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Cover Crop and Nitrogen Fertilization Influence Soil Carbon and Nitrogen Under Bioenergy Sweet Sorghum
Author(s) -
Sainju Upendra M.,
Singh Hari P.,
Singh Bharat P.,
Whitehead Wayne F.,
Chiluwal Anuj,
Paudel Rajesh
Publication year - 2018
Publication title -
agronomy journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.752
H-Index - 131
eISSN - 1435-0645
pISSN - 0002-1962
DOI - 10.2134/agronj2017.05.0253
Subject(s) - vicia villosa , cover crop , agronomy , vicia sativa , secale , sorghum , sweet sorghum , green manure , biology , crop , biomass (ecology)
Core Ideas Removal of aboveground biomass may affect soil C and N under sweet sorghum. The effect of cover crop and N fertilization on soil C and N under sweet sorghum was examined. SOC and STN were greater with vetch and vetch/rye mixture than other cover crops NH 4 ‐N was greater with rye and NO 3 ‐N greater with vetch/rye than other cover crops. Vetch and vetch/rye can enhance soil C and N storage and optimize N availability.Sustainable production of sweet sorghum ( Sorghum bicolor [L.] Moench) grown for bioenergy production depends on practices that maintain soil C and N levels. The objective of this study was to evaluate the effect of winter cover crops (hairy vetch [ Vicia villosa Roth], rye [ Secaele cereale L.], hairy vetch/rye mixture, and the control [no cover crop]) and N fertilization rates (0 and 90 kg N ha − ) on soil organic C (SOC), total N (STN), NH 4 –N, and NO 3 –N contents at the 0‐ to 30‐cm depth from 2010 to 2014 in the southeastern USA. Cover crop biomass yield and C content were greater with vetch/rye than vetch and the control and N content greater with vetch and vetch/rye than the control in 2013 and 2014. The SOC and STN at 0 to 5 cm were greater with vetch/rye than the control and at 15 to 30 cm were greater with vetch than vetch/rye. At 0 to 5 cm, SOC increased at 0.55 Mg C ha −1 yr −1 and STN at 0.06 Mg N ha −1 yr −1 , regardless of treatments. At most depths, NH 4 –N content was greater with rye than the control and greater with 0 than 90 kg N ha −1 , but NO 3 –N content was greater with vetch/rye than rye. Because of greater cover crop C and N inputs, soil C and N stocks can be enhanced and N availability can be optimized by growing vetch and vetch/rye mixture cover crops to replace the stocks reduced by the removal of aboveground sweet sorghum biomass.