An integrated water trading-allocation model, applied to a water market in Australia     

A.M. Zaman  H.M. Malano 《Agricultural Water Management》2009,96(1):149-159

Temporary water trading is an established and growing phenomenon in the Australian irrigation sector. However, decision support and planning tools that incorporate economic and biophysical factors associated with temporary water trading are lacking. In this paper the integration of an economic trading model with a hydrologic water allocation model is discussed. The integrated model is used to estimate the impacts of temporary water trading and physical water transfers. The model can incorporate economic and biophysical drivers of water trading. The economic model incorporates the key trade drivers of commodity prices, seasonal water allocations and irrigation deliveries. The hydrologic model is based on the Resource Allocation Model (REALM) framework, which facilitates hydrologic network simulation modelling. It incorporates water delivery system properties and operating rules for the main irrigation and urban centres in a study area.The proposed integration method has been applied to a case study area in northern Victoria, Australia. Simulations were conducted for wet and dry spells, a range of commodity prices and different irrigation distribution system configurations. Some example analyses of scenarios incorporating water trading were undertaken. From these analyses potential bottlenecks to trade that constrain the economic benefits from temporary water trading were identified. Furthermore, it was found that in certain areas of the system, trading can make impacts of long drought spells worse for water users, e.g. irrigators. Thus, the integrated model can be used to quantify short-term and long-term third party impacts arising from temporary water trading. These findings also highlight the need to link “paper trades” (estimated by economic models) to physical water transfers (estimated by biophysical models).  相似文献   

水黄皮叶斑病的成因、严重性及杀菌剂防止     

M.A.U. Mridha  F.Jabbar  M. K. Bhuiyan  M. Rahman  F. Akter  S. Dewan 《林业研究》2007,18(3)

对孟加拉国4个苗圃(IFES、IFESCU、BFRI和ANC)内水黄皮叶斑病症状和严重性进行了调查,结果表明:IFESCU苗圃内叶斑病侵染率及致病指标最高、BFRI次之、ANC最低.与叶斑病相关联的组织从发病植株分离出来,被分离的真菌形成致病性.结果证实胶孢炭疽菌即为致病菌.观察了杧果炭疽病菌丝体生长抑制性并对杀菌剂(Bavistin, Cupravite and Dithane M-45) 有效性和浓度(0.05, 0.10, 0.50, 1.00, 1.50 和 2.00%)进行了鉴定.0.05% Bavistin和Cupravite潜伏8天后,菌丝体生长分别处于最低和最高水平.结果表明:Bavistin杀菌效果最好、Diathane M-45次之,Cupravite对菌丝体生长的抑制作用最低.图1表4参27.  相似文献   

The severity and cause of leaf spot disease of Pongamia pinnata L. and fungicidal control of the pathogen     

M.A.U. Mridha　F. Jabbar　M. K. Bhuiyan　M. Rahman　F. Akter　S. Dewan 《林业研究》2007,18(3):236-240

A survey on the symptom and severity of the leaf spot disease of Pongamia pinnata L. was conducted in the nurseries of the Institute of Forestry and Environmental Sciences, University of Chittagong （IFESCU）, Bangladesh Forest Research Institute （BFRI） and Aronnak Nursery in Chittagong. The highest infection percentage and disease index were found in IFESCU nursery, followed by BFRI and the lowest was recorded in Aronnak nursery. The associated organism of leaf spot disease of P. pinnata was isolated from the diseased plant parts and the pathogenicity was established with the isolated fungus. Colletorichum gloeosprioides Penz was proved to be pathogenic. The inhibition of mycelial growth of C. gloeosporioides was observed and identified as suitable fungicides （Bavistin, Cupravite and Dithane M-45） and doses （0.05, 0.10, 0.50, 1.00, 1.50 and 2.00）. The lowest and highest mycelial growth were respectively found on Bavistin and on Cupravite at the concentration of 0.05 after 8th day of incubation. It indicates that out of the three tested fungicides, Bavistin showed most effective, followed by Diathane M-45, and Cupravite was ineffective for its very little inhibition on mycelial growth.  相似文献   

Effect of a saponin-based surfactant and aging time on ruminal degradability of flaked corn grain dry matter and starch     

Hristov AN  Zaman S  VanderPol M  Szasz P  Huber K  Greer D 《Journal of animal science》2007,85(6):1459-1466

