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Effects of phosphorus fertilizer application rate on transformation processes of phosphorus fractions in the purple alluvial soil of a riparian zone

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Journal of Mountain Science 2023年第6期20卷 1561-1574页

作者： HE Li-ping JIA Kai-tao LIU Dan WANG Ke-hong DUAN Lin-Yan LIN Jun-jie Key Laboratory of Water Environment Evolution and Pollution Control in the Three Gorges Reservoir Chongqing Three Georges UniversityChongqing 404100China Department of Agricultural and Forestry Science and Technology Chongqing Three Gorges Vocation CollegeChongqing 404000China

Effects of phosphorus(P)fertilizer application rate on soil transformation processes of P fraction are still unclear in the riparian *** alluvial soils in the riparian zone of the Three Gorges Reservoir were collected to conduct a 21-day incubation executed by two hydrological environments(drying and flooding)and ten application rates of P *** percentages of P fertilizer(TPPF)were calculated as content differences of soil P fractions between fertilizer addition and none fertilizer addition divided by soil total P increases caused by fertilizer *** to inorganic P extracted by sodium hydroxide(NaOH-Pi)and hydrochloric acid(HCl-Pi)increase by 20.91%(9.71%)and 24.26%(40.72%)under the drying(flooding)***,TPPF to the other fractions *** fertilizer input mainly has indirect positive and negative effects on organic P via precipitated P under the drying and flooding environments and finally has indirect positive effects on labile P(papplication rate *** fertilizer input mainly increases organic P via precipitated P under the drying environment and decreases organic P via precipitated P under the flooding environment,and organic P is further transformed into labile *** P fertilizer input,P release caused by flooding is derived from NaHCO3-Po release triggered by NaOH-Pi *** results can be helpful for the understan

关键词： Hedley fractionation Phosphorus fraction Hydrological environments Three Gorges Reservoir application rate Riparian zone

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Soil enzymatic activities and microbial community structure with different application rates of Cd and Pb

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Journal of Environmental Sciences 2007年第7期19卷 834-840页

作者： KHAN Sardar CAO Qing HESHAM Abd El-Latif XIA Yue HE Ji-zheng Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Belting 100085 China. Department of Environmental Sciences University of Peshawar 25120 Peshawar Pakistan

This study focused on the changes of soil microbial diversity and potential inhibitory effects of heavy metals on soil enzymatic activities at different application rates of Cd and/or Pb. The soil used for experiments was collected from Beijing and classified as endoaquepts. Pots containing 500 g of the soil with different Cd and/or Pb application rates were incubated for a period of 0, 2, 9, 12 weeks in a glasshouse and the soil samples were analyzed for individual enzymes, including catalase, alkaline phosphatase and dehydrogenase, and the changes of microbial community structure. Results showed that heavy metals slightly inhibited the enzymatic activities in all the samples spiked with heavy metals. The extent of inhibition increased significantly with increasing level of heavy metals, and varied with the incubation periods. The soil bacterial community structure, as determined by polymerase chain reaction- denaturing gradient gel electrophoresis techniques, was different in the contaminated samples as compared to the control. The highest community change was observed in the samples amended with high level of Cd. Positive correlations were observed among the three enzymatic activities, but negative correlations were found between the amounts of the heavy metals and the enzymatic activities.

关键词： soil contamination heavy metals application rate enzymatic activity microbial community

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Wetting patterns and bacterial distributions in different soils from a surface point source applying effluents with varying Escherichia coli concentrations

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Journal of Integrative Agriculture 2016年第7期15卷 1625-1637页

作者： WEN Jie LI Jiu-sheng LI Yan-feng State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin China Institute of Water Resources andHydropower ResearchBeijing 100048P.R.China

Understanding bacterial transportation in unsaturated soil is helpful for reducing and avoiding pathogenic contamination that may be induced by irrigation with reclaimed waste water and for developing better irrigation management practic-es. Experiments were conducted to study the transport of a typical bacterium,Escherichia coli （E. coli）, in a sandy and a sandy loam soil under different application rates and input concentrations. A 30° wedge-shaped plexiglass container was used to represent one twelfth of the complete cylinder in the experiments. The apparent cylindrical application rate varied from 1.05 to 5.76 L h–1 and the input concentration ofE. coli from magnitude of 102 to 107 colony-forming unit （CFU） mL–1. For a given volume of water applied, an increase in application rate resulted in an increase in the wetted radius and a decrease in the wetted depth. In the sandy loam soil, the water spread out in a circular-arc shaped saturated zone on the surface, and the ultimate saturated entry radius increased with the application rate. An increasing application rate of water suspended bacteria alowed a more rapid transport of bacteria, thus acceleratingE. coli transport rate and resulting in a larger distributed volume ofE. coli for both soil types. For the sandy soil, more than 70% of theE. coli that was de-tected within the entire wetted volume concentrated in the range of 10 cm from the point source, and the concentration of E. colidecreased greatly as the distance from the point source increased. More than 98% of theE. coli was detected in a range of 5 cm around the saturated wetted zone for the sandy loam soil. For both soil types tested, an extremely high concentration ofE. coli was observed in the proximity of the point source, and the peak value increased with an increased input concentration. In principle, using an emitter with relative lower application rate would be effective to restrictE. coli transport. To reduce bacterial concentration in the sewage

