不同揭膜时期对半干旱区马铃薯土壤酶活性的动态影响研究

Impact of the mulch unveiling time on the dynamics of the soil enzyme activities in the potato field in the semi-arid region

在半干旱区全膜双垄沟播栽培模式下,以马铃薯品种新大坪为试验材料,通过在幼苗生长期揭膜(T1),现蕾期揭膜培土(T2)和不培土(T3)、盛花期揭膜培土(T4)和不培土(T5)、块茎增长期揭膜(T6)、全程不揭膜(CK)7个管理模式,对耕层土壤酶活性的动态影响、土壤酶活性及产量之间的相关性进行了研究。结果表明:揭膜时期的选择对土壤酶活性的变化影响较大。在马铃薯苗期开始揭膜会使过氧化氢酶活性总体上保持一个较高的水平,现蕾期揭膜能够显著增加土壤过氧化氢酶活性,转化酶活性均以马铃薯生长中后期高于生长前期;在现蕾期进行揭膜及培土能增加土壤转化酶、磷酸酶活性,但会降低脲酶活性;在盛花期揭膜及培土有助于增加土壤脲酶活性。在马铃薯整个生育期,过氧化氢酶活性与脲酶、磷酸酶活性均达到显著或极显著的正相关,脲酶和磷酸酶活性达到显著或极显著的正相关;在各生育期各处理土壤酶活性与产量之间均未达到显著的相关性。

The dynamics of soil enzyme activities and the relationship with the tuber yield were studied with the following seven treatments in a semiarid area： mulch unveiled in the seedling growth period （T1）, mulch unveiled and ridged （T2） and non-ridged （T3） in the budding period, mulch unveiled and ridged （T4） and non-ridged （T5） in the full-blossom period, mulch unveiled in the tuber growth period （T6）, and non-mulch-unveiled during the entire growing period （CK）. A potato of Xin Da Ping was furrow-planted in a full plastic mulching and bedding system. The results indicated that soil enzyme activities in the potato field were greatly influenced by the mulch unveiling periods. Soil catalase activity was increased significantly during the budding period, and it was maintained at a higher level in the whole period since seedling in the mulch unveiling treatments. Soil intervase activities in the later growth period were usually higher than in the early growth period. Soil intervase and phosphatase activities were both increased by the mulch unveiling and ridging in the budding period, while the soil urease activity was decreased. However, the soil urease activity was significantly higher by mulch unveiling and ridging in the full-blossom period than in the early unveiling period. The correlation between the catalase activity and the activities of urease and phosphatase was positive and significant, while the urease and phosphatase activities were significantly correlated. Unfortunately, no significant correlation between soil enzyme activities and the potato tuber yield was observed in all mulch unveiling treatments.