Analysis of the fertilizer application status in root vegetables and potentials of saving energy and reducing emission - a case study of Hebei province

摘要

This study analyzed the fertilizer application status of three root vegetables, i.e., yam, radish and carrot, in Hebei province and calculated the potentials for energy saving and emission reduction through analysis of survey and statistical data. Theresults indicated that the unreasonable fertilization was the main factor contributing to the low yield, poor quality and low nutrient use efficiency of root vegetable production. Over-application of N, P and K fertilizers was common, and was serious inyam production. The total amount of nutrient inputs was not high for the production of radish and carrot, but there was an imbalance of N, P and K nutrition. Based on the assumption of reasonable fertilization and improving fertilizer nutrient use efficiency by 5%, the production of these three root vegetables in Hebei province could reduce the consumption of urea, diammonium phosphate and potassium sulphate by 10.1-11.5,15.8-16.9 and 8.9-10.2 thousand t in one season, respectively; which would resultin savings of 6.4 thousand t of ammonia, 15.1 thousand t of steam, and 1.3 million kWh of electricity from reduced urea production. The reductions in energy consumption and the gas losses would also save 11.4 and 2.6 thousand t of standard coal, respectively. In the production of phosphate fertilizer, 19.7-41.0 thousand t of phosphate rock resources, 6.6 thousand t of water, 2.0 thousand t of coal, and 497 thousand kWh of electricity could be saved. The wasted amount of phosphate rock resources could bedecreased by 9.8-24.6 thousand t. Additionally, the discharge of ammonia-N, the chemical oxygen demand (COD), suspended solids (SS), phosphogypsum and sewage could also be reduced significantly. In conclusion, there were great potentials for saving energy and reducing emissions through scientific fertilization in the productions of root vegetables, which could not only appreciably reduce the cost of production and improve economic benefits, but also achieve considerable ecological and social benefits.