不同覆盖方式对旱地果园水热特征的影响

The effects of different mulching way on soil water thermal characteristics in pear orchard in the arid area

采用垄膜覆盖(T1)、覆草(T2)和免耕无覆盖(T3)等方法,测定分析陇东旱地果园水热状况,结果表明,0—60 cm土壤温度全年T1最高,萌芽开花期至果实膨大期T2温度最低,新梢停止生长期至落叶期T3温度最低。T1地表和20 cm土壤最高温度出现在6月上旬,40 cm和60 cm出现在8月上旬,表现为浅层(0—40 cm)最高温度出现提前,而T2和T3不同土层最高温度均在8月上旬。0—25 cm不同处理土壤温度表现为晴天最高,雨天最低。除7月至8月土壤温差以T1最大外,其余时期均以T3最大,全年T2温差最小。梨树生长前期(4—6月),T3土壤含水量最小,7月以后,T3最高。梨年生长周期中,T1土壤含水量变化最小,T3最大。不同土层T1土壤容重最小,孔隙度最大,T3土壤容重最大,孔隙度最小;0—120 cm土层T1和T3土壤容重均表现为先升后降,T2为先降后稳定变化的特点。不同处理土壤营养元素含量随时间变化而降低,T3降幅最大。地面覆盖减缓了土壤养分的流失,同时增加了土壤铁、锌、硼等元素含量。

By adopting the ridge film mulching （ T1 ）, wheatgrass mulching （ T2 ） and zero tillage without cover （ T3 ） method. To determine and analyze the soil temperature and moisture in a year changes in dry land pear orchard in eastern Gansu. The results show that the soil temperature of T1 is highest in 0-60cm soil horizon in a year. During bud sprouting and flowering to the growth stage of the fruit, the soil temperature of T2 is lowest, and T3 is lowest which new shoots stop growing period to leaf fall period.T1 treatment which The highest temperature of the surface and 20cm soil appears in early June, but 40 em and 60cm appeared in early August. It was concluded that the highest temperature of the shallow layer （0-40 cm） of T1 appears in advance, while the highest temperature of different soil layer of T2 and T3 are in early August. In 0-25cm soil horizon, different treatment soil temperature performance for sunny is highest, lowest rainy day. The soil temperature difference of T1 from July to August is maximum, and T3 is maximum in the remaining time. In a year, the soil temperature difference of T2 is minimum. At growth prophase （4-6 months） of pear tree, the soil moisture content of T3 is minimum. After the July, the soil moisture content of T3 is highest.Annual growth cycle of pear tree, the soil moisture content change of T1 is minimum, and T3 is maximum. The soil bulk density of T1 with different soil horizon is minimum and its soil porosity is maximum. T3 is contrary. In 0-120 em soil horizon, the soil bulk density of T1 and T3 treatment are performing first rises then falls, but T2 treatment is the first drop then stable change. The soil nutrient element contents of different treatment with the time change is reduced, the range of T3 is biggest. Mulching slow down loss speed of the soil nutrients, and also increase the soil trace element contents of iron, zinc, boron, etc.