Date
04 Feb 2014
Cattle grazing maize residues after harvest in Zimbabwe.Photo: Sabine Homann
Can scientific methods for analyzing trade-offs and synergies help smallholder farmers decide on the best use of crop residues to maximize their production?
According to an article in a special issue of Current Opinion in Environmental Sustainability, the answer is yes, provided the analysis includes stakeholder participation.
“Without stakeholder involvement, trade-off analysis has limited use for informing practical decision-making,” says Lotte Klapwijk from the international Institute of Tropical Agriculture (IITA) and the Plant Production Systems Group at Wageningen University (WUR) as well as lead author of the article.
“Perhaps the best use of trade-off analysis is in supporting discussions rather than in supporting decisions.”
Trade-offs are part of managing any farm or landscape. For two-thirds of the population in developing countries who farm a combination of crops and livestock, one of the most important trade-offs concerns the use of crop residues: what percentages should be used to provide fodder for livestock, applied to fields to enrich soils, used for fuel or construction materials or sold for profit?
In recent years, analyzing such trade-offs has become more popular in assessing the performance of agricultural systems and in managing interventions in multifunctional landscapes aimed at sustainability and food security. With this, have come greater advances in techniques for assessing trade-offs.
Klapwijk and colleagues reviewed 4 state-of-the-art approaches for analyzing trade-offs, taking the management of crop residues in smallholder farming systems as an example: participatory methods, empirical analysis, simulation models and optimization models for analyzing trade-offs, acknowledging the strengths and weaknesses of each.
The researchers found that while participatory methods are useful in identifying the importance farmers place on crop residues for different purposes, they usually result in qualitative data, which alone is not well-suited for quantifying trade-offs.
Empirical analysis on the other hand uses experimental approaches to generate quantitative data on the behavior of systems under different conditions. For crop residues, empirical analysis can generate trade-off curves showing impacts of decisions on soil erosion or on the body weight or milk production for livestock. This approach may be powerful for analyzing the outcomes of decisions in the current setting, but cannot be used as a predictive tool.
Simulation models however, are able to predict how the distribution of different percentages of crop residue will affect crop versus livestock production. These models are also useful in assessing the impacts of decisions over the short and long term. But the authors point out that simulation models may require participatory methods to capture the objectives of different land users and social arrangements accompanying different practices. Calibration and validation of the models also requires cross-checking model results with empirical data.
The final method of trade-off analysis reviewed is optimization models such as mathematical programming or multi-objective evolutionary algorithms. These models are designed to find the best possible trade-off through analyzing a range of criteria. They can also assess whether trade-offs can be alleviated through new interventions. The limitation of this approach is that land users do not always behave according to economic rationality and optimize their behavior.
Todd Rosenstock, Climate Change and Environmental Scientist with the World Agroforestry Centre, and co-author the paper, explains that with each approach having its limitations, it is clear that combinations are needed to conduct realistic, relevant and integrated assessments of systems. “These combinations should include some form of participation to define meaningful objectives and indicators that stakeholders perceive as important.”
In East Africa, the CGIAR Research Program on Climate Change Agriculture and Food Security (CCAFS) has successfully incorporated a participatory approach into research on how different policy options can influence future land use development, food production and possibilities for sustainable development. Through capturing what stakeholders perceive as essential, the relevance of their analysis has been strongly enhanced.
But even with the best efforts in involving farmers in model development and use, and with co-learning and co-innovation, the authors warn that trade-off analysis may still not properly account for the diversity in resource availability, the objectives of its diverse end-users or the broader institutional and policy environment in which they operate.
“This way, models can be used to help people engage in deeper discussions around ‘what if’ scenarios, outlines Mark van Wijk from the International Livestock Research Institute (ILRI). “This may be an ambitious approach but it is likely to be more accurate in assessing trade-offs.”
“Such an approach also requires going beyond just technical information to establishing effective partnerships among researchers, producers, traders, consumers, ecologists and policy makers”, says Piet van Asten (IITA systems agronomist) who recently co-organized a workshop within the CGIAR to critically review and discuss the tools and opportunities of trade-off analysis in agricultural research.
Download the full article
Klapwijk CJ, van Wijk MT, Rosenstock TS, van Asten PJA, Thornton PK, Giller KE (2014) Analysis of trade-offs in agricultural systems: current status and way forward, Current Opinion in Environmental Sustainability 6: 110-115.
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This article appears in a special issue of the journal Current Opinion in Environmental Sustainability on the theme ‘Sustainability challenges.’ The full special issue is available Open Access at http://www.sciencedirect.com/science/journal/18773435/6/supp/C
The issue will be launched during the World Congress on Agroforestry in Delhi, India in February2014.