The Technology Of Plastic Micro-catchment And Promote-infiltration Applied In Hillside Apple Orchard In Arid Mountain

As the climate and soil in the loess hilly and gully region of northern shaanxi is suit for apple growth, apple planting has become the pillar industry in this area. Apple tree growth need plenty of water, without irrigation, soil water deficit is in serious condition. Drought and low water use efficiency has become the key factor that restricts apple planting in this area. Landform of hillside apple orchard is complicated and various, rain water runs off quickly and infiltrating in shallow layer, the situation of soil drought is much more serious.This study choose the orchard in Ansai county which was the perfectly representative sample as the object, assemble the technology of plastic micro-catchment and promote-infiltration(PCI) that combined with factors of catchment, promote-infiltration, calescence and water retention. A field experiment was conducted to explore the difference of water transforming, Soil moisture environment change, physiological effect on apple tree growth, yield and fruit quality between plastic mulching and straw mulching. Provide scientific basis for the development and application of new technique of hillside apple orchard in arid mountain area. The main finding follows:(1)The technology of plastic micro-catchment and promote-infiltration could improve the soil temperature environment in hillside apple orchard. The annual average soil temperature in PCI was 22.7℃, which was 0.6 ℃ higher than that in CK.(2)The technology of plastic micro-catchment and promote-infiltration could improve the soil moisture environment in hillside apple orchard in arid mountain, and retard the danger of soil desiccation. Soil water content in 0~60 cm layer of PCI was significantly higher than that of PMC、SM and CK(P<0.05). In drought period, soil water content in PCI could keep at the level between 56.0%~ 58.0% of field capacity, it was 15% higher than that of CK. And in rainy season, it was 38.66% higher. In 60 cm~200 cm layer, soil water storage of PCI was 11.00%~23.32% higher than that in CK in key seasons of apple growth. In 200 cm~500 cm layer, soil water storage of PCI was 13.29% higher than that in CK in the dry year, and 19.93% higher in the normal year.(3)The technology of plastic micro-catchment and promote-infiltration could increase the infiltration depth by a large margin,reduce the soil evaporation significantly..As it could deliver part of rain to 40 cm depth directly, and with the collecting effect of plastic mulching, rainwater could infiltrate to the deep-layer under 60 cm of soil even when the rainfall was in small scale, it was significantly deeper than that in CK. In dry season, average soil evaporation was 64.8% lower than that in CK,and in rainy season, it was 56.9% lower.(4)The technology of plastic micro-catchment and promote-infiltration could increase photosynthetic rate of apple leave, promote growth of apple tree. When the photo flux density was 600 μmol·m-2·s-1, photosynthetic rate of PCI was 12.7 μmol·m-2·s-1, which was 1.7 μmol·m-2·s-1 than that in CK. When the photo flux density was 1500 μmol·m-2·s-1, photosynthetic rate of PCI was 16.8 μmol·m-2·s-1, which was 3.6 μmol·m-2·s-1 than that in CK. The branch length and diameter was 37.4% and 26.5% higher than that in CK respectively. Leaf area, thickness and fresh weight was 13.0%,29.0%, 12.4% higher than that in CK respectively.(5)The technology of plastic micro-catchment and promote-infiltration could increase apple yield and water use efficiency, improve fruit quality. The annual yield in PCI was 12 875kg/hm2, which was 23.3% higher than that in CK. Water use efficiency was 24.02 kg·mm-1, fruit shape index was 0.88, average weight was 258.6 g, all of these indexes were higher than those in CK.The results show that the technology of plastic micro-catchment and promote-infiltration can improve water use efficiency of apple orchard in the loess hilly and gully region, improve soil desiccation status, increase apple yield and fruit quality. There is a realistic significance for raising planting lever and improving quality of mountain apple industry, accelerating the strategic moving of apple industry from south to north in Shaanxi, keeping it developing healthily.