Experimental Study On The Effect Of Cotton Stalk Based Carbon Fertilizer On Soil Fertility Parameters

In this paper,cotton straw was used as raw material to prepare cotton straw based biochar by high temperature carbonization and pyrolysis in muffle furnace.Three main influencing factors were scientifically selected through multiple orthogonal experiments,and the optimal preparation process parameters of cotton based biochar were obtained under the result of the highest carbonization rate.Then,X-ray electron microscopy and Fourier transform infrared spectroscopy were used to determine the characteristics of cotton based biochar,such as element analysis,functional group types,surface distribution and spatial porosity,so as to fully understand the physical and chemical characteristics of cotton based biochar.Combined with the physical and chemical properties of cotton based biochar,the cotton based carbon fertilizer was prepared by adding common analytical pure fertilizer and aqueous solution as binder.Cotton based carbon fertilizer was added to the soil to detect the changes of soil pH,soil bulk density,saturated water content and saturated water conductivity,so as to test the improvement effect of cotton based carbon fertilizer on the soil.The cotton based carbon fertilizer was added to the soil in different proportion to cultivate crops,and the common fertilizer group with the same amount of elements was used as the control.The effect of the cotton based carbon fertilizer on soil fertility was detected by measuring the germination potential,germination rate,root shoot ratio,dry matter accumulation and crop yield per plant.The utilization of new cotton stalk carbon based fertilizer can not only turn waste cotton straw into treasure,but also solve the problem of environmental pollution.The conclusion of this research is as follows:(1)The pyrolysis of cotton based biochar takes the char yield as the final experimental index.Through the orthogonal experiment,the temperature,pyrolysis time and the ratio of agent and material are selected to optimize the preparation process parameters.Through the X-ray and FT-IR analysis of the cotton based biochar prepared under this condition,it is found that the cotton based biochar obtained under the optimum process parameters has good surface characteristics,and different kinds of oxygen-containing functional groups can improve the porosity of the biochar,improve the adsorption capacity of the cotton based biochar,and then apply it to the soil to absorb water and organic matter Material and fertilizer elements reach the goal of improving soil fertility.(2)Finally,distilled water was chosen as the binder for the experimental preparation of cotton based carbon fertilizer,and the prepared cotton based biochar was mixed and stirred evenly with the analytical pure common fertilizer,and then extruded into cotton based carbon composite fertilizer by multi-functional universal material machine.At this time,the prepared cotton based carbon fertilizer particles can be seen under the scanning of the particle analyzer that the particle size is moderate and the surface layer is uniformly bonded with biochar.From the result of the sphericity calculated by the software,it can be seen that the carbon fertilizer presents an elliptical shape similar to a circular shape,which will be conducive to the surface layer fully adsorbing the water and organic matter of the soil to achieve the purpose of fixing the soil elements.The addition of carbon based fertilizer to soil indicated that cotton stalk carbon basedfertilizer could reduce the soil bulk density and make the soil more porous.Due to the weak acidity of the cotton stalk carbon based fertilizer,it can effectively neutralize the alkalinity of the sandy soil,and then adjust the pH of the soil to tend to be neutral.In addition,the addition of carbon based compound fertilizer has a good improvement effect on the saturated hydraulic conductivity of the soil.(3)Finally,the results of indoor pea planting experiment show that the soil with carbon based fertilizer can effectively improve the germination potential and germination rate of pea,and promote the total dry matter accumulation of root and cap in the early stage of pea seedling.By comparing with the common fertilizer treatment group,the final yield of the crop with carbon based fertilizer on cotton stalk also has a significant increase.It can be seen that cotton stalk carbon based fertilizer can effectively improve the physical and chemical properties of soil,achieve carbon sequestration and water conservation,absorb more organic matter and fertilizer elements to improve the overall fertility of soil.This experiment not only prepared cotton stalk based biochar,but also carried out various physical and chemical analysis of biochar,and cotton stalk based carbon fertilizer also provided a new method for improving the physical and chemical properties of sandy soil in the southern Xinjiang and the improvement of soil fertility as a whole,and made a new way to make better use of the waste cotton stalk.