More-effective weed control in agricultural fields can be achieved by utilizing information about the spatial distribution of the previous year’s mature weeds. In our study, variable-rate herbicide applications based on weed infestation maps developed just before the previous year’s harvest provided effective weed control. The results showed that when information about the spatial distribution of the previous year’s weed seedlings or mature weeds was used, weed control was comparable to uniform, one-rate, herbicide applications, while the total amount of herbicide applied decreased. Herbicide use was reduced an estimated 39% for the seedling map and 24% for the mature map approach. However, incorporating the weed-seed redistribution from harvest to application time into the treatment maps could further improve weed control.

High production costs and perceived declines in soil quality due to agricultural intensification have led to recent interest in conservation tillage production practices. We conducted field experiments in Five Points in 1997 and 1998 to evaluate the effectiveness of maintaining a cover crop mulch on the soil surface in a no-till system compared to a standard tillage system for conserving soil moisture and improving water infiltration and other soil physical properties in a furrow-irrigated tomato field. Soil water content did not differ among treatments in 1997, but was higher under no-till cover crop mulches than conventionally tilled plots during the 1998 growing season. Soil carbon was increased more than 8% and more earthworms were found under no-till mulches relative to the conventionally tilled plots in the second year of the study. Soil compaction was lower in no-till treatments, especially at the 1-to-2-foot depth. In this study, furrows were swept clean and therefore furrow irrigation did not constitute a limitation to this no-till system.