The Effects Of Film-covering Modes On Physical And Microbial Characteristics Of The Soil And Crops Growth

With the forage maize and4kinds medicinal plants， include Radix astragal,Scutellaria baicalensis, Platycodon grandiflorum and Rhizoma anemarrhenae, theexperiment that the effects of plastic-film mulching, was conducted on the experimentalfield of Zhangbei Experimental Station Agricultural University of Hebei, which located inBashang region in the northwest of Hebei Province from May in2011to September in2012. Two soil types such as meadow chestnut soil and sandy chestnut soil wasdetermined. The experiment concerns the film-covering modes.4treatments, conventionalmulching film, film-mulched soil, space film-mulched soil and control are designed. Byfield survey and experiments in laboratory, the thesis expatiated the effects of treatments,including soil physics, soil microbial,physiological and crops production. The main resultsare as followed:Soil temperature is increased and warm is kepted with plastic film mulching. Theconventional mulching film can obviously increase temperature of the topsoil from0to20cm. It was3.3℃in seeding stage. The keeping warm effect is founde in deep soil withfilm under surface. The accumulated temperature goes on to list is conventional mulchingfilm, film-mulched soil, space film-mulched soil and control during the growing season inthe soil layer from0to40cm. The result is2079,2036,1986,1964℃in2011, equal toextension of growth period is6.1,3.8,1.2d compared to the control. In2012, the number is1976,1940,1854,1793℃, growth period is qual to extensioned10.1,8.1,3.4d. Thechanging of soil temperature with film-mulched soil, space film-mulched soil and controllags behind conventional mulching film. The sequence is same as accumulated temperatureof the change amplitude of soil temperature in every layers. The soil temperaturedifferential value decrease as the soil layer deepen. It could raise the soil temperature in theearly growth more than late.In dry years, plastic mulching can not reduce water consumption, farmland coated on soil water temporal frontal can better coordinate supply and demand of water regulation,guarantee the critical period of water requirement of crops.Each processing surface of0to10cm soil hardness is uniformity. Soil hardness of15-20cm is higher than0-15cm. Conventional mulching film can maintain loose of soilthat under the membrane, alleviate soil hardness increases, maintain the stability of the soilunder the film, due to good effect in meadow chestnut soil; Soil hardness change is moresmoothly of meadow chestnut soil than sandy chestnut soil.In dry years, the soil respiration rate, Soil microbial biomass C and active soilmicrobiomass of0-20cm go up after dropping. There is no activation tosoil microbial withfilm. The soil microbial indicators of control is more sensitive response to precipitation,and more apparent in sandy.The film under soil ages and the soil hardness decreases,as a result crop yields fall.The higher WUE is proved on meadow chestnut soil, the WUE with conventionalmulching film and film-mulched soil is reduced compared with control, the WUE withfilm-mulched soil is higher12.2%-108.1%compare to controlThe expts showed the film increase the WUE and meadow chestnut soil gave goodresults. The plant height with film on meadow chestnut soil increase1.7%-8.4%, stemdiameter by1.4%. The film could promote growth but the yield of forage maize in dryyear.Perennial medicinal plant emergence was related to particle size.Large seeds wasnot sensitive to the mulching;The mulching can improve significantly the seeding rate ofsmall seeds.The under soil mulching can promote the seeds of4medicinal plant earlyemergence, improve their seedling number and increase plant height.The mulching canmake perennial medicinal plants reviving advance,promote the growth of plant stem butthe under soil mulching can not increase the production.