Study on water and fertilizer managements and evaluation of nitrogen and phosphorus non-point source pollution from paddy field

2014 ◽  
Vol 955-959 ◽  
pp. 941-945
Author(s):  
Dong Feng Huang ◽  
Li Min Wang ◽  
Wei Hua Li ◽  
Xin Jian Lin

Under the condition of natural rain and through the method of field runoff plots, a field experiment with 6 kinds of water and fertilizer managements in 5 years was carried out to study the effects of water and fertilizer managements on the concentration and loss of nitrogen and phosphorus by runoff from paddy field. Results showed that: Water quality of runoff under “none fertilization and routine irrigation”(CK) was the best, and which under “optimization fertilization and optimization irrigation”(OF+OI) took the second place. And the loss of nitrogen and phosphorus under CK was the least, and which under OF+OI was less. Thus, we can conclude that it is an economical and effective measure to control nitrogen and phosphorus non-point source pollution from paddy field by using the treatment of OF+OI.


2016 ◽  
Vol 14 (4) ◽  
pp. 600-608
Author(s):  
Fuyi Du ◽  
Qingjie Xie ◽  
Longxiang Fang ◽  
Hang Su

Nutrients (nitrogen and phosphorus) from agricultural non-point source (NPS) pollution have been increasingly recognized as a major contributor to the deterioration of water quality in recent years. The purpose of this article is to investigate the discrepancies in interception of nutrients in agricultural NPS pollution for eco-soil reactors using different filling schemes. Parallel eco-soil reactors of laboratory scale were created and filled with filter media, such as grit, zeolite, limestone, and gravel. Three filling schemes were adopted: increasing-sized filling (I-filling), decreasing-sized filling (D-filling), and blend-sized filling (B-filling). The systems were intermittent operations via simulated rainstorm runoff. The nutrient removal efficiency, biomass accumulation and vertical dissolved oxygen (DO) distribution were defined to assess the performance of eco-soil. The results showed that B-filling reactor presented an ideal DO for partial nitrification–denitrification across the eco-soil, and B-filling was the most stable in the change of bio-film accumulation trends with depth in the three fillings. Simultaneous and highest removals of NH4+-N (57.74–70.52%), total nitrogen (43.69–54.50%), and total phosphorus (42.50–55.00%) were obtained in the B-filling, demonstrating the efficiency of the blend filling schemes of eco-soil for oxygen transfer and biomass accumulation to cope with agricultural NPS pollution.


2013 ◽  
Vol 807-809 ◽  
pp. 1796-1799 ◽  
Author(s):  
Wei Wei Zhang ◽  
Hong Li

Quantifying agricultural non-point pollution load accurately and understanding contribution of the pollution sources clearly is the base how to control non-point source pollution effectively. Pollution loads from agricultural non-point source in the upper Lianghuai basin of Huairou Reservoir, including Huaisha River and Huaijiu River basin, were estimated according to export coefficient modeling. The results show that total nitrogen and total phosphorus loads in Lianghuai basin respectively are 322.52 t and 35.769 t in 2011.The total nitrogen and total phosphorus load intensities in Huaisha River basin are higher than that in Huaijiu River basin. Farmland planting including orchard and cropland, livestock and poultry breeding and rural domestic waste make a greater contribution to total nitrogen and total phosphorus loads. The study can provide scientific basis for further understanding characteristics of the nitrogen and phosphorus loads and agricultural structure adjustment.


2020 ◽  
Vol 12 (5) ◽  
pp. 2012 ◽  
Author(s):  
Jun Yang ◽  
Jiping Liang ◽  
Gaihe Yang ◽  
Yongzhong Feng ◽  
Guangxin Ren ◽  
...  

Non-point source pollution (NPSP) is a major challenge for current global water resources. The output characteristics of pollutants under different land use types are very important for controlling NPSP. In this study, long-term positioning monitoring and an analysis of rainfall runoff from different land use types were used to evaluate a typical watershed in the water source area of the middle route of the South-to-North Water Diversion Project (MR-SNWDP). The results show significant differences in nitrogen and phosphorus content in the runoff water bodies of various land use types. The nitrogen and phosphorus content in the MR-SNWDP was directly related to rainfall intensity and the fertilization period in the runoff following fertilization of farmland and vegetable plots. This nitrogen and phosphorus content was also observed to be significantly higher in the fertilization period than in other periods. The loss of nitrogen and phosphorus in forestland was greatly affected by rainfall intensity. Nitrogen in runoff comes primarily from farmland and vegetable fields, where its main form is nitrate nitrogen (NN). Vegetable fields are the main source of phosphorus, where its primary form is soluble phosphate (PO43−-P). Nitrogen and phosphorus have a defined incubation period during the dry season. Farmland and vegetable fields receive less rainfall during the dry season and it is difficult to form effective runoff; this allows nitrogen and phosphorus deposition. The runoff formed by the first rainfall at the beginning of the flood season (April or May) will carry a large amount of nitrogen and phosphorus from the soil into water bodies. Therefore, it is crucial to pay careful attention to the season when attempting to control NPSP.


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