Study On The Effect Of Coconut Chaff Water-retaining Agent On Water Holding Capacity Of Lou Soil

In recent years,the shortage of water resources has seriously restricted the development of Guanzhong region in Shaanxi Province.However,local agricultural water is an important part of water resources,so the modernization of water-saving agriculture is the inevitable trend of efficient utilization of water resources in guanzhong area.The water-retaining agent has been widely concerned in agriculture due to its characteristics of high water absorptivity,strong water holding capacity and easy preparation.Meanwhile,the application effect of water retention agent is affected by many factors,including the properties of water retention agent,physical and chemical properties of soil,the application ratio and depth of water retention agent,and the climatic conditions and so on.In this study,coconut bran soil water-retaining agents were selected and prepared.In this paper,the effects of three water retaining agents on the physical properties and water distribution of Lou soil in Shaanxi Province were preliminarily discussed with the combination of indoor basic experiments and simulation of indoor soil environment,and the soil fractions were applied with 1%and 15%respectively.The interaction mechanism among them was studied.The purpose of this study is to provide theoretical basis for the selection and application of coconut bran water-retaining agents in agricultural and forestry production.The basic experiments mainly measure the properties of three kinds of water absorbent,including Determination of water absorption rate and dehydration rate,hydrophilicity test,water absorption ratio,etc.The part of indoor soil environment simulation is to study the effect of different proportion of water-retaining agent on the physical properties of soil moisture,such as bulk density,total porosity,available moisture,and the saturation and residual water content contained in the characteristic curve of soil moisture.Specific water capacity and drought resistance,model parameters such as soil air intake.The effects of water retaining agents on soil moisture and physical properties were studied based on the dosage of three kinds of water retaining agents.The effect of water retention agent on soil water holding property is analyzed and evaluated in various aspects,and the effect on other physical properties of soil is explored.This paper comprehensively analyzes and evaluates the effect of water retaining agent on soil water holding capacity from various aspects,and explores the effect of water retaining agent on other physical properties of soil to provide theoretical basis for efficient utilization of water resources and sustainable development of agriculture.Our study draws the following conclusions:(1)The properties of CBP were not affected by particle diameter,the absorbency of 20-150 was equal to 9.1 g/g,and the dry wet alternating test proved that cbp had good repeated water absorption.The AM/CBP prepared at 140?for 3 hours with the initial concentration of ammonia at 20 wt%and the ratio of solid to liquid is 1:8 is the most suitable water absorbent,and the absorbency is much higher than that of the control group(19.9g/g).The absorbency of CA/CBP at the CA concentration of 2.38 mol/L at 120?for 35 minutes was higher than that in the control group too,which was 20.3g/g.The hydrophilic test shows that the contact angle of CA/CBP is less than 10°,so hydrophilicity is the best.AM/CBP,and the contact angle is14.81°.B is the worst,because the contact angle is 43.13°.(2)Three kinds of coconut chaff water-retaining agents can reduce soil bulk density.Analysis of soil bulk density of 5%CBP-MIXED in Group CBP by increasing soil ripening degree and Total porosity,the soil bulk density is 1.17 g/cm~3,which is more suitable for practical application.5%and 15%are more suitable in group AM/CBP and group CA/CBP.(3)The measurement of soil moisture characteristic curve shows that both of them can enhance the water content and saturated water content of soil under the same suction force,and this trend increases with the increase of the applied ratio.In addition to 1%CBP-MIXED and1%AM/CBP-MIXED,the residual water content conforms to this rule.The soil moisture content of 1%CBP-MIXED and 5%CBP-MIXED and 15%CBP-MIXED increased by 19.3%-310.7%and 34.7-520.1%,respectively,compared with that of the control group.The increase of soil water content in the three proportions of AM/CBP-MIXED from low to high is 0-193.1%and 21.7-381.7%and 31.6-604.3%.CA/CBP-MIXED is 3.80-41.5%29.1-200.1%and 41.8-301.2%respectively.Under the same ratio,the increase of AM/CBP-MIXED and CA/CBP on soil water content is stronger than CBP.(4)The Rardern-Russo model can fit the soil water characteristic curves of three groups of water retaining agents accurately.The application of three kinds of water retaining agents can increase the air intake value of the soil,but the modified water retaining agent has no positive effect on the enhancement of the soil air intake value.At the same ratio,the inlet value of CBP-MIXED is greater than AM/CBP-MIXED or CA/CBP-MIXED.(5)From the point of view of increasing the available water content in Lou soil,15%is the most suitable application ratio in group of CBP,the rate of water loss is the slowest and the drought resistance is the best.AM/CBP has a larger field water capacity and total efficient water use in 5%,the lower unusable water,which is the best applied ratio.The effective water performance of CA/CBP group is also in regular relation with the ratio of water retaining agent application.Therefore,the actual application of soil condition needs specific conditions to select the appropriate CA/CBP application ratio.