【作者】 王军；

【导师】 马娟娟；

【作者基本信息】 太原理工大学 ， 水利工程， 2015， 硕士

【摘要】 温度对作物的生长、发育和土壤质地的形成有着重要的影响，它是农业生产中进行耕作、灌溉和施肥的一个重要影响因素。在一定的范围内，随着土壤温度的升高，作物的生长发育速度加快；在其它条件满足时，灌溉水温过低，会抑制作物根系对土壤水分和养分的吸收利用。蓄水坑灌法是一种新型的节水灌溉方法，可有效解决干旱和起到保持水土的作用。温度是控制土壤微生物活性的一个关键因素。温度的变化会影响土壤中氮素的分布，而氮素对作物生长起着重要作用，土壤中氮素的积累有助于提高土壤肥力，促进作物经济产量的提高。为了明确不同土壤温度和灌溉水温对土壤水氮运移规律的影响，以及设计合理的灌溉制度，本文通过室内土箱模型试验与理论分析相结合的方法，研究了在蓄水单坑灌施条件下不同土壤温度(20，25，30℃)和不同灌溉水温(15，20℃)，所对应单坑灌水量(7l)在灌后不同时间(1，5，10，15d)对土壤水氮运移规律的影响。主要结论为:⑴蓄水单坑灌施条件下不同温度对土壤水分运移规律的影响，主要包括:①随着入渗时间的延长，蓄水坑土体湿润范围不断扩大，土壤含水率在空间分布上表现为先增大后减小的趋势。②灌溉水温一定时，土壤温度越高，水分在蓄水坑土体内的运移范围越大，含水率越小；土壤温度一定时，灌溉水温越高，水分在蓄水坑土体内的运移范围越大，土壤水分在湿润体内分布越均匀。③不同土壤温度和灌溉水温条件下的湿润锋动态差别不大，土壤含水率空间分布规律基本一致。⑵蓄水单坑灌施不同土壤温度(20，25，30℃)条件下氮素运移的规律，主要表现为:①土壤铵态氮含量在垂向分布上随着时间的延长，表现为先增大后减小的趋势。在20—30℃范围内，随着土壤温度的升高，铵态氮含量达到最大值的时间逐渐缩短。土壤铵态氮含量在水平方向上，随着径向距离的增大表现为逐渐减小的趋势。②不同土壤温度条件下的硝态氮含量随着时间的推移而逐渐增大，在灌后15天土壤硝态氮浓度到达最大值。在20—30℃范围内，随着土壤温度的升高，硝态氮含量增幅加快。⑶蓄水单坑灌施不同灌溉水温(15，20℃)条件下土壤氮素运移的规律，主要表现有：①土壤铵态氮含量在垂向分布上，随着时间的延长表现为先增加后减小的趋势，灌溉水温20℃时所对应的铵态氮峰值要大于15℃下铵态氮峰值；土壤铵态氮含量随着径向距离的不断增大而逐渐减小。②土壤硝态氮含量在垂向分布上呈现出中间低两边高的特点，随着时间的不断延长，土壤硝态氮含量逐渐增大；土壤硝态氮含量随着径向距离的不断增大而逐渐增大，在土体湿润锋的边缘处，硝态氮含量达到最大值。在15—20℃范围内，随着灌溉水温的升高，土壤硝态氮浓度增大。⑷铵态氮在蓄水坑土体内的运移方式主要以扩散作用为主，大部分土壤铵态氮集中在湿润体内部；硝态氮在蓄水坑土体内的运移方式以对流作用为主，大部分土壤硝态氮集中在土体湿润锋边缘处。更多还原

【Abstract】 Temperature has a significant impact on the growth and development ofcrop, and the formation of soil texture, and it is a very important factor toagricultural production, irrigation and fertilization. Studies have shown that: in acertain range, with the increase of soil temperature, the growth of crop accelerate;when other condition is satisfied, low water temperature will have a inhibition inthe use of crop root system on soil moisture and nutrients.Water storage pit irrigation method is a new type of water-saving irrigationmethod. It can effectively solve the water deficit and play a role in soil andwater conservation. Temperature is a key factor of controlling soil microbialactivity. The temperature variation will affect the soil nutrient content, and thenitrogen plays an important role in plant growth. The accumulation of nitrogenin the soil will improve soil fertility and increase crop yields. The indoorexperiment was conducted with theoretical analysis. The goals of this study are:1) determining the nitrogen distribution in soil water at the different soiltemperature;2) determining the nitrogen distribution in soil water at different temperature of irrigation water3) designing a reasonable irrigation system basedon results of the first two points. Through the indoor soil box simulation test,studied at the single water storage pit irrigation, different soiltemperatures(20,25,30oC) and irrigation water temperature(15,20oC),corresponding to a single pit irrigation amount(7l) and different times(1,5,10，15d) after filling, effects on soil moisture and nitrogen migration rule.Main research results are:⑴Under the water single pit irrigation condition of different temperature,effects on soil moisture migration，included:①since the water bottom is madeof seal baffle, the simulated soil fertilizer solution poured into the tank, at thebeginning of fertilizer is mainly horizontal infiltration on liquid infiltration, soilwetting range increasing with time. With the increase of soil water storage of pitdepth and the radial distance, soil moisture showed a decreasing trend after thefirst increase; wetting front dynamic under the condition of differenttemperatures has little difference, moisture content of the spatial distribution ruleis almost the same.②Irrigation water temperature is constant, the higher thesoil temperature, the smaller the moisture migration area, the greater themoisture content.③Under the condition of a certain soil temperature，thehigher the irrigation water temperature, the greater the range of moisturemigration, the more hook the soil moisture distribution in the wet.⑵Under the water single pit irrigation condition of different soiltemperature, the law of nitrogen migration, mainly for:①On the vertical distribution of soil ammonium nitrogen content over time, showed a decreasingtrend after the first increase with the increase of soil temperature. The content ofammonium nitrogen reach maximum gradually shorten the time, thenammonium nitrogen content decreases gradually over time, nitrification is morenoticeable during20—30oC.②The content of nitrate nitrogen in different soiltemperature conditions increases over time，in the range of20—30oC, thenitrate content rise faster with the increase of soil temperature.⑶Under the water single pit irrigation condition of water temperature, thelaw of nitrogen migration, main show is:①On the vertical distribution of soilammonium nitrogen content show a trend of decrease after the first increase.Irrigation water temperature20oC when the corresponding ammonium nitrogenpeak is more than15oCunder ammonium nitrogen peak. Soil ammoniumnitrogen content decreases gradually with the increasing of radial distance.②The content of nitrate distribution has the characteristics of the high middlewhile the low around. The soil nitrate content gradually increased with the timecontinues. The content of nitrate decreases with the increasing of radial distance.In the soil wetting front edge, the content of nitrate reaches the maximum. In therange of15—20oC, with the increase of water temperature, the nitrateconcentration increases.⑷The main transport way of ammonium nitrogen is migration, most ofthe ammonium nitrogen concentrated in the inside of moist body. The migrationpatterns of nitrate nitrogen is mainly composed of convection, most of nitrate concentrated at the edges of the wet body.更多还原