Characterizing the dynamics of nitrogen (N) leaching from organic and conventional paddy fields is necessary to optimize fertilization and to evaluate the impact of these contrasting farming systems on water bodies. We assessed N leaching in organic versus conventional rice production systems of the Ili River Valley, a representative aquatic ecosystem of Central Asia. The N leaching and overall performance of these systems were measured during 2009, using a randomized block experiment with five treatments. PVC pipes were installed at soil depths of 50 and 180 cm to collect percolation water from flooded organic and conventional paddies, and inorganic N (NH4-N+NO3-N) was analyzed. Two high-concentration peaks of NH4-N were observed in all treatments: one during early tillering and a second during flowering. A third peak at the mid-tillering stage was observed only under conventional fertilization. NO3-N concentrations were highest at transplant and then declined until harvest. At the 50 cm soil depth, NO3-N concentration was 21–42% higher than NH4-N in percolation water from organic paddies, while NH4-N and NO3-N concentrations were similar for the conventional and control treatments. At the depth of 180 cm, NH4-N and NO3-N were the predominant inorganic N for organic and conventional paddies, respectively. Inorganic N concentrations decreased with soil depth, but this attenuation was more marked in organic than in conventional paddies. Conventional paddies leached a higher percentage of applied N (0.78%) than did organic treatments (0.32–0.60%), but the two farming systems leached a similar amount of inorganic N per unit yield (0.21–0.34 kg N Mg？1 rice grains). Conventional production showed higher N utilization efficiency compared to fertilized organic treatments. These results suggest that organic rice production in the Ili River Valley is unlikely to reduce inorganic N leaching, if high crop yields similar to conventional rice production are to be maintained.
References
[1]
Ghosh BC, Bhat R (1998) Environmental hazards of nitrogen loading in wetland rice fields. Environmental Pollution 102 S1: 123–126. doi: 10.1016/s0269-7491(98)80024-9
[2]
Khind CS, Meelu OP, Singh Y, Singh B (1991) Leaching losses of urea-N applied to permeable soils under lowland rice. Fertilizer Research 28: 179–184. doi: 10.1007/bf01049748
[3]
Zhou S, Sugawara S, Riya S, Sagehashi M, Toyota K, et al. (2011) Effect of infiltration rate on nitrogen dynamics in paddy soil after high-load nitrogen application containing 15N tracer. Ecological Engineering 37: 685–692. doi: 10.1016/j.ecoleng.2010.04.032
[4]
Devkota KP, Manschadi A, Lamers JPA, Devkota M, Vlek PLG (2013) Mineral nitrogen dynamics in irrigated rice–wheat system under different irrigation and establishment methods and residue levels in arid drylands of Central Asia. European Journal of Agronomy 47: 65–76. doi: 10.1016/j.eja.2013.01.009
[5]
Ju XT, Xing GX, Chen XP, Zhang SL, Zhang LJ, et al. (2009) Reducing environmental risk by improving N management in intensive Chinese agricultural systems. Proceedings of the National Academy of Sciences 106: 3041–3046. doi: 10.1073/pnas.0813417106
[6]
Yang L, He GH (2008) The impact of Ili irrigation region construction on environment systems. Water Saving Irrigation 3: 34–35 (In Chinese)..
[7]
Jemison JM, Fox RH (1994) Nitrate leaching from nitrogen-fertilized and manured corn measured with zero-tension pan lysimeters. Journal of Environmental Quality 23: 337–343. doi: 10.2134/jeq1994.00472425002300020018x
[8]
Askegaard M, Olesen JE, Rasmussen IA, Kristensen K (2011) Nitrate leaching from organic arable crop rotations is mostly determined by autumn field management. Agriculture, Ecosystems and Environment 142: 149–160. doi: 10.1016/j.agee.2011.04.014
[9]
Hansen B, Kristensen ES, Grant R, H？gh-Jensen H, Simmelsgaard SE, et al. (2000) Nitrogen leaching from conventional versus organic farming systems-a systems modelling approach. European Journal of Agronomy 13: 65–82. doi: 10.1016/s1161-0301(00)00060-5
[10]
Kirchmann H, Bergstr？m L (2001) Do organic farming practices reduce nitrate leaching? Communications in Soil Science and Plant Analysis 32: : 7–8, 997–1028.
