Evaluation of Non-Point Pollution Control Practices and Copper Treatments on Control of Nuisance Filamentous Algae

摘要

Runoff studies were initiated in May 1984 on an erodible soil with slopes ranging from 4.6 to 13.8%. 100 sq ft plots were divided into two tillage treatments: no-till and conventional plow system. Within each tillage treatment, three nitrogen application techniques were used: surface application of ammonium nitrate pellets (33.5% N), injected anhydrous ammonia, and injected anhydrous ammonia stabilized with the nitrification inhibitor nitrapyrin. A fourth set of plots was left unfertilized. Use of the runoff data in conjunction with a model of the growth of the nuisance filamentous alga Pithophora in Surrey Lake, Indiana suggests that conversion of the agricultural land in the watershed from a conventional till, anhydrous ammonia injected management system to a no-till system with either anhydrous ammonia injected alone or injected with nitrapyrin should lead to a noticeable reduction (approximately 40%) in Pithophora growth.