Journal list menu
Nitrogen Management and Methane Emissions in Direct-Seeded Rice Systems
Corresponding Author
Cameron M. Pittelkow
Dep. of Plant Sciences, Univ. of California, Davis, One Shields Ave., Davis, CA, 95616
Corresponding author ([email protected]).
Search for more papers by this authorYacov Assa
Dep. of Land, Air and Water Resources, Univ. of California, Davis, One Shields Ave., Davis, CA, 95616
Search for more papers by this authorMartin Burger
Dep. of Land, Air and Water Resources, Univ. of California, Davis, One Shields Ave., Davis, CA, 95616
Search for more papers by this authorRandall G. Mutters
Univ. of California Cooperative Extension, Division of Agriculture and Natural Resources, 1111 Franklin St., Oakland, CA, 94607
Search for more papers by this authorChris A. Greer
Univ. of California Cooperative Extension, Division of Agriculture and Natural Resources, 1111 Franklin St., Oakland, CA, 94607
Search for more papers by this authorLuis A. Espino
Univ. of California Cooperative Extension, Division of Agriculture and Natural Resources, 1111 Franklin St., Oakland, CA, 94607
Search for more papers by this authorJames E. Hill
Dep. of Plant Sciences, Univ. of California, Davis, One Shields Ave., Davis, CA, 95616
Search for more papers by this authorWilliam R. Horwath
Dep. of Land, Air and Water Resources, Univ. of California, Davis, One Shields Ave., Davis, CA, 95616
Search for more papers by this authorChris van Kessel
Dep. of Plant Sciences, Univ. of California, Davis, One Shields Ave., Davis, CA, 95616
Search for more papers by this authorBruce A. Linquist
Dep. of Plant Sciences, Univ. of California, Davis, One Shields Ave., Davis, CA, 95616
Search for more papers by this authorCorresponding Author
Cameron M. Pittelkow
Dep. of Plant Sciences, Univ. of California, Davis, One Shields Ave., Davis, CA, 95616
Corresponding author ([email protected]).
Search for more papers by this authorYacov Assa
Dep. of Land, Air and Water Resources, Univ. of California, Davis, One Shields Ave., Davis, CA, 95616
Search for more papers by this authorMartin Burger
Dep. of Land, Air and Water Resources, Univ. of California, Davis, One Shields Ave., Davis, CA, 95616
Search for more papers by this authorRandall G. Mutters
Univ. of California Cooperative Extension, Division of Agriculture and Natural Resources, 1111 Franklin St., Oakland, CA, 94607
Search for more papers by this authorChris A. Greer
Univ. of California Cooperative Extension, Division of Agriculture and Natural Resources, 1111 Franklin St., Oakland, CA, 94607
Search for more papers by this authorLuis A. Espino
Univ. of California Cooperative Extension, Division of Agriculture and Natural Resources, 1111 Franklin St., Oakland, CA, 94607
Search for more papers by this authorJames E. Hill
Dep. of Plant Sciences, Univ. of California, Davis, One Shields Ave., Davis, CA, 95616
Search for more papers by this authorWilliam R. Horwath
Dep. of Land, Air and Water Resources, Univ. of California, Davis, One Shields Ave., Davis, CA, 95616
Search for more papers by this authorChris van Kessel
Dep. of Plant Sciences, Univ. of California, Davis, One Shields Ave., Davis, CA, 95616
Search for more papers by this authorBruce A. Linquist
Dep. of Plant Sciences, Univ. of California, Davis, One Shields Ave., Davis, CA, 95616
Search for more papers by this authorAll rights reserved. No part of this periodical may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or any information storage and retrieval system, without permission in writing from the publisher.
