This study assessed the fish production, culture facilities, operations, water resource management and profitability of fish farming in Katsina State, Nigeria, with a view of understanding the status of aquaculture de...This study assessed the fish production, culture facilities, operations, water resource management and profitability of fish farming in Katsina State, Nigeria, with a view of understanding the status of aquaculture development in Katsina State. Data were collected using structured questionnaire administered to 35 out of the active 42 farms in Katsina State at the period and the data obtained were analyzed using descriptive statistics and linear regression. Among the respondents, 37.1% used concrete tank alone and another 37.2% used concrete tank with other types of culture facilities, 57.1% practised mono-culture techniques and 77.1% used stagnant renewal system as culture system. Management of water quality was done by majority(82.9%) with mere visual evaluation, while 68.6% did not use any forms of water treatment. Most of the farms(80%) depended on imported feed for feeding their fish and gross profits of ■7.29±1.81 and ■157.83±118.08 were obtained on fingerlings and adult fish, respectively. The tested explanatory variables were responsible for 45.4% change in profitability and profitability was found to be dependent on feeding cost(t=–3.38 and p=0.002) and size of fish at harvest(t=2.70 and p=0.011). The research findings established that fish farming in Katsina State was under developed.展开更多
To achieve the purpose of reducing farm non-point source pollution, we integrated site specific nitrogen management precise irrigation, controlled drainage, and wetland eco-repair system in dike area of Taihu basin. D...To achieve the purpose of reducing farm non-point source pollution, we integrated site specific nitrogen management precise irrigation, controlled drainage, and wetland eco-repair system in dike area of Taihu basin. During investigation, it had given prominence for the water and fertilizer coupling effects of precise irrigation and site specific nutrient management, the characteristics of integration on controlled irrigation, controlled drainage and wetland ecosystem non-point source pollution control. Then the water and fertilizer integrated management mode of paddy field was put forward in Taihu basin where the water production efficiency increased to 1.64 kg. m-3, water saved 37.8%, fertilizer use efficiency raised 15,4%, yield raised 10%, and N, P load decreased 26%-72%. The modern agricultural and farmland ecosystems that control and cut down the farm non-point source pollution came into being, which can be a reference by Taihu basin to control its agricultural non-point source pollution and eutrophicated water body.展开更多
The water supply system in Shanghai provides about 2.55×109 m3/a,of which more than 50% is derived from the Upper Huangpu River Watershed. During the process of rapid urbanization and industrialization,the role o...The water supply system in Shanghai provides about 2.55×109 m3/a,of which more than 50% is derived from the Upper Huangpu River Watershed. During the process of rapid urbanization and industrialization,the role of watershed management in sustaining clean drinking water quality at surface sources is emphasized in Shanghai. This paper proposes an integrated watershed management (IWM) approach in the context of the current pressures and problems of source water protection at the Upper Huangpu River Watershed in Shanghai. Based on data sets of land use,water quality and regional development,multi-criteria analysis and system dynamics techniques were used to evaluate effectiveness and improve decision-making of source water protection at a watershed scale. Different scenarios for potential source water quality changing from 2008 to 2020 were predicted,based on a systematic analysis and system dynamics modeling,a watershed management approach integrating land use prioritization and stakeholder involvement was designed to conserve the source water quality. The integrated watershed management (IWM) approach may help local authorities better understand and address the complex source water system,and develop improved safe drinking water strategies to better balance urban expansion and source water protection.展开更多
The rapid increase of urban population in coastal areas of developing countries is nowadays a widespread phenomenon that has several environmental, economical and social consequences.Internal migration, spread of info...The rapid increase of urban population in coastal areas of developing countries is nowadays a widespread phenomenon that has several environmental, economical and social consequences.Internal migration, spread of informal suburban settlements,lack of adequate sanitation,increase in water extraction。展开更多
Water underpins the ambit of processes that de⁃liver hugely valuable ecosystem services across the surface of the Earth.We rely on water to enable pro⁃duction of food,fodder and fuel,and we depend on it to sustain the...Water underpins the ambit of processes that de⁃liver hugely valuable ecosystem services across the surface of the Earth.We rely on water to enable pro⁃duction of food,fodder and fuel,and we depend on it to sustain the functioning of our ecologies and envi⁃ronments.展开更多
[目的]为明确水肥管理和设施间作等措施对蔬菜土壤微生态及黄瓜、芹菜品质的影响。[方法]通过连续3 a的田间试验,采用连续水肥(CF,continuous fertilization in irrigation)和隔水一肥(AF,alternating fertilization in irrigation)2种...[目的]为明确水肥管理和设施间作等措施对蔬菜土壤微生态及黄瓜、芹菜品质的影响。[方法]通过连续3 a的田间试验,采用连续水肥(CF,continuous fertilization in irrigation)和隔水一肥(AF,alternating fertilization in irrigation)2种水肥模式,结合黄瓜单作(CU,cucumber monoculture)、芹菜单作(CE,celery monoculture)、黄瓜与芹菜间作(CC,cucumber and celery intercropping)3种种植模式,系统评估不同处理对作物品质、土壤理化性质和微生物群落的影响。[结果]CCCF处理显著提升黄瓜和芹菜的维生素C含量(提升16.6%~200%),而CUCF处理则在可溶性糖积累方面表现出优势。XGB模型分析揭示,速效钾和pH分别是调控维生素C和可溶性糖含量的关键因子。微生物组分析显示,间作处理富集特异性ASVs(7371~7526个),显著提高Steroidobacter、Flavobacterium等促生菌的丰度,同时抑制病原真菌的生长。功能预测表明,水肥管理主要影响氮循环功能,间作则增强甲烷营养功能。微生物网络分析进一步揭示,CF形成紧密的细菌互作网络,AF提高网络模块性,而CC则在保持高连接性的同时维持适度模块性。[结论]不同水肥和种植管理措施通过调控土壤理化性质、微生物群落结构和生态网络,对作物品质产生差异化影响。其中,CCCF和CUCF分别适合提升维生素C和可溶性糖含量,为设施农业精准调控作物品质提供新思路。展开更多
文摘This study assessed the fish production, culture facilities, operations, water resource management and profitability of fish farming in Katsina State, Nigeria, with a view of understanding the status of aquaculture development in Katsina State. Data were collected using structured questionnaire administered to 35 out of the active 42 farms in Katsina State at the period and the data obtained were analyzed using descriptive statistics and linear regression. Among the respondents, 37.1% used concrete tank alone and another 37.2% used concrete tank with other types of culture facilities, 57.1% practised mono-culture techniques and 77.1% used stagnant renewal system as culture system. Management of water quality was done by majority(82.9%) with mere visual evaluation, while 68.6% did not use any forms of water treatment. Most of the farms(80%) depended on imported feed for feeding their fish and gross profits of ■7.29±1.81 and ■157.83±118.08 were obtained on fingerlings and adult fish, respectively. The tested explanatory variables were responsible for 45.4% change in profitability and profitability was found to be dependent on feeding cost(t=–3.38 and p=0.002) and size of fish at harvest(t=2.70 and p=0.011). The research findings established that fish farming in Katsina State was under developed.
