar harvest dates).
- Clover with a cash crop (to improve soil health and reduce chemical usage).
- Beans and wheat (Reduce weeds in bean crop, and the wheat should not outcompete the beans).
- Legumes and buckwheat (To supress weeds and improve soil health and mineral availability).
- Vetch and Westwold, linseed and peas and yellow trefoil and spring barley (to increase diversity on farm and spread risk).
The group then discussed a potential trial plot intercropping OSR with beans and other cash crops, to be held at the University of Reading (to reduce pest risk in OSR).
1st June 2018
15th May 2019
1st August 2019
15th August 2019
Organic Research Centre
Charlotte is an Evolutionary Ecologist working at The Organic Research Centre as their Crops and Breeding Researcher. She is interested in increasing knowledge and understanding of how ecological and evolutionary responses can be quantified enabling their successful integration in land management for agricultural productivity, sustainability and conservation. This involves work on crop diversity, varietal testing and breeding that focuses on increased genetic and trait variation.