Chapter Four - Fertilizer Intensification and Its Impacts in China's HHH Plains

Abstract

Abstract The accomplishment of China's food security by application of high rates of fertilizers has generated several controversies regarding the quality of soil and water resources. Thus, the objective of this chapter is to assess the effects and causes of the fertilizer intensification in the Huang Huai Hai (HHH) plains in China based on the data from five long-term experiments conducted over a period of 20 years, and those from the National Bureau of Statistics of China. The HHH region produces almost 60–80% of China's wheat and 35–40% of China's corn every year. The average increase in yield (kg ha− 1) between 1985 and 2009 ranged from 1582 to 5860 for wheat and 4492 to 5610 for corn. However, the average rates (kg ha− 1year− 1) of fertilizer use are about 430 of N, 107 of P, and 17 of K. The results from five long-term experiments on sites representative the HHH indicated that fertilizer intensification resulted in an increasing trend of high input of nutrients → high SOM concentration → high yields of wheat (Triticum aestivum) and corn (Zea mays) → higher SOM concentration → higher rate of application of fertilizer in agroecosystems. These mechanisms motivated the farm households to apply higher rate of fertilizer to obtain higher and stable crop yields despite large uncertainties in crop production due to climate change and other risks. Important among future research needs are precision agriculture, soil test, micronutrients, and foliar applications, to enhance the use efficiency of fertilizers and reduce losses.