&lt;sup&gt;15&lt;/sup&gt;N Tracer-based Analysis on Nitrogen Utilization Laws of Rice Under Different Irrigation Modes

Haijun Zhu,Ailong Shi,Xuehua Wang,Yue Wang,Ting Zhang

doi:10.5376/mpb.2022.13.0006

Abstract

In order to promote the efficient and coordinated utilization of water and nitrogen in rice, the  15 N missing technology experiment was adopted to study the effects of nitrogen application rate (N 0 , N 160 , N 200 , N 240 ) and irrigation mode (Wet-dry alternation, conventional irrigation) on nitrogen absorption, transport, residue, loss and nitrogen utilization of super rice. The results showed that with the increase of nitrogen application rate, the accumulation of fertilizer nitrogen and total nitrogen in rice plants at different growth stages, and the accumulation of nitrogen in various organs at mature stage increased significantly, and the accumulation of nitrogen per panicle at mature stage was the highest, reaching 67.20%~69.02%. The transport amount of nitrogen from different sources in different vegetative organs of rice plants increased with the increase of nitrogen application rate, and the comparison of nitrogen transport amount in organs was as follows: leaf > stem > root; After full heading, the accumulation of nitrogen from different sources and its contribution rate to grain nitrogen per spike increased with the increase of nitrogen application rate, but with the increase of nitrogen application rate, the residual amount of soil fertilizer nitrogen increased significantly, the residual rate showed a downward trend, and the nitrogen loss rate increased significantly. Dry-wet alternate irrigation treatment can increase nitrogen accumulation in different organs of rice in different periods, improve nitrogen use efficiency and rice yield to a certain extent. This study summarized the laws of nitrogen absorption, utilization, residue and loss of rice under different irrigation conditions and different nitrogen application conditions, which provided a theoretical basis for efficient cultivation of rice.

Highlights

Rice is one of the three most important staple foods in the world and plays an important role in global food production and consumption (Nguyen and Ferrero, 2006; Cheng and Hu, 2008)
It can be seen from the analysis of the whole growth period that with the increase of nitrogen application rate, the fertilizer nitrogen and total plant nitrogen accumulation increased significantly, the soil nitrogen accumulation basically showed the trend of N240 > N200 > N0 > N160, and compared with G1 treatment, G2 treatment can improve plant nitrogen absorption capacity under different nitrogen application treatments
15N tracer-based technology was used to study the laws of nitrogen absorption, utilization, residue and loss of rice under different irrigation conditions and different nitrogen application conditions

Summary

Introduction

Rice is one of the three most important staple foods in the world and plays an important role in global food production and consumption (Nguyen and Ferrero, 2006; Cheng and Hu, 2008). Previous studies have shown that nitrogen fertilizer losses in different ways, such as absorption by crops, soil residue, pollution of air and water systems through ammonia volatilization, surface runoff, leaching and denitrification (Ji et al, 2006; Li, 2020). Wu et al (2020) proposed that under the condition of alternate wetting and drying, the application of 180 kg/hm nitrogen fertilizer will achieve a synergistic and efficient utilization of water and fertilizer. 15N tracer-based technology can quantitatively study the fate of nitrogen in the soil-rice system (Wang et al, 2007) In this experiment, 15N tracer-based technology was used to study the effects of different nitrogen application rates on the absorption, transport, residue and loss of potted rice in soil and plants under different irrigation conditions, in order to achieve green, efficient, and high-yield rice production

Methods

Results

Conclusion