Abstract
Rice (Oryza sativa L.) establishment systems based on resource-conserving production practices are gaining popularity globally. To investigate the potential for improved N management and mitigation of methane (CH4) emissions, field experiments were conducted in California on three crop establishment systems: water-seeded (WS) conventional, WS stale seedbed, and drill-seeded (DS) stale seedbed. Fertilizer nitrogen recovery efficiency (NRE) and rice yield as affected by N rate, source, and application timing were evaluated for 2 yr in each system. Methane emissions were monitored over a full annual rice production cycle (growing season plus fallow period). Results indicated that neither split N applications nor ammonium sulfate increased yields or NRE compared with a single application of urea, regardless of system. However, the economic optimum N rate increased by approximately 30 kg N ha−1 in WS stale seedbed compared with the conventional system. Since NRE generally remained similar across N treatments that maximized yields, applying the appropriate N rate as a single dose before the permanent flood would satisfy both agronomic and environmental goals of N management within each system. Both WS systems resulted in similar growing season CH4 emissions. However, the DS system reduced CH4 emissions by 47% compared with the conventional WS system, possibly due to a decreased period of anaerobic soil conditions. This study highlights the importance of assessing benefits as well as tradeoffs when evaluating opportunities for increasing the sustainability of direct-seeded establishment systems with respect to N management and CH4 emissions.
REFERENCES
- Adviento-Borbe, M.A., C.M. Pittelkow, M.M. Anders, vanKesselC., J.E. Hill, A.M. McClung, J. Six, and B.A. Linquist. 2013. Optimal fertilizer N rates and yield-scaled global warming potential in drill seeded rice. J. Environ. Qual. 42: 1623–1634. doi:https://doi.org/10.2134/jeq2013.05.0167
- Akiyama, H., K. Yagi, and X. Yan. 2005. Direct N2O emissions from rice paddy fields: Summary of available data. Global Biogeochem. Cycles 19: GB1005. doi:https://doi.org/10.1029/2004GB002378
- Bazaya, B.R., A. Sen, and V.K. Srivastava. 2009. Planting methods and nitrogen effects on crop yield and soil quality under direct seeded rice in the Indo-Gangetic plains of eastern India. Soil Tillage Res. 105: 27–32. doi:https://doi.org/10.1016/j.still.2009.05.006
- Blengini, G.A., and M. Busto. 2009. The life cycle of rice: LCA of alternative agri-food chain management systems in Vercelli (Italy). J. Environ. Manage. 90: 1512–1522. doi:https://doi.org/10.1016/j.jenvman.2008.10.006
- Bossio, D.A., W.R. Horwath, R.G. Mutters, and vanKesselC.. 1999. Methane pool and flux dynamics in a rice field following straw incorporation. Soil Biol. Biochem. 31: 1313–1322. doi:https://doi.org/10.1016/S0038-0717(99)00050-4
- Broadbent, F.E., G.N. Hill, and K.B. Tyler. 1958. Transformations and movement of urea in soils. Soil Sci. Soc. Am. Proc. 22: 303–307. doi:https://doi.org/10.2136/sssaj1958.03615995002200040010x
- Bufogle, A.Jr., P.K. Bollich, J.L. Kovar, C.W. Lindau, and R.E. Macchiavelli. 1998. Comparison of ammonium sulfate and urea as nitrogen sources in rice production. J. Plant Nutr. 21: 1601–1614. doi:https://doi.org/10.1080/01904169809365507
- Bufogle, A.Jr., P.K. Bollich, R.J. Norman, J.L. Kovar, C.W. Lindau, and R.E. Macchiavelli. 1997. Rice plant growth and nitrogen accumulation in drill-seeded and water-seeded culture. Soil Sci. Soc. Am. J. 61: 832–839. doi:https://doi.org/10.2136/sssaj1997.03615995006100030017x
- Burger, M., and W.R. Horwath. 2012. Assessment of baseline nitrous oxide emissions in California cropping systems. Final Report, California Air Resources Board, Contract 08–324. www.arb.ca.gov/research/rsc/05-11-12/item4dfr08-324.pdf (accessed 12 Mar. 2014).
- Cai, Z., H. Tsuruta, M. Gao, H. Xu, and C. Wei. 2003. Options for mitigating methane emission from a permanently flooded rice field. Glob. Change Biol. 9: 37–45. doi:https://doi.org/10.1046/j.1365-2486.2003.00562.x
- Cao, Z.H., De DattaS.K., and I.R.P. Fillery. 1984. Nitrogen-15 balance and residual effects of urea-N in wetland rice fields as affected by deep placement techniques. Soil Sci. Soc. Am. J. 48: 203–208. doi:https://doi.org/10.2136/sssaj1984.03615995004800010037x
- Cassman, K.G., G.C. Gines, M.A. Dizon, M.I. Samson, and J.M. Alcantara. 1996. Nitrogen-use efficiency in tropical lowland rice systems: Contributions from indigenous and applied nitrogen. Field Crops Res. 47: 1–12. doi:https://doi.org/10.1016/0378-4290(95)00101-8
- CAR. 2011. Rice cultivation project protocol. Climate Action Reserve, 523 W. 6th Street, Los Angeles, CA. www.climateactionreserve.org/how/protocols/rice-cultivation (accessed 12 Mar. 2014).
