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Search Results: 1 - 10 of 146426 matches for " LI Fa-Dong "
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Research review of denitrifying microorganisms of groundwater to nitrate denitrification

LI Fa-Dong,ZHANG Yan,LI Jing,
,张 妍,李 静

中国生态农业学报 , 2013,
Abstract: There has been an increasing global trend in nitrate contamination of groundwater, and especially in China. This has raised concern for increased nitrate-caused methemoglobinemia and cancer. Available technical data and experience have indicated that denitrification was a more acceptable method for nitrate removal than reverse osmosis and ion exchange. This paper systematically reviewed the denitrifying micro-organisms, denitrification mechanisms, carbon sources, and laboratory/field-scale nitrate removal processes for effective denitrification of groundwater. Key problems with previous studies were also pointed out. As the reviewed showed that there were more related laboratory research than field research, information on the characteristics of specific micro-organisms involved in on-site nitrate removal from groundwater was limited. In addition, the utilization ratio of carbon sources was low and nitrate removal rate from groundwater was also slow. Despite the above issues, metabolic pathways of effective denitrifying micro-organisms used in nitrate removal from groundwater were still unclear. Hence the proposed relevant suggestions included: 1) In situ exploitation of denitrifying micro-organisms. Identification of the specific functions and ecological behaviors of micro-organisms via advanced molecular methods and function gene analyses. 2) Selection of the best sources of carbon and metabolic processes of microorganisms during nitrate removal from groundwater. 3) Clarification of the denitrification processes of nitrogen transformation in groundwater. All the above suggestions provided the basis of the theory of nitrite removal from groundwater, making both the theory and practice more reliable combination.
Impact of climate change on plant climate productivity in Zhejiang Province

MAO Yu-Ding,SU Gao-Li,LI Fa-Dong,WU Yao-Xiang,

中国生态农业学报 , 2008,
Abstract: 根据1961~2002年浙江省大致分布均匀的39个气象台站的气温和降水资料,利用Thornthwaite Memorial模型,计算了浙江省植物气候生产力,分析了其空间分布特征、长期变化趋势以及20世纪60年代、70年代、80年代和90年代以来的距平场变化,讨论了不同气候变化情景下气温和降水变化对植物气候生产力的影响.研究结果表明:浙江省植物气候生产力在14 424~17 323 kg·hm-2·a-1之间,其空间分布由浙北地区向浙中南地区逐步增加.近42年来浙江省植物气候生产力的趋势系数为0.211~0.603,气候生产潜力呈增加趋势,尤其是20世纪90年代以来(1991~2002年),随着气温的升高和降水量的增加,浙江省植物气候生产力比平均值偏多1.7%~9.6%."暖湿型"气候变化情景有利于提高气候生产力,而"暖干型"气候使浙江省植物气候生产力下降.
Effect of row space on population structure and photosynthetic available radiation in winter wheat-white clover intercropping system

SUN Zhen-Zhong,OUYANG Zhu,LIU Li-Ping,LI Fa-Dong,

中国生态农业学报 , 2011,
Abstract: 2008~2010 年冬小麦/白三叶草不同栽培方式试验(6 种小麦行距配置, 3 个行距×2 个播种量)研究表明,单作条件下, 小麦群体总茎数、叶面积指数、生物量及产量在行距25 cm 与30 cm 处理间差异不大, 均显著高于行距40 cm 处理。行距30 cm、播种量217.5 kg·hm-2 处理的籽粒产量和收获系数分别达7 857.8 kg·hm-2 和0.483。小麦抽穗期和花期, 行距30 cm 与40 cm 处理的冠层底部向上20 cm 处的光合有效辐射(PAR)值差异不大, 行间全天PAR 在50 μmol·m-2·s-1 以上的时间至少有8 h, 而单作条件下白三叶草光补偿点在30~50μmol·m-2·s-1 之间, 这预示着在行距30 cm 与40 cm 处理的小麦行间间作白三叶草能为白三叶草光合作用提供有效光能。行距30 cm 条件下, “小偃81”与“济麦22”单作以及分别与白三叶草间作处理试验表明, “小偃81”与白三叶草间作系统小麦生物量不受间作影响, 小麦叶面积指数与穗数高于“小偃81”单作。“济麦22”与白三叶草间作系统的3 项指标则低于“济麦22”单作。间作条件下, 白三叶草冠层顶部PAR 日变化呈单峰曲线, 冠层底部PAR 较小, 全天最大仅30 μmol·m-2·s-1。与“济麦22”相比, “小偃81”与白三叶草间作冠层底部PAR 全天日变化较小。因此, 行距30 cm 处理小麦行间适合间作白三叶草, 小麦品种“小偃81”比“济麦22”更适合与白三叶草间作。本研究结论可为华北平原发展冬小麦/白三叶草间作种植模式提供参考依据。
Rainwater catching by small watershed and water-saving irrigation in Taihang Mountains

