| With the development of agricultural mulching film and ferrosilicon alloy industry,the white pollution caused by mulching film and the massive accumulation of waste micro silicon powder from smelting ferrosilicon alloy have become two urgent environmental protection problems that need to be solved in today's society.In view of this,this paper solves the problems of agglomeration,dispersion and poor stability of micro silicon powder through surface modification of waste micro silicon powder.At the same time,a new kind of environmentally-friendly liquid film was prepared via adding micro silicon powder into the liquid film substrate to improve the pollution cansued by traditional film and the poor recovery micro silicon powder,which opened a new way for the recovery and reuse of micro silicon powder.This paper focuses on the study of the modification of micro silicon powder by silane coupling agent,discusses the influence of its liquid film rheological properties and the influence of micro silicon powder liquid film mulching on soil temperature,water,seedling rate,plant height,dry matter accumulation,soil available silicon and soil surface nutrient elements.The main conclusions are as follows:(1)Through the treatment of micro silica powder with KH-550 coupling agent,the agglomeration phenomenon between micro silica powder particles is alleviated.Adding it to the liquid film to discuss the rheological properties,it can be found that the rheological properties of the modified micro silica powder liquid film are significantly improved compared with that before modification,but the shear thinning phenomenon of the suspension system treated by coupling agent still exists,which is not affected by temperature,When the amount of coupling agent is about 1.5 wt%,the dispersion of liquid film is the best.Finally,the viscoelasticity of solid content at 0.5 wt% and 1.0 wt% was measured under the amplitude shear mode.When shear strain ? increased to 6% ? 10%,the suspension system at G?>G?? was dominated by elasticity,which showed as solid properties and poor fluidity.when the shear strain ? exceeds 6% ? 10%,G??>G? suspension system is dominated by viscosity and good fluidity.Secondly,the viscoelasticity of suspension system depends on particle size,mass concentration and interactions between particles.(2)Through the pot experiment of wheat to simulate the mulch of farmland,it was found that when the soil depth was 5 cm and 10 cm treated with liquid mulch(LS and LP),the temperature and water content were significantly different from those of the blank control group(P < 0.05).Although the soil temperature of ordinary plastic mulch(PF)treatment is higher than that of LS treatment,the moisture content of wheat in growing period is lower than that of LS treatment.The liquid mulching is beneficial to rainwater infiltration and improve the permeability of soil.Compared with CK,the weight of 1000 grain and the number of grains per ear increased by 5.8% and 23% respectively.All in all,the liquid film treatment can effectively improve the growth and development of wheat plants above ground.(3)The contents of organic matter,alkali-hydrolyzed nitrogen,available phosphorus,available potassium and available silicon in different soil layers from 0 to 15 cm were measured.The results were as follows: liquid mulch >ordinary plastic mulch > bare land control.The organic matter content of liquid mulch was 3.87% higher than that of CK treatment,and the contents of alkali-hydrolyzed nitrogen,available phosphorus,available potassium and available silicon were higher than those of other treatments.The covering of liquid mulch effectively improved the changes of soil surface nutrients. |
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