Author(s)

Zhongqi He^1*, Mingchu Zhang^2*, Aiqing Zhao³, Heidi M. Waldrip⁴, Paulo H. Pagliari⁵, R. Daren Harmel⁶

¹USDA-ARS, Southern Regional Research Center, New Orleans, USA.
²Department of Agriculture and Horticulture, University of Alaska Fairbanks, Fairbanks, USA.
³Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering (TCSAE), Beijing, China.
⁴USDA-ARS, Conservation and Production Research Laboratory, Bushland, USA.
⁵Department of Soil, Water, and Climate, University of Minnesota, Southwest Research and Outreach Center, Lamberton, USA.
⁶USDA-ARS, Center for Agricultural Resources Research, Fort Collins, USA.

Water extractable organic carbon (WEOC) and nitrogen (WEON) are two key parameters of soil water extractable organic matter (WEOM). Proper management of manure application rate in combination with tillage and cropping management could maintain appropriate WEOC and WEON concentrations in soils while decreasing the risk of their runoff from cropland and pastures. The objective of this research was to determine the effect of poultry litter (PL) application on WEOC and WEON in soils under different crops, tillage regimes, and grazing strategies. From 2001 to 2012, PL was applied at multiple rates to cultivated fields in a corn-oat/wheat-hay rotation or to pastures grazed by cattle or ungrazed. Soil samples (0 - 15 cm) were analyzed for KCl-extractable mineral N, and WEOC, and WEON contents. In addition, Ultraviolet-visible (UV-vis) and fluorescence spectroscopies were used to characterize WEOC stability. Organic N levels were higher at the high PL application rates. The soil C:N ratio narrowed as the PL application rate increased. However, the soil from pastures which received PL tended to have a wider range of C:N ratios than soil from the cultivated fields, despite identical PL application rates. The spectral analyses indicated that WEOC properties were responsive to management and PL application rate; therefore, this parameter may be used as a guide to provide best management strategy for manure application.

Biological Index, Humification Index, Poultry Litter, Soil Organic Matter, Spe-cific Absorptivity, UV-Vis Spectroscopy

He, Z. , Zhang, M. , Zhao, A. , Waldrip, H. , Pagliari, P. and Harmel, R. (2017) Impact of Management Practices on Water Extractable Organic Carbon and Nitrogen from 12-Year Poultry Litter Amended Soils. Open Journal of Soil Science, 7, 259-277. doi: 10.4236/ojss.2017.710019.