旧膜及秸秆覆盖对西北旱地马铃薯 产量及土壤水热的影响

为了探究旧膜二茬及秸秆带状覆盖条件下，马铃薯田的土壤水热特征及增产机制，设置旧膜直播(T1)、秸秆带状覆盖种植带不旋耕（T2）、秸秆带状覆盖种植带旋耕（T3）、新覆膜（T4）和露地平作（CK）5个处理进行田间试验。结果表明：各覆盖处理较CK提高产量14.24%~56.33%、商品薯率1.21%~22.60%及水分利用效率8.28%~55.39%（P<0.05）;产量与块茎形成期的单株薯干重正相关（r=0.744），覆盖处理在块茎形成期较CK提高单株薯干重118.0%~720.0%（P<0.05），以T4最高;覆盖处理对马铃薯水热特征有显著影响（P<0.05），T1、T2的降温效应显著小于T3，T3的蓄水保墒效应与T4差异不显著，但显著大于T1、T2及CK。可见，在本试验条件下，秸秆带状覆盖种植带旋耕的产量高于旧膜直播、略低于新覆膜，但蓄水保墒效应与新覆膜相近，同时秸秆带状覆盖种植带旋耕较其余覆盖处理具有较明显的降温增墒效应，有利于促进马铃薯块茎的形成及膨大。

Effects of residual film and straw mulching on potato yield and soil moisture and temperature in northwest arid land of China

In order to explore the characteristics of soil temperature and moistureof potato field and yield increasing mechanism under residual film and straw mulching, an experiment was carried out from April to October in 2015. Five treatments were triplicated including residual film direct seeding (T1), small ridge mulching straw and big ridge removed film of no rotary tillage planting (T2), small ridge mulching straw and big ridge removed film of rotary tillage planting(T3), new film mulching planting (T4), and flat planting no mulch(CK). The results showed that the mulching methods could improve yield, commodity potato rate, and WUE. Compared with CK, the yield increased by 14.24%~56.33%, the commodity potato rate increased by 1.21%~22.60%, the WUE increased by 8.28%~55.39%. The yield and dry weight per potato plant in tuber initiation stage were significantly positively correlated(r=0.744), covering planting significantly increased the dry weight per potato plant in tuber initiation stage by 118.0%~720.0% (P<0.05), and the T4 was the best. The effect of mulching treatment on the characteristics of soil temperature and water for potato field was significant (P<0.05). Compared with CK, the cooling effect of T1 and T2 was significantly smaller than that of T3, and there was no significant difference between T3 and T4 in water storage and moisture conservation, but significantly better than T1, T2, and CK.It can be seen that under the experimental condition, the yield of small ridge mulching straw and big ridge removed film of rotary tillage plantingwere better than that of direct seeding with the old film, and slightly lower than that of the new mulching, but the effect on water storage and soil moisture conservation was similar to that of the new film mulching. At thesame time, small ridge mulchingstraw and big ridge removed film of rotary tillage planting had better effect in decreasing temperature and increasing soil moisture than other mulching treatments, which was beneficial to the formation and expansion of potato tuber.