Effects of amino acid liquid fertilizer on the growth and nitrogen metabo-lism of onion at seedling stage

XIAO Ruiqing; HU Haoxiang; XUN Tianzhuo; LI Jie; XU Hongjun; SUN Yanru; ZHANG Weihua; JIA Kai

doi:10.16861/j.cnki.zggc.2025.0112

Abstract：Amino acid liquid fertilizer is beneficial to crop growth and development and yield increase,so this study inves-tigated the effects of different concentrations of amino acid liquid fertilizer on onion seedling growth and nitrogen metabo-lism of key enzyme activities,to provide appropriate guidance for onion seedling fertilization management.The test mate-rial was white-skinned onion'White Snow',with one control CK(1/4 Hogan's nutrient solution)and three treatments(T1:500-fold dilution of amino acid liquid fertilizer+1/4 Hogan's nutrient solution,T2:300-fold dilution of amino acid liquid fertilizer+1/4 Hogan's nutrient solution,T3:100-fold dilution of amino acid liquid fertilizer+1/4 Hogan's nutrient solu-tion).Plant growth indexes and physiological indexes of nitrogen metabolism were carried out to determine when the seedlings grew to two true leaves.The results showed that,compared with CK,the height of onion seedlings in T1 treatment decreased by 20.8％,the stem thickness increased by 15.8％,the root length increased by 10.7％,the relative water content decreased by 3.3％,and the accumulation of organic matter increased.The relative chlorophyll content of onion seedlings increased by 7.2％,7.9％and 10.1％under the three concentrations of treatments;with the increase of amino acid liquid fertilizer concentration,the key enzymes of nitrogen metabolism,including glutamate dehydrogenase,nitrate reductase,glutamine synthetase and glutamate synthetase,showed an increasing trend,with the highest enhance-ment of 30.9％,43.1％,43.2％and 38.6％;T3 In the treatment group,the growth rate of nitrate reductase,glutamine syn-thetase and glutamate synthetase slowed down.Considering the growth condition of onion seedlings,300-fold dilution of amino acid liquid fertilizer was the optimal treatment.