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Shao G.,Key Laboratory of Efficient Irrigation Drainage and Agricultural Soil Water Environment in Southern China | Shao G.,Hohai University | Guo R.,Key Laboratory of Efficient Irrigation Drainage and Agricultural Soil Water Environment in Southern China | Guo R.,Hohai University | Liu N.,Nanjing University of Information Science and Technology
Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering | Year: 2011

In order to realize water-saving, high quality and high yield of hot pepper by scientifically and rationally regulating soil water, the influence of different irrigation patterns on chlorophyll fluorescence parameters of hot pepper under the condition of rain-shelter with OS5-FL modulated chlorophyll fluorometer was studied. The results showed that with the reduce of irrigation water volume, hot pepper variable fluorescence(Fv), maximum fluorescence(Fm), the ratio of the variable to maximum fluorescence(Fv/Fm), the ratio of the variable to minimal fluorescence(Fv/Fo) and the photochemical quenching coefficient(qP) and non-photochemical quenching coefficient(qN) at the four growing stage decreased, while the minimal fluorescence(Fo) raised. Analysis indicated that photosystem II damaged, and primary light energy conversion of PS II(Fv/Fm), potential activities of PS II(Fv/Fo) decreased, photosynthetic electron transport, photosynthetic primary reaction inhibited, the ability of heat disseminate increased. In the three treatments of DI50, 1PRD and 2PRD. Chlorophyll fluorescence parameters of hot pepper under 1PRD changed smaller compared to CK. However, the chlorophyll fluorescence parameters were not significantly affected by irrigation patterns during four measurement. Source


Bi L.,Key Laboratory of Efficient Irrigation Drainage and Agricultural Soil Water Environment in Southern China | Bi L.,Hohai University | Xia J.,Key Laboratory of Efficient Irrigation Drainage and Agricultural Soil Water Environment in Southern China | Xia J.,Hohai University | And 3 more authors.
Plant, Soil and Environment | Year: 2014

A long-term (33 years) experiments were conducted to investigate the effect of chemical fertilization on rice yield, yield trends, soil properties, agronomic efficiency of applied nutrients and nutrient balance for the double rice cropping systems in subtropical China. The treatments were different combinations of N, P and K fertilizers (N, NP, NK and NPK), double dose of recommended NPK (2NPK) and no fertilizer control (control). Compared with no fertilizer control, all fertilization treatments had no significant effects on soil pH and SOC contents (P > 0.05), but generally increased nutrients content when corresponding elements were applied. The impact of fertilizers on grain yields was 2NPK > NPK > NP > NK > N, and application of P fertilizer not only increased the rice yield, but improved yield stability. The trend of agronomic use efficiency of applied P was significantly positive (P < 0.05) only for the first rice crop, suggesting that P fertilizer played a less important role in the second rice season than in the first rice season. The study indicated that the current local fertilizer recommendations should be optimized for the consideration of differences in indigenous nutrient supplies in different rice seasons. © 2014, Institute of Agricultural and Food Information. All rights reserved. Source


Hou M.,Fujian Agriculture and forestry University | Shao X.,Hohai University | Shao X.,Key Laboratory of Efficient Irrigation Drainage and Agricultural Soil Water Environment in Southern China | Zhai Y.,Hohai University | And 3 more authors.
Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering | Year: 2016

