Effects of Amino Acid Value-Added Urea on Rice Growth and Nitrogen Utilization
Authors: CHENG Lin , Zong-ya WANG , HUANG Shuang-shuang , WU Hong-yan , LI Jun 
Published: May 2024

To study the effects of amino acid value-added urea on rice growth and nitrogen utilization, in order to provide a theoretical basis for the improvement of quality and efficiency of traditional nitrogen fertilizers by small molecule active substances. Set the addition amount of amino acids to 5‰ and 5%, and prepare different levels of amino acid value-added urea (AU0.5 and AU5) by fusion with urea as the test materials. Conduct pot experiments on 'Liangyouhua 6' as the test crop. A total of 4 groups of treatments were set up, including non urea (CK), reAUlar urea (U), and amino acid value-added urea (AU0.5, AU5) with 2 different addition ratios. Except for the control, the application rates of nitrogen, phosphorus, and potassium were the same in all other treatments. After the rice matures, collect rice plants and samples from different depths of soil layers to determine the nutrient composition of rice, the nitrogen content of fertilizer in different soil layers, and the abundance of 15N. The results indicate that: Amino acid added urea significantly promoted the accumulation of biomass in various parts of rice. Compared with U, the biomass of rice straw and grain increased by 25.27–32.74% and 21.71.07–27.77% under AU0.5 and AU5 treatments, respectively; In the nitrogen application treatment, the effective panicle and grain number per panicle of AU0.5 and AU5 rice increased by 17.37%~21.05% and 8.76%~15.33% respectively compared to U, with a significant difference between AU0.5 and U; Compared with U, the total accumulation of aboveground total nitrogen and fertilizer nitrogen in rice treated with AU0.5 and AU5 increased by 3.59%~5.09% and 3.31%~8.49%, respectively, while the accumulation of fertilizer nitrogen in grains and leaves increased by 2.86–6.32% and 4.38–16.25%, respectively. This significantly affected the accumulation of fertilizer nitrogen in straw; Further analysis revealed that the application of amino acid value-added urea significantly improved the apparent nitrogen utilization efficiency and fertilizer nitrogen utilization efficiency. Compared with U, the apparent nitrogen utilization efficiency of AU0.5 and AU5 increased by 23.71% and 33.93%, respectively, and the utilization efficiency of 15N increased by 15.66% and 6.78%, respectively; The residual amount of fertilizer nitrogen in soil treated with amino acid value-added urea is mainly concentrated in the 0-30cm soil layer, which can reduce nitrogen leaching downward. The nitrogen loss rate of fertilizer treated with amino acid value-added urea is significantly reduced by 12.39% -12.97% compared to ordinary urea. The difference between AU0.5 and AU5 is not significant, and AU5 is 18.80% higher than U in fertilizer nitrogen residual rate. Therefore, The promoting effect of amino acid value-added urea on rice growth is manifested by increasing the absorption of fertilizer nitrogen, enhancing the transport of fertilizer nitrogen to the grains, improving the apparent and utilization efficiency of nitrogen fertilizer, while reducing nitrogen leaching downwards and reducing nitrogen loss rate. Among them, the best effect is the addition of 5‰ amino acid.