Influence of Long-Term Fertilization on Crop Production and Soil Quality of a Recent Alluvial Soil

The Yellow River Delta (YRD) has been formed during the last 150 yr and is the youngest land in China. Identifying the current soil quality, the impact of long-term fertilization on crop production, and how to improve crop production in this region are of great concern to scientists and the government. The objectives of this research were to analyze the trends of wheat (Triticum aestivum L.) and corn (Zea mays L.) production and fertilizer application using data covering a period of about 25 yr, determine the current soil quality and compare the changes of that with soils collected in the second national soil census, and discuss the impact of long-term fertilization on crop production and soil quality in the YRD. Records indicated that crop production increased 2.1-fold from 1984 to 2008, with an approximate 3.5-fold increase in fertilizer application. A fuzzy comprehensive assessment of soil quality indicated an improvement during this same time period, but the average soil quality was still low relative to national standards, particularly due to low N availability. Although fertilization strategies appeared to have been successful in this region, declines in fertilizer use efficiency and the currently poor soil quality indicate a need for improved management strategies. Effective technology and education programs are required to improve fertilizer application practices and the management of soil quality, which would increase crop production.