- De DattaS.K. 1987. Nitrogen transformation processes in relation to improved cultural practices for lowland rice. Plant Soil 100: 47–69. doi:https://doi.org/10.1007/BF02370932
- Doane, T.A., and W.R. Horwath. 2003. Spectrophotometric determination of nitrate with a single reagent. Anal. Lett. 36: 2713–2722. doi:https://doi.org/10.1081/AL-120024647
- Dobermann, A., J.L. Gaunt, H.U. Neue, I.F. Grant, M.A. Adviento, and M.F. Pampolino. 1994. Spatial and temporal variability of ammonium in flooded rice fields. Soil Sci. Soc. Am. J. 58: 1708–1717. doi:https://doi.org/10.2136/sssaj1994.03615995005800060019x
- Farooq, M., K.H.M. Siddique, H. Rehman, T. Aziz, D.J. Lee, and A. Wahid. 2011. Rice direct seeding: Experiences, challenges and opportunities. Soil Tillage Res. 116: 260–267.
- Fitzgerald, G.J., K.M. Scow, and J.E. Hill. 2000. Fallow season straw and water management effects on methane emissions in California rice. Global Biogeochem. Cycles 14: 767–776. doi:https://doi.org/10.1029/2000GB001259
- Foley, J.A., N. Ramankutty, K.A. Brauman, E.S. Cassidy, J.S. Gerber, M. Johnston, N.D. Mueller, C. O'Connell, D.K. Ray, P.C. West, C. Balzer, E.M. Bennett, S.R. Carpenter, J. Hill, C. Monfreda, S. Polasky, J. Rockstrom, J. Sheehan, S. Siebert, D. Tilman, and D.P.M. Zaks. 2011. Solutions for a cultivated planet. Nature 478: 337–342. doi:https://doi.org/10.1038/nature10452
- Forster, J.C. 1995. Soil nitrogen. In: K. Alef P. Nannipieri, editors, Methods in applied soil microbiology and biochemistry. Academic Press, San Diego, CA. p. 79–87.
- Gathala, M.K., J.K. Ladha, V. Kumar, Y.S. Saharawat, V. Kumar, P.K. Sharma, S. Sharma, and H. Pathak. 2011. Tillage and crop establishment affects sustainability of South Asian rice-wheat system. Agron. J. 103: 961–971. doi:https://doi.org/10.2134/agronj2010.0394
- George, T., J.K. Ladha, R.J. Buresh, and D.P. Garrity. 1993. Nitrate dynamics during the aerobic soil phase in lowland rice-based cropping systems. Soil Sci. Soc. Am. J. 57: 1526–1532. doi:https://doi.org/10.2136/sssaj1993.03615995005700060022x
- Grace, P.R., I.C. MacRae, and R.J.K. Myers. 1993. Temporal changes in microbial biomass and N mineralization under simulated field cultivation. Soil Biol. Biochem. 25: 1745–1753. doi:https://doi.org/10.1016/0038-0717(93)90179-F
- Griggs, B.R., R.J. Norman, C.E. Wilson, and N.A. Slaton. 2007. Ammonia volatilization and nitrogen uptake for conventional and conservation tilled dry-seeded, delayed-flood rice. Soil Sci. Soc. Am. J. 71: 745–751. doi:https://doi.org/10.2136/sssaj2006.0180
- Harris, D., W.R. Horwath, and Van KesselC.. 2001. Acid fumigation of soils to remove carbonates prior to total organic carbon or CARBON-13 isotopic analysis. Soil Sci. Soc. Am. J. 65: 1853–1856. doi:https://doi.org/10.2136/sssaj2001.1853
- Harrell, D.L., B.S. Tubana, J. Lofton, and Y. Kanke. 2011. Rice response to nitrogen fertilization under stale seedbed and conventional tillage systems. Agron. J. 103: 494–500. doi:https://doi.org/10.2134/agronj2010.0376
- Hill, J.E., Smith, R.J.Jr., and D.E. Bayer. 1994. Rice weed control: Current technology and emerging issues in temperate rice. Aust. J. Exp. Agric. 34: 1021–1029. doi:https://doi.org/10.1071/EA9941021
- Hill, J.E., J.F. Williams, R.G. Mutters, and C.A. Greer. 2006. The California rice cropping system: Agronomic and natural resource issues for long-term sustainability. Paddy Water Environ. 4: 13–19. doi:https://doi.org/10.1007/s10333-005-0026-2
- Huang, M., Y. Zou, P. Jiang, B. Xia, Y. Feng, Z. Cheng, and Y. Mo. 2012. Effect of tillage on soil and crop properties of wet-seeded flooded rice. Field Crops Res. 129: 28–38. doi:https://doi.org/10.1016/j.fcr.2012.01.013
- Hutchinson, G.L., and G.P. Livingston. 1993. Use of chamber systems to measure trace gas fluxes. In: D.E. Rolston, editor, Agricultural ecosystem effects on trace gases and global climate change. ASA Spec. Publ. 55. ASA, Madison, WI.
