Agroecosystem Approach to Soil and Crop Management Research

Research techniques that have greatly advanced agronomic science in the 20th century, and have enhanced our knowledge of cause and effect, have been accompanied by reductionism. As a result, much valuable research has been accomplished, but less synthesis of results has occurred that provides answers to landscape-level research questions. We propose that a systems approach to the study of soil and crop management problems is a useful technique that tests our present research knowledge in a way that answers practical agricultural problems and simultaneously identifies gaps in basic research knowledge. We have used a problem common to the Great Plains to demonstrate the systems approach: minimizing the soiland environment-degrading practice of summer fallowing and simultaneously increasing farm profitability. Although much is known about summer fallow at specific locations, less is known about extrapolating this knowledge across soil and climatic gradients. We show that intensified crop sequences under no-till techniques can replace summer fallow in many environments, and increase the productivity per unit of water received. Simultaneous reductions in the damaging factors of summer fallowing, in particular soil erosion and organic matter losses, also have occurred. We are researching the problem at a landscape level without losing the ability to detect causae and effect, and are able to simultaneously conduct basic research on soil nutrient cycling and water budgets. The approach also is being used effectively as an adult educational tool, thereby facilitating the transfer of technology from the researcher to