为探究暗管排水条件下盐渍化农田最适宜的水氮制度,在河套灌区暗管布设区开展2年田间试验,设置低水(120 mm,I1)、中水(210 mm,I2)和高水(330 mm,I3)3个灌溉水平及低氮(0 kg/hm2,N1)、中氮(105 kg/hm2,N2)和高氮(210 kg/hm2,N3)3个追氮水平,分析不同水氮组合对土壤脱盐率及向日葵水氮利用效率和产量品质的影响。结果表明:暗管排水条件下,高水中氮(I3N2)的脱盐效果最佳,较其他水氮处理的脱盐率平均提高5.82%。高水(高氮)条件下,产量随着施氮量(灌水量)的增加而升高,其中高水高氮(I3N3)的产量最高,平均为5 129.72 kg/hm2。相同灌水量下,高氮(N3)水平的灌溉水利用效率最高,追氮量越大,肥料偏生产力越低。低水(I1)和中水(I2)条件下高氮(N3)水平最有利于籽仁蛋白质和必需氨基酸的合成。高水(I3)条件下,中氮(N2)水平有利于籽仁蛋白质和必需氨基酸的合成,低氮(N1)水平最有利于籽仁粗脂肪的合成。各灌水水平中,中水(I2)和高水(I3)各处理中蛋白质和必需氨基酸含量整体上高于低水(I1)处理,而粗脂肪含量整体上低于低水(I1)处理。基于主成分分析和隶属函数综合评价确定高水中氮(I3N2)即灌水量为330 mm、追氮量为105 kg/hm2是暗管农田中适宜的水氮组合。研究结果可为河套灌区暗管农田制定科学的水氮制度提供理论依据。
In order to explore the most suitable water and nitrogen system in salinized farmland under the condition of subsurface drainage, a 2-year field experiment was carried out in the hidden pipe layout area of Hetao irrigation district. In the experiment, we set three irrigation levels, including low water (120 mm, I1), medium water (210 mm, I2) and high water (330 mm, I3) as well as three nitrogen levels of low nitrogen (0 kg/hm2, N1), medium nitrogen (105 kg/hm2, N2) and high nitrogen (210 kg/hm2, N3). The effects of different water and nitrogen combinations on soil desalination rate, water and nitrogen utilization efficiency, yield and quality of sunflowers were analyzed. The results showed that under the condition of subsurface drainage, the desalination effect of I3N2 treatment was the best, with an average increase of 5.82% in desalination rate compared to other water nitrogen treatments. Under high water (high nitrogen) conditions, the yield increased with the increasing of nitrogen application amount (irrigation amount), among which the yield of high water and high nitrogen (I3N3) was the highest, with an average of 5 129.72 kg/hm2. Under the same irrigation amount, the utilization efficiency of irrigation water was the highest at high nitrogen application (N3), and the higher the nitrogen amount, the lower the productivity of fertilizer. Under low water (I1) and medium water (I2) conditions, high nitrogen (N3) level was the most conductive for synthesis of seed protein and essential amino acid. Under the conditions of high water (I3), medium nitrogen level (N2) was beneficial to the synthesis of seed protein and essential amino acids, while low nitrogen level (N1) was most beneficial to the synthesis of seed crude fat. At each irrigation level, the contents of protein and essential amino acid in medium water (I2) and high water (I3) treatments were generally higher than those in low water (I1) treatments, while the content of crude fat was generally lower than those in low water (I1) treatments. Based on principal component analysis and membership function comprehensive evaluation, it was found that high water and medium nitrogen treatment (I3N2), with an irrigation amount of 330 mm and a nitrogen amount of 105 kg/hm2, was the appropriate combination of water and nitrogen in subsurface farmland. The results could provide a theoretical basis for the formulation of scientific water and nitrogen system in the subsurface farmland in Hetao irrigation district.
赵莎, 李为萍, 冯梁, 池曌男, 张家鹏.水氮调控对暗管农田土壤脱盐效果及向日葵产量品质的影响[J].水土保持学报,2023,37(5):275~282复制