Farming systems for sustainable agriculture and environmental quality

Abstract

Field studies were initiated in 1992 to investigate the impacts of eight integrated crop and chemical management systems on crop production and groundwater quality. The tillage and chemical management systems included the use of late spring NO3-N test (LSNT) in a corn and soybean rotation respectively, with either no-till or chisel ploughing, and broadcast and banding of herbicides under no-till and chisel ploughing. All experimental plots were instrumented for sampling subsurface drainage water for quantity and quality. An automatic data collection system was used to collect water samples for water quality analyses during the 1993, 1994 and 1995 growing seasons from 36 field plots (size 0.4ha). Results of this study indicate that the use of LSNT resulted in equal or better yields and lower NO3-N concentrations in the drainage water for both tillage practices. The LSNT resulted in NO3-N concentrations of 9.3, 8.0 and 8.9 mg l−1 under no-till, and 11.1, 7.1 and 11.4mg l−1 under chisel plough for 1993, 1994 and 1995 respectively. The highest corn yields were obtained with LSNT for both tillage systems in 1993, 1994 and 1995. Also, banding of herbicides resulted in lower herbicide losses to shallow groundwater. The overall results of this study show that alternative chemical and crop management systems are important to the preservation of environmental quality and increased crop productivity.Key wordssustainabilityfarming systemswater quality