LI Fa-Dong,ZHANG Wan-Jun,Shibano HIROFUMI,ZHANG Qiu-Ying,
,张万军,芝野 博文,张秋英

中国生态农业学报 , 2002,
Abstract: The discharge, precipitation and utilizable quantity of rainwater resources were measured by H-type weir and rain gauge. The results show that catching rainwater by small watershed needs less investment and makes the best use of water resources which creates favorable conditions for economic development in Taihang Mountains. Rainwater resources in these areas are distributed mos tly from May to October. The total precipitation (up to 20mm/d) is 399mm in the year of 2000. The quantity of catchable water in this year is 249 thousand m3 in the studied watershed. Elevation difference between outlet of small watershed and lower reaches is from 30 to 100 meters. All of these supply a favorable basis for developing self-pressure micro-irrigation. Furthermore, water-saving irrigation, drip-irrigation, hole irrigation by plastic film, irrigating critical water, limited irrigation, and water-saving gravity irrigation and so on and should be expanded by adjusting measures to local conditions. Finally, the feasibility of developing water-saving irrigation in Taihang Mountains is analyzed.
Changing laws of chlorophyll content and photosynthetic rate in winter wheat leaves

ZHANG Qiu-Ying,LI Fa-Dong,LIU Meng-Yu,

中国生态农业学报 , 2005,
Abstract: The changes of chlorophyll content and photosynthetic rate in wheat leaves from different water treatments were studied.The results show that the chlorophyll content of winter wheat leaves has a decreasing tendency under water stress and chlorophyll b content declines obviously.The changing trends of chlorophyll content and photosynthetic rate under different water stresses and seasons are identical basically.They increase from jointing stage to booting stage and decrease at milking stage,moreover the correlation between chlorophyll content and photosynthetic rate is positive.Yield and economical coefficient of winter wheat decline with a strong water stress.
Slope runoff study in situ using rainfall simulator in mountainous area of North China

XU Jing-Ji,YANG Cong,LIU Chang-Meng,SONG Xian-Fang,HU Shan-Shan,LI Fa-Dong,TANG Chang-Yuan,

地理学报 , 2009,
Abstract: Simulated rainfall is a valid tool to examine the runoff generation on the slope.13 simulated rainfall experiments with different rainfall intensities and durations are completed in a 5 m ×10 m experimental plot in mountainous area of North China.Simultaneously,rainfall,surface runoff,soil-layer flow,mantel-layer flow and soil moisture are monitored respectively.From the results,it is found that the hydrographs in all layers have the characteristics of rapid rise and fall.The recessions of surface flow and soil-layer flow are much faster than that of mantel-layer flow.Surface flow,the main contributor,makes up more than 60% of the total runoff in the study area.It even exceeds 90% in the cases of high intensity rainfall events.Runoff coefficient(ratio of total runoff to rainfall amount) is mainly influenced by rainfall amount,rainfall intensity and antecedent soil moisture,and the relationship can be well expressed by a multiple linear regression function α = 0.002P + 0.182i + 4.88Wa-0.821.The relation between the rainfall intensity and the lag time of three flows(surface runoff,soil-layer flow and mantel-layer flow) is shown to be exponential.Then,the result also shows that the recession constant is 0.75 for surface runoff,is 0.94 for soil-layer and mantel-layer flow in this area.In this study area,the dominant infiltration excess runoff is simulated by Horton model.About 0.10 mm/min percolation is observed under the condition of different rainfall intensities,therefore the value is regarded as the steady infiltration rate of the study area.
Effect of no-tillage on soil aggregate and organic carbon storage

