Nitrogen use efficiency in grain production and the estimated nitrogen input/output balance in China agriculture. (14th September 2012)

• Record Type: Journal Article
• Authors: Li, Shutian; He, Ping; Jin, Jiyun
• Is Part Of: Journal of the science of food and agriculture. Volume 93:Number 5(2013:Mar. 30)
• Page Start: 1191
• Page End: 1197
• Publication Date: 2012-09-14
• Subjects: Food -- Periodicals; Agriculture -- Periodicals; 664
• DOI: 10.1002/jsfa.5874
• Languages: English
• ISSNs: 0022-5142

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p> <bold>BACKGROUND</bold> Understanding the nitrogen (N) use efficiency and N input/output balance in the agricultural system is crucial for best management of N fertilisers in China.</p> <p> <bold>RESULTS</bold> In the last 60 years, N fertiliser consumption correlated positively with grain production. During that period the partial factor productivity of N (PFP<sub>N</sub>) declined greatly from more than 1000 kg grain kg<sup>−1</sup> N in the 1950s to nearly 30 kg grain kg<sup>−1</sup> N in 2008. This change in PFP<sub>N</sub> could be largely explained by the increase in N rate. The average agronomic efficiency of fertiliser N (AE<sub>N</sub>) for rice, wheat and maize during 2000‐2010 was 12.6, 8.3 and 11.5 kg kg<sup>−1</sup> respectively, which was similar to that in the early 1980s but lower than that in the early 1960s. Estimation based on statistical data showed that a total of 49.16 × 10<sup>6</sup> t of N was input into Chinese agriculture, of which chemical N, organic fertiliser N, biological fixed N and other sources accounted for 58.2, 24.3, 10.5 and 7.0% respectively. Nitrogen was surplus in all regions, the total N surplus being 10.6 × 10<sup>6</sup> t (60.6 kg ha<sup>−1</sup>).</p> <p> <bold>CONCLUSION</bold> The great challenge is to balance the use of current N fertilisers between regions and crops to improve N use efficiency while maintaining or increasing crop production under the high‐intensity agricultural system of China. © 2012 Society of Chemical Industry</p> </abstract>