Effects of Tillage System, Crop Residue Level, and Fertilizer Application Technique on Losses of Phosphorus and Pesticides from Agricultural Lands

摘要

A rainfall simulator was used to study the effectiveness of three best management practices-no-till, residue level and fertilizer application technique-for reducing sediment, phosphorus, and pesticide losses from agricultural lands. Simulated rainfall was applied to 12 experimental field plots, each 0.01 ha in size. The plots were divided into conventional and no-till systems. During phase 1, the effectiveness of two fertilizer application methods-subsurface injection and surface application-were investigated for the two tillage systems. In phase II, three crop residue levels-0, 750, and 1500 kg/ha - were studied within each tillage system. Granular fertilizer was applied at the rate 46 kg/ha. Atrazine and 2,4-D were applied at the rates of 2.24 and 0.56 kg/ha active ingredient, respectively. Fertilizer and herbicides were applied 24 to 48 hours before the start of rain simulation. Water samples were collected from the base of each plot and analyzed for sediment, nutrient, and pesticide content.