Author
Eghball, Bahman | |
Shanahan, John | |
Varvel, Gary | |
Gilley, John |
Submitted to: Agronomy Abstracts
Publication Type: Abstract Only Publication Acceptance Date: 7/21/2002 Publication Date: 11/1/2002 Citation: EGHBALL, B., SHANAHAN, J.F., VARVEL, G.E., GILLEY, J.E. REDUCTION OF HIGH SOIL TEST PHOSPHORUS BY CROP REMOVAL. AMERICAN SOCIETY OF AGRONOMY ABSTRACTS #140104. 2002. Interpretive Summary: Soils with high phosphorus (P) level can contribute to excess P in runoff. The objectives of this study were to evaluate crop P removal effects on soil P reduction and to evaluate various corn hybrids and soybean varieties for differences in P removal. Soil with varying P level as a result of beef cattle feedlot manure or compost application was cropped to corn for four years without any P addition. In other studies under various water and N regimes, corn hybrids and soybean varieties were evaluated for grain P concentration and P removal. Four years of corn production without P addition reduced surface soil (0 to 15 cm) P level from 265 mg kg-1 to 171 mg kg-1. Based on a decay equation, it would have required 10 years of crop P removal to reduce the soil P level to the original 69 mg kg-1 before treatment application. The rate of decrease in soil P was greater when soil P was higher and reduced with decreasing soil P level. There was as much as 35% difference among corn hybrids for grain P removal. Soybean grain P concentration was nearly twice that for corn but grain P removal was less for soybean than for corn. Crop P removal can significantly reduce soil P level with time. Technical Abstract: Soils with high phosphorus (P) level can contribute to excess P in runoff. The objectives of this study were to evaluate crop P removal effects on soil P reduction and to evaluate various corn hybrids and soybean varieties for differences in P removal. Soil with varying P level as a result of beef cattle feedlot manure or compost application was cropped to corn for four years without any P addition. In other studies under various water and N regimes, corn hybrids and soybean varieties were evaluated for grain P concentration and P removal. Four years of corn production without P addition reduced surface soil (0 to 15 cm) P level from 265 mg kg-1 to 171 mg kg-1. Based on a decay equation, it would have required 10 years of crop P removal to reduce the soil P level to the original 69 mg kg-1 before treatment application. The rate of decrease in soil P was greater when soil P was higher and reduced with decreasing soil P level. There was as much as 35% difference among corn hybrids for grain P removal. Soybean grain P concentration was nearly twice that for corn but grain P removal was less for soybean than for corn. Crop P removal can significantly reduce soil P level with time. |