不同覆膜方式对陇东旱塬玉米田土壤温度的影响

Influence of different approaches of plastic film mulching on soil temperature of maize field in dry plateau of Longdong

在海拔1 700 m以下的陇东旱塬选择年降雨量和年平均积温相近的3个试验点,以玉米为栽培作物,进行秋季全膜双垄沟播栽培、春季顶凌全膜双垄沟播栽培、播前全膜双垄沟播栽培、半膜平铺和不覆膜5种栽培模式试验,分别测定地表5 cm、10 cm、15 cm、20 cm的土层地温,以探索全膜双垄沟播栽培技术对土壤地温的影响。结果表明,在玉米生长的每一个生育期,不同的土壤深度的地温和有效积温均是A.秋季全膜双垄沟播栽培>B.春季顶凌全膜双垄沟播栽培>C.播前全膜双垄沟播栽培>D.半膜平铺>E.不覆膜。并且在海拔1 700 m以下区域,秋季全膜双垄沟播栽培、春季顶凌全膜双垄沟播栽培、播前全膜双垄沟播栽培、半膜平铺的有效积温均能满足玉米正常生长所需的积温。不覆膜的有效积温不能满足玉米正常生长所需的积温。

In order to analyse the influence of full plastic film mulching over double ridges and sowing on soil temperature, three similar plots were set up according to annual precipitation and average annual accumulated temperature in the regions below 1 700 m altitude on the dry plateau of Longdong. Using maize as planting object, five different experiments were made, such as full plastic film mulching on double ridges and sowing in catchment furrows in fall, in early spring, before sowing, half flat-mulching and non-mulching, and the temperature in each treatment in five different soil layers （surface, 5 cm, 10 cm, 15 cm, 20 cm ） was measured separately. The results show that soil temperature and effective accumulated temperature in different soil depths at each growth period follows the principles： 1） full mulching on double ridges in fall and sowing in catchment furrows 〉 2） full mulching on double ridges and sowing in catchment furrows in early spring 〉 3 ） full mulching on double ridges before sowing in catchment furrows 〉 4） half flat - mulching 〉 5） non-mulching. In the regions below 1700m altitude, almost all mulching approaches mentioned above, except non-mulching, could provide accumulated temperature needed for the normal growth of maize.