【作者】 高鹏程；

【导师】 张一平；

【作者基本信息】 西北农林科技大学 ， 土壤学， 2002， 博士

【摘要】 旱地农业是世界范围内普遍关注的重大农业问题，我国干旱、半干旱地区占全国土地面积的52.5％，其生产力的高低，对我国农业生产有举足轻重的作用。干旱地区，特别是我国西北干旱地区自然条件的突出特点是干旱缺水，昼夜及季节温差大，显然旱地农田土壤水分散失、养分转化、作物养分吸收和作物生长状况必然会较突出地受到水热条件的影响。因此，研究水热条件对土壤、作物性状影响，对旱地农田生产有十分重要的意义。本文通过室内和田间试验研究对土壤水分蒸发，肥料氮素挥发转化及谷苗生长和氮素吸收的水热耦合效应及其定量关系和能量特征进行了系统探讨。 本文以水热耦合效应为主题，基于研究对象的动态变化特征，应用化学动力学原理，建立了含水、热因子以及水热耦合效应的土壤水分蒸发、肥料氨挥发动力学方程，以及施入土壤中的尿素转化为铵态氮的动力学型方程；为使水势—含水量关系式更好适应变温条件应用的要求，建立了含温度因子直接表征土壤持水曲线的经验方程，以及含温度因子的谷苗叶水势与土壤含水量关系经验方程。在所研究各种体系水热耦合效应基础上，提出了水热效应零值参数概念，揭示了水热耦合效应零值现象及水热耦合作用下土壤水分蒸发，肥料氮挥发和谷苗生长及氮素吸收的能量特征。此外，在研究中获得了作物生长水热耦合效应限制温度等对调节作物生长和合理施用肥料具有应有价值和指导意义的一些判据和指标。 通过研究，所得主要结论如下： 1．土壤水分累积蒸发量符合Elovich动力学方程Y=a+blnt，方程中系数与温度和土壤初始含水量有关，a、b值随土壤初始含水量和温度增高而增大，由此得到含温度因子或土壤湿度因子的土壤水分蒸发动力学方程，并建立了含水、热因子的土壤水分蒸发水热耦合效应动力学方程，为含环境影响因子动力学方程的研究和应用提供了新的信息。同时通过田间试验研究得到田间土壤水分蒸散与土壤储水量、气温及谷苗生物量之间水热耦合效应模型。 2．肥料氨累积挥发量符合零级反应动力学方程Y=a+bt，方程中系数与肥料种类、温度和土壤含水量有关，碳铵a、b值均比硫酸铵高，土壤含水量增大，a、b值降低，温度升高，a、b值增大，并由此得到含温度或土壤湿度因子的肥料氨挥发动力学方程，并建立了含水、热因子的肥料氨挥发水热耦合效应动力学方程。 3．通过室内试验，进一步证实了土壤水分蒸发引发氨挥发的现象，并对水分蒸发引发氨挥发进行了定量描述。此外，通过回归分析还建立了表征施入土壤中尿素转化为铵态氮的动力学型方程，其参数均与土壤水分、温度有关，并得到这些参数的水热耦合效应关系式。 4．盆栽试验对谷苗生长与水热条件定量关系的系统研究表明，谷苗含水量、叶片水势、含氮量、生长速率等均与温度和土壤含水量有关，土壤含水量增大，这些值均增大，温度由15℃升高至25℃时，这些值也均增大，温度继续升高至30℃，这些值均降低，通过回归分析得到这些项目的水热祸合效应模型。同时，通过田间试验，进一步证实温度与土壤含水量的祸合效应，并得到田间谷苗氮含量相对增长量和田间土壤水分蒸散量水热祸合模型，为定量研究水热祸合效应提供了新的依据。 5.通过对不同温度下土壤水吸力与土壤含水量关系的研究，依据土壤持水曲线经验方程e=aS一，建立了含温度因子直接表征土壤持水曲线的经验方程e=e‘rbt，s一‘。‘，”;此外通过回归分析建立了含温度因子的谷苗叶水势与土壤含水量关系的经验方程，平叶=一e‘a一b与土一‘。‘””，利于实践中运用。 6.通过对所得水热祸合效应模型的研究，揭示了水热祸合效应零值现象，提出了水热效应零值参数概念，为水热藕合效应研究和农田水热调控提供了新的判据。 7.应用Arrhenius方程和过渡态理论对水热祸合作用下土壤水分蒸发、肥料氨挥发和谷苗生长及氮素吸收的能量特征进行研究，结果表明活化能、活化自由能、活化烩是表征其能量特征的重要能量参数。 8.吹风条件和覆盖条件下土壤水分累积蒸发量符合Elovich动力学方程，研究结果显示吹风时间长短与吹风强度对土壤水分初始蒸发量影响较大，对土壤水分蒸发速度影响较小，在土壤含水量较高时，增加覆盖量对抑制土壤水分蒸发有明显作用。 9.通过水热祸合效应研究，获得了对调节作物生长，合理使用肥料具有应用价值和指导意义的一些判据和指标，其中主要有作物生长水热祸合效应限制温度、作物生长水热祸合效应限制土壤湿度，作物低温吸氮适宜土壤湿度，最大水分引发氨挥发率土壤湿度，以及氨挥发湿度系数极值时间等。更多还原

