Submitted to: Communications in Soil Science and Plant Analysis
Publication Type: Peer reviewed journal
Publication Acceptance Date: 3/26/2008
Publication Date: 3/1/2009
Citation: He, Z., Tazisong, I.A., Senwo, Z.N., Honeycutt, C.W., Zhang, D. 2009. Nitrogen and Phosphorus Accumulation in Pasture Soil from Repeated Poultry Litter Application. Communications in Soil Science and Plant Analysis. 40:587-599. Interpretive Summary: Nitrogen (N) and phosphorus (P) are two major nutrients in poultry litter (PL). Whereas the two elements are required for profitable agricultural practices, N- and P-driven eutrophication of water ecosystems is a serious environmental concern. Thus, a best management of poultry litter application should maintain adequate N and P for plant growth while minimizing adverse environmental impacts of PL application. For evaluating the long-term impact of PL application, a field experiment of land applied litter to pasture soils has been maintained for two decades at the Sand Mountain region of north Alabama, USA. In this study, we evaluated the impact of PL application history (0, 5, 10, 15, and 20 years) on accumulation and distribution of N and P through soil profiles (0-60 cm). Our observation suggested that N and P from poultry litter accumulated in soil. Predicting the build-up based on the cumulative amounts of PL application, rather than isolated factors (i. e. application year or rate), would improve the accuracy of evaluating long-term impacts of poultry litter application on soil nutrient levels.
Technical Abstract: Poultry litter is a traditionally inexpensive and effective fertilizer to improve soil quality and agricultural productivity. However, over application to soil has raised concern because excess nutrients in runoff could accelerate the eutrophication of fresh water. In this work, we determined the contents of total P, Mehlich 3 extracted P, total N, NH4-N, and NO3-N, in pasture soils receiving annual poultry litter applications of 0, 2.27, 2.27, 3.63, and 1.36 Mg/ha/ yr, respectively, for 0, 5, 10, 15, and 20 years. Samples were collected from three soil depths (0 – 20, 20-40, and 40-60 cm) of the Hartsells series (fine-loamy, siliceous, subactive, thermic, Typic Hapludults) on a 3-8% slope in the Sand Mountain region of north Alabama. PL application increased levels of total P, Mehlich-3 extractable P, and total N significantly. However, the change in NH4-N and NO3-N contents by the PL application was not statistically significant (a=0.05). Correlation analysis indicated that the contents of total P, Mehlich 3 extracted P, and total N were more related to cumulative amounts of poultry litter applied than the years of application or annual application rates alone. This observation suggested that N and P from poultry litter accumulated in soil. Predicting the build-up based on the cumulative amounts of PL application, rather than isolated factors (i. e. application year or rate), would improve the accuracy of evaluating long-term impacts of poultry litter application on soil nutrient levels.