Motivated by recent increases in water pollution in major US agricultural watersheds and by the shortcomings of government programs to control non–point source pollution, this paper examines the prospects for using product certification (ecolabeling) and business-to-business supply chain standards for environmental protection in commodity crop production. We introduce the sources of demand for certification and supply chain standards and the political and economic context in which they have expanded since the 1990s. We explore how various agrifood certification and supply chain standards have been used to achieve changes in production methods and/or in product attributes to meet social goals, and we discuss the prospects for applying these models to commodity crops. We conclude that the nature of corn and soybean production, distribution, and consumption—with numerous sales outlets and invisible consumption as part of processed foods and other products—makes certification schemes to limit agricultural pollution unrealistic and supply chain standards extremely challenging.

No abstract

In Rwanda, farmers' traditional farming systems based on intercropping and varietal mixtures are designed to meet a variety of livelihood objectives and withstand risks associated with fluctuation in market and agro-climatic conditions. However, these mixed systems have been disappearing since 2008 when government mandated intensification strategies. In this paper we use a mixed methods approach to evaluate intercropping and sole cropping systems against farmers' criteria for success: yield, market value, contribution to nutritional quality, and land-use efficiency. We used qualitative interviews to understand the criteria by which farmers evaluate cropping systems, and data from crop trials to assess common bean ((Phaseolus vulgaris L.) and maize (Zea mays L.)) sole crops and intercrops against those criteria. We found that an improved intercropping system tends to outperform the government-mandated system of alternating sole-cropped bean and maize season-by-season, on all four of the criteria tested. Although Rwanda's agricultural intensification strategy aims to improve rural livelihoods through agricultural modernization, it fails to acknowledge the multiple and currently non-replaceable benefits that diverse cropping systems provide, particularly food security and risk management. Agricultural policies need to be based on a better understanding of smallholders' objectives and constraints. Efforts to improve farming systems require innovative and inclusive approaches that enable adaptation to the socio-ecological context.

Perennial crops have numerous ecological and agronomic advantages over their annual counterparts. We estimate discrete choice models to evaluate farmers' preferences for perennial attributes of pigeon pea intercropped with maize in central and southern Malawi. Pigeon pea is a nitrogen-fixing leguminous crop, which has the potential to ameliorate soil fertility problems related to continuous maize cultivation, which are common in Southern Africa. Adoption of annual pigeon pea is relatively low but perennial production of pigeon pea may be more appealing to farmers due to some of the ancillary benefits associated with perenniality. We model perennial production of pigeon pea as a function of the attributes that differ between annual and perennial production: lower labor and seed requirements resulting from a single planting with multiple harvests, enhanced soil fertility and higher levels of biomass production. The primary tradeoff associated with perennial pigeon pea intercropped with maize is competition with maize in subsequent years of production. While maize yield is approximately twice as valuable to farmers as pigeon pea yield, we find positive yet heterogeneous demand for perenniality driven by soil fertility improvements and pigeon pea grain yield.