Impact of Management Practices on Water Extractable Organic Carbon and Nitrogen from 12-Year Poultry Litter Amended Soils

Abstract

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.

Soil water extractable organic matter under long‐term dryland cropping systems on the Texas High Plains

“…Like SUVA 254 values, the E2/E3 of native grassland did not change significantly with depth, with a narrow E2/E3 range of 1.47-2.00 (Figure 4b; Table 1). These values are slightly lower than those reported by He et al (2017) (3.15-3.57) for native T A B L E 5 Correlation coefficients among quality and quantity parameters measured for water-extractable organic matter, year sampled (1977,2013), crop type up to 1977 (continuous wheat, wheat-fallow), tillage (disk plow, stubble mulch, delayed stubble mulch), and depth sampled (0-80, 80-150, 150-230, and 230-300 6, 4.3, 5.8, and 14.4 at D1, D2, D3, and D4, respectively. Despite a trend for higher E2/E3 values with CW-DP, CW-ST, and WF-DST below the plow layer (D4) in 1977, there was no statistical significance (Table 4).…”

“…The importance of WEOM on soil fertility has been recognized within the past few decades (Haynes, 2005). Soil WEOM typically comprises only a small portion (<3%) of total soil organic matter (SOM; Zhao et al, 2013), but is dynamic, mobile, and more sensitive to climate and land management practices than SOM (Bremer et al, 1994;He et al, 2016He et al, , 2017. Chaudhary et al (2017), Ohno et al (2009), and…”

Short-term legacy effects of feedlot manure amendments on water-extractable organic carbon in a clay loam soil profile

“…Some studies have reported both accumulation and redistribution of EOC or WEOC in soils (Gonet and Debska 2006), whereas others found evidence of accumulation but not redistribution of EOC/WEOC or DOC to depth (Angers et al 2006;Long et al 2015;He et al 2017).…”

“…In a lysimeter study in China, Long et al (2015) reported greater DOC in the surface soil for liquid pig manure compared to unamended control, but not at deeper depths to 90 cm. He et al (2017) found that poultry litter application to five cultivated soils in Texas increased WEOC in the surface (0-15 cm) soil compared to the unamended control; but they did not sample deeper depths.…”

“…Some more recent studies have reported both accumulation and redistribution of EOC or WEOC in soils (Gonet and Debska 2006), whereas others found evidence of accumulation but not redistribution or EOC/WEOC or DOC to depth (Angers et al 2006;Long et al 2015;He et al 2017). Angers et al (2006) reported accumulation of WEOC in soils (Quebec) amended with liquid and solid cattle manure at the 0 to 0.10 m depth but not 0.10 to 0.30 m depth compared to unamended control and mineral fertilizer, and attributed no redistribution to decomposition and adsorption.…”