Do corn-soybean rotations enhance decomposition of soil organic matter?
- 104 Downloads
Corn and soybean crops are often grown in rotation, requiring lower nitrogen (N) inputs than continuous corn. However, soil organic carbon (C) may be declining in corn-soybean systems despite sustained residue inputs. We asked whether corn-soybean rotations increase decomposition of litter and soil C as compared with continuous corn.
We incubated soils from a long-term field experiment including continuous corn and both phases of the corn-soybean rotation. Soils were amended with corn litter, soybean litter, or no litter. We measured natural abundance C stable isotopes (δ13C values) in respiration and microbial biomass to partition C sources.
Addition of soybean litter increased microbial biomass while corn did not. However, corn litter addition consistently increased (i.e., primed) soil C decomposition while soybean litter did not. Soils most recently planted to corn following soybeans had the greatest soil C decomposition and N mineralization irrespective of litter addition, and they decomposed corn litter faster and had a faster priming response than the other treatments.
Our data support the hypothesis that alternating inputs of N-rich soybean litter and relatively N-poor corn litter could enhance litter and SOC decomposition by driving microbial growth following the soybean phase and stimulating priming following the corn phase. Increased decomposition and N mineralization from litter and SOC in corn-soybean rotations may contribute to the soybean N credit but could also contribute to longer-term soil C and N declines, consistent with field data.
KeywordsCarbon-use efficiency Carbon stable isotopes Microbial biomass Nitrogen mineralization Priming Soybean nitrogen credit
Funding was provided in part by the Center for Global and Regional Environmental Research at the University of Iowa. We thank Matt Liebman for thoughtful comments and for facilitating access to the field site, Carlos Tenesaca for assistance in the lab, the McNair Scholars program for providing research support for ARM, and two anonymous reviewers who provided thoughtful and useful comments.
AER, ARM, and SJH conceived the research and designed and performed the experiment. SJH analyzed data and wrote the paper, with contributions from AER.
- Bowling DR, Pataki DE, Randerson JT (2008) Carbon isotopes in terrestrial ecosystem pools and CO2 fluxes. New Phytol 178:24–40. https://doi.org/10.1111/j.1469-8137.2007.02342.x
- Brown KH, Bach EM, Drijber RA, et al (2014) A long-term nitrogen fertilizer gradient has little effect on soil organic matter in a high-intensity maize production system. Glob Change Biol 20:1339–1350. https://doi.org/10.1111/gcb.12519
- Bundy LG, Andraski TW, Wolkowski RP (1993) Nitrogen credits in soybean-corn crop sequences on three soils. Agron J 85:1061. https://doi.org/10.2134/agronj1993.00021962008500050020x
- Córdova SC, Olk DC, Dietzel RN, Mueller KE, Archontouilis SV, Castellano MJ (2018) Plant litter quality affects the accumulation rate, composition, and stability of mineral-associated soil organic matter. Soil Biol Biochem 125:115–124. https://doi.org/10.1016/j.soilbio.2018.07.010 CrossRefGoogle Scholar
- Cotrufo MF, Wallenstein MD, Boot CM, et al (2013) The Microbial Efficiency-Matrix Stabilization (MEMS) framework integrates plant litter decomposition with soil organic matter stabilization: do labile plant inputs form stable soil organic matter? Glob Change Biol 19:988–995. https://doi.org/10.1111/gcb.12113
- Ehleringer JR, Buchmann N, Flanagan LB (2000) Carbon isotope ratios in belowground carbon cycle processes. Ecol Appl 10:412–422. https://doi.org/10.1890/1051-0761(2000)010[0412:CIRIBC]2.0.CO;2 CrossRefGoogle Scholar
- Green CJ, Blackmer AM (1995) Residue decomposition effects on nitrogen availability to corn following corn or soybean. Soil Sci Soc Am J 59:1065. https://doi.org/10.2136/sssaj1995.03615995005900040016x CrossRefGoogle Scholar
- Huggins DR, Buyanovsky GA, Wagner GH, Brown JR, Darmody RG, Peck TR, Lesoing GW, Vanotti MB, Bundy LG (1998) Soil organic C in the tallgrass prairie-derived region of the Corn Belt: effects of long-term crop management. Soil Till Res 47:219–234. https://doi.org/10.1016/S0167-1987(98)00108-1 CrossRefGoogle Scholar
- Janssens IA, Dieleman W, Luyssaert S, et al (2010) Reduction of forest soil respiration in response to nitrogen deposition. Nat Geosci 3:315–322. https://doi.org/10.1038/ngeo844
- Jarchow ME, Liebman M, Dhungel S, Dietzel R, Sundberg D, Anex RP, Thompson ML, Chua T (2015) Trade-offs among agronomic, energetic, and environmental performance characteristics of corn and prairie bioenergy cropping systems. GCB Bioenergy 7:57–71. https://doi.org/10.1111/gcbb.12096 CrossRefGoogle Scholar
- Jaynes DB, Karlen DL (2008) Sustaining soil resources while managing nutrients. In: Final report: gulf hypoxia and local water quality concerns workshop. American Society of Agricultural and Biological Engineers, St. Joseph, pp 149–158Google Scholar
- Jenkinson DS, Powlson DS (1976) The effects of biocidal treatments on metabolism in soil—I. Fumigation with chloroform. Soil Biol Biochem 8:167–177. https://doi.org/10.1016/0038-0717(76)90001-8
- Kuzyakov Y (2002) Review: Factors affecting rhizosphere priming effects. J Plant Nutr Soil Sci 165:382–396. https://doi.org/10.1002/1522-2624(200208)165:4<382::AID-JPLN382>3.0.CO;2-#
- Mahal NK, Osterholz WR, Miguez FE, Poffenbarger HJ, Sawyer JE, Olk DC, Archontoulis SV, Castellano MJ (2019) Nitrogen fertilizer suppresses mineralization of soil organic matter in maize agroecosystems. Front Ecol Evol 7. https://doi.org/10.3389/fevo.2019.00059
- Manzoni S, Taylor P, Richter A, et al (2012) Environmental and stoichiometric controls on microbial carbon-use efficiency in soils. New Phytol 79–91. https://doi.org/10.1111/j.1469-8137.2012.04225.x
- Parton W, Silver WL, Burke IC, et al (2007) Global-scale similarities in nitrogen release patterns during long-term decomposition. Science 315:361–364. https://doi.org/10.1126/science.1134853
- Poffenbarger HJ, Barker DW, Helmers MJ, Miguez FE, Olk DC, Sawyer JE, Six J, Castellano MJ (2017) Maximum soil organic carbon storage in Midwest U.S. cropping systems when crops are optimally nitrogen-fertilized. PLoS One 12:e0172293. https://doi.org/10.1371/journal.pone.0172293 CrossRefGoogle Scholar