【作者】 付增光；

【导师】 韩思明；

【作者基本信息】 西北农林科技大学 ， 种植， 2004， 硕士

【摘要】 冬小麦是陕西渭北旱原重要的粮食作物，其产量高低、品质好坏，对该区乃至陕西全省粮食安全和农业可持续发展均具有重大意义。然而，由于干旱缺水的原因，该区冬小麦一年一熟，多实行夏季休闲。夏闲地也多采用传统翻耕技术，形成裸露的地表和疏松的耕层结构。这样的地表状态和耕层结构，在高温多雨的夏季，不仅会造成水土严重流失，而且会加剧土壤水分的无效蒸发，加之土壤比较贫瘠，因而冬小麦产量长期低而不稳。目前生产上应用的残茬（秸秆）覆盖技术、深松耕作技术以及地膜覆盖技术等，虽各自有不同程度的蓄水保水和增产效应，但由于多为单项技术应用，因而其蓄水保水和增产效果受到很大程度的限制。为了充分发挥各项技术的整体效应，达到降水就地拦蓄，就地入渗，最大限度地提高降水资源的利用效率，将“高留茬”、“深松耕”和“地膜覆盖”三项技术有机结合，组成以“留茬覆盖深松膜测沟播”为主体的旱地小麦机械化保护性耕作体系，在过去试验研究的基础上，2003~2004小麦生产年度，以传统翻耕露地小麦为对照，进一步将该技术与留茬免耕秸秆全程覆盖技术和留茬深松秸秆全程覆盖技术一起进行了对比试验。研究结果表明：1.各种保护性耕作技术模式与传统翻耕技术相比，均有一定的蓄水保水效果。其中以留茬覆盖深松膜测沟播模式的效果最好，其次是留茬深松秸秆全程覆盖模式，而留茬免耕秸秆全程覆盖模式则较差。2.旱地小麦留茬覆盖深松膜侧沟播模式，夏闲期通过深松和秸秆覆盖的双重作用，可以把夏闲期占小麦生产年度50%以上的降水最大限度地蓄积并保存于土壤之中。2m土层内较传统耕作模式多蓄水85.1mm，蓄水率达到55.0%，较传统耕作模式提高17.6%；小麦播种时，采用起垄覆膜膜<WP=6>侧沟播技术，既可把夏闲期蓄积到土壤中的水分最大限度地保住，又可以把小麦生育期有限的降水依靠隆起的地膜将其最大限度地蓄住保住，同时又可增加土壤温度，融“深松深层贮水效应”、“秸秆覆盖保水增肥效应”和“起垄覆膜沟播聚水保水增温透光效应”于一体，可以显著改善旱地麦田水、肥、气、热环境条件。3.旱地小麦留茬深松秸秆全程覆盖模式，夏闲期同样实行深松加秸秆覆盖，与传统耕作模式相比，多蓄水85.1mm，蓄水率达到55.0%；但小麦播种以后，由于秸秆覆盖的保墒效果差，加之土壤温度较低的制约，小麦生长受到一定抑制，因而增产效果不够突出。4.旱地小麦留茬免耕秸秆全程覆盖模式，夏闲期尽管同样有秸秆覆盖，但由于免耕耕层土壤较紧，加之犁底层的存在，不利于降水下渗，因而蓄水较少，和传统耕作模式相比，贮量仅多27.9mm，蓄水率为43.2%，同时由于秸秆覆盖的保墒效果差，土壤温度低等原因，小麦生育迟缓，增产效果不明显，较传统耕作模式仅增产7.4%。5.各技术模式的增产增收效果，以留茬覆盖深松膜侧沟播模式最好，与传统耕作模式相比，每公顷增产小麦2110.5kg，增产率达到40.1%，增加收入1218.7元，增收率达到15.5%；而留茬深松秸秆全程覆盖模式与传统耕作模式相比，每公顷增产小麦883.6kg，增产率为17.0%，但增收效果却差于传统耕作模式，这与该模式将秸秆费用计算在内有关。留茬免耕秸秆全程覆盖模式，也是有一定的增产效果，同样由于将秸秆费用计算在内，因而也是增产不增收。更多还原

【Abstract】 Winter wheat is an important grain crop in Weibei dryland region, and its yield and quality play a significant role in food safety and sustainable development of the region, even Shaanxi province. However, because of draught, the region practices one cropping of wheat per annum, mostly with summer fallowing. The lands in summer fallow are mostly tilled with traditional plowing techniques and thus form naked soil surface and loose topsoil structure. The nakedness and loose structure do not only cause severe soil erosion and water loss but also intensify inefficient evaporation of soil water in hot and rainy summer, which, in addition to poor soil fertility, resulted in a low and unstable yield of winter wheat in the region.Although the stubble (straw) mulching technique, the deep tillage technique and the plastic film mulching technique currently practiced in wheat production all have the capacities to retain soil moisture and increase winter wheat yield to different extents, the capacities are limited to a large extent because all these techniques are individually adopted. In order to realize the whole capacities of each technique and make rainfall be retained and infiltrate into soil in situ, ‘high stubble retention ’, ‘deep and loose cultivation’ and plastic film mulching are properly integrated into the mechanically protecting tillage system for wheat whose major components are stubble retention, plastic film mulching, deep and loose cultivation and furrow planting next to plastic film’. On the basis of previous research results and with wheat planted without mulching under traditional plowing as the control, the mechanically protecting tillage system for wheat was further compared with the technique of the stubble mulching under no-tillage during whole growth of wheat and the stubble mulching under deep and loose cultivation during the whole growth of winter wheat in 2003-2004. The results of the research showed: 1. Compared with traditional plowing techniques, various protecting tillage techniques had the capacities to retain and conserve water. The capacities ranked from high to low as <WP=8>follows: the mechanically protecting tillage system, the technique of the stubble mulching with deep and loose tillage during whole growth of summer wheat and the technique of stubble retaining without tillage during whole growth of summer wheat.2. The model of furrow planting next to film under deep and loose cultivation made use of the effects of both deep cultivation and stubble mulching on soil moisture to retain and conserve the rainfall in summer fallow in soil, which accounted for more than 50 % annual rainfall during whole growth of winter wheat. The amount of soil water retained and conserved under the model was 85.1mm more than that under traditional plowing models, and thus the ratio of retained and conserved water to the rainfall falling onto the soil under the former reached 55.0%, 17,6% higher than that under the latter; in addition to increasing soil temperature, the technique of furrow planting with mulched ridges taken at the sowing time of winter wheat could keep not only as much water accumulated in soil during summer fallow as possible but also as much rainfall during the growth period of winter wheat as possible so that ‘water-conserving effects of topsoil under deep and loose cultivation’, the water-conserving and fertility-improving effects of stubble mulching’ and the water-retaining, water-conserving, temperature-increasing and sunlight-penetrating effects of furrow planting with mulched ridges combined into an integrative whole, which significantly improved the environmental conditions of wheat fields concerned with water, fertility, aeration and warmth. 3. The amount of water retained and conserved by the model of stubble mulching under deep and loose cultivation during whole growth of wheat in combination with straw mulching under deep and loose cultivation during whole summer fallow was 81.5 mm higher than that retained and conserved by traditional tillage models and the rati更多还原