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Sakai Y.,Kogakuin University | Ren S.,Tianjin Institute of Agricultural Resources and Environment | Wang C.,Tianjin University | Sadakata M.,Kogakuin University
Journal of Chemical Engineering of Japan

Soil salinization has progressed rapidly in northeastern and western China. In addition, air pollution is one of the most serious environmental problems. To alleviate the problems of soil salinization, food shortages, and air pollution, we have studied the amelioration of salt-affected soil using the by-products of flue gas desulfurization (FGD). Moreover, the recycling of waste gypsum produced at both new construction sites and demolition work sites has become a serious challenge in Japan. FGD gypsum in China and gypsum separated from waste gypsum board (WGB) in Japan were added to salt-affected soil as soil amendments. The effects of lignite and peat, which contains humic substances, were also investigated. With treatment, the soil's chemical parameters were restored, and agricultural production increased in all fields. Therefore, we have confirmed the effectiveness of amelioration of salt-affected soil by both FGD and WGB gypsum. Moreover, the use of lignite and peat with gypsum accelerated the effect of soil amelioration. This result suggests that the application rates of both types of gypsum could be reduced. Thus, we can propose a new salt-affected soil reclamation method using WGB, lignite, and peat in China. © 2011 The Society of Chemical Engineers. Source

Wang W.-F.,Chinese Academy of Agricultural Sciences | Li C.-H.,Chinese Academy of Agricultural Sciences | Huang S.-W.,Chinese Academy of Agricultural Sciences | Gao W.,Tianjin Institute of Agricultural Resources and Environment | Tang J.-W.,Chinese Academy of Agricultural Sciences
Chinese Journal of Applied Ecology

A fixed-site greenhouse vegetable fertilization experiment was carried out to study effects of 6 fertilization patterns on soil enzyme activities in Tianjin City, Northern China. The results showed that during the growing stages of tomato, activities of soil α-glucosidase, β-xylosidase, β-glucosidase, β-cellobiosidase, chitinase and phosphatase in different treatments all increased first and then decreased, while soil urease activities increased first and then became flat. Compared with the chemical nitrogen fertilizer treatment, soil enzyme activities were much higher in treatments of combined application of organic materials with chemical fertilizers, and rose with the increasing input of pig manure and especially the application of straw. A significant positive correlation was found between soil enzyme activities, microbial biomass carbon (MBC), microbial biomass nitrogen (MBN), and dissolved organic carbon (DOC) and dissolved organic nitrogen (DON) contents at different growing stages of tomato. Under the condition of same nutrient input, the combined application of inorganic fertilizers with organic materials, especially a certain amount of corn straw, was capable of increasing soil enzyme activities and keeping soil fertility and sustainability in greenhouse vegetable production. © 2016, Science Press. All right reserved. Source

Zhang Z.-Q.,Chinese Academy of Agricultural Sciences | Wang X.-B.,Chinese Academy of Agricultural Sciences | Li C.-H.,Chinese Academy of Agricultural Sciences | Huang S.-W.,Chinese Academy of Agricultural Sciences | And 3 more authors.
Journal of Integrative Agriculture

Organic manure application is an important measure for high yield and good quality vegetable production, whereas organic manure is also a main source of residual antibiotic in soils. A 3-yr experiment was conducted on a fluvo-aguic soil in Tianjin of northern China. The objective of this study was to investigate the effects of different fertilization patterns on yield of six-season vegetables with celery and tomato rotation, and dynamic change of tetracyclines residues in the soil during the sixth growing season (tomato season). The field experiment comprised six treatments depending on the proportion of nitrogen of each type of fertilizer: 4/4 CN (CN, nitrogen in chemical fertilizer), 3/4 CN+1/4 MN (MN, nitrogen in pig manure), 2/4 CN+2/4 MN, 1/4 CN+3/4 MN, 2/4 CN+1/4 MN+1/4 SN (SN, nitrogen in corn straw), and CF (conventional fertilization, the amounts of nitrogen application were 943 and 912 kg N ha-1 for celery and tomato season, respectively). In addition to CF treatment, the amount of nitrogen application in other treatments was greatly reduced and equal (450 and 450 kg N ha-1 for celery and tomato season, respectively). Results showed that the combined application of 3/4 CN+1/4 MN achieved the highest yield and economic benefit in the first four seasons, but addition of straw (2/4 CN+1/4 MN+1/4 SN treatment) performed better in the subsequent two seasons, and the average yields of 2/4 CN+1/4 MN+1/4 SN treatment were respectively higher by 9.9 and 12.8% than those of 4/4 CN treatment, and by 5.6 and 10.5% than those of CF treatment. The residual chlortet-racycline (CTC) in manure-amended soil for three consecutive years increased along with the increase of applied amount of pig manure. Under the same amount of pig manure application, content of CTC in straw-amended soil was obviously decreased compared with no straw-amended soil (3/4 CN+1/4 MN treatment), and averagely decreased by 41.9% for four sampling periods in the sixth season. Addition of crop straw facilitated the degradation of CTC in manure-amended soil. As a whole, the conventional fertilization was not the desirable pattern based on yield, economic benefit and environment, the optimal fertilization pattern with the highest yield and profit and the least soil chlortetracycline residue was the treatment of 2/4 CN+1/4 MN+1/4 SN under this experimental condition. © 2015, CAAS. Source

