不同覆盖处理对旱塬苹果土壤环境因子和水分吸收的影响

Effects of different mulching on soil environmental factors and water utilization of apple in the dry tableland

为了进一步了解覆盖措施对苹果园土壤微生物环境和水分吸收的影响,以6年生‘长富2号’苹果园为试验材料,通过地膜覆盖、秸秆覆盖和地布覆盖3个处理,测定覆盖措施对土壤含水量、地温、土壤微生物数量和功能多样性、土壤有机碳含量,以及树体和土壤稳定同位素含量的影响。结果表明:地膜覆盖处理使浅层土壤含水量较裸地对照处理升高了13.67%,但水分利用效率却有所减小。不同覆盖处理间,随着土壤含水量的降低,深层土壤水分对树体水分供给率越高;秸秆覆盖使土壤细菌、真菌、放线菌和微生物总量以及香农指数分别显著升高到裸地对照的140.58%、536.36%、120.36%、140.40%和123.08%。土壤总有机碳含量在秸秆覆盖后显著升高到裸地对照处理的114.41%。地膜覆盖处理土壤有机碳含量显著低于秸秆覆盖处理,降低到裸地对照的96.89%。综合分析表明,秸秆覆盖处理较地膜和地布覆盖处理更有利于改善树体生长和土壤环境,优化不同土层区域水分合理利用,还可以提高地表降水的有效利用效率。

In order to further understand the effects of mulching measures on soil microbial environment and water utilization in apple orchards,a mulching experiment was conducted using a 6-year-old‘Changfu No.2’apple orchard as the experimental material.Three treatments of plastic film mulching,stalk mulching and fabric mulching were set up to determine the effects of mulching measures on soil water content,ground temperature,soil microbial quantity and functional diversity,soil organic carbon content,and tree and soil stable isotope content(δD,δ13C).The results showed that,compared with the control treatment,the water content of shallow soil was increased by 13.67%,but the water use efficiency was decreased.With the decrease of water content,the utilization rate of deep soil water by roots was higher.Straw mulching significantly increased the total amount of soil bacteria,fungi,actinomyces,microorganisms and Shannon index to 140.58%,536.36%,120.36%,140.40%and 123.08%of those of the control treatment,respectively.Soil total organic carbon content was increased significantly after straw mulching to 114.41%of that of control treatment.Soil organic carbon content under plastic mulching treatment was significantly lower than that under stalk mulching treatment,and was decreased to 96.89%of that under bare soil control.It suggested that,compared with plastic film and fabric mulching,stalk mulching could improve the tree growth and soil environment,optimize the rational utilization of water in different soil layers,and improve the effective utilization efficiency of surface rainfall.