In order to study how the later-season flue-cured tobaccos absorb and utilize the fertilizer N that remained by the first season, in 2011, an experiment controlled with different irrigation amount (600, 800 and 1 000 mm) and different fertilizer nitrogen amount (15N double labeled NH4NO3, 90 and 120 kg/hm2) was conducted using the lysimeters, and the 15N-N (fertilizer N originated from 2011) amount in the tobacco organs and the soils were observed during the flue-cured tobacco cultivation from 2012 to 2014.Meanwhile, the impact factors of the tobaccos' reutilization rate to the first-season fertilizer N were analyzed. Results showed that: 1) the amount of fertilizer N that originated from the first season in the later-season tobacco leaf, stem and root, was increased as the nitrogen application increased in the first season, but overall decreased as the irrigation amount increased; 2) the total reutilization rate of the 3 later-season tobaccos to the fertilizer N that applied by the first season was 10.79%-14.58%, and 600 mm amount of irrigation combined with 90 kg/hm2 amount of nitrogen application was most advantageous for the later-season tobaccos to absorb the fertilizer N that remained by the first season; 3) the average reutilization rate of the 3-later season tobaccos to the fertilizer N that applied by the first season, was negatively related with the irrigation amount in the first season (P<0.01), and was positively related with the amount of fertilizer N that remained by the first season in 0-20 cm soils (P<0.05). The first-season irrigation affected the reutilization rate of later-season tobaccos to the fertilizer N that applied by the first season through changing the distribution pattern of the fertilizer N, especially through changing the amount of fertilizer N in the 0-20 cm soils. However, the detailed impact mechanism still needed to be further clarified. Above all, the later-season flue-cured tobaccos can absorb many of the fertilizer N that applied by the earlier season, and the reasonable formulation of irrigation and nitrogen application regimes in the earlier season was extremely important for improving the fertilizer N reutilization rate of later-season tobaccos. The research conclusions can provide useful information for the improvement of the soil ecological environment of tobacco-cultivated areas and the sustainable development of the tobacco agriculture. © 2016, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved. Source


Jin Q.,Jiangsu Water Conservancy Research Institute | Wu Y.B.,Jiangsu Water Conservancy Research Institute | Ji J.Z.,Huaian Investigation and Design Institute of Water Conservancy | Chen L.H.,Key Laboratory of Efficient Irrigation Drainage and Agricultural Soil Water Environment in Southern China
Advances in Energy Science and Equipment Engineering - Proceedings of International Conference on Energy Equipment Science and Engineering, ICEESE 2015 | Year: 2015

A large quantity of landfill leachate with many kinds of toxic and harmful substances produced during the degradation process of solid waste in landfill can cause serious environmental pollution, so it is important to find out an available technology to solve this problem. The use of Effective Microorganisms (EM) technology for reducing organic pollutant of landfill leachate has often been suggested as a feasible method in landfills, but the activity of EM can be influenced by surroundings such as aerobic or anaerobic, temperature, pH and the addition of volume rate between EM and landfill leachate. Laboratory tests show that the efficiency of the treatment of landfill leachate by EM technology reaches the highest rate under the condition of aerobic, 25∼35°C, pH 7.0∼8.0 and 1/2000∼1/1000 volume ratio between EM and landfill leachate, the removal rate of Chemical Oxygen Demand (COD) and ammonium nitrogen (NH3-N) of landfill leachate is about 60% after 10 days of the treatment. Under anaerobic conditions as control subjects, COD of landfill leachate with EM can not reduce, while the concentration of NH3-N increased because of the effect of denitrification. It must be noted that the COD of EM is over 20,000 mg/L, if the proportion of EM and leachate is too high, the COD of leachate may increase in opposition to what is expected, so the addition of volume rate between EM and landfill leachate should be tested to content with the various demands of the special purposes by a laboratory study before applying it in landfills. © 2015 Taylor & Francis Group, London. Source


Zhang J.,Key Laboratory of Efficient Irrigation Drainage and Agricultural Soil Water Environment in Southern China | Zhang J.,Hohai University | Chang T.,Hohai University | Shao X.,Key Laboratory of Efficient Irrigation Drainage and Agricultural Soil Water Environment in Southern China | Shao X.,Hohai University
Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering | Year: 2012

In order to solve the problem of secondary salinization of greenhouse soil, a subsurface drainage system was set up with plastic bellows buried in the soil of the greenhouse to probe into the measures against secondary salinization of soil, and to study the changes of soil basic physicochemical properties through subsurface drainage. Soil electrical conductivity (EC), soil saturated hydraulic conductivit, bulk density, porosity and yield of tomato were studied. The system was installed with two arrangements, space of 6 m and depth of 40 cm; space of 8 m and depth of 70 cm. Results showed that the subsurface drainage system lowered the EC of different soil layers, especially the EC of soil which above the subsurface drainage. Meanwhile, saturated hydraulic conductivity of soil increased, bulk density decreased, but bulk porosity increased. The tomato yield increased as the average weight of single fruit increased. All these indicators of the system with space 8 m and depth 70 cm were better than those of the system with space 6 m and depth 40 cm. It is concluded that the effect of drainage system with space 8 m and depth 70 cm on improvement of soil secondary salinization was more significant than that of the system with space 6 m and depth 40 cm in greenhouse. Source

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