O4: Legumes: multi-species and multifunctional
Chair: Christine Watson (SAC)
This session reports on current work with legume mixtures in the LegLINK and other projects and explores applications beyond fertility building and ground cover. These include greater use of home-grown legumes in monogastric diets and even as part of a ration for fish (organised with SAC).
This session explored the use of grain legumes as a potential home-grown source of feed for monogastrics, and the use of forage legume mixtures in achieving a reliable and productive ley. Lesley Smith (SAC) presented the Green Pig Project, which looks at whether peas and faba beans can be an alternative to soyabean meal. Pigs (both growers and finishers) were fed diets containing various concentrations of peas or beans, and their growth performance monitored. In the growers, the inclusion of peas or beans had no effect on their growth performance, but in the finishers, pulse inclusion reduced BWG (body weight gain) slightly, although there was no effect on ADFI (average daily feed intake) or food conversion ratio. The conclusion was therefore that peas and faba beans can be a viable protein source for inclusion in pig rations, although there are concerns regarding ensuring sufficient intake of methionine in organic systems; potential solutions are increasing methionine through other sources (prairie meal, potato protein), using different pig breeds which may tolerate lower levels of methionine in their diet, and ensuring that the animals can gain additional methionine from the range.
The Legume LINK project was jointly presented by a researcher working on the project, Heather McCalman (IBERS), and one of the participatory farmers, John Newman (Abbey Home Farm). Legume LINK aims to improve the nitrogen use efficiency in arable systems by creating a diverse mixture of legume and grass species. As part of this project, an ‘All Species Mixture’ (ASM) is being grown on 35 farms across the UK, alongside the farmer’s own choice of ley. Heather presented the feedback from the Welsh and Cornish participatory farms, which overall showed that the majority would use a mixture again. John gave a personal perspective of the trial on his farm. The ASM was slow to establish on his farm, but did improve over time and seemed to yield more than his control ley, and was grazed preferentially by sheep. Initially the ASM had a greater weed burden, but this has reduced over time and it now has fewer weeds than the control. Over the three years that it has been in the ground, the ASM has managed to retain its diversity.
The Legume Futures EU project was also highlighted. More details can be found at www.legumefutures.eu/.
- The economics of feeding peas/beans to monogastrics; it is cheaper if you are able to produce it on farm.
- The feasibility of achieving a 100% organic feed for pigs
- Effect of red clover on fertility in ewes; whilst there is no firm opinion either way, it is best to avoid red clover in tupping ewes.
- Cost of seed for a diverse legume mixture
- Effect of inoculums: no conclusive evidence so far from LegLINK but more data to come
Individual speaker presentations and abstracts
Lesley Smith (SAC): Peas and faba beans as home grown alternatives for soybean meal in fattening pig diets (PDF 547KB)
Both UK organic and conventional pig production rely on soybean meal (SBM), which increases concerns about sustainability, security and environmental impact. Alternative, home-grown protein sources such as peas and faba beans may reduce these concerns. The Green Pig consortium carried out a small-scale growth trial to test effects of peas and faba beans on pig performance. Faba beans (var. Fuego, coloured-flowered spring beans) or peas (var. Prophet) were used in grower and finisher pig diets at 75, 150, 225 and 300 g/kg, gradually and completely replacing SBM. Pure methionine was used to correct amino acid deficiency. Grower and finisher pig data combined suggest that using pea or faba bean based diets throughout the fattening phase unlikely affects overall performance. This indicates that peas and faba beans may be used as viable home-grown alternatives to SBM in balanced diets. Since methionine supply is a bigger constraint in organic diets, an organic demonstration trial is underway to show the feasibility of replacing organic SBM with organic pulses.
John Newman (Abbey Home Farm) and Heather McCalman (IBERS): Developing alternative legume mixtures
- farmers' perspectives  (PDF 295KB)  (PDF 1.4MB)
White clover is the mainstay of grass leys grown by organic farmers. There are, however, a wide range of herbage legumes available with differing agronomy mixtures which may offer advantages in biodiversity, N release dynamics, productivity and effects on the following crop. Ten farmers from Wales and Cornwall were among 35 nationwide to grow an ‘all species mixture (ASM)’ (comprising 10 legumes and 4 grasses) alongside their usual ley in their farm rotation. Linked to regional research hubs, where the ASM was grown in plots, the participating farmers observed the two leys types over the duration of the project. These farmers’ views are collated and indicate the potential for inclusion of the less common legumes in ley mixes. At Abbey home farm the ASM was grown alongside the farm’s usual three year white clover cutting/ grazing ley to build fertility for a following cereal crop. Differences in establishment, canopy height and yield and suitability for Abbey Home Farm are discussed.