Phosphorus(P)in surface runoff from purple soil is a critical element of agricultural nonpoint source pollution,leading to eutrophication of surface waters in the Three Gorges Reservoir Area(TGRA)of China.This work ai...Phosphorus(P)in surface runoff from purple soil is a critical element of agricultural nonpoint source pollution,leading to eutrophication of surface waters in the Three Gorges Reservoir Area(TGRA)of China.This work aimed to understand the processes and mechanisms of P losses from bare purple soil.Based on an indoor rainfall simulation experiment,we focused on the processes of surface runoff and P losses via different hydrological pathways.Experimental treatments included three simulated rainfall intensities,four slope gradients,and three fertilizer treatments.P loss from sediment was the main pathway in the purple soil,and bioavailable P was mainly transferred in dissolved P(DP)of runoff water.The P loss loads tend to grow with the increase of the slope until 25°for the maximum load of runoff water and 20°for the maximum load of sediment.Concentrations of DP in the surface runoff after fertilizer application can exceed the estimates of those required for accelerated eutrophication.Sediment P control might be an essential way for reducing P loss in purple soil for the local government and farmers of TGRA.展开更多
1 Introduction China has a vast area of continental shelf and is very rich in marine resources,but because of the complex geological environment and frequent geological disasters,the utilization of marine resources an...1 Introduction China has a vast area of continental shelf and is very rich in marine resources,but because of the complex geological environment and frequent geological disasters,the utilization of marine resources and the construction of marine engineering are limited(Zhu et al.,2016).As the展开更多
Soil Organic Carbon （SOC） is the most important component of soil. Though small, it determines soil fertility and prevents soil losses. In this study, we examined relationships between the Particle-Size Distribution...Soil Organic Carbon （SOC） is the most important component of soil. Though small, it determines soil fertility and prevents soil losses. In this study, we examined relationships between the Particle-Size Distribution （PSD） of the eroded sediment and SOC loss, and evaluated the effects of plant coverage ratios （0%, 15%, 30%, 45%, 60% and 90%）, slope lengths （2 m, 4 m）, fertilizer treatments （unfertilized control （CK）, compound N-P-K fertilizer （CF）, and organic fertilizer （OF）） on SOC loss and the SOC enrichment ratio （ERsoc） in the eroded sediments. The experimental results showed that longer slope length and lower surface cover ratios produced larger surface runoff and the eroded sediments, resulting in larger SOC losses. The average SOC loss was greatest in the OF treatment and SOC loss was mainly associated with the eroded sediment. Surface runoff, which causes soil erosion, is a selective transportation process, hence there were more clay- sized particles （〈2 μm） and silt-sized particles （2-50μm） in the eroded sediments than in the original soils. SOC was enriched in the eroded sediments relative to in the original soil when ERsoc 〉 1. ERsoc was positively correlated with ERclay （〈2 pro） （R^2 = o.68） and ERie at （2-20 μm） （R2 = 0.63）, and from all the size particle categories of the original soil or the eroded sediments, more than 95% of SOC was concentrated in small-sized partieles （〈50 μm）. The distribution of SOC in different-sized particles of the original soil and the eroded sediment is primarily associated with clay-sized part-ides and fine silt-sized particles, thus we eonelude that as the eroded sediment partieles became finer, more SOC was absorbed, resulting in more severe SOC loss.展开更多
基金jointly supported by the National Natural Science Foundation,China(41907124,3210130653,51908233)Program for Innovative Research Team of Excellent Middle-Aged and Young in Higher Education Institutions of Hubei Province(T2021011)+2 种基金Nature Science Foundation of Hubei Province,China(2020CFB465)Educational Commission of Hubei Province,China(D20202503)Open Fund of Research Center for Transition and Development of Resources-exhausted City,China(KF2020Z03)。
文摘Phosphorus(P)in surface runoff from purple soil is a critical element of agricultural nonpoint source pollution,leading to eutrophication of surface waters in the Three Gorges Reservoir Area(TGRA)of China.This work aimed to understand the processes and mechanisms of P losses from bare purple soil.Based on an indoor rainfall simulation experiment,we focused on the processes of surface runoff and P losses via different hydrological pathways.Experimental treatments included three simulated rainfall intensities,four slope gradients,and three fertilizer treatments.P loss from sediment was the main pathway in the purple soil,and bioavailable P was mainly transferred in dissolved P(DP)of runoff water.The P loss loads tend to grow with the increase of the slope until 25°for the maximum load of runoff water and 20°for the maximum load of sediment.Concentrations of DP in the surface runoff after fertilizer application can exceed the estimates of those required for accelerated eutrophication.Sediment P control might be an essential way for reducing P loss in purple soil for the local government and farmers of TGRA.
基金supported by NSFC Open Research Cruise (Cruise No. NORC2015-05 and Cruise No. NORC2015-06)funded by Shiptime Sharing Project of NSFC
文摘1 Introduction China has a vast area of continental shelf and is very rich in marine resources,but because of the complex geological environment and frequent geological disasters,the utilization of marine resources and the construction of marine engineering are limited(Zhu et al.,2016).As the
基金funded by Water and Soil Conservation Monitoring Technology Innovation Team and Construction of China(Grant No.2009F20022)National Natural Science Foundation of China(Grant No.41471221)
文摘Soil Organic Carbon （SOC） is the most important component of soil. Though small, it determines soil fertility and prevents soil losses. In this study, we examined relationships between the Particle-Size Distribution （PSD） of the eroded sediment and SOC loss, and evaluated the effects of plant coverage ratios （0%, 15%, 30%, 45%, 60% and 90%）, slope lengths （2 m, 4 m）, fertilizer treatments （unfertilized control （CK）, compound N-P-K fertilizer （CF）, and organic fertilizer （OF）） on SOC loss and the SOC enrichment ratio （ERsoc） in the eroded sediments. The experimental results showed that longer slope length and lower surface cover ratios produced larger surface runoff and the eroded sediments, resulting in larger SOC losses. The average SOC loss was greatest in the OF treatment and SOC loss was mainly associated with the eroded sediment. Surface runoff, which causes soil erosion, is a selective transportation process, hence there were more clay- sized particles （〈2 μm） and silt-sized particles （2-50μm） in the eroded sediments than in the original soils. SOC was enriched in the eroded sediments relative to in the original soil when ERsoc 〉 1. ERsoc was positively correlated with ERclay （〈2 pro） （R^2 = o.68） and ERie at （2-20 μm） （R2 = 0.63）, and from all the size particle categories of the original soil or the eroded sediments, more than 95% of SOC was concentrated in small-sized partieles （〈50 μm）. The distribution of SOC in different-sized particles of the original soil and the eroded sediment is primarily associated with clay-sized part-ides and fine silt-sized particles, thus we eonelude that as the eroded sediment partieles became finer, more SOC was absorbed, resulting in more severe SOC loss.