The objectives of this study were to investigate the effect of a saponin-based surfactant, Grain Prep surfactant (GP), and hot flake aging time on starch characteristics and ruminal DM and starch degradability of steam-flaked corn grain. In 2 experiments, the moisture content of incoming corn was automatically adjusted using the Grain Prep Auto Delivery System to 19.8% (Exp. 1) and 18.5% (Exp. 2). The application rate of GP was 22 mg/kg (as-is basis). Control corn was treated with water alone. Processed corn in Exp. 2 was stored in insulated containers for 0, 4, 8, or 16 h. Flaked corn samples were incubated in the rumen of lactating dairy cows for 0, 2, 4, 6, 16, or 24 h. In Exp. 1, GP increased, compared with the control, the soluble fraction and effective degradability (ED) of DM by 17.2 and 8.6%, respectively. The ED of cornstarch was increased by 6.7%. In Exp. 2, the concentration of soluble DM and starch were increased by GP by 15 and 24% compared with the control. The ED of DM and starch were also increased by 3 and 4%, respectively. No differences in gelatinization temperatures were observed due to treatment, except that GP-treated grain had a slightly greater mean gelatinization enthalpy in Exp. 2. In a pilot study, DM degradability parameters were not affected by germination of the corn kernels. Aging of the hot flakes for up to 16 h resulted in a quadratic decrease in DM and starch ruminal degradability. The aging process affected starch gelatinization enthalpy values of flaked grain in a manner opposite to that observed for ruminal DM and starch degradation. This phenomenon was most likely explained by increased starch intramolecular associations or crystallinity associated with starch annealing, or both. This study confirmed our previous observations that Grain Prep surfactant increases flaked corn DM and starch degradability in the rumen. Because the rate of degradation was not affected by the surfactant, the increase in degradability was attributed mainly to increases in DM and starch solubility.  相似文献   

Water Use and Seed Yield of Horsegram Under Different Moisture Regimes and Mulches in Semi-Arid Region of Eastern India   总被引：1，自引：0，他引：1  

A. Zaman  S. Mallick 《Journal of Agronomy and Crop Science》1991,167(1):39-42

In a two years field study on effect of irrigation at vegetative and flowering stages occurring at 40 and 60 days after sowing, respectively alongwith straw mulch ca. 5 t/ha were found to have beneficial effect on growth, yield attributes and seed yield of horsegram ( Dolichos biflorus Roxb.). Application of mulches significantly increased pods/plants, seeds/pod, test weight and seed yield and maintained better soil moisture during crop growth in semi-arid lateritic region of Indian sub-tropics. Mulches proved useful to conserve more moisture in soil profile and thereby increased the water use efficiency of the crop; straw mulch was found superior to leaf mulch.  相似文献   

Estimation of the rootzone depth above a gravel layer (in wild blueberry fields) using electromagnetic induction method     

Fahad S. Khan  Qamar U. Zaman  Young K. Chang  Aitazaz A. Farooque  Arnold W. Schumann  Ali Madani 《Precision Agriculture》2016,17(2):155-167

Wild blueberry (Vaccinium angustifolium Ait.) fields in the north east Canada are naturally grown in a course textured thin layer of soil and below this layer is a soilless layer of gravel. The root zone depth of this crop varies from 10 to 15 cm. Investigating the depth to the gravel layer below the course textured soil is advantageous, as it affects the water holding capacity of the root zone. Water and nutrient management are the two primary determinants of crop yield and the amount of leaching. The objective of this study was to estimate the depth to the gravel layer using DualEM-2 instrument. A C++ program written in Visual Studio 2010 was used to develop mathematical models for estimating the depth to the gravel layer from the outputs of DualEM-2 sensor. Two wild blueberry fields were selected in central Nova Scotia, Canada to evaluate the performance of DualEM-2 instrument in estimating the rootzone depth above the gravel layer. The mid points of squares created by grid lines were used as the sampling points at each experimental site. The actual depth to the interface was measured manually at selected grid points (n = 50). The apparent ground conductivity (EC_a) values of DualEM-2 were recorded and the depth to the interface was estimated for the same sampling points within the selected fields. The fruit yield samples were also collected from the same grid points to identify the impact of the depth to the gravel layer on crop yield. After calibrations, comprehensive surveys were conducted and the actual and estimated depths to the interface were established. The interpolated maps of fruit yield, and the actual (z_in) and estimated (\( {\text{z}}_{\text{in}}^{*} \)) depths to the interface were created in ArcGIS 10 software. Results indicated that the z_in was significantly correlated with \( {\text{z}}_{\text{in}}^{*} \) for the North River (R ² = 0.73; RMSE = 0.27 m) and the Carmel (R ² = 0.45; RMSE = 0.20 m) sites. Results revealed that the areas with shallow depth to the gravel layer were low yielding, indicating that the variation in the depth to the gravel layer can have an impact on crop productivity. Non-destructive estimations of the depth to the gravel layer can be used to develop erosion control strategies, which will result in an increased crop production.  相似文献   

Substrate type,temperature, and moisture content affect gross and net N mineralization and nitrification rates in agroforestry systems   总被引：7，自引：0，他引：7  

M.?Zaman  S.?X.?ChangEmail author 《Biology and Fertility of Soils》2004,39(4):269-279

