EXPLORING POTENTIAL SOIL PHOSPHORUS MOVEMENT IN FOUR ORGANIC AGRICULTURE FORAGE SYSTEMS
Open Access
- Author:
- Seiler, Lauren Katherine
- Area of Honors:
- Environmental Resource Management
- Degree:
- Bachelor of Science
- Document Type:
- Thesis
- Thesis Supervisors:
- Jason Philip Kaye, Thesis Supervisor
Jason Philip Kaye, Thesis Supervisor
Robert David Shannon, Thesis Honors Advisor - Keywords:
- phosphorus
runoff
organic
soil
agriculture - Abstract:
- Phosphorus (P) runoff from agricultural lands is a significant environmental problem for freshwater aquatic systems because the input of P into these waters aggravates the process of eutrophication. Many studies are now being conducted in an attempt to pinpoint agricultural practices that prevent P from agricultural areas from entering the environment via runoff. Organic agriculture systems are a special concern for researchers because the use of manure as a fertilizer leads to the buildup of P in soils, which may become subject to runoff. In this study, four organic forage systems that differed in manure application rates, tillage practices, and other variables were assessed for P vulnerable to subsurface drainage and plant available P. It was found that none of the treatments differed in P vulnerable to subsurface drainage, and P concentrations ranged from 0.019 mg/kg to 0.110 mg/kg. However, after manure was applied to one of the treatments, the treatment with the manure addition had a mean P concentration of 0.053 mg/kg, while other treatment means were significantly lower. Additionally, none of the treatments differed in plant available P, and P concentrations ranged from 21.00 mg/kg to 64.00 mg/kg. Therefore, despite a variety of treatments and manure applications, none of the treatments exhibited a high degree of potential for P loss. These results indicate that sustainable P management can be achieved in a diverse set of organic systems and that organic agriculture does not necessarily create soil P levels that generate pollution concerns.