Sunday, 16 February 2014
Regency D (Hyatt Regency Chicago)
Agricultural systems are dependent upon the natural resources because they use these components, e.g., water, air, solar radiation, as part of the growth process. The primary natural resource base upon which agriculture is built is the soil resource which supplies water and nutrients. We assume that we can manage this resource by supplying water and nutrients to the soil and agriculture has readily adopted technologies which supply irrigation water and inorganic nutrients to meet crop demands. However, adopting these practices coupled with more intense tillage and lack of residue cover left on the soil from previous crops has contributed to soil degradation. Soil degradation is most often observed in reduced soil organic matter and increased erosion and both of these factors contribute to loss of soil productivity. The soil resource is a critical component in resilience of agricultural system to climate change but the linkage to direct changes in the soil resource often goes unnoticed. Examination of the variation in crop yields across a typical agricultural field reveals the impact of climate stresses on productivity in all but the most optimal growing conditions. The degraded areas of the field show the largest yield losses when subjected to any level of crop stress and if we extend those impacts to future climates and increased soil degradation the result would be greater variation in crop production. The goal of future agricultural systems should be to become as efficient as possible in the use of water, capture of solar radiation, and use of nutrients. To achieve this goal will require a renewed understanding of the importance of the natural resource supporting agriculture and begin to realize the value of enhancing and maintaining the quality of the natural resource base.