Effects of nitrogen fertilizer level on root morphology,yield and quality of open-field pepper

ZHANG Wenqian; LIU Zhongliang; XU Jiali; GAO Junjie; WANG Ting; CHEN Zhen

doi:10.16861/j.cnki.zggc.2024.0843

Abstract：To explore the effects of different nitrogen fertilizer levels on the leaf nitrogen metabolism enzyme activity,root growth,yield and quality of open-field peppers,the pepper variety Jiaowanjia was used as the experimental material,customary nitrogen fertilizer amount(262.50 kg·hm-2)as the base,six treatments were set up:No nitrogen fertilizer(CK),conventional nitrogen fertilizer(T1),nitrogen fertilizer reduction 15％(T2),nitrogen fertilizer reduction 30％(T3),nitro-gen fertilizer increment 15％(T4),nitrogen fertilizer increment 30％(T5).The results showed that compared with CK,NR and GS activity showed a trend of first increasing and then decreasing,GOGAT activity showed a trend of increas-ing-decreasing-increasing,with the highest activity under the T2 treatment,increased significantly by 30.25％,94.16％and 59.58％compared to CK,respectively.Increasing nitrogen fertilizer could effectively increase root length,root sur-face area and root volume,reaching the maximum under T2 treatment.The IAA content of root was increased,reached the highest under T2 treatment for 599.34 ng·g-1.The highest yield of T2 treatment was 35 436.93 kg·hm-2,and increased significantly by 42.65％than CK.The nitrate content of each nitrogen fertilizer treatment were increased by 19.13％-66.03％.In conclusion,proper application of nitrogen fertilizer can significantly improve leaf nitrogen metabo-lism enzyme activity,IAA content,yield and quality of pepper,and 223.13 kg·hm-2 nitrogen fertilizer treatment(T2)has the best effect.