- Hutchinson, G.L., and A.R. Mosier. 1981. Improved soil cover method for field measurements of nitrous oxide fluxes. Soil Sci. Soc. Am. J. 45: 311–316. doi:https://doi.org/10.2136/sssaj1981.03615995004500020017x
- Itoh, M., S. Sudo, S. Mori, H. Saito, T. Yoshida, Y. Shiratori, S. Suga, N. Yoshikawa, Y. Suzue, H. Mizukami, T. Mochida, and K. Yagi. 2011. Mitigation of methane emissions from paddy fields by prolonging midseason drainage. Agric. Ecosyst. Environ. 141: 359–372. doi:https://doi.org/10.1016/j.agee.2011.03.019
- Jat, M.L., M.K. Gathala, J.K. Ladha, Y.S. Saharawat, A.S. Jat, V. Kumar, S.K. Sharma, V. Kumar, and R. Gupta. 2009. Evaluation of precision land leveling and double zero-till systems in the rice-wheat rotation: Water use, productivity, profitability and soil physical properties. Soil Tillage Res. 105: 112–121. doi:https://doi.org/10.1016/j.still.2009.06.003
- Johnson-Beebout, S.E., O.R. Angeles, M.C.R. Alberto, and R.J. Buresh. 2009. Simultaneous minimization of nitrous oxide and methane emission from rice paddy soils is improbable due to redox potential changes with depth in a greenhouse experiment without plants. Geoderma 149: 45–53. doi:https://doi.org/10.1016/j.geoderma.2008.11.012
- Jones, D.B., and G.H. Snyder. 1987. Seeding rate and row spacing effects on yield and yield components of drill-seeded rice. Agron. J. 79: 623–626. doi:https://doi.org/10.2134/agronj1987.00021962007900040007x
- Ju, X.T., G.X. Xing, X.P. Chen, S.L. Zhang, L.J. Zhang, X.J. Liu, Z.L. Cui, B. Yin, P. Christie, Z.L. Zhu, and F.S. Zhang. 2009. Reducing environmental risk by improving N management in intensive Chinese agricultural systems. Proc. Natl. Acad. Sci. USA 106: 3041–3046. doi:https://doi.org/10.1073/pnas.0813417106
- Kumar, V., and J.K. Ladha. 2011. Direct seeding of rice: Recent developments and future research needs. Adv. Agron. 111: 297–413. doi:https://doi.org/10.1016/B978-0-12-387689-8.00001-1
- Kundu, D.K., and J.K. Ladha. 1998. Sustaining productivity of lowland rice soils: Issues and options related to N availability. Nutr. Cycling Agroecosyst. 53: 19–33. doi:https://doi.org/10.1023/A:1009721912761
- Ladha, J.K., H. Pathak, T.J. Krupnik, J. Six, and vanKesselC.. 2005. Efficiency of fertilizer nitrogen in cereal production: Retrospects and prospects. Adv. Agron. 87: 85–156. doi:https://doi.org/10.1016/S0065-2113(05)87003-8
- Ladha, J.K., V. Kumar, M.M. Alam, S. Sharma, M.K. Gathala, P. Chandna, Y.S. Saharawat, and V. Balasubramanian. 2009. Integrating crop and resource management for enhanced productivity, profitability, and sustainability of the rice-wheat system in South Asia. In: J.K. Ladha O.Erenstein Yadvinder-Sing B. Hardy, editors, Integrated crop and resource management in the rice-wheat system of South Asia. IRRI, Los Banos, Philippines. p. 69–108.