基金Supported by NSFC (50839002)Society Development Program of Jiangsu Province (BS2007139)
文摘To achieve the purpose of reducing farm non-point source pollution, we integrated site specific nitrogen management precise irrigation, controlled drainage, and wetland eco-repair system in dike area of Taihu basin. During investigation, it had given prominence for the water and fertilizer coupling effects of precise irrigation and site specific nutrient management, the characteristics of integration on controlled irrigation, controlled drainage and wetland ecosystem non-point source pollution control. Then the water and fertilizer integrated management mode of paddy field was put forward in Taihu basin where the water production efficiency increased to 1.64 kg. m-3, water saved 37.8%, fertilizer use efficiency raised 15,4%, yield raised 10%, and N, P load decreased 26%-72%. The modern agricultural and farmland ecosystems that control and cut down the farm non-point source pollution came into being, which can be a reference by Taihu basin to control its agricultural non-point source pollution and eutrophicated water body.
基金Project(70603013) supported by the National Natural Science Foundation of ChinaProjects(08JC1408800,08JC1417602) supported by Key Program for Basic Research of Shanghai,China
文摘The water supply system in Shanghai provides about 2.55×109 m3/a,of which more than 50% is derived from the Upper Huangpu River Watershed. During the process of rapid urbanization and industrialization,the role of watershed management in sustaining clean drinking water quality at surface sources is emphasized in Shanghai. This paper proposes an integrated watershed management (IWM) approach in the context of the current pressures and problems of source water protection at the Upper Huangpu River Watershed in Shanghai. Based on data sets of land use,water quality and regional development,multi-criteria analysis and system dynamics techniques were used to evaluate effectiveness and improve decision-making of source water protection at a watershed scale. Different scenarios for potential source water quality changing from 2008 to 2020 were predicted,based on a systematic analysis and system dynamics modeling,a watershed management approach integrating land use prioritization and stakeholder involvement was designed to conserve the source water quality. The integrated watershed management (IWM) approach may help local authorities better understand and address the complex source water system,and develop improved safe drinking water strategies to better balance urban expansion and source water protection.
文摘The rapid increase of urban population in coastal areas of developing countries is nowadays a widespread phenomenon that has several environmental, economical and social consequences.Internal migration, spread of informal suburban settlements,lack of adequate sanitation,increase in water extraction。
文摘Water underpins the ambit of processes that de⁃liver hugely valuable ecosystem services across the surface of the Earth.We rely on water to enable pro⁃duction of food,fodder and fuel,and we depend on it to sustain the functioning of our ecologies and envi⁃ronments.
文摘[目的]为明确水肥管理和设施间作等措施对蔬菜土壤微生态及黄瓜、芹菜品质的影响。[方法]通过连续3 a的田间试验,采用连续水肥(CF,continuous fertilization in irrigation)和隔水一肥(AF,alternating fertilization in irrigation)2种水肥模式,结合黄瓜单作(CU,cucumber monoculture)、芹菜单作(CE,celery monoculture)、黄瓜与芹菜间作(CC,cucumber and celery intercropping)3种种植模式,系统评估不同处理对作物品质、土壤理化性质和微生物群落的影响。[结果]CCCF处理显著提升黄瓜和芹菜的维生素C含量(提升16.6%~200%),而CUCF处理则在可溶性糖积累方面表现出优势。XGB模型分析揭示,速效钾和pH分别是调控维生素C和可溶性糖含量的关键因子。微生物组分析显示,间作处理富集特异性ASVs(7371~7526个),显著提高Steroidobacter、Flavobacterium等促生菌的丰度,同时抑制病原真菌的生长。功能预测表明,水肥管理主要影响氮循环功能,间作则增强甲烷营养功能。微生物网络分析进一步揭示,CF形成紧密的细菌互作网络,AF提高网络模块性,而CC则在保持高连接性的同时维持适度模块性。[结论]不同水肥和种植管理措施通过调控土壤理化性质、微生物群落结构和生态网络,对作物品质产生差异化影响。其中,CCCF和CUCF分别适合提升维生素C和可溶性糖含量,为设施农业精准调控作物品质提供新思路。
