调亏灌溉促进涌泉根灌枣树生长提高产量

调亏灌溉是作物通过主动调节自身营养达到节水和提高果实产量等目的。该文通过微灌枣树试验,研究了涌泉根灌下调亏灌溉对山地枣树生长与产量的影响。2013年分别在萌芽展叶期和开花坐果期进行轻度、中度和重度3个调亏水平调亏处理试验。结果表明:轻度和中度水分亏缺均对枣吊的生长起到抑制作用,能够有效减少新梢生长及夏季修剪量,而对枣树果实的生长起到了促进作用,达到增产的目的。轻度、中度和重度水分亏缺与充分灌溉相比,枣吊长度分别减少了7.2%、13.2%和19.7%(P0.05)。枣树坐果期,果实生长缓慢,轻度、中度、重度调亏以及充分灌溉果实生长量分别为果实最终体积的14.5%、14.1%、13.8%和13.5%。与充分灌溉相比,轻度调亏的枣树最终产量提高了22.1%(P0.05)。可见,调亏灌溉会较为显著的影响枣树的最终产量。适宜的水分亏缺对枣树果实生长与产量有促进作用,且提高了水分利用率。

Regulated deficit irrigation promoting growth and increasing fruit yield of jujube trees

Abstract: Drought and water shortage have been the main factors restricting the sustainable and healthy development of jujube industry in the Northern Shaanxi Province. In the stage of crop growth, regulated deficit irrigation (RDI) can balance the degree of nutrition among each organ of plants, and lead to high fruit yield and quality and water use efficiency. This study investigated the effect of RDI on the jujube growth and its fruit yield under surge-root irrigation. The jujube (Ziziphus jujube Mill) widely cultivated in Yulin of Northern Shaanxi Province was selected for the field experiment in a jujube demonstration zone orchard in Yuanzhi village, Mizhi Country, in 2013. Three treatments of water deficit were designed in sprout leaves period and flowing and fruit-setting stage, respectively. The relative soil moisture of 70%, 60%, and 40% simulated mild, moderate and severe water deficit. The full irrigation with relative soil moisture of 80% was taken as control. During the experiment, the meteorological factors, including the wind speed, wind direction, air temperature, air relative humidity, atmospheric pressure, solar radiation intensity, and rainfall were monitored. Soil moisture was measured. Jujube panicle length, and vertical and horizontal diameter of jujube fruit were measured. The average weight of 100 jujubes was determined. The results showed that compared to the full irrigation, the mean soil moisture in 0-60 cm depth were reduced by 8.9%, 14.4% and 22.4% (P<0.05) for the treatments of mild, moderate, and severe RDI respectively. Compared to full irrigation, the jujube panicle length were reduced by 7.2%, 13.2% and 19.7% (P<0.05) for the treatments of mild, moderate, and severe RDI, respectively. During the period of the flowing and fruit-setting stage, the fruit growth was slow, which only reached 14.5% , 14.1%, 13.8% and 13.5% of the final volume of jujube fruit for the treatments of mild, moderate, severe RDI and full irrigation fruits, respectively. About 65% of jujube volume grew in the fruit enlargement stage. Compared with full irrigation, the yield of jujube has increased by 22.1% and 16.7% for mild and moderate RDI, respectively, but decreased by 9.5% for severe RDI. The jujube volume was highest for the mild RDI, followed by moderate RDI, full irrigation and severe RDI. The moderate RDI had the highest water use efficiency of 2.32 kg/m3, but the severe RDI had the lowest water use efficiency of 1.28 kg/m3. It suggested that the mild and moderate water deficit played an inhibitory effect on the growth of jujube panicle, and could reduce the amount of shoot growth and summer pruning. However, they could promote the growth of the fruit and increase yield during the sprout leaves period and flowing and fruit-setting stage of jujube. Among all the treatments, the mild water deficit of RDI had the best effects on jujube growth and yield.