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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.


Guang-Cheng S.,Key Laboratory of Efficient Irrigation Drainage and Agricultural Soil Water Environment in Southern China | Guang-Cheng S.,Hohai University | Na L.,Nanjing University of Information Science and Technology | Zhan-Yu Z.,Key Laboratory of Efficient Irrigation Drainage and Agricultural Soil Water Environment in Southern China | And 3 more authors.
Scientia Horticulturae | Year: 2010

Greenhouse-grown hot pepper was used to investigate the effect of Time-Space deficit irrigation (TSDI), a newly developing irrigation technique based on regulated deficit irrigation (RDI) and partial rootzone drying (PRD), by measuring plant growth, yield and irrigation water use efficiency. The treatments consisted of factorial combinations of three factors, organized following an orthogonal L9 (3)4 test design with four growing stages. Three irrigation strategies (conventional furrow irrigation with full-water when soil water content was lower by 80% of field capacity (F), conventional furrow irrigation with 50% of full-water (D) and alternate furrow irrigation with 50% of full-water (P)) as the main plot factor were applied to select the optimum irrigation parameter at different stages of crop development, the treatment in which irrigation water was applied to both sides of root system when soil water content was lower by 80% of field capacity during all stages was considered as control (FFFF). Water consumption showed some significant effect of irrigation treatment during the growing period of different drought stress patterns application, and therefore decreased in these treatments to a level around 54.68-70.33% of FFFF. Total dry mass was reduced by 1.17-38.66% in TSDI treatments compared to FFFF. However, the root-shoot ratio of FFFF was lower than other treatments and the differences from FFFF and other TSDI treatments were statistically significant. The highest total fresh fruit yield (19.57Tha-1) was obtained in the FFFF treatment. All deficit irrigations increased the water use efficiency of hot pepper from a minimum of 1.33% to a maximum of 54.49%. At harvest, although there was difference recorded as single fruit weight and single fruit volume were reduced under the TSDI treatments, total soluble solids concentration of fruit harvested under the water-deficit treatments were higher compared to FFFF. © 2010 Elsevier B.V.


Guang-Cheng S.,Key Laboratory of Efficient Irrigation Drainage and Agricultural Soil Water Environment in Southern China | Guang-Cheng S.,Hohai University | Rui-Qi G.,Key Laboratory of Efficient Irrigation Drainage and Agricultural Soil Water Environment in Southern China | Rui-Qi G.,Hohai University | And 5 more authors.
African Journal of Agricultural Research | Year: 2011

There is increasing evidence that the spatial distribution of water within the root zone, as well as total soil water status, determines plant physiological and agronomic responses. To examine the response of photosynthesis, chlorophyll fluorescence and growth of hot pepper (Capsicum annuum L.) to deficit irrigation (DI50, 50% of the control) and partial root-zone drying (PRD, with half of the root system exposed to soil drying and the other half watered with 50% irrigation water of the control), two water deficit treatments were imposed on greenhouse grown hot pepper during the growing period in 2006. Control plants received irrigation to both halves of the root system when soil water content was < 80% of field capacity. Both PRD and DI50 treatments decreased total dry mass by 33 to 44%, shoot biomass by 31 to 44% compared to the control. These treatments increased root-shoot ratio by 35 to 44% in relation to the control, with significant differences between PRD, DI50 and the control. Deficit irrigation led to a relative leaf water content of about 77.91 to 92.71%. Two water deficit treatments reduced photosynthetic rate (P n) slightly and transpiration rate (Tr) significantly, thus improving leaf water use efficiency (WUEL, defined as the ratio of P n to Tr) by 24 to 26%. During water stress, a down-regulation of PSII activity was observed along with some impairment of photochemical activity, as revealed by decreases in the maximum quantum yield of PSII (Fv/Fm). Although Fv/Fm did not significantly differ between the deficit treatments and the control, Fv/Fm of PRD plants was higher than that of DI50 plants. The mean values of Fv, Fm, qP at four stages decreased and Fo and qN increased in the soil drought environment. Development of non-radiative energy dissipation mechanisms was evidenced during stress by increases in non-photochemical quenching and decreases in efficiency of excitation capture by open centers. © 2011 Academic Journals.


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.


