黄土高原种植不同人工牧草对土壤酶活性的影响

Effects of Different Forage Varieties on Soil Enzyme Activities in Loess Plateau

[目的]研究黄土高原人工种植牧草土壤酶活性的变化,为提高黄土高原人工植被的稳定性和土壤肥力提升等相关研究提供科学依据。[方法]以种植3a的冷地早熟禾、垂穗披碱草、猫尾草、陆地中间偃麦草、紫花苜蓿、沙打旺、红豆草等牧草地为研究对象。分别在3,6,9,12月的0—5cm和5—10cm土层取土壤样品,测定的脲酶、蔗糖酶、碱性磷酸酶和过氧化氢酶的活性变化。[结果]脲酶、蔗糖酶、碱性磷酸酶的活性在0—5cm土层显著高于5—10cm土层,但土壤过氧化氢酶活性在这两个土层之间差异不显著。在6月土壤脲酶、蔗糖酶和碱性磷酸酶的活性高于3月、9月和12月,但过氧化氢酶的活性差异不显著。7种人工种植的牧草中紫花苜蓿的土壤酶活性表现较高,而种植沙打旺的土壤酶活性较低。土层深度和季节的交互作用对4种土壤酶活性产生极显著影响(p<0.01),牧草品种和季节对脲酶、蔗糖酶和碱性磷酸酶活性的具有显著的交互作用。[结论]黄土高原人工牧草地土壤酶活性呈现季节性变化,且种植人工牧草能够有效提高土壤酶活性而改善土壤肥力条件。

[Objective] The soil enzyme activities in different artificial forage in the Loess Plateau was researched in order to provide a scientific basis for improving the stability of artificial vegetation and soil fertility on the Loess forage.[Methods] Seven grasslands planted 3 years including Poa crymophila, Elymus nutans, Uraria crinite, Elytrigia intermedia, Medicago sativa, Astragalus adsurgens, Onobrychis viciaefolia, were selected as the research objects. Soil samples were taken from 0-5 cm and 5-10 cm soil layers in March, June, September and December, to investigate the activity of urease, sucrose enzyme, alkaline phosphatase and catalase.[Results] The activity of urease, sucrose enzyme, alkaline phosphatase in 0-5 cm layer was higher than that in 5-10 cm layer, but there was no significant difference in the activities of catalase between the two soil layers. The activity of urease, sucrose enzyme, and alkaline phosphatase in June was higher than that in March, September and December, but the activity of catalase was not significant different. The activity of soil enzyme in M. sativa was the highest, while the lowest in A. adsurgens. The interaction of soil depth and season had a significant effect on the activities of four enzymes( p <0.01). Herbage variety and season showed significant interaction on the activity of the urease, sucrose enzyme and phosphatase.[Conclusion] The soil enzyme activities of different grasslands in the Loess Plateau changed seasonally, and planting artificial forage could effectively improve soil enzyme activities and soil fertility conditions.