Effect of manure management on carbon evolution and water extractable phosphorus

• Published in: Communications in soil science and plant analysis 2003-11, Vol.34 (19-20), p.2901-2912
• Main Authors: Stout, W.L, Dell, C.J, Schnabel, R.R
• Format: Article
• Language: English
• Subjects: Agronomy. Soil science and plant productions; animal manure management; bioavailability; Biological and medical sciences; cattle manure; dry matter accumulation; Eutrophication; Fundamental and applied biological sciences. Psychology; nitrification; nitrogen and phosphorus based animal manure management; nutrient availability; nutrient uptake; organophosphorus compounds; phosphorus; Soil and water pollution; soil fertility; soil microorganisms; soil respiration; Soil science; Triticum aestivum; Water quality; water solubility; wheat
• ISSN: 0010-3624; 1532-2416
• DOI: 10.1081/CSS-120025215

Soils with excessive phosphorus (P) levels due to manure application are an environmental concern because water extractable P (WEP) in runoff from these soils can contribute to increased amounts P in surface water, which can contribute to eutrophication of freshwater. Phosphorus based manure management is an option to reduce WEP and thereby reduce agricultural P runoff. In P based manure management, manure is applied to meet the P needs of a crop or not to exceed a given soil test level. Because P base manure management does not supply enough nitrogen (N) to meet the needs of the crop, addition fertilizer N needs to be applied. Fertilizer N applied to soils may increase the rate of mineralization of organic matter and lowers soil pH and therefore may affect the solubility of soil inorganic and organic P pools. The extent to which this may affect WEP or plant P availability is not known. Thus, laboratory and greenhouse studies were conducted to determine the effects of P based manure management on WEP and on short-term P plant availability. Phosphorus based manure management had no significant effect on the shift of organic P to WEP, but the increased acidity due to urea hydrolysis and subsequent nitrification of ammonia had a significant effect on the solubilization of P form the Ca-bound IP pool, thereby increasing WEP. This could be a significant consideration where Ca-bound IP dominates IP, P based manure management is implemented and increased WEP is subject to export to surface waters via runoff.