Wang X.,China Agricultural University | Zhang F.,China Agricultural University | Wang Y.,China Agricultural University | Feng T.,China Agricultural University | And 2 more authors.
Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering

Since the 1950s, China has begun to develop irrigation and water conservation project construction to control the saline-alkali soil. However, there are few reports about the effect on soil salinity improvement resulting from large-scale farmland and water conservancy engineering construction. So to check the effect of irrigation and drainage engineering on soil salinity improvement action, this research took Tianjin, in which the saline-alkali soil area is wide, as an example for the discussion and analysis of the improvement effect on soil salinity of farmland and water conservancy engineering construction. This study illustrated the relationship of interaction and change between farmland and water conservancy engineering construction and soil salinity improvement from the formation environment of saline-alkali soil and salinity change based on ArcGIS9.3 and laboratory analyses. The results showed that with the constant improvement of irrigation and drainage engineering construction and facilities, during the period from 1982 to 2002, the area where the salinity soil was easy to form reduced from 65.55×104 hm2 to 54.60×104 hm2, which was down by up to the percentage of 9.96%. During the period from 1982 to 2008, the salinity soil area reduced from 49.40×104 hm2 to 32.42×104 hm2, in the meantime, 18.76% of the saline alkali soil had completed the desalinization with other areas whose soil salinity degree was also reduced substantially further. During the period from 2006 to 2010, newly increased cultivated land which originally belonged to saline-alkali land had decreased by 2.54×104 hm2, at the same time the area that the irrigation canals and ditches had exchanged into the cultivated land was up to 1.11×104 hm2. As for the profiles (0-60 cm) of the coastal saline-alkali land, more than 69.81% of the cultivated land was under the slight salinity which had a perfect drainage system. On the contrary, more than 40% of the wasteland was the solonchak, with only 14.85% of it under the slight salinity whose drainage system was relatively poorer. During the period from 1982 to 2005, the soil which was easy to undergo salinization was reduced from 65.55×104 hm2 to 49.60×104 hm2. In addition, the spatial distribution pattern of the reduced area was in accordance with the area where the degree of soil salinity had lowered. In conclusion, irrigation and water conservancy projects control the saline-alkali by decreasing the area of salinity soil, lowering the salinization rank, and reducing the newly increased cultivated land that originally belonged to saline-alkali soil by means of improving the forming environment of the saline-alkali soil. For some areas that had completed the desalinization, there were almost no floods and they were crisscrossed by irrigation canals and ditches in where the original abandoned and dilapidated irrigation canals and ditches should be classified into the reserved land resources suitable for cultivation. Through the scientific planning of irrigation and water conservancy engineering and competitive land consolidation, the cultivated lands that are cut to pieces can connect with each other and improve farmland scale, which relieves the pressure of the protection and requisition-compensation balance of cultivated land. Source

Wu D.,Tianjin Institute of Agricultural Resources and Environment | Gao X.,Tianjin Institute of Agricultural Resources and Environment | Li Y.,Tianjin Institute of Agricultural Resources and Environment | Qian S.,Tianjin Institute of Agricultural Resources and Environment | And 2 more authors.
Chinese Journal of Environmental Engineering

The amount of organic matter, nitrogen and phosphorus removal in the simulative rural domestic sewage was investigated using the anaerobic and local circulating oxygen-supply biofilm technology with the intermittent feeding method . The available volume rate between the anaerobic tank and the local circulating oxygen-supply tank was 1:1.6. The aeration device was located on the bottom of the local circulating oxygen-supply tank, in the center of which there was an unnular splitters to separate central aerationic region and around anaerobic region. The inclined-tube sedimentation tank was arranged in the middle of the anaerobic tank and local circulating oxygen-supply tank. There was one water circle tank near the water outlet. This equipment continuously run stably for twelve months. The capacity for treating sewage of this equipment was 140 L/d and the hydraulic retention time in bio-reaction zone was 1.3 d. The average effluent concentration of COD, BOD5, NH3-N, TN and TP were 40.31, 3.38, 2.69, 11.98 and 0.75 mg/L, respectively. Those effluent rate can meet the first class criteria specified in the Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant (GB 18918-2002). Those results illustrated that the anaerobic and local circulating oxygen-supply biofilm technology was suitable for treating the domestic sewage in rural areas and could efficiently reduce agricultural non-point source pollution. Source

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