@article{WANG2023, 
author = {DanDan WANG and HuanXuan CHEN and Chong ZHANG and XiaoTang JU},
title = {Spatial Differences and Driving Factors of Aboveground Nitrogen Uptake in Per Hundred Kilograms Grain of Maize in China},
year = {2023},
journal = {Scientia Agricultura Sinica},
volume = {56},
number = {20},
pages = {3996-4009},
keywords = {maize, aboveground N uptake in per hundred kilograms grain, yield levels, rational N fertilization, agro-ecological zones},
url = {https://www.sciopen.com/article/10.3864/j.issn.0578-1752.2023.20.006},
doi = {10.3864/j.issn.0578-1752.2023.20.006},
abstract = {【Objective】We aim to quantify aboveground nitrogen (N) uptake in per hundred kilograms grain (N100) of maize in different agro-ecological zones at different yield levels in China, and analyze the effects of climate, soil, variety and N fertilization on N100 of maize, thus to provide a scientific basis for determining rational N fertilizer rate.【Method】We divided Chinese cropland into six major regions, i.e., northeast, northwest, North China Plain, middle and lower Yangtze River, southwest, and southeast, and collected 349 peer-reviewed papers published during 1980-2022 to analyze the spatial variation of N100 and its changes at different yield levels, and compared the differences in calculated theoretical N rate between constant and region-specific N100. The effects of climate, soil and fertilization on N100 were analyzed using Pearson correlation coefficient, Random forest model and Meta-analysis, to reveal the causes of spatial variation in N100.【Result】Under the optimized N management, N100 of spring maize was significantly lower than that of summer maize which were 2.21 and 2.46, respectively; and there were significant differences in N100 of maize among different agro-ecological zones, which were 2.19 (Northeast spring maize), 2.12 (Northwest spring maize), 2.54 (Northwest summer maize), 2.45 (North China Plain summer maize), 2.77 (Middle and Lower Yangtze River spring maize), 2.38 (Middle and Lower Yangtze River summer maize), and 2.39 (Southwestern maize zone), respectively. The difference between calculated the theoretical N rate based on the national average N100 (2.34) and that based on regional-specific N100 was -22-31 kg N·hm-2. Aboveground N uptake, yield, and mean annual temperature were the most important factors affecting N100. The N100 showed a significant quadratic decrease with increasing yield (P<0.01), and grain yield was a good predictor of N100. Varieties significantly affected maize N100, the N100 of common Chinese maize varieties Zhengdan 958, Xianyu 335, and Denghai 605 are 2.42, 2.12, and 2.39, respectively. New varieties had a significant lower N100 than old varieties. The application of N fertilizer significantly increased the N100 of maize, and the greatest increase effect of N100 caused by N fertilizer application was observed at 200-300 kg N·hm-2. Once application of slow and controlled release fertilizer, deep placement, reduction of the ratio of basal N fertilization and increasing the frequency of N fertilizer application all significantly increased N100.【Conclusion】When calculate the rational N fertilization, we need to considerate the regional differences of N100, thus to obtain accurate fertilizer N rate, and the N100 of maize is mainly driven by variation in aboveground N uptake, yield and mean annual temperature.}
}