Effect Of Mulching On The Growth And Overwintering Of Young Apple Trees And Micro-soil Environment Under Drip Irrigation

Covering gardening cloth in rows, drip irrigation under the cloth and growing grassbetween the lines, belong to the management modes carried out by the close planting shortrootstocks orchards in our country. This model is more saving water, and can effectivelysolve the problem of weeding between the lines. However the influence of coveringhorticultural cloth on tree growth, wintering and soil physical and chemical propertieslacks systematic research. SH40dwarfing interstocks was widely applied in North Chinaas test materials, studied comparatively the influence of different mulches（black cloth、black film、white film、CK）on seedlings growth, soil temperature, humidity and theconductivity. It deeply analyzed the impact of cloth covering on the saplings growth,wintering, photosynthetic capacity and nutrients absorption. The main results were asfollows:1.The research result of different covering material on the1year Red Fuji showedthat, comparing with CK, total amount of growth of Red Fuji covered with black clothwere increased by19.28%, and short shoot ratio increased by21%than CK,and improvedthe chlorophyll relative content of Red Fuji. The capability of using weak light of the treescovered with black film was stronger，the consumption of photosynthetic product waslower under the condition of no light. It can adapt to the condition of weak light or no light.Light saturation point of Red Fuji covered with black cloth separately was increased by23.70%,so covering with black cloth can make Red Fuji tolerant strong light.Under stronglight it also can keep high light collection capacity, so it was conducive to shortened siestatime, extended effective light collection time to improve light collection efficiency,increased accumulation of light collection product.In conclusion,for1a Red Fuji coveredwith black cloth was better to grow.2.The effect of heating in each soil layer of covering with white film was better. Butcovering with black cloth increased relative water content of different depth of soil. It isbeneficial to reduce the soil bulk density covered with black cloth, and the treatment ofcovering with black film and black cloth reduced the soil salt content ofdepth of20-40cm.In conclusion，it is more advantageous to create suitable soil micro-environment for themicro-environment of apple saplings tree covered with black cloth. 3.The effect of covering cloths among2years Red Fuji of SH40dwarfing interstocksshows that total amount growth of Red Fuji covered with black cloth was1.19times ofCK,the short branch ratio increased by3%. Ccovered with black cloth treatments increasedleaf blade mineral element content of Red Fuji.Light saturation point and maximum netphotosynthetic rate of Red Fuji of covering cloth separately increased by15.47%and46.74%comparing to CK, was advantageous in the better use of glare. Covered with blackcloth treatment obviously increased the relative soil water content of40cm depth, as wellas advantageous improved low temperature in early spring of depth of20cm. Covered withblack cloth reduced soil bulk density and the soil salinity content in20-40cm depth.Insummary,covering cloth on Red Fuji of2years was better for tree growth, strengthenedthe photosynthesis, improved soil micro-environment.3.The main wintering problems of M9T337dwarfing rootstocks apple saplings areshrilling and the sunburn of roots and stems in Sanhe and similar climate regions.Wrappedwith film increased the free water content, keep water of tree,reduced the loss ofwater,prevent shrilling and sunburn of apple saplings effectively.5.SH40dwarfing interstocks apple saplings wrapped branches with film or coveredwith black cloth reduced shrilling.The soil temperature of20cm under the surface coveredwith black cloth decreasing temperature lower in early winter,increasing fast during earlyspring, which can promote the activity of root as early as possible, in order to supply waterfor the over ground part,hightened the resistance of shrilling. The wintering measure ofcombining branches wrappedfilm with surface coverage of covering with black cloth ismore beneficial to apple saplings in safety against the damage of shrilling in winter.