关键词： application rate drip irrigation Escherichia coli input concentration

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Effect of Polyacrylamide application on Runoff,Erosion,and Soil Nutrient Loss Under Simulated Rainfall

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Pedosphere 2011年第5期21卷 628-638页

作者： WANG Ai-Ping LI Fa-Hu YANG Sheng-Min Inner Mongolia Coal Mine Design and Research Institute No. 55 Xinhua Road Hohhot 010010 (China) College of Water Conservancy and Civil Engineering China Agricultural University No. 17 Qinghua East Avenue Haidian District Beijing 100083 (China) State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau No. 26 Xinong Road Yangling 712100 (China) Beijing Vocational College of Agriculture No. 5 Daotiannanli Changyang Town Beijing 102442(China)

Soil erosion affects soil productivity and environmental quality.A laboratory research experiment under simulated heavy rainfall with tap water was conducted to investigate the effects of anionic polyacrylamide(PAM) application rates(0,0.5,1.0,and 2.0 g m-2) and molecular weights(12 and 18 Mg mol-1) on runoff,soil erosion,and soil nutrient loss at a slope of 5°.The results showed the two lower rates of PAM application decreased runoff while the highest rate increased runoff as compared with the *** concentration and soil mass loss increased significantly with the increasing PAM application *** with the control,PAM application decreased K+,NH4+,and NO3-concentrations in sediment and K+ and NH+4 concentrations in runoff,but significantly increased the mass losses of K+,NH4+,and NO-3 over soil surface except for the NH4+ at PAM application rate lower than 1.0 g *** application decreased the proportion of K+ loss with runoff to its total mass loss over soil surface from 60.1% to 16.4%.However,it did not affect the NH4+ and NO3-losses with runoff,and more than 86% of them were lost with runoff.A higher PAM molecular weight resulted in less soil erosion and K+ mass loss but had little effect on runoff and NH+4 and *** application did not prevent soil erosion and the mass losses of K+ and NO3-under experimental conditions.

关键词： application rate mass loss molecular weight nutrient concentration sediment concentration

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Specific Responses of Soil Microbial Residue Carbon to Long-Term Mineral Fertilizer applications to Reddish Paddy Soils

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Pedosphere 2018年第3期28卷 488-496页

作者： ZHANG Xinyu XIE Juan YANG Fengting DONG Wenyi DAI Xiaoqin YANG Yang SUN Xiaomin Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of Sciences Beijing 100101( China) College of Resources and Environment University of Chinese Academy of Sciences Beijing 100190( China) Institute of Environment and Sustainable Development in Agriculture Chinese Academy of Agricultural Sciences Beijing 100081(China)

Mineral nutrient inputs to soil may alter microbial activity and consequently influence the accumulation of microbial residues. In this study, we investigated the effects of application rates and ratios of mineral fertilizers on the microbial residue carbon(MRC) of reddish paddy soils after long-term(15-year) fertilizer applications in southern China. Contents of three soil amino sugars as microbial residue contents were determined and MRC were calculated based on amino sugars. Results showed that three individual amino sugar contents increased as fertilizer application rates increased until maximum values were reached at a rate of 450-59-187 kg ha^(-1) year^(-1)(N-P-K). The three amino sugar contents then declined significantly under the highest mineral fertilizer application rate of 675-88-280 kg ha^(-1) year^(-1)(N-P-K). In addition, to enhance the microbial residue contents, it was more beneficial to double P(N:P:K= 1:0.26:0.41) in fertilizers applied to the P-deficient reddish paddy soils than to double either N(N:P:K = 2:0.13:0.41) or K(N:P:K= 1:0.13:0.82). The contents of the three individual amino sugars and microbial residues under different fertilizer application rates and ratios were significantly and positively correlated with soil organic carbon(SOC), total N, total P, and p H. Increases in values of the fungal C to bacterial C ratios showed that soil organic matter(SOM) stability increased because of the fertilizer applications over the past 15 years. The contents and ratios of amino sugars can be used as indicators to evaluate the impact of mineral fertilizer applications on SOM dynamics in subtropical paddy soils. The results indicated that fertilizer applications at a rate of 450-59-187 kg ha^(-1) year^(-1)(N-P-K) may improve crop yields, SOC contents, and SOC stability in subtropical paddy soils.