[11]
Chhabra A, Manjunath KR, Panigrahy S (2010) Non-point source pollution in Indian agriculture: Estimation of nitrogen losses from rice crop using remote sensing and GIS. International Journal of Applied Earth Observation and Geoinformation 12: 190–200. doi: 10.1016/j.jag.2010.02.007
[12]
Xing G, Cao Y, Shi S, Sun G, Du L, et al. (2001) N pollution sources and denitrification in waterbodies in Taihu Lake region. Science in China Series B: Chemistry 44: 304–314. doi: 10.1007/bf02879621
[13]
Tian Y, Yin B, Yang L, Yin S, Zhu Z (2007) Nitrogen runoff and leaching losses during rice-wheat rotations in Taihu Lake Region, China. Pedosphere 17: 445–456. doi: 10.1016/s1002-0160(07)60054-x
[14]
Li F, Pan G, Tang C, Zhang Q, Yu J (2008) Recharge source and hydrogeochemical evolution of shallow groundwater in a complex alluvial fan system, southwest of North China Plain. Environmental Geology 55: 1109–1122. doi: 10.1007/s00254-007-1059-1
[15]
Li CF, Cao CG, Wang JP, Zhan M, Yuan WL, et al. (2008) Nitrogen losses from integrated rice-duck and rice-fish ecosystems in southern China. Plant Soil 307: 207–217. doi: 10.1007/s11104-008-9597-1
[16]
Zhu JG, Han Y, Liu G, Zhang YL, Shao XH (2000) Nitrogen in percolation water in paddy fields with a rice/wheat rotation. Nutrient Cycling in Agroecosystems 57: 75–82. doi: 10.1023/a:1009712404335
[17]
Luo LG, Wen DZ (1999) Nutrient balance in rice field ecosystem of northern China. Chinese Journal of Applied Ecology 10: 301–304 (In Chinese)..
[18]
Bauder JW, Montgomery BR (1980) N-source and irrigation effects on nitrate leaching. Agronomy Journal 72: 593–596. doi: 10.2134/agronj1980.00021962007200040005x
[19]
Xiong Z, Huang T, Ma Y, Xing G, Zhu Z (2010) Nitrate and ammonium leaching in variable-and permanent-charge paddy soils. Pedosphere 20: 209–216. doi: 10.1016/s1002-0160(10)60008-2
George T, Ladha JK, Garrity DP, Buresh RJ (1993) Nitrate dynamics during the aerobic soil phase in lowland rice-based cropping systems. Soil Science Society of America Journal 57: 1526–1532. doi: 10.2136/sssaj1993.03615995005700060022x
[22]
Ouyang H, Xu YC, Shen QR (2009) Effect of combined use of organic and inorganic nitrogen fertilizer on rice yield and nitrogen use efficiency. Jiangsu Journal of Agricultural Science 25: 106–111 (In Chinese)..
[23]
Wang X, Suo Y, Feng Y, Shohag M, Gao J, et al. (2011) Recovery of 15N-labeled urea and soil nitrogen dynamics as affected by irrigation management and nitrogen application rate in a double rice cropping system. Plant Soil 343: 195–208. doi: 10.1007/s11104-010-0648-z
[24]
Islam MM, Lyamuremye F, Dick RP (1998) Effect of organic residue amendment on mineralization of nitrogen in flooded rice soils under laboratory conditions. Communications in Soil Science and Plant Analysis 29: : 7–8, 971–981.