Accurate prediction of soil N availability requires a sound understanding of the effects of environmental conditions and management practices on the microbial activities involved in N mineralization. We determined the effects of soil temperature and moisture content and substrate type and quality (resulting from long-term pasture management) on soluble organic C content, microbial biomass C and N contents, and the gross and net rates of soil N mineralization and nitrification. Soil samples were collected at 0–10 cm from two radiata pine (Pinus radiata D. Don) silvopastoral treatments (with an understorey pasture of lucerne, Medicago sativa L., or ryegrass, Lolium perenne L.) and bare ground (control) in an agroforestry field experiment and were incubated under three moisture contents (100, 75, 50% field capacity) and three temperatures (5, 25, 40 °C) in the laboratory. The amount of soluble organic C released at 40 °C was 2.6- and 2.7-fold higher than the amounts released at 25 °C and 5 °C, respectively, indicating an enhanced substrate decomposition rate at elevated temperature. Microbial biomass C:N ratios varied from 4.6 to 13.0 and generally increased with decreasing water content. Gross N mineralization rates were significantly higher at 40 °C (12.9 g) than at 25 °C (3.9 g) and 5 °C (1.5 g g^–1 soil day^–1); and net N mineralization rates were also higher at 40 °C than at 25 °C and 5 °C. The former was 7.5-, 34-, and 29-fold higher than the latter at the corresponding temperature treatments. Gross nitrification rates among the temperature treatments were in the order 25 °C >40 °C >5 °C, whilst net nitrification rates were little affected by temperature. Temperature and substrate type appeared to be the most critical factors affecting the gross rates of N mineralization and nitrification, soluble organic C, and microbial biomass C and N contents. Soils from the lucerne and ryegrass plots mostly had significantly higher gross and net mineralization and nitrification rates, soluble organic C, and microbial biomass C and N contents than those from the bare ground, because of the higher soil C and N status in the pasture soils. Strong positive correlations were obtained between gross and net rates of N mineralization, between soluble organic C content and the net and gross N mineralization rates, and between microbial biomass N and C contents.  相似文献   

A study of health and productivity of traditionally managed cattle in Zambia     

B.D. Perry  B. Mwanaumo  H.F. Schels  E. Eicher  M.R. Zaman 《Preventive veterinary medicine》1984,2(5):633-653

A three-tiered survey was devised comprising a detailed questionnaire, a serological survey and a sentinel herd scheme for disease surveillance. The survey was carried out in the traditional farming sector in 7 districts of Zambia to obtain background information on cattle management and productivity, data on the prevalence of tick-borne and other disease problems in these areas and to monitor changes in individual herds.In the questionnaire survey, 288 farmers were interviewed. They owned a total of 15 360 head of cattle, representing approximately one percent of the national herd. Mean herd sizes ranged from 31 to 114 for each district. Mean calving percentages were 44–80%. Average national offtake from these herds was 10%. Calf mortality rates ranged from 4 to 32%, while adult yearly mortality rates ranged from 4 to 16%. Factors affecting the regional variation of these figures are discussed.  相似文献   

Mini Nutritional Assessment of rural elderly people in Bangladesh: the impact of demographic, socio-economic and health factors     

Kabir ZN  Ferdous T  Cederholm T  Khanam MA  Streatfied K  Wahlin A 《Public health nutrition》2006,9(8):968-974

OBJECTIVE: In stating the Millennium Development Goals, the United Nations aims to halve malnutrition around the world by 2015. Nutritional status of the elderly population in low-income countries is seldom focused upon. The present study aimed to evaluate the magnitude of malnutrition among an elderly population in rural Bangladesh. DESIGN AND SETTING: Data collection for a multidimensional cross-sectional study of community-based elderly people aged 60 years and over was conducted in a rural area in Bangladesh. SUBJECTS: Of 850 randomly selected elderly individuals, 625 participated in home interviews. Complete nutritional information was available for 457 individuals (mean age 69+/-8 years, 55% female). Nutritional status was assessed using an adapted form of the Mini Nutritional Assessment (MNA) including body mass index (BMI). Age, sex, education, household expenditure on food and self-reported health problems were investigated as potential predictors of nutritional status. RESULTS: BMI<18.5 kg m(-2), indicating chronic energy deficiency, was found in 50% of the population. MNA revealed a prevalence of 26% for protein-energy malnutrition and 62% for risk of malnutrition. Health problems rather than age had a negative impact on nutritional status. Level of education and food expenditure were directly associated with nutritional status. CONCLUSION: In order to reduce world hunger by half in the coming decade, it is important to recognise that a substantial proportion of the elderly population, particularly in low-income countries, is undernourished.  相似文献   

Genetic relationship of body measurement traits at early age with carcass traits in Japanese black cattle     

Tahmina Munim  Takuro Oikawa  Takayuki Ibi  Tetsuo Kunieda 《Animal Science Journal》2013,84(3):206-212

Estimates of genetic parameters were obtained for body measurement traits of 648 animals at 4 months of age, of 545 at 8 months and carcass traits of 14 972 animals with the use of an animal model by the restricted maximum likelihood procedure. The estimated heritabilities for carcass traits were high (0.41 to 0.54). At 4 months the estimated direct heritabilities for body measurement traits were moderate to high (0.28 to 0.64), except for chest width (0.19); at 8 months they were also moderate to high (0.23 to 0.49), except for chest depth and chest width (0.18 and 0.06, respectively). Maternal heritabilities for all body measurement traits were low at both ages. The results indicate that because of their moderate direct genetic correlations with body measurement traits, carcass weight, rib thickness and subcutaneous fat thickness can be improved; however, rib eye area and beef marbling standard show little such possibility considering their correlation with body measurement traits.  相似文献