【作者】 孔东；

【导师】 史海滨； 陈亚新；

【作者基本信息】 内蒙古农业大学 ， 农业水土工程， 2004， 博士

【摘要】 水资源短缺已成为影响社会、经济、生态环境持续发展的重要制约因素。本研究以我国西部内蒙古河套灌区如何实施节水灌溉同时又要防治土壤盐渍化，即“节水防盐”的双重目标为研究对象，对当地主要经济作物油料向日葵（Helianthus annuus L.），采用田间试验和苗期盆栽相结合的方法，通过对河套灌区不同盐渍化土壤进行的节水灌溉试验，分析了不同水分、盐分胁迫对向日葵生长发育的影响。对作物生理生育指标（株高、干物质量、叶面积指数、叶水势、光合作用和籽实产量等）进行了统计分析以探索作物水盐响应规律，对净光合速率各影响因子进行了相关分析及路径分析，在此基础上，引进SWAP模型探讨了向日葵在不同水分、盐分胁迫条件下作物实际腾发规律，参照常用作物-水模型引入盐分胁迫因子建立了作物-水-盐响应模型。向日葵种籽对盐分具有一定的耐盐性，而土壤含盐不同对种籽的萌发时间和出苗率影响不同。在轻度(<0.3%)盐渍土和中度(0.3~0.5%)盐渍土中都可以正常出苗，但重度(>.5%)盐渍土对向日葵种子的萌发有严重的抑制作用，且出苗时间比轻中度晚2~5天；含盐量达到0.8%时，超过其耐盐能力，种子不能萌发。向日葵各个生育阶段对盐分的反应并不相同。苗期对盐分较敏感，作物各生育指标对盐分的响应很大。在现蕾期土壤中含有适量的盐分（0.3~0.4%），作物对苗期受盐分影响有补偿性生长。但当盐分含量超过0.5%范围后，同等条件下补偿生长不大或无补偿生长，会与其它处理之间的植株生长差距加大。全生育期含盐高于0.5%严重抑制作物生长，最高减产率达45.52%。在本试验条件下，用LI-6400型光合仪测定了向日葵在不同盐分胁迫下现蕾期的光合速率日变化及其影响因子，并在仅变化光强和温度的状态下，测定其光合速率及其影响因子的变化。结果表明，3种不同盐分处理其净光合速率日变化曲线均为单峰曲线，且随着含盐量的增加，其光合速率的总体趋势呈现下降。在不同盐分胁迫下叶片对高温和强光的适应性不同，各处理光合速率随光强的改变差异不显著，随温度的改变则存在显著差异性。通过相关及路径分析表明，光强并不是Pn的主要限制因素。0.29%盐分处理Pn的下降主要受气孔因素的影响，0.39%盐分处理Pn的下降则是受气孔因素及气孔与非气孔因素协同作用的结果，0.68%盐分处理Pn的下降主要是非气孔因素和气孔与非气孔因素协同作用的影响。作物群体叶面积、叶片水势和产量随土壤含盐量的增加而呈下降趋势。在不同国家自然科学基金资助项目（50269002）资助。<WP=3>水盐处理下，含水率在(65~75%)θfc，含盐量在(0.3~0.5)%时对向日葵的生长及最终产量的形成影响不大，其叶面积指数、叶水势和产量与轻度盐土（<0.3%），分别相差5.90%、0.27 MPa和5.92%。而含盐量超过0.5%时，高土壤水分水平(65~75%)θfc下也对向日葵的生长及最终产量的形成产生严重抑制，其产量仅是轻盐土的57.39%，低水分处理(55~65%)减产率达62.32%。通过3年的田间对比试验得出，在盐渍化土壤中进行节水灌溉其盐分临界值不应高于0.5%。在轻度盐分(<0.3%)土壤中，当土壤水分含量过高（>5%θfc）时，不仅不会对作物产生促进作用，反而抑制了作物的生长。在苗期其适宜含水率为（55~65%）θfc，现蕾期的灌水量则制约作物的生长，其适宜含水率为（65~75%）θfc。中度含盐土壤中(0.3~0.5%)土壤含水量在整个生育期保持在 (65~75%)θfc即可保持作物良好的生长态势。重度含盐土壤中(>0.5%)，随着水分胁迫程度的增加和胁迫时间的延长，株高的生长受到的抑制越严重。因此重度含盐土壤中土壤含水量在整个生育期其水分含量最好保持在75%θfc以上。在本试验条件下，引入了SWAP2.0模型探讨了向日葵在不同水盐处理下作物需水量的计算。通过模拟计算将根系层土壤含水率的模拟值与实测值进行比较其结果表明拟合效果很好。因此SWAP模型是求解作物实际腾发量的一个有效工具。根据SWAP模型模拟的结果，选取了4个国际上应用最多的作物水分响应模型，在以腾发量（ET）和蒸腾量（T）为自变量计算所得的敏感指数中，Blank模型的回归效果最显著且与前面统计分析的结果相吻合，最能体现本试验条件下作物与水分的定量关系。根据相关试验资料求得，各生育阶段向日葵土壤临界电导率和可容忍电导率值。根据所得各生育阶段土壤实测盐分胁迫因子、实测产量和实际腾发量，参照4个常见的作物水模型，以向日葵实际腾发量为自变量，引入盐分胁迫因子构建了Jensen型、Blank型、Singh型和Minhas型作物-水-盐响应模型。求得4个模型中各生育阶段水分、盐分敏感指数。通过实测资料检验确认Blank型作物-水-盐响应模型具有较高精度，且与向日葵的生长规律相一致，可以较准确地揭示作物产量与土壤水分、盐分的量化关系，在此基础上制定了不同盐渍化土壤中的灌溉制度，可用于指导农业生产。 本研究探索了含盐土壤中进行节水灌溉，作物对水盐双重胁迫时的响应规律，对于本研究展开的节水灌溉试验，基于灌溉方式、土壤质地以及灌溉水量的多少和灌溉时间的控制和选择上实现了一定的节水意义，可为在土壤含盐条件下进行节水灌溉研究提供一定的理论基础，用于实际生产。更多还原

