Multipurpose Legumes for Soil Rehabilitation

Pigeonpea stand at time of maize harvest

Pigeonpea stand at time of maize harvest

Description

In Malawi there is a growing body of evidence that soil organic matter rehabilitation is urgently needed – yet widely promoted approaches such as agroforestry, conservation agriculture and livestock integration all face major challenges. A farmer-approved approach, widely shown to be feasible for adoption, is expanded production of pigeonpeas (Cajanus cajan) and other multipurpose legumes (e.g. Doubled Up Legumes). These shrubby or viney plants are unique because they can provide food and other agricultural products while at the same time regenerating soil carbon, fixing nitrogen, and solubilizing phosphorus for improved soil productivity.Read more

Principles:

  • Soil quality rehabilitation, in particular building soil organic matter and improved nutrient use efficiency
  • Improved agricultural biodiversity
  • Biological nitrogen fixationRead more

Debates:

  • Growing large amount of vegetation may put demands on water use and the ability for the water availability to recharge in time for the next crop
  • A pigeonpea mixed system may be overly competitive for nutrients and other resources, or the growth traits may be sufficiently complementary. There is a complexity here and the answer is expected to vary with agroecology and socio-economic conditions.
  • Scalability of multipurpose legumes such as pigeonpea and climbing bean. That is, do specific household characteristics predict interest and adoption of multipurpose legumes? Under which market conditions, agroecozones, soil types and climate do different pigeonpea varieties, climbing bean or doubled up legume technologies perform well?Read more

Links:

FAO profile of our research on legumes and land productivity in Malawi (pdf)

Learning Lab Resources:

Beedy, T.L., S.S. Snapp, F.K. Akinnifesi and G.W. Sileshi. 2010. Long-term impact of Gliricidia sepium intercropping and inorganic fertilizer on soil organic matter fractions in maize-based cropping systems. Agric. Ecosystems and Environment 138:139-146.

Chikowo, R., Zingore S, Nyamangara J. Bekunda M, Messina J, Snapp S.S. 2014. Approaches to reinforce crop productivity under water- limited conditions in sub-humid environments in Africa. In: Sustainable Intensification to Advance Food Security and Enhance Climate Resilience in Africa (Lal R, Mwase D, Hansen F, Eds). Springer. 235-253pp.

Gwenambira, C. (2015). Below- and Aboveground Pigeonpea Productivity in on-Farm Sole and Intercrop Systems in Central Malawi. Michigan State University. Ann Arbor: ProQuest. Web.Read more

Extended Bibliography and Works Cited:

Kong, A.Y.Y., J. Six, D.C. Bryant, R.F. Denison, and C. van Kessel. 2005. The relationship between carbon input, aggregation and soil organic carbon stabilization in sustainable cropping systems. Soil Sci. Soc. Am. J. 69:1078-1085.

Powlson, D.S., C.M. Stirling, M.L. Jat, B.G. Gerard, C.A. Palm, P.A. Sanchez and K.G. Cassman. 2014. Limited potential of no-till agriculture for climate change mitigation. Nature Climate Change. 4:678-683. DOI: 10.1038/NCLIMATE2292

Puget, P. and L.E. Drinkwater. 2001. Short-term dynamics of root- and shoot-derived carbon from a leguminous green manure. Soil Sci. Soc. Am. J. 65:771-779.

Sekiya, N. and K. Yano.  2004.  Do pigeon pea and sesbania supply groundwater to intercropped maize through hydraulic lift? —Hydrogen stable isotope investigation of xylem waters.  Field Crops Research 86: 167–173.

Challenges Addressed: Poverty & food insecurity; Soil quality and low productivity; Climate change; Poor access to organic and inorganic inputs; Contested agronomy- moving beyond silver bullets; Carbon, nitrogen and phosphorus as drivers

Tags: Agrobiodiversity; Agronomy; Climate Change; Extension; Sociology; Soil Science; and Sustainability Science

Table 1. Legume life-forms and example species grown in Malawi agriculture and the value of associated products. Adapted from Mhango et al., 2013.

Table 1. Legume life-forms and example species grown in Malawi agriculture and the value of associated products. Adapted from Mhango et al., 2013.

Figure 1. Adaptability analysis of maize yield performance of maize grown with multipurpose legume systems compared to monoculture maize at different N input rates, relative to average maize yield performance at a site over time. Results reported for two sites, high potential Linthipe and low potential Golomoti, both in Central Malawi. Model simulation carried out using APSIM for over a decade of weather files from the two sites (Smith et al., unpublished data, 2015).

Figure 1. Adaptability analysis of maize yield performance of maize grown with multipurpose legume systems compared to monoculture maize at different N input rates, relative to average maize yield performance at a site over time. Results reported for two sites, high potential Linthipe and low potential Golomoti, both in Central Malawi. Model simulation carried out using APSIM for over a decade of weather files from the two sites (Smith et al., unpublished data, 2015).