不同灌溉方式下旱区枣树根区土壤颗粒组成和孔隙特征

    Soil particle composition and pore characteristics in the root zone of date palm in the dry zone under different irrigation methods

    • 摘要: 新疆是典型的灌溉农业区,节水灌溉技术是新疆农业持续发展的基础,但长久灌溉方式的不同对土壤颗粒组成和孔隙结构的影响也存在一定的差异。为探究不同灌溉方式对枣树根区土壤粒度组成及连通孔隙结构的影响,以南疆14 a采用3种不同灌溉方式(FI:漫灌,DI:滴灌,STI:砂管灌)的枣园土壤为研究对象,以未灌溉区域且远离根区的土壤作为对照,结合土壤粒度分析(particle size distribution,PSD)与CT扫描技术测定土壤粒度组成并分析其连通孔隙结构参数,旨在揭示土壤结构特征,为新疆节水灌溉技术提供微观理论依据。结果表明:1)不同灌溉方式对土壤颗粒组成的影响显著(P<0.05),漫灌方式下土壤平均粉粒体积分数显著高于滴灌与砂管灌方式,长期的滴灌与砂管灌方式会降低0~60 cm各层土壤粉粒含量,增加土壤砂粒含量。2)长期的漫灌方式会显著提高0~60 cm土壤平均体积分形维数(P<0.05),土壤更紧实,通透性更差;长期的滴灌与砂管灌方式则会降低0~60 cm土壤平均体积分形维数。3)砂管灌方式下土壤0~20 cm孔径区间(0~1 000 μm)频数均高于滴灌与漫灌方式。砂管灌方式下0~40 cm土壤总孔隙度与孔隙连通率均显著高于漫灌方式(P<0.05),且0~20 cm土壤总孔隙度与孔隙连通率显著高于滴灌方式,土壤的通透性更好,从改善土壤孔隙角度来说,砂管灌方式更适合该地区枣树灌溉。研究结果为南疆节水灌溉事业发展及农业水资源高效利用提供理论参考。

       

      Abstract: Xinjiang is a typical irrigated agricultural area, and water-saving irrigation technology is the basis for the sustainable development of agriculture in Xinjiang, but there are some differences in the effects of different long-lasting irrigation methods on soil particle size composition and pore structure. In order to investigate the effects of different irrigation methods on soil particle size composition and pore structure in the root zone of jujube trees, the soil of jujube gardens with three different irrigation methods (FI: diffuse irrigation, DI: drip irrigation, and STI: sandy tube irrigation) in the southern Xinjiang area was used as the object of study for 14 years. Soils in the unirrigated area and far away from the root zone were used as the control, and the soil was analyzed with the combination of soil particle size distribution (PSD) and soil water-saving irrigation techniques, and the soil was analyzed with the combination of soil water-saving irrigation techniques. The study determined the soil particle size composition by particle size distribution (PSD) and CT scanning techniques and its connectivity pore structure parameters were analyzed. The study aimed to reveal the soil structural characteristics and provided a microscopic theoretical basis for water-saving irrigation technology in Xinjiang. The results showed that: 1) the effects of different irrigation methods on the particle composition of soil layers were significant (P<0.05). The average volume fraction of soil powder particles was significantly higher in the diffuse irrigation than in the drip irrigation and sand-pipe irrigation, and the long-term drip irrigation and sand-pipe irrigation methods decreased the content of soil powder particles in each layer from 0 to 60 cm and increased the content of soil sand particles. 2) the long-term diffuse irrigation method significantly increased the average volume fractal dimension of soil from 0 to 60 cm (P<0.05) and the average volume fractal dimension of soil from 0 to 60 cm was significantly higher (P<0.05) and the soil was more compact and less permeable. Long-term drip irrigation and sand pipe irrigation decreased the average volume fractal dimension of 0-60 cm soil. 3) The frequency of 0-20 cm pore size interval (0-1000 μm) was higher than that of drip irrigation and diffuse irrigation under sand pipe irrigation. The total porosity and pore connectivity of the soil from 0 to 40 cm were significantly higher than those of the diffuse irrigation method (P<0.05), and the total porosity and pore connectivity of the soil from 0 to 20 cm were significantly higher than those of the drip irrigation method, and the permeability of the soil was better. In conclusion, the sand pipe irrigation method was more suitable for the irrigation of jujube trees in this area. The results of the study provide theoretical references for the development of water-saving irrigation and efficient utilization of agricultural water resources in South Xinjiang.

       

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