南疆枣树间接地下滴灌条件下根系调控及养分吸收利用机理

The development of forestry and fruit industry has been double meaning in the win-win between economic and ecological benefits in south Xinjiang, and it has already become the pillar industry of local economy. Drip irrigation technique has been widely adopted in jujube fruit trees in south Xinjiang, but conventional surface drip irrigation has presented deficiency with the increased scale of production, such as the crop's root system distribute relatively shallow, and nutrient accumulated in the upper soil layer, which decrease yield and quality of jujube. Root adjustment is a key, which can effect on yield and quality of jujube and it is affected by soil water and nutrients also. How to apply feasible techniques of water-saving irrigation to promot nutrient use efficiency ,yield and quality of jujube by adjustment of root growth which is worth studying. The dwarf and close jujube is taken as the subject of study in this project, adjustment of root growth, yield and quality of jujube and characteristics of nutrient of root region soil effected on different of emitter depth, irrigation quantity and fertilizer rate,which would be studied under indirect subsurface drip irrigation through using investigation on root distribution and plot experiment.The regulation mechanism of root growth and distribution effected on irrigation and fertilization should be elucidate, the mechanism of nutrient uptake by jujube roots should be clarified, the control index of irrigation and fertilization suiting for jujube in south Xinjiang should be proposed for high-efficient nutrient utilizing, high quality and high yield by evaluated regulation effect of technological parameters of indirect subsurface drip on irrigation root distribution, yield and quality of jujube and nutrient uptake and utilization. The result will provide the technical support for the indirect subsurface drip irrigation technology extension as well as efficient and sustainable development of characteristic fruit in south Xinjiang.

林果业在南疆的发展具有经济与生态效益共赢的双重意义，已成为当地经济的支柱产业。滴灌技术在南疆果树灌溉中被广泛采用，但随着其生产规模的增大，不足已凸现，如根系分布较浅、养分易在土壤表层累积等，影响到产量品质的提高。根系调控是影响产量品质的关键，也受水分、养分的影响。如何采用适宜的节水灌溉技术来调控根系生长，提高养分利用率及枣树产量品质是值得研究的问题。本项目以矮化密植红枣为研究对象，采用调查、小区试验相结合的方式，研究间接地下滴灌条件下灌水装置埋深、灌水量和施肥量对根系生长分布的调控作用、对产量品质及根区土壤养分变化特征的影响，阐明灌溉施肥对根系生长分布特征的调控机制；探明根系养分吸收利用机理，评价灌溉施肥技术要素对根系生长分布、产量品质及养分吸收利用的调控效果，提出养分高效优质高产的适宜南疆干旱荒漠区枣树的灌溉施肥控制指标。为间接地下滴灌技术提升及南疆林果业高效、可持续发展提供技术支持。

本项目以矮化密植红枣为研究对象，采用调查、小区试验相结合的方式，研究间接地下滴灌条件下灌水装置埋深、灌水量和施肥量对根系生长分布的调控作用、对产量品质及根区土壤养分变化特征的影响，阐明灌溉施肥对根系生长分布特征的调控机制；阐明灌溉施肥技术要素对根系生长分布、产量品质及养分吸收利用的调控效果，提出养分高效优质高产的适宜南疆干旱荒漠区枣树的灌溉施肥控制指标。以期为间接地下滴灌技术提升及南疆林果业高效、可持续发展提供技术支持。主要研究结果如下：.1）随着导水装置埋深的增加，细根根长密度在垂直方向上分布范围由“浅”到“深”；在水平方向上的分布范围由“宽”到“窄”，增加间接地下滴灌导水装置埋深的可以诱导根系生长由地表向土壤深层生长，细根的分布从“宽浅型”向“深根型”发展。.2）不同施肥量对根系分布的调控中，在导水装置埋深一定的条件下，在垂向上，在0-60cm土层呈现出随着施肥量的增加，各土层的细根（0mm＜d＜2 mm）根长密度和疏导根（2mm＜d＜5 mm）根长密度基本逐渐减小；在水平方向上，不同施肥处理下各土层在水平距离0-40cm的细根根长密度均显著大于水平距离40-80 cm和80-120 cm的细根根长密度。.3）随着导水装置埋深和施肥量的增加，显著增加了20-40cm、40-60cm土层的速效氮、速效钾含量，尤其是有效地增加了土层20-40cm速效磷的含量；导水装置埋深一定时，红枣产量和红枣果实中Vc、蛋白质和还原性糖的含量随施肥量的增加基本呈增加趋势；当施肥量一定时，随着导水装置埋深的增加，产量呈现先增加后减少的趋势，有机酸呈现逐步减少的趋势。