JIANG Xue-Bing,LI Yun-Sheng,OUYANG Zhu,HOU Rui-Xing,LI Fa-Dong,

中国生态农业学报 , 2012,
Abstract: No-tillage(NT) is an increasingly agronomic practice in China.Tillage practices deeply affect soil quality and organic carbon(SOC) accumulation.The effect of NT,as a form of conservation tillage,on soil organic carbon storage had remained highly contentious.To shed further view on the effect of NT on soil structure and quality in the Huang-Huai-Hai Plain(HP),a long-term no-tillage experimental site for the main crop rotation-winter wheat(Triticum aestivum L.) and summer maize(Zea Mays L.)-was investigated.The experimental site belongs to the Yucheng Comprehensive Experimental Station(YCES) of Chinese Academy of Sciences(CAS) and has been used in studying the changes in soil aggregates and organic carbon storage under different tillage systems for 7 years now.NT,no-tillage with removed residue and organic fertilization(NTRR) and conventional tillage(CT) treatments were set up in the study.The impact of the three tillage systems on total soil organic carbon content and storage,water-stable aggregate stability,water-stable aggregate SOC content and storage,and relationship between total SOC content and water-stable aggregate SOC content were analyzed.Compared with CT,SOC content and storage,and water-stable aggregate mean weight diameter(MWD) and geometric mean diameter(GMD) along with macro-aggregate organic carbon content and storage in the 0~20 cm soil layer significantly increased in NT and NTRR treatments.This was possibly due to reduced soil disturbances and residue mulch and organic fertilizer applications.No tillage plots with residue mulch stored more SOC and macro-aggregate organic carbon than those with applied organic fertilizer.For the treatments,the order of the content of SOC and macro-aggregate organic carbon in the 20~60 cm soil depth was NT < NTRR < CT.In comparison with NT and NTRR,CT limited deep-soil organic carbon accumulation.Compared with straw mulch,the application of organic fertilizer enhanced deep-soil organic carbon accumulation under no tillage.On the average,SOC storage in NT and NTRR was lower than in CT in the 0~60 cm soil depth.There was a significant positive correlation between SOC and 0.25~2 mm aggregate organic carbon,indicating that the 0.25~2 mm soil macro-aggregates could be used as a proxy for changes in SOC.In conclusion therefore,no-tillage significantly improved the distribution and stability of surface soil water-stable aggregates.While no-tillage significantly increased the storage of surface total SOC in the 0.25~2 mm soil aggregates,reduced it in deep soil layers.Compared with organic manure,straw mulch promoted the accumulation of SOC in surface soils and reduces it in deep soils under no tillage practice.
Regulation mechanism of irrigation schedule on population photosynthesis of winter wheat

LIU Li-Ping,OUYANG Zhu,WU Lan-Fang,SUN Zhen-Zhong,LI Fa-Dong,

中国生态农业学报 , 2012,
Abstract: With competition between agriculture and other industries in the northwest arid areas of China, determination of healthy volume of agricultural water consumption provides the basis for reasonable distribution of available water resources. Based on healthy agricultural water volume connotation and standard, a multi-objective optimization layer calculation model was developed for the northwest arid areas of China. The model achieved its objective function not only for maximum water consumptions in different industries, but also for total water consumption. It also successfully calculated the healthy volumes of agricultural water consumption in different areas under given optimization sequences. The model was successfully tested in calculating healthy volume of agricultural water consumption in the Heihe River Basin (HRB). For different county-level administrative units, the healthy volume of agricultural water consumption was evaluated under different water inflow frequencies for the past (1999), present (2006) and future (2020) years. The results show that model-adjusted water resources allocation in 1999, 2006 and 2020 reduced the basin water volume consumption (in the agricultural and industrial sectors) by 2.7%, 4.6% and 2.1%, respectively. Water benefit was comprehensively increased by 7.1%, 16.6% and 13.1% in 1999, 2006 and 2020, respectively. Similarly, ecological benefit respectively increased by 27.6%, 37.4% and 13.6% in the above periods. Not only was the model reliable, but the feasibility of healthy agricultural water consumption in the region increased. Comparisons of healthy agricultural water consumption among different years revealed that the water situation in the agricultural sector in 2006 was healthier than in 1999. Also the situation in 2020 was healthier than in 2006. While agricultural water use ratios reduced by 3.4% and 2.0%, water efficiency increased by 31.1% and 91.6%, respectively. Based on previous agricultural water distributions, the basin water deficit in 2020 was predicted at 10.6%, 13.8% and 25.9% under 50%, 75% and 95% of water inflow frequencies. It showed higher scarcity of water resources then. It was concluded that in order to meaningfully curb water shortage, water resources allocation should be adjusted based on healthy volumes of agricultural water consumption.
Spatial distribution and sources of groundwater phosphorus in Dezhou Region

CAI Wen-Jing,CHANG Chun-Ping,SONG Shuai,LI Jing,ZHANG Fang,LI Fa-Dong,
,常春平,宋 帅,李 静,张 芳,李发东