【Abstract】 Arid Farmland is an important issue paid close attention to in worldwide, the arid land and semi-arid land cover about 52.5 percent of land in our country, whose productivity is very important for our agriculture. The outstanding natural characteristic in northwest arid region of our country is lacking water, and temperature difference between day and night, so that they are affected greatly by soil water and temperature that moisture vaporizes nutrients transform, crops grow and crops absorb nutrients. So it has a great significance for arid land production to study the effect of water and temperature on the properties of soil and crops. The interaction, quantitative relation and character of energy that moisture vaporize from soil, nitrogen fertilizers transform, crop grows and crop absorbs nitrogen are discussed systematically in this paper through lab and field trial.The dynamics equations of soil water vaporizing and ammonia volatilizing hcluding the factors of water and temperature, and the dynamics-like equation of urea transforming into ammonium nitrogen in soil are founded in the paper, by taking the effect of interaction of water and temperature as subject, the dynamic change character of object studied as basis and using principle of chemical dynamic; The empirio-equations of soil water retention curve including temperature and the empirio-equations including temperature between water potential of millet seedling leaves and soil water are founded in order to make the equation of relation between water potential and water content in soil suit the demand of temperature change much better. Zero-value coefficients about interaction of water and temperature is put forward, Zerovalue phenomenon about interaction of water and temperature and energy character that moisture vaporizes, ammonia volatilizes, millet seeding grows and it absorbs nitrogen are brought to light. In addition, some criterions and targets such as restricting temperature on crops growing affected by interaction of water and temperature, which have very value for adjusting crop growth and using fertilizer, are gotten.The main solutions in the paper are:1. The vaporization of soil water is suit to the dynamic equation as Y=a+blnt, the coefficients in the equation are related to temperature and water content of soil, and the dynamic equation about vaporization including water and temperature and the is developed, which provide some new information for studying and applying dynamic including environmental factors. In addition, the model of interaction of water and temperature between field water vaporization and soil water storage, temperature and millet weight is gotten by field trial.2. The ammonia volatilizing of fertilizer is suit to the dynamic equation as Y=a+bt, thecoefficients in the equation are related to the kind of fertilizer, temperature and water content of soil, and the dynamic equation about ammonia volatilization including water and temperature and the is developed. In addition, the dynamic equation about ammonia fertilizer affected by interaction of water and temperature is gotten.3. The phenomenon about water vaporization-induced ammonia volatilizing is verified, and it is studied quantitatively. In addition the dynamic-like equation about urea in soil transforming into ammonium nitrogen is gotten by regression analysis, and the coefficients are related to water and temperature.4. Water content, water potential of leaves, nitrogen content and growth rate of millet seedhg are all related to temperature and soil water content, their model for interaction of water and temperature is gotten by regression analysis,.5. The empirio-equations of soil water retention curve including temperature is developed on the basis of the empirio-equations of soil water retention curve without temperature by studying the quantitative relation between water absorption capacity and soil water content. In addition, the empirio-equations including temperature of millet seedling and soil water content is got更多还原