Spatial and temporal variations of crop fertilization and soil fertility in the loess plateau in china from the 1970s to the 2000s.
Increased fertilizer input in agricultural systems during the last few decades has resulted in large yield increases, but also in environmental problems. We used data from published papers and a soil testing and fertilization project in Shaanxi province during the years 2005 to 2009 to analyze chemical fertilizer inputs and yields of wheat (Triticum aestivum L.) and maize (Zea mays L.) on the farmers' level, and soil fertility change from the 1970s to the 2000s in the Loess Plateau in China. The results showed that in different regions of the province, chemical fertilizer NPK inputs and yields of wheat and maize increased. With regard to soil nutrient balance, N and P gradually changed from deficit to surplus levels, while K deficiency became more severe. In addition, soil organic matter, total nitrogen, alkali-hydrolysis nitrogen, available phosphorus and available potassium increased during the same period. The PFP of N, NP and NPK on wheat and maize all decreased from the 1970s to the 2000s as a whole. With the increase in N fertilizer inputs, both soil total nitrogen and alkali-hydrolysis nitrogen increased; P fertilizer increased soil available phosphorus and K fertilizer increased soil available potassium. At the same time, soil organic matter, total nitrogen, alkali-hydrolysis nitrogen, available phosphorus and available potassium all had positive impacts on crop yields. In order to promote food safety and environmental protection, fertilizer requirements should be assessed at the farmers' level. In many cases, farmers should be encouraged to reduce nitrogen and phosphate fertilizer inputs significantly, but increase potassium fertilizer and organic manure on cereal crops as a whole.
College of Natural Resources and Environment, Northwest A&F University, Yangling, China; Key Laboratory of Plant Nutrition and the Agri-environment in Northwest China, Ministry of Agriculture, Yangling, China.
Xiaoying
X
Wang
College of Natural Resources and Environment, Northwest A&F University, Yangling, China; Key Laboratory of Plant Nutrition and the Agri-environment in Northwest China, Ministry of Agriculture, Yangling, China.
Yanan
Y
Tong
College of Natural Resources and Environment, Northwest A&F University, Yangling, China.
Yimin
Y
Gao
College of Natural Resources and Environment, Northwest A&F University, Yangling, China.
Pengcheng
P
Gao
College of Natural Resources and Environment, Northwest A&F University, Yangling, China.
Fen
F
Liu
College of Natural Resources and Environment, Northwest A&F University, Yangling, China.
Zuoping
Z
Zhao
College of Natural Resources and Environment, Northwest A&F University, Yangling, China.
Yan
Y
Pang
D000383:Agriculture / Q000379:methods; D002681:China; D003247:Conservation of Natural Resources; D018556:Crops, Agricultural / Q000254:growth & development*; D005308:Fertilizers / Q000032:analysis*; D009584:Nitrogen / Q000032:analysis; D010758:Phosphorus / Q000032:analysis; D011188:Potassium / Q000032:analysis; D012987:Soil / Q000737:chemistry*; D014908:Triticum / Q000254:growth & development*; D003313:Zea mays / Q000254:growth & development*
D005308:Fertilizers; D012987:Soil; D010758:Phosphorus; D009584:Nitrogen; D011188:Potassium