Grain Legumes Increase Yield Stability in Maize Based Cropping Systems

Abstract

Functional crop diversity enhances crop productivity, stability, and food security through efficient nutrient cycling and water utilization; however, performance is variable under marginal environments. We applied stability analysis to assess impacts of grain legume integration on maize (Zea mays L.) grain yield, yield stability, N use efficiency (NUE), and ability to meet household protein requirements. Six field trials were conducted across three agroecological zones over five cropping seasons. We used additive main effect and multiplicative interaction to assess grain yield stability of maize in unfertilized maize, maize fertilized with 69 kg N ha−1 (Mz69), maize–pigeonpea [Cajanus cajan (L.) Millsp.] intercrop (MzPp), and maize in rotation with soybean [Glycine max (L.) Merr.] (SbRot), peanut (Arachis hypogaea L., PnRot), and peanut–pigeonpea intercrop (PnDLR). Maize in rotation or intercrop received 10.5 kg P2O5 and 35 kg N ha−1, whereas the Mz69 treatment received 21 kg P2O5 and 69 kg N ha−1. Maize grain yield in rotation with legumes was not significantly different from yield for Mz69. In wetter environments, MzPp intercrops had low maize grain yield (−35%) relative to Mz69, whereas in drier environments, maize had higher grain yield (14%) relative to rotated maize. Rotating maize with legumes increased NUE (56%) and protein contributions (65%) relative to Mz69. Grain yield of maize in SbRot consistently had the highest yield and was the most stable technology. Simple statistical models can be used to test multicrop stability. Integrating maize with legumes as intercrops or rotation can allow farmers to achieve high and stable yield under varying rainfall, with modest fertilizer investments.

Long-Term Evidence Shows that Crop-Rotation Diversification Increases Agricultural Resilience to Adverse Growing Conditions in North America

“…23 Going beyond average yield increases, far less is known regarding how diversified crop rotations (beyond just two crops) affect yield resilience, 6,11,22,[24][25][26] especially in intensive agricultural systems in which inputs supplant some of the functions that rotations provide in low-input systems. 27 In diversified rotations, increased yield resilience to drought and other types of stressful growing conditions may result from improved soil properties, such as increases in soil water capture and storage and abundance of beneficial soil microbes. One study recently showed 7% higher maize yields during hot and dry years in a diversified five-crop rotation than in a maize-soybean rotation, 24 but whether this is a general effect of rotation diversification or a site-specific effect due to particular environmental conditions or crop-rotation composition is not known.…”

Maize-Brachiaria intercropping: A strategy to supply recycled N to maize and reduce soil N2O emissions?

“…However, we only measured the AE of the cash crop and did not evaluate the effect of intercropping at the system level. Functional crop diversity, including intercropping and rotation, may lead to higher and more stable yields over time ( Chimonyo et al, 2019 ). Although this study did not show short-term evidence, the benefits of cycling N and other nutrients and supplying organic C to the soil system will probably be noticed in the medium to long term ( Qin et al, 2015 , Crusciol et al, 2015 ), as most of the N from plant residues enriches the soil organic N pool ( Fortes et al, 2013 , Smith and Chalk, 2018 , Rocha et al, 2019 , Oliveira et al, 2019 ).…”

Farmer Participatory Research Advances Sustainable Agriculture: Lessons from Michigan and Malawi

“…This involved an early maturing grain legume (e.g., peanut or soybean) grown as an understory with a late maturing pigeonpea crop, sequenced in rotation with maize. Other SA technologies included maize grown as an intercrop with a locally selected improved pigeonpea variety, and maize sequenced in a rotation with peanut crop at a high population density and judicious fertilizer doses (Chimonyo et al, 2019).…”

“…The performance of SA technology on MBT plots has also been assessed at our sites via ANOVA combined with additive main effect and multiplicative interaction models (Chimonyo et al, 2019). Means, SDs, and t ‐test characterization along with visualization through radar charts have also proven useful (Snapp et al, 2018).…”

“…Key to this, structured surveys, on‐farm monitoring, and scheduled report‐back sessions all added depth and richness to our research and increased relevance for farmers (Farrington and Martin, 1988; Snapp et al, 2002). Visualization tools such as radar charts, structural equation modeling, and adaptability analysis have been key to interpreting complex findings in MBT approaches conducted in Southern Africa, as well as the United States (Chimonyo et al, 2019; Smith et al, 2014). This is in concurrence with a recent report on MBT variety selection with vegetable growers in the United States (Lyon et al, 2019).…”