Regulation Of Humic Acid And Amino Acid Synergist On Crop Growth

In order to improve the utilization rate of fertilizer,reduce the potential harm to the ecological environment and achieve the goal of"double reduction",it is one of the effective measures to modify and improve the efficiency of fertilizer.Humic acid,amino acid can stimulate crop growth,promote nutrient absorption,and improve fertilizer utilization efficiency.Humic acid,amino acid as fertilizer synergist,has been widely concerned about the application of fertilizer modification and synergism.In this paper,the effects of humic acid and amino acid synergist on seedling growth,root physiological activity,nitrogen metabolism and endogenous hormone level of crops were studied by culture experiment and ¹⁵N tracer test.The regulation mechanism of amino acid synergist on crop seedling growth and its effect on nitrogen uptake and utilization were studied,which provided scientific basis for the development and application of humic acid and amino acid synergist.The main findings are as follows:1.Humic acid and amino acid synergist could significantly promote the growth of tomato and maize at seedling stage,resulting in a significant increase in the relationship between tomato and maize,dry weight above ground and chlorophyll content in leaves.The dry weight of maize root increased by 31.68%and 20.19%respectively when tomato was treated with HA3 of 5ml/L humic acid,and the dry weight of maize root increased 71.22%by G3 treatment of 16.24%.5ml/L amino acid,and the dry weight of maize shoot increased by71.22%,and the dry weight of maize root increased by 71.22%.The dry weight of shoot increased by 60.11%and 61.14%respectively.2.Humic acid and amino acid synergist could increase root activity,increase root absorption area and active absorption area,increase root activity by 57.07%and 32.49%in tomato and maize treated with HA3,respectively,and increase root activity of tomato and maize by 57.07%and 32.49%,respectively.G3 treatment increased root activity of tomato and maize by 78.65%and 69.94%,respectively.3.Humic acid and amino acid synergist could promote nitrogen metabolism and nitrogen absorption in tomato and maize.The GS,GDH activities of tomato roots and leaves were increased by 47.26%and 66.60%on average when treated with HA3,and the GS,GDH activities of roots and leaves of maize were also greatly increased by HA3,G3 treatment.The activities of NR,GS and GDH in tomato roots increased by 140.55%,49.84%,47.01%,respectively,and the activities of GS and GDH in leaves increased by 97.37%and 86.51%,respectively.In addition,the nitrogen metabolizing enzymes in maize treated with G3 were increased by 97.37%and 86.51%,respectively.The activity also increased obviously.4.The content of auxin,gibberellin and cytokinin in roots and leaves of tomato and maize seedlings could be significantly increased by appropriate humic acid and amino acid synergist,and the content of abscisic acid in roots could be reduced by amino acid synergist,and the regulation of amino acid on endogenous hormones was better.5.Humic acid nitrogen fertilizer could increase wheat grain yield and biomass,promote nitrogen uptake and accumulation in shoot,¹⁵N tracer results showed that adding activated humic acid can increase the nitrogen fertilizer utilization rate by 4.60%,9.44%and6.46%,respectively.