Logo image
Back
Model Applications for Sustainable Intensification of Maize‐Based Smallholder Cropping in a Changing World
Book chapter

Model Applications for Sustainable Intensification of Maize‐Based Smallholder Cropping in a Changing World

Mary Ollenburger and Sieglinde Snapp
Practical Applications of Agricultural System Models to Optimize the Use of Limited Water, Volume 5, pp.375-397
Advances in Agricultural Systems Modeling, American Society of Agronomy and Soil Science Society of America
12/15/2014
DOI: https://doi.org/10.2134/advagricsystmodel5.c14

Abstract

changing environment legume diversification maize‐based farming system Malawi model applications smallholder crop production sustainable intensification
The challenge of sustainable intensification (SI) of smallholder production is a growing one, as climate change is acerbating an already vulnerable situation. Rainfed cereals are the mainstay of food security across much of sub‐Saharan Africa, a system that is at risk from variable rainfall. Crop production response to fertility is known to interact strongly with water availability, in complex ways. There are few examples of model applications in a smallholder context to evaluate SI technologies under climate change scenarios. We present a case study from Malawi on alternate approaches to maize (Zea mays L.) intensification, evaluating the response at two sites with variable rainfall intensity for a range of climate scenarios and fertility levels. The SI technologies evaluated included intercrops and rotations of maize with pigeonpea [Cajanus cajan (L.) Millsp.], a bushy, food‐producing legume crop, and comparisons with a continuous sole maize crop. This allowed testing of biological N fixation response, water use, and complementarity of resource partitioning over space and time, as well as consequences for maize and farming system performance. Competition and synergy were assessed through modeling growth, N stress, and drought stress. Interestingly, conditioning effects of soil fertility and site rainfall patterns were observed, with complex interactions and consequences for plant species and climate scenario performance. Higher fertility soils in some cases posed a risk of crop failure under poor rainfall distribution scenarios, as plant growth outstripped water availability. In summary, crop simulation modeling elucidated how tradeoffs among N and water limitations influenced yield and crop failure risk among sole crops, rotations, and intercrop systems.

Metrics

1 Record Views

Details

Logo image