关键词： amino sugar application rate application ratio bacterial C fungal C soil nutrient soil organic C

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Experimental Study of Preferential Solute Transportation During Dump Leaching

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Journal of China University of Mining and Technology 2006年第4期16卷 416-420页

作者： YIN Sheng-hua WU Ai-xiang Key Laboratory of Educational Ministry for High Efficient Mining and Safety in Mental Mine University of Science and Technology Beijing Beijing 100083 China

The production of dump leaching of the Dexing Copper Mine was affected by a preferential solution flow. Formative mechanism of the preferential solution flow was investigated by analyzing the relationship between both dump permeability and surface tension and ore diameter. The preferential solution flow occured in the fine ore area when the application rate was low. The preferential solution flow entered into the coarse ore area because the negative pore water pressure disappeared with an increase of the application rate. The preferential solute transportation experiment was conducted by selecting NaCl as mineral. Results of the experiment showed that the concentration of the outflow solution reduced over time. The concentration of the coarse ore area outflow solution was greater than that of the fine ore area. The process of NaCl leaching can be divided into two stages. NaCl was carried out directly by diffusion--convection during the first stage, so the leaching rate increased sharply. But in the second stage, only a small amount of NaCl dissolved in the immobile water. The leaching rate increased slowly because NaC1, dissolved in the immobile water, can only be leached by diffusion.

关键词： dump leaching preferential solution flow solute preferential transportation application rate leaching rate

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Sprinkler irrigation system for tea frost protection and the application effect

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International Journal of Agricultural and Biological Engineering 2016年第5期9卷 17-23页

作者： Hu Yongguang Zhao Chen Liu Pengfei Asante Eric Amoah Li Pingping Key Laboratory of Modern Agricultural Equipment and Technology Jiangsu UniversityZhenjiang 212013China College of Biology and the Environment Nanjing Forestry UniversityNanjing 210037China

A sprinkler irrigation system was designed and applied for a tea field to achieve frost protection through latent heat release when water turning into *** protection effects during night were tested at different irrigation application rates by monitoring air temperature around tea canopy(Tc).Temperature sensors were arranged at different distances from the *** preliminary results showed that,when the sprinkler system worked continuously at the application rate of 2-4 mm/h before sunrise,tea canopy was covered with ice and Tc remained around 0℃,preventing tea plants from frost *** no more temperature rise was obviously observed at the application rates above 4 mm/h,which means less cost *** system was stopped after sunrise when background air temperature rose back to 0℃and Tc increased by 2.2℃in one hour,while Tc of non-irrigated area increased by 4.8℃,which might cause thawing injuries to tea *** leaf surface temperature was lower than Tc,and the difference between the leaf surface temperature and Tc decreased with the increase of application ***,the sprinkler irrigation system could achieve tea frost protection,and the recommended application rate was 2-4 mm/h for better protection *** system should keep running throughout frost night till half an hour after *** start and stop of the sprinkler irrigation system should be controlled based on Tc.

关键词： sprinkler irrigation frost protection Camellia Sinensis L application rate temperature rise frost damage

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Uptake of Phosphorus from Modified P-Enriched Douglas Fir Biochar and Its Effects on Crop Growth and P Use Efficiency

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Journal of Geoscience and Environment Protection 2022年第9期10卷 207-229页

作者： Beatrice Arwenyo Jac J. Varco Andrew Dygert Jaime Berry Julianna Mills Dinesh Mohan Charles U. Pittman Jr. Todd Mlsna Department of Chemistry Mississippi State University Mississippi State USA Department of Chemistry Gulu University Gulu Uganda Department of Plant and Soil Science Mississippi State University Mississippi State USA School of Environmental Sciences Jawaharlal Nehru University New Delhi India

The potential use of biochar as a sustainable soil amendment has recently gained global recognition. The use of biochar as a soil additive is attributed to its ability to improve soil chemical, physical and biological properties. Studies have shown that biochar amendments can enhance soil nutrient retention and availability, pH, water holding capacity, microbial activity and sequester carbon. In this study using corn (Zea mays L.) as an experimental crop, the influence of P availability from modified P enriched Douglas fir biochar (PEB), triple super phosphate fertilizer (SPF), and modified Douglas fir biochar (MB) on plant growth and P Use Efficiency (PUE) were compared. The rate of P applied (0, 30, 60, 90 and 120 kg·ha-1) was calculated based on % P content of each soil additive. Except for MB treatments, P recovery, crop growth and P Use Efficiency increased with application rates. The maximum above ground dry matter yields corresponding to PEB, SPF and MB treatments were estimated at 3488 kg·ha-1, 2449 kg·ha-1 and 639 kg·ha-1, while their respective agronomic P use efficiency (AGE) rates were 32 kg·kg-1, 17 kg·kg-1, 0.5 kg·kg-1. Also, recovery of K, Mg, Ca, Zn, Fe, Cu, B and Mn improved in both PEB (p value 0.9) and SPF (p value 2 > 0.9) treatments. More studies at field scale are needed to demonstrate the practicability of using modified P enriched Douglas fir biochar for soil amendments.

关键词： Macronutrients Dry Matter Yield Micronutrients application rate

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