盐土条件下不同栽培措施对4种禾本科饲草阳离子分布的影响

为探讨盐土条件下牧草栽培技术,以4种禾本科牧草为材料,研究了3种不同栽培措施对饲草体内Na⁺, K⁺, Ca²⁺, Mg²⁺含量和分布的影响.结果表明:同一品种不同栽培措施处理下植株体内各离子含量差异显著(P < 0.05),覆秸秆与添加保水剂处理饲草各部分Na⁺含量及Na⁺/Ca²⁺显著低于对照;K⁺, Ca²⁺, Mg²⁺含量和K⁺/Na⁺显著高于对照.离子运输选择性系数S_K⁺/Na⁺均以覆秸秆处理与添加保水剂处理显著高于对照(P < 0.05).相同栽培措施下甜高粱(Sorghum saccharatum)与高丹草(Sorghum bicolor×sorghum Sudanese)体内的K⁺/Na⁺在茎、叶中的分布显著高于青贮玉米(Zea mays)和墨西哥玉米(Euchlaena mexicana).在盐土条件下,覆秸秆和添加保水剂处理可使饲草地上部分的Na⁺含量降低,K⁺含量升高,维持饲草体内较高的K⁺/Na⁺和S_K⁺/Na⁺值,提高饲草的耐盐性;不同饲草品种之间耐盐性差异较大.

Effects of Cultivation Measures on the Cationic Content and Distribution of Forage in Saline Soil

The contents of Na⁺, K⁺, Ca²⁺, Mg²⁺ and the four cationic accumulations in different parts of plant were measured in order to explore a suitable culture technique for forages in saline soil. The results showed that the contents of Na⁺, K⁺, Ca²⁺ and Mg²⁺ of different parts of grasses in the same variety were significant difference from different cultivation measures (P<0.05). The contents of Na⁺ and Na⁺/Ca²⁺ in tested materials under covering straw and the addition of water retaining agent treatments were significantly lower than control, but the contents of K⁺, Ca²⁺, Mg²⁺, K⁺/Na⁺ and S_K⁺/Na⁺ (stem/root) were higher than that of control. Among different varieties, the K⁺/Na⁺ ratios in the leaves and stems of Sorghum saccharatum and sudangrass were higher than that of silage maize and Zea Mexicana. In a word, the above-ground part of forage contained less Na⁺, higher K⁺ contents and higher K⁺/Na⁺ under the cultivation measures of straw mulching and addition of water retaining agent, but the degrees of improvement differed from different varieties.