Abstract:

Infiltration irrigation is an advanced technique of water saving agriculture. It has the advantages of saving water, enhancing yields, upgrading quality and high utility. Infiltration irrigation experiments with planting alfalfa were conducted in Yangliuqing company, Jinchang City, Gansu Province. The soil of infiltration irrigation under alfalfa seeding stage was chosen as the research object to explore the effect of infiltration irrigation frequency on soil chemical characteristics of different soil depths and different pipe positions.The combination of field experiments and laboratory analysis was conducted. The results showed that in 0~10 cm and 10~20 cm soil depth, the maximum pH values were on the pipes, which were 8.21% and 8.68% higher than those in CK, respectively, and the minimum values were in the middle of two pipes,2.70% and 3.37% lower than that in CK, respectively. The pH values of different soil depths and different positions were increased significantly by infiltration irrigation twice and three times. Salt content in the middle of two pipes was higher than that in other pipes positions in infiltration irrigation different times and different soil depths, and irrigation once had the maximum value, 83.26% and 96.34% greater than CK. The average salt content of infiltration irrigation twice was lower than irrigation once and three times in different soil depths. Infiltration irrigation different times and different soil depths, the maximum contents of sodium ion and potassium ion appeared in the middle of the two pipes where hydrolysis nitrogen content was higher than other pipes positions, and the maximum value in the middle of the two pipes infiltration of irrigation once were 112.68% and 34.48% higher than CK. With increasing the number of subsurface irrigation, the available phosphorus content in 0~10 cm soil depth showed a downward trend at different pipe positions, but available potassium content increased. With the increase of the number of infiltration irrigation in different soil depths, organic matter content showed a downward trend after the first rise in different pipe positions, and organic matter content significantly increased at infiltration irrigation twice. In conclusion, infiltration irrigation twice was relatively suitable because soil salt content was lower and organic matter content was higher, which was beneficial to seeding growth of alfalfa.

Key words: Infiltration irrigation, Alfalfa, Soil chemical characteristics

摘要：

渗灌是节水农业中最有效的措施之一，有利于作物产量和水分利用率的提高。本研究以甘肃省金昌市杨柳青公司紫花苜蓿‘艾迪娜’（M.sativa L.‘Aidina’）试验地渗灌区土壤为研究对象，通过田间试验与室内分析相结合的方法，研究不同渗灌次数（0次、1次、2次、3次）对苜蓿出苗期不同土层深度及管距位置土壤化学性质的影响。结果表明：在0~10 cm和10~20 cm土层深度，pH最高值均出现在管上，较CK升高了8.21%和8.68%，最低值都出现在管中，较CK降低了2.70%和3.37%；2水和3水均能显著提高不同土层深度及不同管距位置的pH值（P <0.05）。不同渗灌次数，不同土层深度管中的水溶性盐含量均高于管上和管近，且最大值都出现在1水，较CK分别增加了83.26%和96.34%；不同土层深度，2水的水溶性盐含量平均值都低于1水和3水；不同渗灌次数，不同土层深度，钠离子和钾离子含量的最大值均出现在管中。不同渗灌次数，不同土层深度，管中的水解性氮含量均高于管上和管近，最大值都出现在1水管中，较CK分别增加了112.68%和34.48%。随着渗灌次数的增多，0~10 cm土层深度不同管距的速效磷含量均呈现下降趋势，速效钾含量均呈现上升趋势。随着灌水次数的增加，不同土层深度及管位的有机质含量均呈现先上升后下降的趋势，2水显著提高了各位置土壤有机质含量（P <0.05）。综上所述，渗灌2次比较好，土壤水溶性盐含量较低且有机质含量较高，利于苜蓿幼苗生长。

关键词: 渗灌, 苜蓿, 土壤化学性质