黄土旱塬集雨保墒措施对苹果发育和土壤水分变化的影响

为了有效缓解黄土旱塬区苹果园深层干燥化,保证苹果产业的可持续发展,该文选取甘肃镇原盛果期苹果园,连续6 a定位测定了黑色地膜覆盖和黑色地膜覆盖+立体化入渗对苹果产量、新梢生长量和土壤含水量等指标。分析了6 a不同处理苹果产量、形态指标和不同生育期果园0~500 cm土壤相对水分亏缺指数的变化,研究结果表明:黑色地膜覆盖+立体化入渗较对照平均增产16.49%,优果率增加8.91%;300~500 cm土壤含水量较对照增加0.50~2.63百分点,降水入渗深度达到了480 cm,在60~500 cm水分相对亏缺指数为-0.05~-0.12,最大补偿区域为200~300 cm,水分补偿为春季花期和收获期。因此,黑色地膜覆盖+立体化入渗技术提高了果树产量与优果率,改善了果园深层水分状况,缓解土壤深层干燥化。

Effects of rain-harvesting and moisture-conserving measures on apple tree growth and development and soil water moisture in arid areas of loess plateau

The arid areas of the loess plateau represent the second largest apple advantage production area in China.However, the desiccation in deep soil layers of the apple gardens in these areas constrains the sustained development of apple industry.Therefore, it is of vital importance to study the desiccation in deep soil layers.This research aims to effectively alleviate the desiccation in deep soil layers of the apple gardens in arid areas of the loess plateau, and to ensure the sustainable development of apple industry.From 2009 to 2014, gardens with full bearing period (20 years) apple trees in Zhenyuan County, Gansu Province were selected as testing areas.The treatments included rain-harvesting patterns as black film mulching and black film mulching+ Rainfall collection tri-infiltration, which made the outside of the main trunk incline ramp, covered with black film, was in close contact with the ground compaction and ease of catchment.The tree disks been covering about Apr-20, and adopting the cultivating pattern of local farmers as controlled group (CK).In consecutive 6 years, such indexes as apple yield, new shoot growth and soil water content were localized and measured within soil layer depths of 0~500 cm, and morphological indexes of apple trees were periodically measured.Changes in apple yield, morphological indexes and relative water deficit indexes within soil layer depths of 0~500 cm at different growth stages were analyzed.The result showed that compared with those under CK and black film mulching, black film mulching+ Rainfall collection tri-infiltration made average apple yield within 6 years increase by 16.49% and 3.63%, respectively, and the rate of optimal fruit improve by 8.91% and 3.86%, respectively, so the technology prevented apple tree from yield fluctuation during years.The proportion of short shoots in black film mulching+ Rainfall collection tri-infiltration was significantly higher than under both black film mulching and CK, and enhanced by 22.75% and 11.84%, respectively.Compared with those under CK, soil water contents within soil layer depths of 300~500 cm increased by 0.50%~2.63% in black film mulching+Rainfall collection tri-infiltration.and its infiltration depth of precipitation amounts to 480cm, which was 120cm and 280 cm deeper than those under black film mulching and CK, respectively.Compared with those under black film mulching and CK, average water storage in black film mulching+Rainfall collection tri-infiltration, increased by 6.2 mm and 17.3 mm, respectively, Because the black mulching can suppress evaporation of moisture invalid, lay a 40 cm depth of infiltration, increase the accumulative and average depth of infiltration, change the physical properties of the soil, and improve root growth environment, fruit morphology index has been effectively improved.Compared with that under CK, relative water deficit indexes reached -0.038 and -0.054 0, respectively under black film mulching and black film mulching+ Rainfall collection tri-infiltration, which indicated that both treatments repressed water deficit within soil layer depths of 0~500 cm and exerted moisture-conserving effects on soil water content in apple gardens.Black film mulching+ Rainfall collection tri-infiltration made infiltration depth of precipitation remain balanced, and soil water content in the main areas of root system distribution remained unabated.Their relative water deficit indexes within soil layer depths of 60~500 cm ranged within -0.12~-0.05, and the maximum compensation depths range was within 200~300 cm.Water compensations occur at the flowering period in spring and the harvesting period, can effectively relieve drought in next spring.Therefore, extruded infiltration + black film mulching can enhance apple yield and optimal fruit rate, improve water conditions and alleviates desiccation in deep soil layers of apple gardens through ensuring water consumption for apple tree growth during drought periods in spring and winter.