Effect of glycine combined with urea on the absorption, transportation and transformation of nitrogen in wild peach seedlings (Amygdalu spersica (L.) Batsch)

The mechanism of how glycine combined with urea affects the development of peach trees through nitrogen absorption and metabolism is still unclear. In this study, we investigated the transformation of nitrogen in soil, the nitrogen absorption in roots, and the transformation and transportation of nitrogen in the peach tree at different treatment (no nitrogen fertilizer (CK), urea (T1), glycine (T2), glycine:urea (1:1) (T3), glycine:urea (3:7) (T4), and glycine:urea (7:3) (T5)). Compared with CK, the total dry weight of T5 and T2 was significantly increased by 22.95% and 19.09%, while it was lower at T3. The root activity of T5 was significantly higher than CK by 169.27%. The residual NH4+ in the soil was consistent with the application ratio of urea, while the conversion of NO3- was promoted at T5. Under T5, soil amoA and nifH abundance was higher, while the nirK abundance was higher under T1 and T3. In addition, urease activity was higher at T1, while phosphatase, catalase, and dehydrogenase activities were higher at T5. The NO3- content in the root was higher at T5. In roots, the activities of GDH, GOGAT and GS were significantly increased at T5 and T2, while the NR activities of T5 and T1 were significantly increased by 34.60% and 33.64% compared with CK. The aspartic acid and glutamic acid were the main forms of nitrogen transport in wild peaches. PLS-PM analysis showed that nitrogen use efficiency had a very significant direct positive effect on the biomass of peach trees.

Automated summary

The mechanism of how glycine combined with urea affects the development of peach trees through nitrogen absorption and metabolism was investigated in this study. The results showed that the total dry weight of T5 and T2 significantly increased, while it was lower at T3. The root activity of T5 was significantly higher than CK. The residual NH4+ in the soil was consistent with the application ratio of urea, while the conversion of NO3- was promoted at T5. Additionally, T5 had higher soil amoA and nifH abundance, while T1 and T3 had higher nirK abundance. Nitrogen use efficiency had a very significant direct positive effect on the biomass of peach trees.