Preparation Of Chelated Copper With Activated Humic Acid And Its Application In Rice Nursery Substrate

Rice is the staple food for 60%of the population in China,and rice production plays an important role in food supply.However,in the actual production of rice,rice sheath blight often occurs and is difficult to control,which can lead to a reduction of at most 60%⁷0%.In addition,with the development of science and technology,mechanized rice nursery substrate plants was established more and more,but it was found that the problem such as the difficulty of collecting soil,soil was polluted seriously,and the imbalance of soil nutrients was becoming more and more serious,which was not conducive to rice production.Preparation of special rice seedling nursery substrate as an effective way to solve the above problems has become the focus of current research.In order to the activated humic acid with growth-promoting function was modified by the copper ion with bacteriostatic function to prepare humic acid chelated copper,and the humic acid chelated copper was characterized by XPS,SEM,TEM and so on.Saving labor and time this study explored the new matrix of peat through combining the materials with different physical and chemical properties,such as mushroom dregs,local topsoil,vermiculite,perlite,organic fertilizer,urea-formaldehyde,ground phosphate rock,feldspar in powder,fly ash,zinc sulphate and sulfuric acid as raw materials,and screened out the most suitable rice seedling breeding matrix.The purpose of this sudy is to develop a novel multifunctional rice seedling raising substrate adding activate humic acid chelating copper and preparation the most suitable matrix addition ratio,which reduced rice sheath blight and promoted rice growth.This research provided some technical and theoretical support for the future rice production practice.The main results are as follows:（1）To increase active small molecule and soluble humic acid of activated humic acid,the 100ml,0.2mg L^-11 activated humic acidwas mixed with 20ml,0,0.001,0.01,0.1mol L^-1copper sulfate pentahydrate and shocked with 150r/min speed in the thermostatic shock machine for 24h at 35℃.The results showed that Cu（II）in activated humic acid chelate copper（Cu-WH）was grafted to the oxygen-containing functional groups of humic acid,with the increase of copper ion concentration,the chelating amount also increased,among which the chelating degree of activated humic acid chelate copper with 0.1mol L^-11 copper ion（Cu3-WH）is the highest.The grain blight was inoculated on rice seedlings and then treated using Cu3-WH at 1,3,5d after infection,respectively,and the rice grain blight control efficiency was 90.54%,78.96%,66.31%,respectively,which was obviously superior to commercial fungicides.（2）Through the analysis of the physical and chemical properties of the matrix and the indicators of seedling growth,the matrix with different recipe was evaluated compared with the traditional matrix as a control.The results showed that the the seedling index of T8treatment:42.5%peat,8.5%local topsoil,17%vermiculite,17%perlite,8%organic fertilizer,7%excipients（urea-formaldehyde:ground phosphate rock:feldspar in powder:fly ash:zinc sulphate=0.8:10:20:20:0.5）,compared with the local soil and commercial seedling substrate,increased by 68.75%and 35%,respectively,and the number of root hair,chlorophyll content activity increased significantly.Aslo,one-off application of the new seedling substrate can meet the nutrient requirement of rice seedling stage and meet the standard of mechanized transplanting.（3）Different amount of Cu3-WH were added to seedling raising matrix and applied to rice seedling.The results showed that with the increase of Cu3-WH dosage（2%¹0%）,the physicochemical properties of the matrix were improved,and the maximum water holding capacity was 107.4%,114.8%,118.7%and 125.5%,respectively.After incubating 15d,7.4%,9.5%,14.2%and 15.1%of water were retained in the matrix,respectively,which effectively improved the water utilization efficiency.Furthermore,the growth index of rice was measured and showed that the addition of Cu3-WH increased root activity,nutrient absorption and crop growth,thus effectively improved the growth of rice seedlings.Compared with the no Cu3-WH rice seedling substrate,the 8wt%Cu3-WH treated substrate increased plant height,stem base width,fresh weight and chlorophyll content 19.23%,35.91%,14.52%and 42.85%,respectively.In addition,8wt%Cu3-WH treatment also the SOD activity,resistance seedlings,resistance to stress and ability to inhibit bacteria were significantly improved.