420-7
Impact of Management Practice On Weoc and Weon From a12-Yr Poultry Litter Amended Soil.

Poster Number 2733

Wednesday, November 6, 2013
Tampa Convention Center, East Hall, Third Floor

Mingchu Zhang, University of Alaska-Fairbanks, Fairbanks, AK, Robert Harmel, USDA-ARS, Grassland Soil and Water Research Laboratory, Temple, TX, Zhongqi He, USDA-ARS, New Orleans, LA, Heidi Waldrip, USDA-ARS, Bushland, TX and Paulo H. Pagliari, University of Minnesota, Lamberton, MN
Nutrient runoff from manured land can cause water quality problems; however, properly managing application rate in combination with tillage and crop system may reduce water soluble organic C (WEOC) and N (WEON), and decrease the risk of nutrient runoff.  The objective of this research was to determine the effects of poultry litter on WEOC and WEON in a Vertisol-dominated Texas Blackland Prairie soil under different crops, tillage regimes, and grazing managements. Since 2001, poultry litter was applied at rates of 0, 4.5, 6.7, 9.0, 11.2, and 13.4 Mg/ha (i.e. 0, 2, 3, 4, 5 and 6 t/ac) to fields under a corn/oat/wheat rotation that received annual tillage.  In addition, a control field was included that received inorganic fertilizer. For comparison, poultry litter (6.7 and 13.4 Mg/ha) was also applied to pasture with or without cattle grazing. Cumulatively, manure was applied for 12 years. Soil samples (0-15 cm) were taken and analyzed for KCl-mineral N, WEOC and WEON, and the UV-Vis spectral properties of WEOC were analyzed.  Results showed that soil mineral N concentration was higher (p<0.05) in cultivated soils that received the 13.4 Mg/ha rate of poultry litter than soils that received inorganic fertilizer or a lower litter application rate, or when litter was applied to pasture.  The concentration of WEOC was higher (p< 0.05) in pasture soils than in cultivated soils, indicating that decomposition was promoted by tillage. The concentration of WEON was increased with the higher rates of poultry litter application, while C:N ratios decreased as the litter application rate increased. However, the soil from pasture which received litter appeared to have a greater C:N ratios than cultivated soils that received the same rate of litter. The spectral analysis indicated that properties of soil WEOC differed under different management and rate of litter applications.       
See more from this Division: SSSA Division: Soils & Environmental Quality
See more from this Session: Soil Amendment Effects On Environmental Processes: Posters

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