Waqas Ahmed1,2,3, Huang Jing1, Liu Kailou4, Sehrish Ali1, Han Tianfu1, Sun Geng5, Chen Jin5, Muhammad Qaswar1, Du Jiangxue1, Sajid Mahmood2,3, Ali Akbar Maitlo1,6,7, Zulqarnain Haider Khan8,9, Huimin Zhang1, Di-Yun Chen2,3. 1. National Engineering Laboratory for Improving Quality of Arable Land, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, China. 2. Guangdong Provincial Key Laboratory for Radionuclides Pollution Control and Resources, School of Environmental Science and Engineering, Guangzhou University, Guangzhou, China. 3. School of Civil Engineering, Guangzhou University, Guangzhou, China. 4. National Engineering and Technology Research Center for Red Soil Improvement, Jiangxi Institute of Red Soil, Nanchang, China. 5. Hunan Institute of Soil and Fertilizer, Hunan Academy of Agricultural Sciences, Changsha, China. 6. Soil Fertility Research Institute, Agriculture Research Center, Tando Jam, Pakistan. 7. Department of Agriculture, Government of Sindh, Karachi, Pakistan. 8. Agro-Environmental Protection Institute, Ministry of Agriculture of China, Tianjin, China. 9. Chinese Academy of Agricultural Sciences, Beijing, China.
Abstract
Soil phosphorus (P) adsorption and desorption occur in an important endogenous cycle linked with soil fertility problems and relevant to the environmental risk assessment of P. In our study, the effect of long-term inorganic and organic fertilization on P adsorption and desorption characteristics in relation to changes in soil properties was evaluated by selecting three long-term experimental sites in southern China. The selected treatments at each site were CK (unfertilized), NPK (synthetic nitrogen, phosphorus and potassium) and NPKM (synthetic NPK plus manure). The adsorption and desorption characteristics of P were evaluated using Langmuir and Freundlich isotherms. The results showed that long-term application of NPK plus manure significantly increased soil organic carbon (SOC), total P and available P at all three sites compared with the NPK and CK treatments. All three treatments fit these equations well. The maximum adsorption capacity (Qm) of P increased with NPKM treatment, and the binding energy of P (K) and the maximum buffering capacity (MBC) showed increasing trends. NPKM showed the highest Qm (2346.13 mg kg-1) at the Jinxian site, followed by Nanchang (221.16 mg kg-1) and Ningxiang (2219.36 mg kg-1). Compared to CK and NPK, the NPKM treatment showed a higher MBC as 66.64, 46.93 and 44.39 L kg-1 at all three sites. The maximum desorption capacity (Dm) of P in soil was highest with the NPKM treatment (157.58, 166.76, 143.13 mg kg-1), showing a better ability to release P in soil. The correlation matrix showed a significant positive correlation of SOC, total and available P with Qm, Dm and MBC. In conclusion, it is suggested that manure addition is crucial to improve P utilization in red paddy soils within the recommended range to avoid the risk of environmental pollution.
Soil phosphorus (P) adsorpn>tion and desorpn>tion occur in an impn>ortant endogenous cycle linked with soil n>an class="Chemical">fertility problems and relevant to the environmental risk assessment of P. In our study, the effect of long-term inorganic and organic fertilization on P adsorption and desorption characteristics in relation to changes in soil properties was evaluated by selecting three long-term experimental sites in southern China. The selected treatments at each site were CK (unfertilized), NPK (synthetic nitrogen, phosphorus and potassium) and NPKM (synthetic NPK plus manure). The adsorption and desorption characteristics of P were evaluated using Langmuir and Freundlich isotherms. The results showed that long-term application of NPK plus manure significantly increased soil organic carbon (SOC), total P and available P at all three sites compared with the NPK and CK treatments. All three treatments fit these equations well. The maximum adsorption capacity (Qm) of P increased with NPKM treatment, and the binding energy of P (K) and the maximum buffering capacity (MBC) showed increasing trends. NPKM showed the highest Qm (2346.13 mg kg-1) at the Jinxian site, followed by Nanchang (221.16 mg kg-1) and Ningxiang (2219.36 mg kg-1). Compared to CK and NPK, the NPKM treatment showed a higher MBC as 66.64, 46.93 and 44.39 L kg-1 at all three sites. The maximum desorption capacity (Dm) of P in soil was highest with the NPKM treatment (157.58, 166.76, 143.13 mg kg-1), showing a better ability to release P in soil. The correlation matrix showed a significant positive correlation of SOC, total and available P with Qm, Dm and MBC. In conclusion, it is suggested that manure addition is crucial to improve P utilization in red paddy soils within the recommended range to avoid the risk of environmental pollution.
Authors: Gregory J McDonald; Stephen A Norton; Ivan J Fernandez; Kathy M Hoppe; Jeff Dennis; Aria Amirbahman Journal: Sci Total Environ Date: 2019-01-07 Impact factor: 7.963
Authors: Waqas Ahmed; Huang Jing; Liu Kaillou; Muhammad Qaswar; Muhammad Numan Khan; Chen Jin; Sun Geng; Huang Qinghai; Liu Yiren; Liu Guangrong; Sun Mei; Li Chao; Li Dongchu; Sehrish Ali; Yodgar Normatov; Sajid Mehmood; Huimin Zhang Journal: PLoS One Date: 2019-05-10 Impact factor: 3.240