PJB-2023-36
Effects of the nitrogen application rate on dry matter accumulation, nitrogen uptake and utilization, and key enzyme activities of nitrogen metabolism in sorghum
Meng Yang Li, Zhen Qing Guo, Yu Xin Bai, Peng Fei Zhu, Jian Wang, Yu Cui Han, Fei Zhang and Xiao Hu Lin
Abstract
The effects of different nitrogen application rates (NAR) on sorghum yield and nitrogen (N) uptake and utilization in eastern Hebei Province, China were investigated. In this experiment, var. Liaoza 37 and var. Liaonian 3 were used as test materials, and 5 treatments were set up: 0 (N0), 120 (N1), 180 (N2), 240 (N3), 300 kg ha-1 (N4). The results showed that when NAR of 120 kg ha-1, the maximum N accumulation of Liaoza 37 at maturity was 80.33 kg ha-1. The average yield reached a maximum of 6631.43-6336.89 kg ha-1 when the NAR was 240-300 kg ha-1. The results showed that when NAR of 180 kg ha-1, the maximum N accumulation of Liaoza 37 at maturity was 80.80 kg ha-1. The average yield reached a maximum of 6202.58-6610.07 kg ha-1 when the NAR was 180-240 kg ha-1. Under high N conditions (240-300 kg ha-1), nitrate reductase, glutamine synthetase, asparagine synthetase and nitrite reductase of Liaoza 37 maintained higher activities than those of Liaonian 3. Under low N conditions (120-180 kg ha-1), nitrogen use efficiency (NUE), nitrogen agronomic efficiency (NAE), nitrogen absorption and utilization (NAAU), nitrogen partial production efficiency (NPPE), leaf N transport efficiency and leaf transfer volume contributed more N to the grain. Under high N condition (240-300 kg ha-1), NAE, NAAU, leaf N transfer, leaf transfer efficiency, stem N transfer, stem transfer efficiency and leaf transfer volume contribution more N to the grain. Appropriately increasing the NAR helped to improve the transfer volume and transfer efficiency of the leaves and stems. A correlation analysis showed that the average yield of Liaoza 37 was positively correlated with the stem N transport efficiency and leaf ear N accumulation. The average yield of Liaonian 3 positively correlated with NAE, NAAU, leaf dry matter transfer efficiency and leaf dry matter transfer volume. These results suggested that there were significant differences in N uptake and the utilization of different sorghum varieties under different NAR. The study provided theoretical support for rational application of N fertilizer to sorghum varieties in eastern Hebei Province to obtain high yield
To Cite this article:
Li, M.Y., Z.Q. Guo, Y.X. Bai, P.F. Zhu, J. Wang, Y.C. Han, F. Zhang and X.H. Lin. 2024. Effects of the nitrogen application rate on dry matter accumulation, nitrogen uptake and utilization, and key enzyme activities of nitrogen metabolism in sorghum. Pak. J. Bot., 56(3): DOI: http://dx.doi.org/10.30848/PJB2024-3(30)
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