[Research of potassium flow and circulation based on substance flow analysis].
Mass of potassium is consumed in the process of crop production, which is the dominating section of potassium flow and circulation in China. However, the degree of self-sufficiency is relatively low due to the deficient domestic resource of potassium. This study analyzed the key links of potassium issues in crop production and consumptive use in 2009 based on substance flow analysis. The results indicated that the farmland nutrient balance of input/output couldn't make even, with a heavy deficit of 50.4 kg x hm(-2) at the national level. Meanwhile, about 2.31 million ton of potash fertilizer was washed away into the hydrologic cycle, which accounts for 40.97% of chemical fertilizer applied in the whole year. Domestic wastewater in urban and rural areas was identified as another primary source for the transformation of potassium from terrestrial ecosystem to water environment system, annually contributing 671 and 547 thousand tons, which takes up 19.00% and 15.50%, respectively. And the amount of potassium in effluent of wastewater treatment plants was 505 thousand tons per year, accounting for 75.25% of the total emission in urban areas.
School of Environment, Tsinghua University, Beijing 100084, China. baihua0001@163.com
Hua
H
Bai
Si-Yu
SY
Zeng
Xin
X
Dong
Ji-Ning
JN
Chen
D002681:China; D018556:Crops, Agricultural / Q000254:growth & development / Q000378:metabolism*; D017753:Ecosystem; D005308:Fertilizers; D011188:Potassium / Q000032:analysis*; D012987:Soil / Q000737:chemistry*; D062065:Wastewater / Q000737:chemistry; D014867:Water / Q000737:chemistry*
D005308:Fertilizers; D011188:Potassium; D012987:Soil; D062065:Wastewater; D014867:Water