- Lal, R. 1986. Effects of 6 years of continuous no-till or puddling systems on soil properties and rice (Oryza sativa) yield of a loamy soil. Soil Tillage Res. 8: 181–200. doi:https://doi.org/10.1016/0167-1987(86)90333-8
- Linquist, B.A., S.M. Brouder, and J.E. Hill. 2006. Winter straw and water management effects on soil nitrogen dynamics in California rice systems. Agron. J. 98: 1050–1059. doi:https://doi.org/10.2134/agronj2005.0350
- Linquist, B.A., J.E. Hill, R.G. Mutters, C.A. Greer, C. Hartley, M.D. Ruark, and vanKesselC.. 2009. Assessing the necessity of surface-applied preplant nitrogen fertilizer in rice systems. Agron. J. 101: 906–915. doi:https://doi.org/10.2134/agronj2008.0230x
- Linquist, B.A., K. Koffler, J.E. Hill, and vanKesselC.. 2011. Rice field drainage affects nitrogen dynamics and management. Calif. Agric. 65: 80–84. doi:https://doi.org/10.3733/ca.v065n02p80
- Linquist, B., vanGroenigenK.J., M.A. Adviento-Borbe, C. Pittelkow, and vanKesselC.. 2012. An agronomic assessment of greenhouse gas emissions from major cereal crops. Glob. Change Biol. 18: 194–209. doi:https://doi.org/10.1111/j.1365-2486.2011.02502.x
- McMillan, M.S., M.L. Goulden, and S.C. Tyler. 2007. Stoichiometry of CH4 and CO2 flux in a California rice paddy. J. Geophys. Res. 112:G01008.
- Mikkelsen, D.S. 1987. Nitrogen budgets in flooded soils used for rice production. Plant Soil 100: 71–97. doi:https://doi.org/10.1007/BF02370933
- Mikkelsen, D.S., De DattaS.K., and W.N. Obcemea. 1978. Ammonia volatilization losses from flooded rice soils. Soil Sci. Soc. Am. J. 42: 725–730. doi:https://doi.org/10.2136/sssaj1978.03615995004200050014x
- Miller, B.C., J.E. Hill, and S.R. Roberts. 1991. Plant population effects on growth and yield in water-seeded rice. Agron. J. 83: 291–297. doi:https://doi.org/10.2134/agronj1991.00021962008300020006x
- Mutters, R.G., C.A. Greer, K.M. Klonsky, and P. Livingston. 2007. Sample costs to produce rice. University of California Cooperative Extension, Division of Agriculture and Natural resources and Department of Agriculture and Resource Economics, Davis, CA. http://coststudies.ucdavis.edu/files/ricesv07.pdf (accessed 12 Mar. 2014).
- Olsen, S.R., and L.E. Sommers. 1982. Phosphorus. In: A.L. Page, editor, Methods of soil analysis. Part 2. 2nd ed. Agron. Monogr. 9. ASA and SSSA, Madison, WI. p. 403–430.
- Patrick, W.H.Jr., and K.R. Reddy. 1976. Fate of fertilizer nitrogen in a flooded rice soil. Soil Sci. Soc. Am. J. 40: 678–681. doi:https://doi.org/10.2136/sssaj1976.03615995004000050023x
- Patrick, W.H.Jr., and R. Wyatt. 1964. Soil nitrogen loss as a result of alternate submergence and drying. Soil Sci. Soc. Am. Proc. 28: 647–653. doi:https://doi.org/10.2136/sssaj1964.03615995002800050021x
- Peng, S., R.J. Buresh, J. Huang, X. Zhong, Y. Zou, J. Yang, G. Wang, Y. Liu, R. Hu, Q. Tang, K. Cui, F. Zhang, and A. Dobermann. 2010. Improving nitrogen fertilization in rice by site-specific N management. A review. Agron. Sustain. Dev. 30: 649–656. doi:https://doi.org/10.1051/agro/2010002
- Pinheiro, J., D. Bates, S. DebRoy, D. Sarkar, and and the R Development Core Team. 2013. nlme: Linear and nonlinear mixed effects models. R package version 3.1–113. R Foundation for Statistical Computing, Vienna.
