S02-1-ISU, Farmer Decision Making Strategies for Improved Soil Fertility Management in Maize-Bean Production Systems

Iowa State University as Lead University

U.S. PIs and Institutions and Collaborating Host Countries

Lead U.S. PI

  • Robert E. Mazur,  Iowa State University, Iowa, USA

Collaborating Scientists: U.S.

  • Eric Abbott, Iowa State University
  • Andrew Lenssen, Iowa State University
  • Ebby Luvaga, Iowa State University
  • Russell Yost, University of Hawaii at Manoa
  • Julia Bello-Bravo, University of Illinois at Urbana- Champaign
  • Barry Pittendrigh, University of Illinois at Urbana-Champaign

Collaborating Scientists: International

  • Moses Tenywa, Makerere University, Uganda
  • Onesimus Semalulu, Soils & Agro-meteorology, National Agricultural Research Laboratories, Uganda
  • Ricardo Maria, Institute of Agriculture Research of Mozambique
  • Richard Miiro, Makerere University, Uganda


Project Problem Statement and Justification (Brief)

Smallholder farmers in Africa, both women and men, manage complex multifunctional maize–bean cropping systems in diverse landscapes and agroecosystems. Common beans serve multiple important roles in their cropping systems, food security, nutrition, incomes, and livelihood resilience. They register low yields, and experience pervasive poverty and food insecurity. Low productivity of beans in maize-bean systems is due to low soil fertility, limited availability of improved seed varieties, excess water during plant growth, insects, and diseases. Typical yields of 200 to 500 kg ha-1 are significantly less than the 2000 kg ha-1 often obtained in researcher-managed fields. Poor and declining soil fertility is considered by far the primary constraint to common bean productivity, responsible for 30% of the widely acknowledged yield gap. Grain legume research programs identify and develop improved technologies and management practices that can substantially increase yields. However, adoption of improved crop management practices, particularly those addressing soil fertility, has been modest for beans.

This research project is based on two premises: (1) sustainable intensification of agriculture production requires improved soil fertility management in which legumes are an integral part of cropping systems and (2) addressing soil-related constraints requires not simply increasing access to fertilizers or use of other soil amendments, but - fundamentally – enhancing smallholder farmers’ capabilities in diagnosing and finding solutions to important yield constraints.

This project seeks to develop methods and procedures that enable smallholder farmers with varying levels of education to better diagnose soil-related production constraints, and make improved site-specific crop system management decisions that contribute to higher productivity (including grain legumes) in the short term as well as improvements in soil fertility in the long term.


  1. Characterize Smallholder Farmers’ Motivations, Current Knowledge and Practices, Problem Diagnoses and Solutions, and Risk Management Strategies
  2. Develop and Refine Models about Smallholder Bean Farmers’ Decision Making
  3. Develop and Validate Diagnostic and Decision Support Aids
  4. Develop and Assess Effectiveness of Innovative Approaches for Dissemination of Information and Decision Support Aids, Training, and Follow-up Technical Support
  5. Enhance Institutional Research Capacity Relative to Grain Legumes

Target Outputs:

  1. Characterization of smallholder bean farmers’ agricultural motivations, current knowledge and practices, problem diagnoses, and livelihood and risk management strategies (by 2015)
  2. Models of farmer decision making strategies that reflect Influences of social, cultural, economic, institutional and contextual factors are developed and refined (by 2016)
  3. Innovative diagnostic aids using observable characteristics that enable farmers to make site-specific management decisions are developed and validated (by 2016)
  4. Process for identifying alternative strategies and management practices for improving cropping system productivity and soil fertility is developed (by 2017)
  5. Effective and efficient methods and media for information dissemination to intermediate and end users are developed and assessed (by 2017)
  6. Capacity building through applied research-based training is conducted (2013 onwards)
  7. Research results published in peer-reviewed literature and at the Feed the Future Innovation Lab for Legume Systems Research website hosted by the Management Office at Michigan State University (2015 onwards)