Effect of infiltration rate on nitrogen dynamics in paddy soil after high-load nitrogen application containing 15N tracer
Effect of infiltration rate on nitrogen dynamics in paddy soil after high-load nitrogen application containing 15N tracer
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DOI：
10.1016/j.ecoleng.2010.04.032
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发表时间：
2011-05
影响因子：
3.8
通讯作者：
Sheng Zhou;Sho Sugawara;Shohei Riya;M. Sagehashi;K. Toyota;A. Terada;M. Hosomi
中科院分区：
文献类型：
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作者：
Sheng Zhou;Sho Sugawara;Shohei Riya;M. Sagehashi;K. Toyota;A. Terada;M. Hosomi
被水淹没的稻田发挥着许多生态和保护功能，据报道还有助于牲畜废物的处理。稻田土壤入渗速率对氮素动态有重要影响。通过室内试验研究了不同入渗速率对氮素淋溶、土壤吸附、微生物同化、植物吸收和反硝化等氮素动态的影响。水稻土采用两种入渗速率：18.6±10.3mmd−1（高入渗柱：HIC）和4.49±3.15mmd−1（低入渗柱：LIC）。总氮负荷为484 kg-Nha −1，铵离子形式包括基肥和双补充肥料施用。（15 NH_4）_2SO_4示踪剂在每个入渗速率下作为补肥施用。硝化和反硝化作用，植物吸收，土壤吸附，淋溶不同的渗透率。与高浓度硝态氮相比，低浓度硝态氮中硝态氮含量较少，施用后较长时间内保持较高的土壤水铵态氮浓度。低入渗土壤中水稻吸收的15 N含量高于高入渗土壤，说明低入渗有利于水稻对氮素的吸收、吸附和固定。虽然氮素的淋失量在HIC中高于LIC，但仅占15 N输入总量的3.94%。HIC中15 N输入的69.4%未被计算，而LIC中15 N输入的38.3%未被计算。根据29 N2/28 N2和30 N2/28 N2比值变化计算的反硝化速率，HIC施用后的反硝化速率高于LIC，达到最大速率2.9gm−2d−1。这表明高入渗速率增强了硝化和反硝化作用，HIC中大部分未计入的15 N可能通过硝化和反硝化作用损失。
Flooded paddy fields perform many ecological and conservation functions and are also reported to facilitate livestock waste disposal. Paddy field infiltration rates are important for nitrogen dynamics. A laboratory study was conducted to compare the effects of infiltration rate on nitrogen dynamics including nitrogen leaching, soil adsorption, microorganism assimilation, plant uptake and denitrification. Two infiltration rates were applied to paddy soil: 18.6±10.3mmd−1(High Infiltration Columns: HIC) and 4.49±3.15mmd−1(Low Infiltration Columns: LIC). Total nitrogen load was 484kg-Nha−1, with the ammonium ion form including basal fertilizer and a double supplemental fertilizer application. A (15NH4)2SO4tracer was applied in each infiltration rate as supplemental fertilizer. Nitrification and denitrification, plant uptake, soil adsorption, and leaching differed between infiltration rates. Compared with high nitrate concentration in HIC soil water, little nitrate appeared in the LIC, and it maintained relatively higher soil water ammonium concentrations long after application. The15N assimilated by rice and contained in the LIC soil was higher than in the HIC, suggesting that low infiltration is beneficial to nitrogen assimilation, adsorption and fixation. Although loss of nitrogen via leaching was higher in the HIC than the LIC, it accounted for only 3.94% of total15N input. About 69.4% of total15N input was unaccounted for in the HIC, whereas 38.3% of total15N input was unaccounted for in the LIC. According to the denitrification rate calculated from changes in29N2/28N2and30N2/28N2ratios, the denitrification rate after HIC application was higher than the LIC, reaching a maximum rate of 2.9gm−2d−1. This suggests that high infiltration rate enhances nitrification and denitrification, with most of the unaccounted inputted15N in the HIC was probably lost through nitrification and denitrification.