Author
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EGHBALL, BAHMAN |
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Submitted to: Communications in Soil Science and Plant Analysis
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 11/1/2003 Publication Date: 12/1/2003 Citation: EGHBALL, B. LEACHING OF PHOSPHORUS FRACTIONS FOLLOWING MANURE AND COMPOST APPLICATIONS. COMMUNICATIONS IN SOIL SCIENCE AND PLANT ANALYSIS 34:2803-2815. 2003. Interpretive Summary: Manure and composted manure contain several phosphorus (P) fractions (organic, inorganic, etc.). The P fractions added when manure or composted manure is applied can influence P leaching in soil. Phosphorus leaching can pollute ground water in areas with shallow and/or fluctuating ground water especially in sandy areas. Manure and composted manure were applied to meet the nitrogen (N) or P needs of corn for either a one or two-yr period. Fertilized and unfertilized control plots were also used. The P-based treatments also received additional synthetic N fertilizer. After 4 yr of manure and compost applications, inorganic P leached to a soil depth of 12 inches while organic P leached to = 24 inches. Nitrogen-based compost application resulted in greater P leaching in the soil then P-based treatments as soil under N-based management strategy received more P than that under P-based. Organic P leaching from N-based manure application was deeper in the soil than the untreated check indicating less adsorption of organic P by soil constituents than inorganic P. Following manure and compost applications, P was mainly leached in the soil in soluble, organic, and iron-P or aluminum-P forms. These P compounds can pollute the ground water when they leach deep enough in the soil to come in contact with the ground water. Most ground water eventually emerges as surface water and if it contains sufficient P can cause eutrophication, which is a nutrient rich condition that encourages algae growth. Technical Abstract: Phosphorus (P) leaching in manure-amended soil can be influenced by the P fractions added when manure or composted manure is applied. This study was conducted to determine leaching of different P fractions following beef cattle feedlot manure or compost application. Manure and composted manure were applied to meet the nitrogen (N) or P needs of corn (Zea mays L.) for either a one or two-yr period. Fertilized and unfertilized control plots were also used. The P-based treatments also received additional N fertilizer. Soil P fractions were determined for various soil depth increments. After 4 yr of manure and compost applications, inorganic P leached to a soil depth of 30 cm while organic P leached to = 60 cm. Greater concentrations of total, available, and inorganic P fractions were observed for the N-based compost treatments as these management strategies received more P than P-based. Organic P was similar among treatments between 0 and 60 cm soil depth but was significantly higher for the N-based manure treatment than the check in the 60-90 cm increment indicating movement of organic P in the soil. Leaching of soluble and non-occluded P accounted for most of the inorganic P leaching. More than 70% of beef cattle manure or composted manure P was inorganic. Leaching of P following manure and compost applications was a function of soluble, non-occluded, and organic P movement in the soil. Phosphorus leaching can pollute ground water in areas with shallow and/or fluctuating ground water especially in sandy soils |