【Abstract】 Serious lack of the water resources had become the importance factor that will influence the development of society, economy and entironment. This project research how to execution of water-saving irrigation and prevention saline soil at the same time in Hetao Irrigation District in the Inner Mongolia in the western of China, the oil sunflower which native main crop ( Helianthus annuus L.) was planted in the field and pot, growth process of sunflower was studied under different water-salt stress condition through insufficient irrigation under different saline soil. We investigated crop response to water-salt stress regularity through growth and physiological index of plant (height of plant, dry matter accumulation, index of leaves, leaf potential, photosynthesis and yield) on the base of statistical analysis, the relation between photosynthetic rate and its factors was analyzed by the correlation analysis and path analysis. On the basis of this, import the model of SWAP to seek after the regulation of sunflower evapo-transpiration under difference water-salt stress, established a model of crop response to water-salt stress that import the factor of salt stress through consult in common use the model of crop to water.The effect of germinating time and rate emergence are different in soil with different salt content. No effect of germinating time and rate emergence in the light and middle saline soil, and limited seriously in heavy saline soil, 2~5 days later than that of seed in light and middle saline soil. Seed could not germinate while salt content exceed 0.8% in the soil.It has different response to salt content during the difference growth stage. It is sensitive to salt in seeding stage, the physiological indexes of crop is respondent to salt obviously. Ability of tolerance salt is increased during squaring period, compensate growth is showed for the effect of seeding period. A little compensate growth or no compensate growth in the same condition and it will increase growth gap of crop with other treatments if exceeding 0.5% salt content. It will restrain growth of sunflower and decrease yield of 45.52% while exceeding 0.5% salt content in the total growth stage. Under field conditions, the sunflower grown in different salt level was studied to photosynthetic rate (Pn) and its influence factors during squaring stage in saline soil. The project is supported by National Natural Science Fund (No. 50269002).<WP=5>Diurnal changes of Pn and its major factors in modified light intensity and temperature measured respectively with LI-6400. The results indicated that the Pn of three treatments varied as a single-peaked curve and was decreased while salt content increasing. Under difference salt stress, difference response on high temperature and strong light of sunflower leaf. No effect of photosynthetic rate on difference treatments under the change of PAR, but distinct effect of photosynthetic rate under the change of temperature. The relation between photosynthetic rate and its factors was analyzed by the correlation analysis and path analysis. The results indicated that under difference salt stress, difference factors decreased photosynthetic rate. PAR was not major effect factor to Pn. Pn was controlled by the stomata factor in light salt stress (0.29%). Stomata, stomata and non-stomata factors were controlled mutually while the middle salt stress (0.39%). Under the high salt stress (0.68%), it was controlled by non-stomata factor and stomata and non-stomata factors were controlled mutually.Index of leaves, leaf potential and yield was decreased while soil salinity increasing. In the difference water-salt treatment, it is feasible while soil salinity is 0.2-0.3% and soil moisture is (55~65%)θfc. It did certain harm to crop growth under soil moisture is(65~75%)θfc and soil salinity is 0.3-0.5%, but the harm was little. Index of leaves, leaf potential and yield was 5.90%, 0.27MPa, and 5.92% of the light salt stress respectively. But when soil salinity >0.5%, although high water treatment (soil moisture更多还原