秸秆覆盖下穴灌土壤水氮热运移规律研究

发布时间：2017-12-28 14:03

本文关键词：秸秆覆盖下穴灌土壤水氮热运移规律研究　出处：《河北工程大学》2017年硕士论文　论文类型：学位论文

【摘要】：随着我国农业的快速发展,秸秆覆盖技术为我国农业生产带来了巨大的经济效益。而穴灌技术是农业生产一种有效的节水灌溉方式,本文充分利用穴灌和秸秆覆盖的技术特点,通过大田试验和理论分析相结合的技术路线,研究了不同灌水技术要素和施肥技术措施对穴灌土壤水氮热运移规律的影响。主要研究成果如下:(1)研究了灌水技术要素对秸秆覆盖下穴灌土壤水氮热运移分布的影响。其中灌水技术要素包括:穴坑深、穴坑直径和灌水量三个因素。穴坑越深,灌后同一时刻的垂直湿润锋运移距离越大;不同穴坑深度的土壤含水率均随着距坑底距离的增加而减小,相同灌水要素条件下,穴坑深度越大,同一点处土壤含水率越大;不同穴坑深度的土壤硝态氮均随着距坑底越远含量越高,相同灌水要素条件下,穴坑深度越大,同一点处土壤硝态氮含量越低。不同穴坑深度的土壤温度在穴坑底部均随着土壤深度的增加先升高后降低,穴坑深度越大,相同位置处土壤温度越低。穴坑直径越大,灌后同一时刻的垂直湿润锋运移距离越小;不同穴坑直径的土壤含水率均随着距坑底距离的增加而减小,相同灌水要素条件下,穴坑直径对穴灌土壤含水率的影响并不显著;不同穴坑直径的土壤硝态氮均随着距坑底越远含量越高,土壤中硝态氮含量也随着穴坑直径的增大而增大。不同穴坑直径的土壤温度在穴坑底部均随着土壤深度的增加先升高后降低,穴坑直径越大,相同位置处土壤温度越高。灌水量越大,灌后同一时刻的垂直湿润锋运移距离越大;不同灌水量的土壤含水率均随着距坑底距离的增加而减小,相同穴坑结构条件下,灌水量越大,同一点处土壤含水率越大;不同灌水量的土壤硝态氮均随着距坑底越远含量越高,相同穴坑结构条件下,灌水量增大,穴坑附近硝态氮含量减小,穴坑深层土壤硝态氮含量增大。不同灌水量的土壤温度在穴坑底部均随着土壤深度的增加先升高后降低,灌水量越大,相同位置处土壤温度越低。灌后再分布阶段有秸秆覆盖下的穴坑土壤含水率要大于无秸秆覆盖处理,秸秆覆盖有效的促进了硝态氮向深层土壤运移,减少了硝态氮的损失。而且有秸秆覆盖下的穴坑坑底土壤温度日变化幅度明显要小于无秸秆覆盖处理。(2)研究了施肥技术措施对秸秆覆盖下穴灌土壤水氮热运移分布的影响。其中施肥技术措施包括:施肥量和施肥方式两个因素。施肥量越大,灌后同一时刻的垂直湿润锋运移距离越大;不同施肥量的土壤含水率均随着距坑底距离的增加而减小,相同灌水要素条件下,施肥量越大,同一点处土壤含水率越大;不同施肥量的土壤硝态氮均随着距坑底越远含量越高,相同灌水要素条件下,增加施肥量,同一点处的土壤硝态氮含量就越高。不同施肥量的土壤温度在穴坑底部均随着土壤深度的增加先升高后降低,施肥量越大,相同位置处土壤温度越高。在灌后0h,不同施肥方式的垂直湿润锋运移距离大小顺序为:灌施、深施、表施。不同施肥方式的土壤含水率均随着距坑底距离的增加而减小,相同试验条件下,在湿润体同一点处灌施和深施的土壤含水率要大于表施土壤含水率。灌施条件下土壤硝态氮随着距坑底距离越远含量越高,表施和深施土壤硝态氮含量均随着距坑底距离的增加呈先变大后减小的趋势。灌后再分布阶段,剖面土壤含水率和硝态氮均随着灌后时间的延长逐渐降低。不同施肥方式处理的土壤水氮分布规律与灌水结束时相似。
[Abstract]:With the rapid development of China's agriculture, straw mulching technology has brought great economic benefits to agricultural production in China. The hole irrigation technology is an effective agricultural water-saving irrigation technology, make full use of the characteristics of this hole irrigation and straw mulching, technical route through the combination of field experiment and theoretical analysis of the effects of different irrigation and fertilization measures irrigation technical elements between soil water and nitrogen heat transport to the point. The main research results are as follows: (1) the effect of irrigation technology factors on the distribution of water and nitrogen heat transfer in soil under straw mulching is studied. The technical elements of irrigation include three factors, the depth of the hole, the diameter of the hole and the amount of water. The deeper the hole, with the vertical wetting front distance at the same time the greater the hole depth of different soil moisture content; rate decreases with increasing distance from the bottom of the elements of the same irrigation condition, hole depth increases, the same point of soil moisture is higher; soil nitrate nitrogen in different the depth of the hole with the distance from the bottom far higher content of elements of the same irrigation condition, hole depth increases, the same point of soil nitrate content was lower. The soil temperature at different pit depths increased at first and then decreased with the increase of soil depth. The greater the pit depth, the lower the soil temperature at the same location. Hole diameter is large, after irrigation, vertical wetting front distance at the same time the smaller hole diameter; different soil water content rate decreases with increasing distance from the bottom of the elements of the same irrigation condition, hole diameter of hole irrigation effects of soil water content is not significant; different hole diameter of soil nitrogen was far above the bottom with higher content of soil nitrate nitrogen content also increases with increasing hole diameter. The soil temperature at