基于土壤水分下限的灵武长枣微孔渗灌灌溉制度研究

为探明土壤水分下限对灵武长枣微孔渗灌的影响及确定各生育时期的最佳灌水量,以6年生灵武长枣为研究对象,采用GC-003物联网控制和土壤水分传感器监测系统,对枣树4个生育时期分别设置不同的土壤水分下限,共6个处理,研究枣树光合特性、形态指标的变化,产量、水分利用效率与耗水规律、灌水量之间的关系。结果表明,开花座果期和果实膨大期,土壤水分下限的提高有利于枣树光合作用;萌芽展叶期降低土壤水分下限和开花座果期提高土壤水分下限有利于提高枣树形态指标;T6处理(土壤水分下限萌芽展叶期为65%θf(θf为田间持水率)、开花座果期为75%θf、果实膨大期为75%θf、果实成熟期为65%θf)在各生育时期土壤水分下限较高,与其他处理的光合特性和形态指标均有显著性差异(P<0.05)。随着土壤水分下限的增加,枣树耗水量、产量随之增加;T6处理耗水量、产量最高,T3处理(土壤水分下限萌芽展叶期为55%θf、开花座果期为75%θf、果实膨大期为65%θf、果实成熟期为65%θf)的水分利用效率最佳;T3与T6处理的产量无显著差异(P>0.05),T6处理产量仅比T3处理高5.68%(2018年)、0.90%(2019年),T3处理较T6处理灌水量分别降低了22.57%(2018年)、13.59%(2019年)。因此,枣树各生育时期最适宜的土壤水分下限分别为:萌芽展叶期55%θf、开花座果期75%θf、果实膨大期65%θf、果实成熟期65%θf,上限均为90%θf。本研究结果可为微孔渗灌种植宁夏灵武长枣和水分管理提供科学依据。

Irrigation Schedule of Microporous Infiltration Irrigation for Lingwu Jujube Based on Lower Limit of Soil Moisture

In order to find out the effect of lower limit of soil moisture control on microporous infiltration irrigation of Lingwuchangzao (Ziziphus jujuba Mill.cv. ‘Lingwuchangzao’) and the optimal irrigation amount in each growth period, the six-year-old Lingwuchangzao was used as the research object. Adopting the GC-003 Internet of Things control system and soil moisture sensor monitoring, six different treatments for different lower limits of soil moisture were set for the four growth periods of jujube trees. The relationship between the change of photosynthetic characteristics, and morphological indicators, water use efficiency, yield, water consumption law and irrigation water amount of jujube trees was studied. The results showed that the increase of lower soil water limit during flowering and fruiting bearing periods and during fruit expansion was beneficial to the photosynthesis of jujube trees;the decrease of lower water limit during sprouting and leaf spreading period and the increase of lower water limit during flowering and fruit bearing period were favorable for the growth of morphological indicators of jujube trees. T6 treatment, that was, the lower limits of soil moisture during sprouting and leaf spreading period was 65%θf(θf was field water holding capacity), and during flowering and fruiting bearing period was 75%θf, during fruit expansion was 75%θf, and during fruit maturation was 65%θf, the lower limit was higher in each growth period, which had significantly different photosynthetic characteristics and morphological indicators from other treatments (P<0.05). With the increase of the lower water limit, the water consumption and yield of jujube trees were increased. The water consumption and yield of T6 treatment were the highest, but the water use efficiency of T3 treatment(the lower limits of soil moisture during sprouting and leaf spreading period was 55%θf, during flowering and fruiting period was 75%θf, during fruit expansion was 65%θf, and during fruit maturation was 65%θf)was the best, and there was no significant difference with the yield of T6 treatment(P>0.05). The yield of T6 treatment was only 5.68% (2018) and 0.90% (2019) higher than that of T3 treatment. Compared with T6 treatment, T3 treatment decreased the irrigation water volume by 22.57% (2018) and 13.59% (2019). The most suitable lower limit of irrigation water during the four growth periods of jujube were: during sprouting and leaf spreading period was 55% θf, during flowering and fruiting bearing period was 75%θf, during fruit expansion was 65%θf, and during fruit maturation was 65%θf, and all the upper limit were 90% θf. The study results can provide scientific basis for planting Ningxia Lingwuchangzao with microporous infiltration irrigation and water management.