- Pittelkow, C.M., M.A. Adviento-Borbe, J.E. Hill, J. Six, vanKesselC., and B. Linquist. 2013. Yield-scaled global warming potential of annual nitrous oxide and methane emissions from continuously flooded rice in response to nitrogen input. Agric. Ecosyst. Environ. 177: 10–20. doi:https://doi.org/10.1016/j.agee.2013.05.011
- Pittelkow, C.M., A.J. Fischer, M.J. Moechnig, J.E. Hill, K.B. Koffler, R.G. Mutters, C.A. Greer, Y.S. Cho, vanKesselC., and B.A. Linquist. 2012. Agronomic productivity and nitrogen requirements of alternative tillage and crop establishment systems for improved weed control in direct-seeded rice. Field Crops Res. 130: 128–137. doi:https://doi.org/10.1016/j.fcr.2012.02.011
- R Core Team. 2012. R: A language and environment for statistical computing. R Foundation for Statistical Computing, Vienna.
- Ratering, S., and R. Conrad. 1998. Effects of short-term drainage and aeration on the production of methane in submerged rice soil. Glob. Change Biol. 4: 397–407. doi:https://doi.org/10.1046/j.1365-2486.1998.00162.x
- Reddy, K.R., and W.H. Patrick. 1976. Yield and nitrogen utilization by rice as affected by method and time of application of labeled nitrogen. Agron. J. 68: 965–969. doi:https://doi.org/10.2134/agronj1976.00021962006800060031x
- Reddy, K.R., and W.H. Patrick. 1978. Utilization of labeled urea and ammonium sulfate by lowland rice. Agron. J. 70: 465–467. doi:https://doi.org/10.2134/agronj1978.00021962007000030025x
- Rice, C.W., and M.S. Smith. 1984. Short-term immobilization of fertilizer nitrogen at the surface of no-till and plowed soils. Soil Sci. Soc. Am. J. 48: 295–297. doi:https://doi.org/10.2136/sssaj1984.03615995004800020013x
- Rible, J.M., and J. Quick. 1960. Method S-19.0. Cation exchange capacity. In: Water soil plant tissue. Tentative methods of analysis for diagnostic purposes. Univ. of California Agric. Exp. Service, Davis, CA.
- Richards, L.A. 1954. Diagnosis and improvement of saline and alkali soils. USDA Agric. Handb. 60. U.S. Gov. Print. Office, Washington, DC.
- Rhoades, J.D. 1982. Soluble salts. In: A.L. Page, editor, Methods of soil analysis. Part 2. 2nd ed. Agron. Monogr. 9. ASA and SSSA, Madison, WI. p. 167–179.
- Robertson, G.P., and P.M. Vitousek. 2009. Nitrogen in agriculture: Balancing the cost of an essential resource. Annu. Rev. Environ. Resour. 34: 97–125. doi:https://doi.org/10.1146/annurev.environ.032108.105046
- Rogers, C.W., K.R. Brye, R.J. Norman, E.E. Gbur, J.D. Mattice, T.B. Parkin, and T.L. Roberts. 2013. Methane emissions from drill-seeded, delayed-flood rice production on a silt-loam soil in Arkansas. J. Environ. Qual. 42: 1059–1069. doi:https://doi.org/10.2134/jeq2012.0502
- Seck, P.A., A. Diagne, S. Mohanty, and M.C.S. Wopereis. 2012. Crops that feed the world 7. Rice. Food Security 4: 7–24. doi:https://doi.org/10.1007/s12571-012-0168-1
- Sheldrick, B.H., and C. Wang. 1993. Particle-size distribution. In: M.R. Carter, editor, Soil sampling and methods of analysis. Canadian Society of Soil Science, Lewis Publishers, Ann Arbor, MI. p. 499–511.