[25]
Qian C, Cai ZZ (2007) Leaching of nitrogen from subtropical soils as affected by nitrification potential and base cations. Plant Soil 300: 197–205. doi: 10.1007/s11104-007-9404-4
[26]
Weier KL, Doran JW, Power JF, Walters DT (1993) Denitrification and the dinitrogen/nitrous oxide ratio as affected by soil water, available carbon, and nitrate. Soil Science Society of America Journal 57: 66–72. doi: 10.2136/sssaj1993.03615995005700010013x
[27]
Stanford G, Smith SJ (1972) Nitrogen mineralization potentials of soils. Soil Science Society of America Journal 36: 465–472. doi: 10.2136/sssaj1972.03615995003600030029x
[28]
Reddy KR, Patrick WH Jr (1986) Denitrification losses in flooded rice fields. Fertilizer Research 9: 99–116. doi: 10.1007/bf01048697
[29]
Reddy KR, Patrick WH, Lindau CW (1989) Nitrification-denitrification at the plant root-sediment interface in wetlands. Limnol. Oceanogr 34: 1004–1013. doi: 10.4319/lo.1989.34.6.1004
[30]
Uhel C, Roumet C, Salsac L (1989) Inducible nitrate reductase of rice plants as a possible indicator for nitrification in water-logged paddy soils. Plant and soil 116: 197–206. doi: 10.1007/bf02214548
[31]
Luo L, Itoh S, Zhang Q, Yang S, Zhang Q, et al. (2010) Leaching behavior of nitrogen in a long-term experiment on rice under different N management systems. Environmental monitoring and assessment 177: 141–150. doi: 10.1007/s10661-010-1624-z
[32]
Cassman KG, Peng S, Olk DC, Ladha JK, Reichardt W, et al. (1998) Opportunities for increased nitrogen-use efficiency from improved resource management in irrigated rice systems. Field Crops Research 56: 7–39. doi: 10.1016/s0378-4290(97)00140-8
[33]
Sun XP, Li GX, Meng FQ, Guo YB, Wu WL, et al. (2011) Nutrients balance and nitrogen pollution risk analysis for organic rice production in Ili reclamation area of Xinjiang. Transactions of the CSAE 27: 158–162 (In Chinese)..
[34]
Gao JS, Qin DZ, Liu GL, Xu MG (2002) The impact of long term organic fertilization on growth and yield of rice. Tillage and Cultivation 2: 31–33 (In Chinese)..
[35]
Li X, Liu Q, Rong XM, Xie GX, Zhang YP, et al. (2010) Effect of organic fertilizers on rice yield and its components. Hunan Agricultural Sciences 5: 64–66 (In Chinese)..
[36]
Xi YG, Qin P, Ding GH, Fan WL, Han CM (2007) The application of RCSODS model to fertilization practice of organic rice and its effect analysis. Shanghai Agricultural Sciences 23: 28–33 (In Chinese)..
[37]
Chowdary VM, Rao NH, Sarma PBS (2004) A coupled soil water and nitrogen balance model for flooded rice fields in India. Agriculture, Ecosystems & Environment 103: 425–441. doi: 10.1016/j.agee.2003.12.001
[38]
Ma J, Sun W, Liu X, Chen F (2012) Variation in the stable carbon and nitrogen isotope composition of plants and soil along a precipitation gradient in Northern China. PloS one 7: e51894. doi: 10.1371/journal.pone.0051894
[39]
Kirchmann H, Tterer KT, Bergstr？m L (2008) Nutrient supply in organic agriculture: plant availability, sources and recycling. In: Kirchmann H, Bergstr？m L (eds) Organic crop production–ambitions and limitations. Springer, Netherlands, 89–116.
[40]
Rodrigues MA, Pereira A, Cabanas JE, Dias L, Pires J, et al. (2006) Crops use-efficiency of nitrogen from manures permitted in organic farming. European journal of agronomy 25: 328–335. doi: 10.1016/j.eja.2006.07.002
[41]
Guan JX, Wang BR, Li DC (2009) Effect of chemical fertilizer applied combined with organic manure on yield of rice and nitrogen using efficiency.Chinese Agricultural Science Bulletin. 25: 88–92 (In Chinese)..
