Author
WANG, JUN - Northwest University | |
Sainju, Upendra |
Submitted to: PLOS ONE
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 6/18/2014 Publication Date: 8/19/2014 Publication URL: http://handle.nal.usda.gov/10113/59519 Citation: Wang, J., Sainju, U.M. 2014. Soil carbon and nitrogen fractions and crop yields affected residue placement and crop species. PLoS One. 9(8):1-11. DOI: 10.1371/journal.pone.0105039. Interpretive Summary: Soil organic matter, as indicated by C and N levels, is an important component of soil quality and productivity. Increasing soil organic matter through enhanced C and N sequestration can also reduce the potentials for global warming by mitigating greenhouse gas emissions and N leaching by storing N in the soil. High variability in soil properties in the field results in non-response of management practices on soil C and N fractions. We evaluated the effects of crop species (spring wheat, pea, and fallow), N fertilization (0.11 and 0.96 g N pot-1), and residue placement (no residue, surface placement, and incorporation into the soil) on soil C and N fractions under controlled soil and climatic conditions in a greenhouse. Soil samples collected from the field were grown with crops in a greenhouse and analyzed for soil organic C (SOC), total N (STN), particulate organic C and N (POC and PON), microbial biomass C and N (MBC and MBN), potential C and N mineralization (PCM and PNM), NH4-N, and NO3-N contents. The SOC, STN, PCM, and MBC were greater in surface residue placement under wheat with 0.11 g N pot-1, PNM, MBN, and NO3-N greater in surface residue placement under wheat or fallow with 0.96 g N pot-1, but POC, PON, and NH4-N greater in residue incorporation under wheat with 0.11 to 0.96 g N pot-1 than other treatments. Under controlled soil and environmental conditions, surface residue placement under wheat increased crop yield, soil C and N storage, microbial biomass and activity, and N mineralization, but residue incorporation increased coarse organic matter N and N availability. Short-term soil quality and productivity responses to management practices are readily obtained under controlled soil and environmental conditions in the greenhouse compared to those expected in the field. The results can be applied to the field with uniform soil properties when short-effect of management practices on soil quality and productivity are measured. Technical Abstract: High variability in soil properties in the field results in non-response of management practices on soil C and N fractions. We evaluated the effects of crop species (spring wheat [Triticum aestivum L.], pea [Pisum sativum L.], and fallow), N fertilization (0.11 and 0.96 g N pot-1), and residue placement (no residue, surface placement, and incorporation into the soil) on soil C and N fractions in a greenhouse. Soil samples collected from the field were grown with crops in a greenhouse and analyzed for soil organic C (SOC), total N (STN), particulate organic C and N (POC and PON), microbial biomass C and N (MBC and MBN), potential C and N mineralization (PCM and PNM), NH4-N, and NO3-N contents. The SOC, STN, PCM, and MBC were greater in surface residue placement under wheat with 0.11 g N pot-1, PNM, MBN, and NO3-N greater in surface residue placement under wheat or fallow with 0.96 g N pot-1, but POC, PON, and NH4-N greater in residue incorporation under wheat with 0.11 to 0.96 g N pot-1 than other treatments. Soil quality responses to short-term management were readily obtained under controlled soil and environmental conditions in the greenhouse. |