- Singh, Y., V.P. Singh, G. Singh, D.S. Yadav, R.K.P. Sinha, D.E. Johnson, and A.M. Mortimer. 2011. The implications of land preparation, crop establishment method and weed management on rice yield variation in the rice-wheat system in the Indo-Gangetic plains. Field Crops Res. 121: 64–74. doi:https://doi.org/10.1016/j.fcr.2010.11.012
- Smith, P., D. Martino, Z. Cai, D. Gwary, H. Janzen, P. Kumar, B. McCarl, S. Ogle, F. O'Mara, C. Rice, B. Scholes, and O. Sirotenko. 2007. Agriculture. In: B. Metz O.R. Davidson P.R. Bosch R. Dave L.A. Meyer, editors, Climate change 2007: Mitigation. Contribution of Working Group III to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge Univ. Press, Cambridge, UK and New York. p. 497–540.
- Steel, R.G., J.H. Torrie, and D.A. Dickey. 1997. Principles and procedures of statistics: A biometrical approach. McGraw-Hill, Boston, MA.
- Thomas, G.W. 1982. Exchangeable cations. In: A.L. Page, editor, Methods of soil analysis. Part 2. 2nd ed. Agron. Monogr. 9. ASA and SSSA, Madison, WI. p. 159–165.
- University of California Cooperative Extension (UCCE), editors. 2013. Rice production workshop manual. Richvale, CA, 25 July 2013. Univ. of California, Division of Agriculture and Natural resources, Oakland, CA. http://ucanr.edu/sites/UCRiceProject/Publications/Rice_Production_Workshop_Manual (accessed 12 Mar. 2014).
- USDA-NASS. 2011. Quick Stats. USDA-NASS, Washington, DC. http://quickstats.nass.usda.gov/ (accessed 17 Mar. 2014).
- Verdouw, H., vanEchteldC.J.A., and E.M.J. Dekkers. 1978. Ammonia determination based on indophenol formation with sodium salicylate. Water Res. 12: 399–402. doi:https://doi.org/10.1016/0043-1354(78)90107-0
- Watkins, K.B., M.M. Anders, and T.E. Windham. 2004. An economic comparison of alternative rice production systems in Arkansas. J. Sustain. Agric. 24: 57–78. doi:https://doi.org/10.1300/J064v24n04_06
- Westcott, M.P., D.M. Brandon, C.W. Lindau, and Patrick, W.H.Jr. 1986. Effects of seeding method and time of fertilization on urea-nitrogen-15 recovery in rice. Agron. J. 78: 474–478. doi:https://doi.org/10.2134/agronj1986.00021962007800030016x
- Williams, J.F. 2010. Rice nutrient management in California. Publ. 3516, Univ. of California, Division of Agriculture and Natural Resources, Oakland, CA.
- Xia, Y., and X. Yan. 2011. Life-cycle evaluation of nitrogen-use in rice-farming systems: Implications for economically-optimal nitrogen rates. Biogeosciences 8: 3159–3168. doi:https://doi.org/10.5194/bg-8-3159-2011
- Xu, H., and Y. Hosen. 2010. Effects of soil water content and rice straw incorporation in the fallow season on CH4 emissions during fallow and the following rice-cropping seasons. Plant Soil 335: 373–383. doi:https://doi.org/10.1007/s11104-010-0426-y
- Xu, Y., L. Nie, R.J. Buresh, J. Huang, K. Cui, B. Xu, W. Gong, and S. Peng. 2010. Agronomic performance of late-season rice under different tillage, straw, and nitrogen management. Field Crops Res. 115: 79–84. doi:https://doi.org/10.1016/j.fcr.2009.10.005
- Yan, X., Z. Cai, T. Ohara, and H. Akimoto. 2003. Methane emission from rice fields in mainland China: Amount and seasonal and spatial distribution. J. Geophys. Res. 108: 4505. doi:https://doi.org/10.1029/2002JD003182
- Yan, X., K. Yagi, H. Akiyama, and H. Akimoto. 2005. Statistical analysis of the major variables controlling methane emission from rice fields. Glob. Change Biol. 11: 1131–1141. doi:https://doi.org/10.1111/j.1365-2486.2005.00976.x
- Zou, J., Y. Huang, J. Jiang, X. Zheng, and R.L. Sass. 2005. A 3-year field measurement of methane and nitrous oxide emissions from rice paddies in China: Effects of water regime, crop residue, and fertilizer application. Global Biogeochem. Cycles 19: GB2021. doi:https://doi.org/10.1029/2004GB002401