中国生态农业学报 , 2013,
Abstract: 地下水质量与居民饮水安全及人类健康密切相关, 地下水污染会直接影响水体生态环境。饮用水中过高的磷会降低人体对钙和维生素D的吸收, 对老年人的身体健康存在潜在负面影响。本文以德州地区地下水(常作为农村饮用水源)为研究对象, 采集了研究区内的27个地下水样, 并于现场测定pH和电导率等指标。参考我国《水和废水监测分析方法》和美国环境保护局(EPA)的方法, 利用紫外分光光度计分析了地下水中总磷、正磷酸盐、溶解性总磷和溶解性正磷酸盐的含量及污染状况。借助于空间分析, 探讨了其空间分布和来源。结果表明, 德州地区地下水总磷含量为0~1.49 mg·L-1, 正磷酸盐含量为0~0.11 mg·L-1, 溶解性总磷含量为0.04~0.69 mg·L -1, 溶解性正磷酸盐含量为0~0.06 mg·L-1。电导率和4种形态磷的含量均存在不同的空间差异性。整个研究区地下水电导率较高, 变化范围为770~5 530 μS·cm-1, 总体上从河流上游到下游呈明显阶梯状递增趋势; 总磷和溶解性总磷含量的空间分布整体趋势从上游到下游逐渐降低, 正磷酸盐出现了较明显的高值区, 而溶解性正磷酸盐的空间分布整体上较均匀。影响地下水中磷含量的因素主要有地表水中磷的下渗和人类活动。该研究区各采样点地下水的埋深都在50 m以内, 含水层为黄河冲积砂层, 岩性主要为粉砂、细砂和中砂, 累计厚度10~25 m, 这样的土壤地质构造较易使地表水中的磷素渗漏到地下水中, 且河流是该区地下水主要的补给源, 越靠近河流越容易入渗。人类活动包括工业废水和生活污水处理不当等点源污染以及农药施肥等农业非点源污染。整个研究区地下水溶解性总磷含量的最大值达0.69 mg·L-1, 平均值为0.20 mg·L-1, 根据欧盟规定的饮用水中总磷酸盐的标准值(0.5 mg·L-1)和我国地表水环境质量标准(GB 3838-2002)的Ⅱ类(0.02<溶解性总磷≤0.1 mg·L-1)或Ⅲ类(0.1<溶解性总磷≤0.2 mg·L-1)标准, 德州地区地下水中磷的超标率分别达7.41%、62.96%和40.74%。本研究为评价地下水中磷污染对人类健康及水体生态环境的影响提供了科学依据。
Hydrochemical characteristics of surface water in main rivers of the irrigation districts in the downstream of Yellow River

ZHANG Fang,LI Fa-Dong,LI Jing,SONG Shuai,CAI Wen-Jing,CHANG Chun-Ping,
张 芳
,李发东,李 静,宋 帅,蔡文静,常春平

中国生态农业学报 , 2013,
Abstract: 通过对德州引黄灌区主要河流及引黄灌渠水质的离子化学成分分析, 探讨了引黄灌区地表水化学成分特点、水化学类型及其空间变化和主要离子来源, 为长期观测引黄灌溉对该区地表水、地下水的水化学特征变化的影响及地表水、地下水的循环交换提供依据, 同时为该区水环境评价以及水体污染防控提供理论指导。研究结果显示, 该区地表水的pH、电导率(EC)及各主要离子含量存在明显的空间差异。水体pH的变化范围为7.65~9.34, 属弱碱性水; EC的变化范围为965~1 530 μs·cm-1; 主要阴阳离子的浓度范围分别为: NO3- 1.32~60.15 mg·L-1、SO42- 53.41~781.90 mg·L-1、HCO3- 143.35~ 823.50 mg·L-1、Cl- 98.00~ 564.00 mg·L-1、Ca2+ 22.57~265.00 mg·L-1、Mg2+ 29.41~195.50 mg·L-1、Na+ 103.20~472.00 mg·L-1、K+ 0.83~59.05 mg·L-1。该研究区水化学类型以Na+·Ca2+-HCO3- ·SO42- 水为主。各阴离子浓度的平均值HCO3- (330.45 mg·L-1) SO42- (308.48 mg·L -1) Cl (286.83mg·L-1) NO3-(29.60 mg·L-1), 阳离子浓度的平均值Na+(236.85 mg·L-1) Ca2+(98.15 mg·L-1) Mg2+(82.62 mg·L-1) K+(9.05 mg·L -1)。pH、Cl 的最高值均出现在马颊河流域, 并且该流域Mg2+浓度均值高于其他两个流域。德惠新河流域EC、NO3 和HCO3 的均值最高。引黄灌渠的SO42- 、Na+、Ca2+和K+的平均浓度高于其他两个流域。通过Piper图分析得出, 不同小流域水体类型不同。对研究区灌溉水质评价结果显示, 该区地表水适合灌溉。经相关分析发现, 该研究区地表水中, Ca2+、Mg2+、Na+与SO42- 和Cl- 均具有极显著的相关性, 此外, Ca2+与Mg2+、Na+与K+、SO42- 与Cl 也显示出了极显著的相关性, 表明这些离子相互影响, 或者具有相同的来源, 受人类活动影响较大。
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