Abstract: The purpose of this study was to explore effective ways to improve soil water storage and conservation during fallow period and ensure the stable and high yield of dryland wheat. A two-factor split-plot experiment was conducted to investigate effects of the combined application of tillage practice with super absorbent polymers on soil water content (SWC), soil nutrient content, wheat yield, water and precipitation use efficiency (WUE and PUE). The main plot was tillage practice (subsoiling tillage, deep plow tillage and rotary tillage), and subplot was super absorbent polymers (SAP) applied at rates of 0, 45, and 90 kg·hm^-2. The correlation among the SWC, yields, yield components and WUE were analyzed. The results showed that, compared with rotary tillage at fallow stage, subsoiling tillage at fallow stage increased SWC of 20~160 cm soil layer before sowing, deep plow tillage at fallow stage increased SWC of 0~20 cm and 60~140 cm soil layer before sowing. And the water utilization in the 20~200 cm soil depth during harvest stage was accelerated. Consequently, by increasing the spike number and grain number per spike, wheat yield was significantly increased by 12.63% and 6.88%, respectively. WUE and PUE were significantly increased. The soil organic matter, alkaline-N, Olsen-P content at the 20-40 cm depth increased. Tillage at fallow stage, combined with the application of 45 kg·hm^-2 SAP significantly increased soil water conservation ability during the fallow period, water utilization efficiency and yield of dry-land wheat. The effect of subsoiling tillage on yield and WUE was better than deep plow tillage. Both wheat yields and PUE had a positive correlation with SWC of 60-120 cm soil depth before sowing in the dry land. Our findings provide a theoretical basis for improving the yield and water use efficiency of dryland wheat in the south of Shanxi Province by optimizing the tillage methods and the application rate of SAP, which are of great significance for the stable and high yield of dryland wheat and reducing the annual yield fluctuation.

Key words: dry-land wheat, tillage at fallow period, super absorbent polymers application, grain yield, precipitation use efficiency

摘要： 为探讨提高旱地麦田休闲期土壤蓄水保水能力、保证旱地小麦稳产高产的有效途径,本研究采用双因素裂区试验,主区为耕作方式(深松、深翻和旋耕),副区为保水剂施用量(0、45、90 kg·hm^-2),研究了耕作方式和施用保水剂对土壤含水量、土壤养分、旱地小麦产量和水分利用率的影响,并分析了土壤含水量、生育期耗水量与旱地小麦产量及其构成因素和水分利用率之间的相关关系。结果表明,与休闲期旋耕相比,休闲期深松提高了播前20~160 cm土层的土壤含水量,休闲期深翻提高了播前0~20 cm和60~140 cm土层的土壤含水量,加速了收获期20~200 cm土层的水分利用;并通过增加穗数和穗粒数使旱地小麦产量分别提高了12.63%和6.88%,显著提高了水分利用率和降水利用率,20~40 cm土层有机质、碱解氮、速效磷含量总体提高。休闲期耕作,配施保水剂45 kg·hm^-2显著提高了旱地小麦休闲期蓄水保水能力、水分利用率和产量。休闲期深松增产效果和提高水分利用率效果优于休闲期深翻。旱地小麦产量和降水利用率与播前60~120 cm土层含水量呈正相关。本研究结果为晋南旱地小麦优化耕作方式和保水剂施用量提高产量和水分利用率提供了理论依据,对旱地小麦稳产高产、减小年际间产量波动具有重要意义。

关键词: 旱地小麦, 休闲期耕作, 保水剂, 小麦产量, 降水利用率