【作者】 郑险峰；

【导师】 李生秀； 周建斌；

【作者基本信息】 西北农林科技大学 ， 植物营养学， 2006， 博士

【摘要】 人口增长和人民生活水平的提高增加了对农业产品更高的需求,土地资源和水资源日益减少却对农业生产构成了巨大威胁。在这两种压力下,人们把注意力投向了旱地农业。旱地以旱为特点,以簿为基础,长期以来产量一直低而不稳。解决旱地农业持续发展的根本问题是充分利用降水资源、提高水分利用效率;协调养分供应,通过营养调控改善作物生理功能,提高作物吸水、用水能力。因此,研究旱地不同栽培制度下作物养分调控,确定养分供应与水分利用、养分流向与产量及品质的关系一直是人们关注的焦点。本研究以传统的无覆盖栽培为对照,在冬小麦田间试验中设置5种栽培模式(对照、平地覆膜、麦草覆盖、补充灌溉以及垄沟栽培)、3个氮肥水平、2个密度组成包括30个处理的完全方案;夏玉米田间试验中设置3种栽培模式(对照、垄沟栽培、麦草覆盖)、3个氮肥水平组成9个处理的完全方案;以当地普遍栽培小麦品种小偃22、夏玉米陕单902为对象,在定位试验条件下,确定不同栽培模式的水分养分效率及其产量效应;确定不同栽培模式对作物体内养分分配、转运的影响;探讨氮肥分配方式和根外喷施营养元素对旱地作物养分流向的调控和对产量的影响。主要研究结果如下:1.在旱作条件下,平地覆膜栽培小麦具有明显的生育和产量优势,各生育时期生物量较高;连续2年,产量较传统栽培增产16.1%和18.4%.麦草覆盖栽培,小麦越冬期间生长受到抑制,发育不良;后期生长加快。由于抑制和恢复情况不同,产量有年际变化:与传统栽培相比,第一年平均减产10.4%,第二年施氮量低者未增产,施氮量高者增产14.3%;补充灌溉的冬小麦与覆草栽培有类似趋势。垄沟栽培(垄上覆膜,沟内栽培)第一年因播量偏低而减产,第二年加大播量后在低密度高氮肥条件下产量较高。由于其合理密度范围狭窄,成穗数的高低是影响产量的关键因素之一。氮肥能显著提高小麦产量和品质:施氮平均增产19.2%~24.6%;施N量由120 kg/hm~2提高到240kg/hm~2后,产量不再上升,但籽粒蛋白质含量进一步提高。2.平地覆膜栽培创造了良好的水、热状况,有利于小麦生长发育。覆膜后,小麦分蘖增加,总茎数和成穗数最高;叶面积大,有利于光合作用和干物质累积;花前干物质累积量高,花后能保持较快灌浆速率。覆草和补灌小麦叶面积和对照差别不大;施用氮肥后,两者灌浆期旗叶持绿时间较长,但灌浆速度与传统栽培相当。垄沟栽培,冬小麦生育前期个体之间差异较大,自动调节能力差;密度合适,穗数适宜方能增产,是制约其产量的主要因素;但垄沟栽培特有的光、热、水、肥条件有利于小麦花后干物质持续大量累积,灌浆期旗叶持绿时间较长且灌浆速率快。3.不同栽培模式条件下,冬小麦氮肥利用率不同。平地覆膜,土壤氮素强烈矿化,更多还原

【Abstract】 With the increase of population and improvement of living standard, people have higher demands for agricultural production. But the land and water resources are becoming less and less in the world. For a long time, perplexed by drought and barrenness, the grain yield on dryland in China is low and unstable. Under this stress, people had to pay more attention to dryland. Now a lot of practical problems have been identified that urgently need to be solved. The solution to the problem concerns the smooth implementation of a strategy of sustainable development for dryland agriculture. The core of solving these problems is to understand the nutrient distribution and fluxes, relevant mechanism of physiology and ecological in the continuous ecosystem of soil– plant on dryland; and to make the best use of the resources of precipitation. It is important to enhancing water using efficiency; harmonizing nutrition supplying; improving physiological by nutrition regulation to increase the capacity of absorbing and using water of crops. Therefore, the transport and distribution of crop nutrients and its regulation in dryland crops with different cultivated systems have becoming one of the focuses of agri-scientific research workers in the world.Local high-quality wheat and maize varieties, and four water-saving dryland culture modes (plastic film mulching, straw mulching, supplemental irrigations, and furrow mode with a ridge mulching–ditch planting) were chosen in this study, and the non-covered culture mode was used as the control treatment. The study was carried out in Yangling, Shaanxi Province, the semi-arid region. The aims of the study were to study the effects of the different cultivating modes on the growth and yields of winter wheat and summer maize, and to access the nutrient uptake, transport and distribution at different cultivation modes, and to evaluate the effects of the different nutrient managements included the application time of nitrogen fertilizer and foliar spray method on nutrient translocation in the crops. The main results were as follows:1. The treatment mulched with plastic film had significantly positive effect on the growth of winter wheat under the dryland during the two years; the yields of this treatment were 16.1% and 18.4% higher than the control treatment (non-covered cultivating mode) in 2003更多还原