负压灌溉下土壤水分运移特性及氮素分布规律研究
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摘要
【目的】揭示负压水肥一体化灌溉对红壤水分及氮素运移特征的影响。【方法】配置6种不同质量浓度硝酸铵溶液(0、10、15、20、25、30 mg/L),设置无压(负水头高度为0)和负压(1/2极限负水头高度)2个水平进行红壤入渗试验,分析了其入渗特性及氮素分布规律。【结果】硝酸铵溶液促进水分入渗,无压和负压状态下,入渗溶液质量浓度为25 mg/L和15 mg/L时水平与垂直方向湿润锋运移均达到最大,与相应CK相比累积入渗量最大分别增长2.69倍和3.00倍,平均入渗率分别增长2.38倍和2.18倍;土壤硝态氮和铵态氮量显著增加(p<0.05),与相应CK相比无压和负压状态下硝态氮量最大分别增长8.05倍和7.75倍,铵态氮量最大分别增长13.37倍和10.42倍。停渗时刻,同一质量浓度入渗溶液无压状态下水平与垂直方向湿润锋运移距离、累积入渗量均显著高于负压状态,各处理最大分别高出2.01、2.148和4.69倍;距出水点相同的距离,无压状态下土壤含水率、硝态氮和铵态氮量均高于负压状态。【结论】负压灌溉显著缩短水平与垂直方向湿润锋运移距离,降低土壤累积入渗量、含水率、硝态氮和铵态氮量。2种入渗条件下,土壤硝态氮量随入渗距离增加而增加,而土壤铵态氮量随入渗距离增加则呈下降趋势。
【Objective】Negative-pressure irrigation is a new irrigation technology and in this paper, we investigate its impact on water flow and nitrogen distribution in red soil under different combinations of irrigation amount and nitrogen application.【Method】Ammonium nitrate was used in the experiment and we compared six concentrations: 0, 10, 15, 20, 25 and 30 mg/L, under two water pressure treatments: zero pressure and pressure at1/2 of the limit negative head height.【Result】Application of ammonium nitrate facilitated water infiltration. Under zero and negative-pressure irrigation, water movement in the horizontal and vertical direction reached maximum when the ammonium nitration concentration was 25 and 15 mg/L respectively, at which the maximum cumulative infiltration increased by 269% and 300% and the associated infiltration rate increased by 238% and218% respectively. Both nitrate and ammonium in soil increased significantly(p<0.05). Under zero and negative pressure, the maximum nitrate content in soil increased by 805% and 775% respectively, while the maximum ammonium content increased by 1 337% and 1 042% respectively. After the irrigation ceased, the distances the wetting front moved in the horizontal/vertical direction and the cumulative infiltration under zero pressure were more than that under negative pressure. At the same location, nitrate, ammonium and soil moisture under negative pressure were higher than those under zero pressure.【Conclusion】Negative-pressure irrigation significantly impedes water movement, thereby reducing cumulative infiltration, water content, nitrate and ammonium in soil. For the two pressures we examined, soil nitrate increased along the infiltration distance as opposed to soil ammonium that decreased along the infiltration distance.
【Objective】Negative-pressure irrigation is a new irrigation technology and in this paper, we investigate its impact on water flow and nitrogen distribution in red soil under different combinations of irrigation amount and nitrogen application.【Method】Ammonium nitrate was used in the experiment and we compared six concentrations: 0, 10, 15, 20, 25 and 30 mg/L, under two water pressure treatments: zero pressure and pressure at1/2 of the limit negative head height.【Result】Application of ammonium nitrate facilitated water infiltration. Under zero and negative-pressure irrigation, water movement in the horizontal and vertical direction reached maximum when the ammonium nitration concentration was 25 and 15 mg/L respectively, at which the maximum cumulative infiltration increased by 269% and 300% and the associated infiltration rate increased by 238% and218% respectively. Both nitrate and ammonium in soil increased significantly(p<0.05). Under zero and negative pressure, the maximum nitrate content in soil increased by 805% and 775% respectively, while the maximum ammonium content increased by 1 337% and 1 042% respectively. After the irrigation ceased, the distances the wetting front moved in the horizontal/vertical direction and the cumulative infiltration under zero pressure were more than that under negative pressure. At the same location, nitrate, ammonium and soil moisture under negative pressure were higher than those under zero pressure.【Conclusion】Negative-pressure irrigation significantly impedes water movement, thereby reducing cumulative infiltration, water content, nitrate and ammonium in soil. For the two pressures we examined, soil nitrate increased along the infiltration distance as opposed to soil ammonium that decreased along the infiltration distance.
