南疆设施番茄低压微润灌灌水技术指标及其耗水特性研究

dSouth Xinjiang has dry climate and large evaporation and little rainfall which is belonging to the extreme arid area of inland. Irrigate by surface irrigation manner is easy to cause the soil salinity accumulation in facility because the strong evaporation in soil surface and water loss quickly, at the same time, the water holding capacity of desert soil characteristics is so poor that result in a reduced of soil moisture availability, on the basis of South Xinjiang special climate and soil conditions, this project introduces the technique of moistube-irrigation in low pressure which is appropriate to the irrigation facilities of South Xinjiang, and Start from the hydraulic properties of moistube-irrigation in low pressure, irrigation technique index, water consumption character of protected cultivated tomato, water use efficiency, physiological characteristics and quality, study on the relationship between the pressure head, flow and soil water potential, effects of soil parameters on soil water infiltration and wetting front transport properties, evapotranspiration and water demand law at different stages of protected cultivated tomato, effect of irrigating by moistube-irrigation in low pressure on the quality and physiological characteristic of protected cultivated tomato, find the characteristics of soil moisture diffusivity and movement regulation which irrigate by moistube-irrigation in low pressure, physiological regulatory mechanisms and quality change of protected cultivated tomato, reveal the irrigation technique index and water consumption characteristics of protected cultivated tomato which irrigate by moistube-irrigation in low pressure, establish the technology model of high efficiency water-saving facilities of moistube-irrigation in low pressure, the research results can provide the theoretic foundation and design parameter of the system for the technology of moistube-irrigation in low pressure which is recommendable to be used in South Xinjiang protected cultivation.

南疆地区气候干燥、年蒸发量大，降水量稀少，属于内陆极端干旱区。地面灌溉方式由于土壤表层蒸发强烈、失水较快，容易引起设施内土壤积盐，同时，荒漠性土壤保水性差的特性，也降低了土壤水分的有效性。本项目基于南疆特殊的气候和土壤条件，引入了适宜南疆设施灌溉的低压微润灌技术，并从低压微润灌水力学特性、灌水技术指标、设施番茄耗水特性、水分利用效率及其生理特性和品质入手，研究低压微润灌压力水头、流量及土壤水势间的相互关系、土壤参数对土壤水分入渗及湿润锋运移特性的影响、设施番茄不同生育阶段的蒸散耗水量及需水规律、低压微润灌对设施番茄生理特性及品质的影响，探明低压微润灌土壤水分扩散特性及运移规律、设施番茄生理调节机制及其品质变化，揭示设施番茄低压微润灌灌水技术指标及其耗水特性，建立高效低耗节水的设施低压微润灌灌溉技术模式，研究成果将为微润灌技术在南疆设施生产中的推广应用提供理论依据和系统设计参数。

南疆地区气候干燥，属于内陆极端干旱区。地面灌溉方式由于土壤表层蒸发强烈、荒漠性土壤保水性差的特性，土壤水分的有效性较低。本项目基于南疆特殊的气候和土壤条件，针对微润灌条件下土壤水盐运移规律及番茄耗水特性及生理生长等指标进行了研究，并提出适宜南疆设施番茄的微润灌灌溉水头压力和微润带埋设深度。根据研究目标，项目组开展了连续4年的微润灌灌溉试验，主要研究结论如下：.（1）随着水头压力的提高，湿润区形状呈现由椭圆形向圆形转化的趋势；土壤湿润区位置以微润带埋设位置为中心，左右呈对称关系，灌水均匀性优于滴灌；提高水头压力，可有效增大土壤湿润区面积和土壤含水率；以微润带为中心，形成有效的土壤脱盐区，土壤脱盐区面积及脱盐率与水头压力呈正相关关系；随着微润带埋设深度的增加，脱盐区内的土壤平均含盐量逐渐升高，脱盐率逐渐下降；.（2）在番茄生育期内，土壤含水率、储水量及湿润区范围逐渐下降，下降量及下降幅度与水头压力呈反比关系，水头压力越高，土壤水分环境越稳定；番茄开花坐果期和结果盛期耗水量较大，苗期和结果末期耗水量相对较低，生育期内耗水量随着水头压力的提高逐渐增大；植株生长量及生长速率与水头压力呈正相关关系，润带埋设深度15 cm时对植株生长较为有利；2 m水头压力，产量及水分利用效率最大。.（3）水头压力处于1～2m之间，番茄总根长、总根表面积及总根体积均随着水头压力的提高逐渐增大， 2.5 m水头压力，总根长增加不明显，总根体积及总根表面积具有明显下降趋势；微润带埋深15 cm，番茄总根长、总表面积等根系特征参数明显高于埋深10 cm和埋深20 cm；可溶性固形物、维生素C及可溶性糖均随着水头压力的提高，呈现先增大后降低趋势，有机酸含量随着水头压力的提高，逐渐降低。可溶性固形物、维生素C及可溶性糖随着微润带埋设深度的增加逐渐下降，埋深15 cm下降幅度较小，埋深20 cm，下降幅度较大。