Study On Agricultural Use Of Solid Waste And Its Improvement On Coastal Saline Soil

Soil is the basis for human survival,and soil obstacles are the main factor affecting crop growth and yield.Coastal saline soil is the original soil barriers,which are difficult to improve and utilize land resources.The inventory of industrial and agricultural solid waste is large and growing year by year,which not only wastes resources,but also pollutes the ecological environment.Therefore,how to effectively use industrial and agricultural solid waste has become an urgent problem to be solved at present.Based on the above problems,this study uses industrial and agricultural solid waste to systematically study its impact on soil physical and chemical properties and crop growth through chemical,engineering and other improvement technologies,aiming to propose theories and technical approaches for the agricultural use of industrial and agricultural solid waste.Coastal saline soil is improved by laying salt barriers,applying modifiers,and leaching to explore its impact on soil physical and chemical properties and crop growth;the agricultural use of waste ore is to add water-retaining agent on the basis of industrial solid waste lithium ore,organic fertilizers and other amendments,to explore whether waste ore has agricultural value and the impact of amendment application on crop growth.Main research results:1.Applying organic fertilizer on the coastal saline soil can significantly reduce the soil bulk density by 5.2%-14.8%.The application of gypsum has no significant effect on bulk density;The application of organic fertilizer and gypsum can significantly reduce the pH of the soil by 0.17-0.29 and 0.05-0.17 pH units respectively;The application of organic fertilizer and gypsum can significantly increase the soil cation exchange capacity by 18.9%-61.7%,7.0%-17.3%;Application of organic fertilizer significantly increases soil organic matter,available phosphorus,available potassium,and alkali-hydrolyzable nitrogen and other nutrients.Applying organic fertilizer and gypsum on the coastal saline soil to increase the soil salinity,laying a salt barrier and fresh water leaching significantly reduce the soil salinity and the content of K+,Ca2+,Mg2+,Cl-and other base ions.Application of organic fertilizers Ca2+and Cl' content decreased by 14.8%and 25.7%respectively.The content of Na+,K+and Cl-in gypsum can be reduced by 32.5%,39.1%,and 31.3%respectively.The soil conductivity,K+,Ca2+,Mg2+,and Cl-content of the paved salt barrier are significantly reduced,which can be reduced by 52.4%,42.9%,20.7%,26.1%,and 28.1%respectively.Application of organic fertilizer and gypsum on the coastal saline soil can significantly increase the yield of alfalfa and sweet clover,and the effect of organic fertilizer is more obvious.The correlation between the amount of organic fertilizer and the yield of the two plants was in accordance with the one-dimensional quadratic equation.There was no significant difference in plant yield between the amount of organic fertilizer 150 t/hm2 and 300 t/hm2.The yield of melilotus and alfalfa increased by 22.2%-48.5%and 16.5%-35.5%,respectively.There was no significant difference in plant yield between the amount of gypsum 3.75 t/hm2 and 7.50 t/hm2.The yields of Gypsum Melilotus and Alfalfa increased by 9.1%-10.2%,15.6%-20.4%,respectively.The improvement plan of coastal saline soil is proposed as salt barrier+150 t/hm2 organic fertilizer+3.75 t/hm2 gypsum.2.Adding water-retaining agent to waste ore can increase the yield of peanuts.The peanut yield increased by 10.7%-17.8%with water-retaining agent,but there was no significant difference between 0.25 t/hm2 and 0.50 t/hm2 of water-retaining agent;adding water-retaining agent had no significant effect on the growth of Scutellaria baicalensis Georgi.Appropriate application of organic fertilizer in the waste ore can significantly increase the yield of peanuts,promote the growth of the rhizome of Scutellaria baicalensis Georgi and increase the biomass of Scutellaria baicalensis Georgi.The yield of peanuts increased by 50.4%-58.8%through the increased application of organic fertilizer,but there was no significant difference between the amount of organic fertilizer 15 t/hm2 and 30 t/hm2;The increased application of organic fertilizer increased the root thickness and biomass of Scutellaria baicalensis Georgi by 35.0%-48.0%,91.9%-113.2%.However,there was no significant difference between the amount of organic fertilizer between 15,30 t/hm2.The agricultural plan for waste ore sand is proposed to plant peanuts under the condition of 0.25 t/hm2 water retaining agent+15 t/hm2 organic fertilizer,and plant scutellaria under the condition of 15 t/hm2 organic fertilizer.It can not only realize the agricultural use of solid waste,but also maximize the use of waste ore to grow crops,and realize the common development of environment and economy.The main conclusions are as follows:(1)Improvement of coastal saline soil:Applying organic fertilizer can significantly reduce soil bulk density;The application of organic fertilizer and gypsum significantly increased the soil salinity,while the laying of salt barrier and fresh water leaching significantly decreased the soil salinity and the content of base ions;The application of organic fertilizer and gypsum significantly increased the biomass of sweet clover and alfalfa;The soil improvement scheme was put forward,which included salt barrier,150 t/hm2 organic fertilizer and 3.75 t/hm2 gypsum.(2)Agricultural use of waste mineral sand:Adding appropriate amount of water retaining agent can increase peanut yield;Proper application of organic fertilizer can increase peanut yield,promote the growth of scutellaria root and stem,and increase biomass;The agricultural scheme of waste mineral sand was put forward.Peanut was planted under the condition of 0.25 t/hm2 water retaining agent+ 15 t/hm2 organic fertilizer,and Scutellaria baicalensis was planted under the condition of 15 t/hm2 organic fertilizer.