引文
[1]邹朝望,薛绪掌,张仁铎,等.负水头灌溉原理与装置[J].农业工程学报,2007, 23(11):17-22.
[2]雷廷武,江培福,BRALTS V F,等.负压自动补给灌溉原理及可行性试验研究[J].水利学报,2005, 36(3):298-302.
[3]马艳华,任秀娟,杨慎骄,等.负压供水下水氮耦合对温室辣椒品质及产量的影响[J].灌溉排水学报,2017, 36(5):17-20.
[4]林叶春,钱欣,曾昭海,等.负水头供水裸燕麦需水特性及其对不同土壤湿度的生理响应[J].农业工程学报,2012, 28(16):93-99.
[5]李生平,武雪萍,党建友,等.负压灌溉对黄瓜产量品质及水氮利用效率的影响[J].中国土壤与肥料,2017(2):55-62.
[6]李生平,武雪萍,龙怀玉,等.负压水肥一体化灌溉对黄瓜产量和水、氮利用效率的影响[J].植物营养与肥料学报,2017, 23(2):416-426.
[7]肖海强,丁亚会,黄楚瑜,等.负压灌溉对烤烟生长及水肥利用率的影响[J].中国烟草学报,2016, 22(2):52-60.
[8]赵秀娟,宋燕燕,岳现录,等.负压灌溉下不同钾水平对小油菜生长的影响[J].中国农业科学,2017,50(4):689-697.
[9]李邵,薛绪掌,郭文善,等.供水吸力对温室黄瓜产量与水分利用效率的影响[J].中国农业科学,2010, 43(2):337-345.
[10]赵亚楠,肖娟,梁锦陶,等.供水水头和灌水器对负压灌溉土壤水运移的影响[J].灌溉排水学报,2011,30(5):71-74.
[11]雷志栋,杨诗秀,谢森传.土壤水动力学[M].北京:清华大学出版社,1999.
[12]刘昭兵,纪雄辉,王国祥,等.赤泥对Cd污染稻田水稻生长及吸收累积Cd的影响[J].农业环境科学学报,2010, 29(4):692-697.
[13]高然,程东娟,费良军,等.膜孔灌自由入渗铵态氮运移特性试验研究[J].人民黄河,2011, 33(5):80-81.
[14]华利民,刘慧颖,韩瑛祚.不同氮输入方式对草甸土土壤铵态氮运移的影响[J].江苏农业科学, 2013, 41(10):278-281.
[2]雷廷武,江培福,BRALTS V F,等.负压自动补给灌溉原理及可行性试验研究[J].水利学报,2005, 36(3):298-302.
[3]马艳华,任秀娟,杨慎骄,等.负压供水下水氮耦合对温室辣椒品质及产量的影响[J].灌溉排水学报,2017, 36(5):17-20.
[4]林叶春,钱欣,曾昭海,等.负水头供水裸燕麦需水特性及其对不同土壤湿度的生理响应[J].农业工程学报,2012, 28(16):93-99.
[5]李生平,武雪萍,党建友,等.负压灌溉对黄瓜产量品质及水氮利用效率的影响[J].中国土壤与肥料,2017(2):55-62.
[6]李生平,武雪萍,龙怀玉,等.负压水肥一体化灌溉对黄瓜产量和水、氮利用效率的影响[J].植物营养与肥料学报,2017, 23(2):416-426.
[7]肖海强,丁亚会,黄楚瑜,等.负压灌溉对烤烟生长及水肥利用率的影响[J].中国烟草学报,2016, 22(2):52-60.
[8]赵秀娟,宋燕燕,岳现录,等.负压灌溉下不同钾水平对小油菜生长的影响[J].中国农业科学,2017,50(4):689-697.
[9]李邵,薛绪掌,郭文善,等.供水吸力对温室黄瓜产量与水分利用效率的影响[J].中国农业科学,2010, 43(2):337-345.
[10]赵亚楠,肖娟,梁锦陶,等.供水水头和灌水器对负压灌溉土壤水运移的影响[J].灌溉排水学报,2011,30(5):71-74.
[11]雷志栋,杨诗秀,谢森传.土壤水动力学[M].北京:清华大学出版社,1999.
[12]刘昭兵,纪雄辉,王国祥,等.赤泥对Cd污染稻田水稻生长及吸收累积Cd的影响[J].农业环境科学学报,2010, 29(4):692-697.
[13]高然,程东娟,费良军,等.膜孔灌自由入渗铵态氮运移特性试验研究[J].人民黄河,2011, 33(5):80-81.
[14]华利民,刘慧颖,韩瑛祚.不同氮输入方式对草甸土土壤铵态氮运移的影响[J].江苏农业科学, 2013, 41(10):278-281.