Effects Of Different Mulching Patterns On Growth Of Apple Tree And The Soil Physicochemical Properties

This experiment was chosen at Qianyang Apple Study Demonstration Station in hilly andgully region of Weibei dryland, Five treatments were set up, including white film mulching,black film mulching, ground cover mulching, ryegrass mulching and cleaning tillage to studyeffects of different mulching patterns on growth of apple tree and the soil Physicochemicalproperties.1. The adjustment of mulching on soil temperature is mainly to upper layer and theregulatory function of temperature variation is more and more less as soil depth increased.The effect of ground cover on soil temperature is the best. The temperature of four seasons ofa year reaches23.72℃,29.73℃,14.49℃,2.01℃respectively, which has the advantages ofincreasing temperature in spring and autumn, deceasing temperature in summer and keepingtemperature in winter.2. Different mulching treatments increase soil moisture to different extent. Comparingeach of the four mulching treatments with cleaning tillage, the moisture content of differentsoil layers of the former is higher than the latter. Among the mulching treatments, the groundcover has the highest percentage of average moisture content of soil layer from0to80cm(16.38％). The percentage of ryegrass mulching, white film mulching and black filmmulching is16.01%,15.86%, and15.41%respectively, which is higher than2.14%、1.77%、1.17%and1.62%respectively compared with cleaning tillage (14.24%).3. All of the different mulching patterns can increase respiration intensity of soil，Andthe higher the soil temperature is, the more intense the soil respiration is，Besides, as timegoes by, the effects of white film mulching on respiration intensity of soil is more and moreless. All the treatments, the effects of black cover mulching and ground cloth are the best, andwhite cover mulching and straw covering are better. In June, the measured value of this Juneshows as follows: black mulching film (0.96g/m2/h), white mulching film (0.76g/m2/h),ground cloth (0.6g/m2/h), straw covering (0.44g/m2/h), and cleaning tillage (0.16g/m2/h). Theformer four cover mulching ways are higher than cleaning tillage by0.78g/m2/h,0.6g/m2/h, 0.44g/m2/h and0.28g/m2/h respectively. In August, the measured value shows as follows:black mulching film (1g/m2/h), ground cover (0.98g/m2/h), white mulching film (0.58g/m2/h),ryegrass mulching (0.56g/m2/h), and clean tillage (0.27g/m2/h). The former four covermulching ways are higher than cleaning tillage by0.73g/m2/h,0.71g/m2/h,0.31g/m2/h and0.29g/m2/h respectively.4. All of the different mulching patterns can promote the growth of saplings, whichresults to the growth indications of each tree are sharply higher than cleaning tillage. Any ofthe different mulching patterns has positive effect on the growth of apple trees. In2013, fromApril30th to July15th, average increase of branch length of each treatment is as follows:ryegrass mulching (6.73cm), white film mulching (6.65cm), ground cover mulching (6.35cm), black film mulching (5.83cm) and cleaning tillage (5.47cm). The former four mulchingpatterns are higher than cleaning tillage by1.26cm,1.18cm,0.88cm and0.31cm respectively.Up to August15th, leaf area of each treatment leaf is as follows: black film mulching(3858.13mm2), ground cover mulching (3480.56mm2), ryegrass mulching (3408.21mm2)white film mulching (2928.18mm2) and cleaning tillage (2703.75mm2)，which increases by42.55%、28.73%、26.05%、8.30%respectively compared with cleaning tillage.5. All of the different mulching patterns can promote the photosynthesis of apple treefavorably. Among of these, white film mulching and ground cloth have the best effects, whichfollowed by ryegrass mulching, black film mulching and cleaning tillage. Comparing withcleaning tillage, the Pn increases by8%、7.36%、6.1%、7.3%respectively, the Gsincreases by11.26%、11.09%、10.76%、4.37%respectively, the Ci increases by11.16%、10.31%、8.17%、4.96%respectively.