Regional distribution of nitrogen fertilizer use and N-saving potential for improvement of food production and nitrogen use efficiency in China

Abstract

The study suggests that to achieve the goals of regional yield improvement, it is necessary to readjust and optimize regional distribution of N fertilizer use between the N-poor and N-rich regions in China, in combination with other nutrient management practices.

Factors controlling regional grain yield in China over the last 20 years

“…However, several long-term field studies have observed a reduced yield response to continuously increasing chemical fertilizer use . Previous analysis showed that the growth rate of grain yields was closely related to the increase in fertilizer use during 1980-1985, while there was a declining trend of yield response to the increase in fertilizer use over the subsequent time period , and an increasing number of regions with little or no yield response to changes in fertilizer rate over time after the 1990s (Wang et al 2011). As our results indicated, regional yield responses to fertilizer added were positive (Table 1) over time, while they were higher for Northeast China and East China, as compared to North China and Central and Southwest China, with regression model coefficients (in kg kg −1 ) of 9.3, 5.7, 1.7, and 1.2, respectively, for Northeast China, East China, North China, and Central and Southwest China.…”

“…Over the last 20 years, fertilizer use in China has rapidly increased to meet the increasing food demand of its growing population. Fertilizer use plays an irreplaceable role in China's food production, resulting in a 50 % increase in the total grain production in China (Wang et al 2011). However, several long-term field studies have observed a reduced yield response to continuously increasing chemical fertilizer use .…”

“…Total fertilizer consumption increased by about 276 %, while the total grain production increased by about 51 % over this period (Wang et al 2011). The average fertilizer rate per unit cropland in China increased from 87 to 307 kg ha −1 , and the average grain yields per unit cropland increased from 2734 to 4642 kg ha −1 over this period.…”

“…The average fertilizer rate per unit cropland in China increased from 87 to 307 kg ha −1 , and the average grain yields per unit cropland increased from 2734 to 4642 kg ha −1 over this period. However, the fertilizer-use efficiency, expressed as grain production per unit of fertilizer applied, decreased by about 52 %, from 32 to 15 kg kg −1 during 1980-2005, along with a declining trend of grain yield responses to the increase in fertilizer use over time (Wang et al 2011). Several long-term field studies also observed a reduced yield response to continuously increasing application of inorganic fertilizer alone, but not when inorganic and organic fertilizers were applied together ).…”

“…Several long-term field studies also observed a reduced yield response to continuously increasing application of inorganic fertilizer alone, but not when inorganic and organic fertilizers were applied together ). An analysis based on China statistical data suggested that the fertilizer-use efficiency could be improved by reducing regional N fertilizer input by at least 15 % in the N-rich regions and thus increasing regional fertilizer-use efficiency by 23 %, while yields in the N-poor regions could be improved by 21 % through an increased N input of 13 % (Wang et al 2011). …”