JOURNAL OF NATURAL RESOURCES ›› 2016, Vol. 31 ›› Issue (2): 321-330.doi: 10.11849/zrzyxb.20141612

• Resource Evaluation • Previous Articles     Next Articles

Comparison on Phosphorus Budgets in Two Typical Subtropical Small Watersheds of China

WANG Mei-hui1, ZHOU Jiao-gen1, HAN Zeng1, MENG Cen1, YANG Wen1, 2, JIAO Jun-xia1, CHENG Mu-chun1, 3, LI Yu-yuan1, WU Jin-shui1   

  1. 1. Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, CAS, Changsha 410125, China;
    2. College Resources and Environmental Science, Hunan Normal University, Changsha 410081, China;
    3. College of Engineering, Hunan Agricultural University, Changsha 410128, China
  • Received:2014-12-09 Online:2016-02-25 Published:2016-02-25
  • Supported by:
    National Natural Science Foundation of China, No.41171396 and 41201299; National Key Technology Research and Development Program of China, No.2014BAD14B02

Abstract: Surplus phosphorus is a main source of non-point source pollution. Tuojia, a small agricultural watershed (52 km2) and Jianshan, a small forest-agricultural watershed (50 km2), located in Changsha County, Hunan Province, are taken as the case study. Based on the household surveys and 4-successive-year of observations of the phosphorus (P) flows at the terminal of river, substance flow analysis was used to quantify the budgets of P. Results showed that the concentrations of P in the agricultural ranged 0.03-0.68 mg·L-1, with the average 0.21 mg·L-1, while the corresponding one in the forest-agricultural ranged 0.01-0.35 mg·L-1 with the average 0.08 mg·L-1. The surface water quality in the forest-agricultural watershed was obviously better than that in the agricultural watershed. The phosphorus surplus intensity in the agricultural watershed was apparently higher (32.0 kg·hm-2·a-1) than that in the forest-agricul-tural watershed (20.6 kg·hm-2·a-1), and thus had a greater effect on environment. In 2013, livestock feeding accounted for 53.1% of total P inputs in the agricultural watershed, while fertilizer contributed 53.0% in the forest-agricultural. Generally, the phosphorus from plant and animal products dominated in both watersheds, approximately accounting for 94.0% of the total. Thus, controlling the amount of P fertilizer and improving its utilization efficiency are good ways to mitigate the eutrophication in the study area.

CLC Number: 

  • X131.2