different pit hole diameters increases first and then decreases with the increase of soil depth. The larger the pit diameter is, the higher the soil temperature is at the same location. The greater the amount of irrigation, irrigation after the vertical wetting front distance at the same time the greater the amount of irrigation; different soil moisture content rate decreases with increasing distance from the bottom of the hole, the same structural conditions, the greater the amount of irrigation, the same point of soil moisture is higher; soil nitrate nitrogen in different irrigation the amount of both with the distance from the bottom is far higher, the same hole structure under the condition of irrigation quantity increased, nitrate content near the hole hole depth decreases, increasing soil nitrate content. The soil temperature of different irrigation amounts increased first and then decreased with the increase of soil depth, and the greater the amount of irrigation, the lower the soil temperature at the same position. After irrigation, the soil moisture content of the hole with straw mulching is larger than that without straw mulching. Straw mulching effectively promoted nitrate nitrogen transport to deep soil and reduced nitrate nitrogen loss. But under straw mulch cave pit soil temperature daily variation amplitude was significantly higher than no straw mulching. (2) the effects of fertilization techniques on the distribution of water and nitrogen heat transfer in soil under straw mulching were studied. The measures of fertilization include two factors: the amount of fertilizer and the way of fertilization. The greater the amount of fertilization, irrigation after the vertical wetting front distance at the same time more; soil moisture on different fertilization rate decreases with increasing distance from the bottom of the elements of the same irrigation conditions, fertilization amount is larger, the same point of soil moisture is higher; soil nitrate nitrogen fertilization with the distance from the bottom are far higher content of elements under the same irrigation, increasing the amount of fertilizer, the nitrogen content at the same point of soil nitrate is higher. The soil temperature at the bottom of the hole increased first and then decreased with the increase of soil depth, and the higher the amount of fertilizer, the higher the soil temperature at the same position. At 0h after reperfusion, different fertilization methods of the vertical wetting front distance order, deep fertilization, irrigation and fertilization application. The soil water content of different fertilization rate decreases with increasing distance from the bottom, under the same experimental conditions, at the same point in wetting irrigation and deep application of soil moisture is greater than the surface soil moisture content. Under the conditions of irrigation and fertilization of soil nitrate nitrogen with the distance from the bottom farther higher surface and deep application of soil nitrate content decreased with the increase of the distance from the bottom is first increases and then decreases trend. In the redistribution stage after irrigation, the soil moisture content and nitrate nitrogen in the section gradually decreased with the prolongation of the post irrigation time. The distribution of water and nitrogen in soil treated with different fertilization methods was similar to that at the end of irrigation.
【学位授予单位】：河北工程大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S152

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