Zhang Z.,Key Laboratory of Efficient Irrigation Drainage and Agricultural Soil Water Environment in Southern China | Zhang Z.,Hohai University | Chen J.,Key Laboratory of Efficient Irrigation Drainage and Agricultural Soil Water Environment in Southern China | Chen J.,Hohai University | And 3 more authors.
Paiguan Jixie Gongcheng Xuebao/Journal of Drainage and Irrigation Machinery Engineering | Year: 2013

A typical agricultural small watershed in summer season in Lishui county, Nanjing city was specified as a study model to explore the temporal and spatial variation trend of nitrogen in the small watershed. The temporal and spatial variation of soil nitrogen in the watershed was investigated by insitu observation, indoor laboratory analysis and statistics regression, eventually the distribution characteristics of nitrogen concentration in the drainage ditch were clarified. It was turned out that the profiles of three forms of soil nitrogen content against time show some differences, namely, the total soil total nitrogen content gets the maximum at a time instance, but both the soil nitrate nitrogen and ammonium nitrogen are subject to a steady decrease and the maximum declines are 37.1% and 60.9%. In the central area of the watershed the soil total nitrogen content is the highest, meanwhile the total nitrogen in the southern area is higher than that in the northern part. The averaged concentrations of the total nitrogen, nitrate nitrogen and ammonium nitrogen are 3.54, 0.81, 0.59 mg/L in the drainage ditch during summer. In water migration process in the ditch, the concentrations of three forms of nitrogen at the outlet of the ditch are always higher that those at the entrance.


Shao G.,Key Laboratory of Efficient Irrigation Drainage and Agricultural Soil Water Environment in Southern China | Shao G.,Hohai University | Lan J.,Key Laboratory of Efficient Irrigation Drainage and Agricultural Soil Water Environment in Southern China | Lan J.,Hohai University | And 4 more authors.
Paiguan Jixie Gongcheng Xuebao/Journal of Drainage and Irrigation Machinery Engineering | Year: 2013

In order to realize water-saving, good quality and high yield of tomato in Southern China, the influence of irrigation and drainage mode on water demand and fruit yield under rain-shelter condition was studied. The results showed that the soil moisture reduces steadily with time in various deficit irrigations, and it drops off more quickly when the underground pipes are in the depth of 0.8 m than that when the pipes in the depth of 0.6 m; however, the moisture curves against time don't show a significant difference in those cases. The evapotranspiration of tomato was quite different at three growth stages of tomato, namely, it declines in the following subsequence of the growth stage, blossoming and fruit-setting, fruit maturing and harvest, seedling; moreover, the daily evapotranspiration usually shows a rising trend with growth of tomato. The ranges of daily evapotranspiration for tomato are 1.07-2.71 mm/d in seeding stage, 1.60-3.09 mm/d in blossoming and fruit-setting period, and 1.78-3.35 mm/d in fruit maturing and harvest period for the different irrigation and drainage modes and under the rain-shelter cultivation condition. The tomato fruit yield is reduced, but the water-use efficiency and irrigation water use efficiency are increased with decreasing irrigation amount in the same drainage depth of underground pipes. These outcomes can provide a reference for selection of irrigation and drainage mode to realize water-saving, good quality and high yield of tomato under the rain-shelter cultivation condition in Southern China.


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 | And 5 more authors.
Paiguan Jixie Gongcheng Xuebao/Journal of Drainage and Irrigation Machinery Engineering | Year: 2012

In order to find an irrigation and drainage treatment under which tomatoes have a good quality and high yield under rain-shelter cultivation conditions in South China, effects of ten different irrigation and drainage schemes on plant growth, physiological indicators and fruit quality, yield of tomato were observed in a plot experiment, and a comprehensive index was proposed to assess the quality of tomatoes based on their main ingredients measured. The quality comprehensive index, yield, water consumption and irrigation amount were served as the indicators, then entropy weight evaluation values for the ten irrigation and drainage treatments were determined by using the entropy weight coefficient method. It was shown that the ninth treatment with the entropy weight value of 0.873was optimal, the better one is the fifth treatment with the weight valve of 0.85, and the poorest one was the first treatment with the lowest weight value of 0.593. The results indicated that for the ninth treatment where a 60% irrigation amount of the control treatment was applied, and the plastic drainage tube was located at 0.8m depth under the soil surface in the rain-shelter cultivation condition, even the reduction in tomato yield was slightly reduced, the quality indexes such as soluble solids, titratable acidity, vitamin C, ratio of sugar over acid and so on were improved, causing better fruit taste and flavor; meanwhile, a high water use efficiency was achieved. Clearly, that treatment can be used as the irrigation and drainage scheme for tomato to have good quality and high yield in South China in rain-shelter cultivation.


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.


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.


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.

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