Use of Alfalfa for Soil Phosphorus Removal Following Long-Term Manure Application

摘要

This study was conducted to examine alfalfa remediation effects on a cornfield treated during a 10-yr period with manure at rates matching either the N (MN) or P (MP) requirements of silage com (Zea mays L.). A commercial fertilizer (NCK) was used asa control. The site was removed from corn production with cessation of treatments and planted to alfalfa in 2005. Alfalfa plants were harvested from a 1 m~2 square area at eight replicates of MN, MP and NCK prior to each cutting of alfalfa. The harvestedplants were analyzed for total P. Soil samples were taken at the end of each growing season to depths of 0-15 cm and 15-30 cm. Analysis showed the MN plant samples from the MN treatments (total of 8 cuttings) had significantly (P < 0.05) higher P content compared to the NCK treatment with exception the last cutting of 2007. The alfalfa removed 90 kg/ha of P from the MN treatment over the two years compared to a 71 kg/ha for the MP treatment and 52 Kg/ha for the NCK treatment.