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Updated: Jan 30, 2026

Microplot Design and Plant and Soil Sample Preparation for 15Nitrogen Analysis
Published on: May 10, 2020
Polyaspartic acid (PASP)-urea and optimised nitrogen management increase the grain nitrogen concentration of rice
Fei Deng1,2, Li Wang1,3, Xiu-Feng Mei1
1Key Laboratory of Crop Ecophysiology and Farming System in Southwest China of Ministry of Agriculture, Sichuan Agricultural University, Chengdu, China.
Abstract:
Increase in grain nitrogen concentration (GNC), which is directly affected by nitrogen (N) application, can help overcome the issues of malnutrition. Here, the effects of urea type (polyaspartic acid (PASP) urea and conventional urea) and N management method (two splits and four splits) on GNC and N concentration of head rice were investigated in field experiments conducted in Sichuan, China, in 2014 and 2015. N concentration of grain and head rice were significantly (P < 0.05) increased by N redistribution from the leaf lamina, activities of glutamine synthetase (GS), and glutamate synthase (GOGAT) at the heading stage, and N concentration and GOGAT activity in the leaf lamina at the maturity stage. Compared to conventional urea, PASP-urea significantly improved N concentration of grain and head rice by improving the activities of GS and GOGAT, thereby increasing N distribution in the leaf lamina. The four splits method, unlike the two splits method, enhanced N concentration and activities of key N metabolism enzymes of leaf lamina, leading to increased GNC and N concentration in head rice too. Overall, four splits is a feasible method for using PASP-urea and improving GNC.
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