جستجوی مقالات مرتبط با کلیدواژه "بهره وری" در نشریات گروه "آبخیزداری، بیابان، محیط زیست، مرتع"

In this study, a model was developed to determine the optimal irrigation schedule for the Qazvin Plain in such a way that economic productivity is maximized with the amount of water available and the area under cultivation. The AquaCrop plant growth model was used to determine crop performance in different irrigation programs. The plant growth model was connected to the MATLAB programming environment. Ants’ optimization algorithm was used to determine the optimal irrigation schedule. Products, the volume of different water, depth of irrigation water, and irrigation cycle were included as decision options. Finally, after determining the best parameters of ACO, the best irrigation program was determined by considering five different scenarios in terms of irrigation depth and frequency and crop cultivation priority. In order for the irrigation program to be generalizable in water deficit conditions, an irrigation deficit from 5% to 35% was considered in different stages of growth. If we want to have the same frequency and depth of water for all crops (scenario of constant irrigation frequency and constant irrigation depth) with the goal of maximum economic efficiency, the best irrigation schedule is frequency of 9 days with a depth of 86 mm. And if the goal is maximum water productivity, the best irrigation schedule is 8 days with a depth of 78 mm. In total, among all scenarios, the best irrigation program with the aim of maximum economic productivity was related to the second scenario with variable irrigation frequency of 7 and 8 days. The optimal water depth for autumn crops was 40 and 52 mm and for spring crops was 84 mm. In addition, the priority of planting was determined in the order of tomato, potato, fodder corn, beans, wheat, barley, rapeseed, seed corn, and sugar beet. In case of a decrease in the amount of available water, the best low-irrigation program for crops was determined in such a way as to create maximum economic productivity.

Due to the various uses, sugar beet is of economic and commercial importance in today's world. Regarding that this crop is the raw material of sugar factories, the government has recently paid a particular attention to its production. The main aim of this study was to specify environmental convergence of production factors among sugar beet growers in the country during the 2013-2017 years. The required data retrieved from the statistical reports of Ministry of Agriculture Jihad and then were analyzed using GAMZ2.1 and Ewiews9 software. For this purpose, the standard technical efficiency and the environmental technical efficiency of the sugar beet factors were first calculated using the data envelop analysis model of the window data under the conditions of variable return to scale. Consequently, the environmental convergent of sugar beet production factors was examined through the Dickie Fuller test. The findings showed that the average standard technical efficiency and environmental efficiency were 0.76 and 0.67, respectively. With regard to the average level of technical efficiency of the environment, it can be concluded that there is an environmental inefficiency in these provinces. Based on these results and further investigation of upon the efficiency and transferring these results to the provincial farms using agricultural extension and education system and supportive polices, the technical efficiency of the environment in production of this strategic crop can be increased. Environmental convergence tests showed that environmental convergence of production factors exists in the all studied provinces. It means that all sugar beet growers have a tendency to increase the technical and environmental efficiency of production factors. Given the issue of environmental pollution in the present century, this conclusion is very promising for future generations in terms of protection of the environment. Promoting and disseminating new technologies including pressurized irrigation systems and minimizing the application of pesticides and chemical fertilizers are among the policy solutions to increase the technical efficiency of the environment in the provinces dealing with the issue of environmental efficiency

Agriculture potentially is one of the main factors that cause environmental destruction. Because most of time wasteful using of chemical fertilizer and poisons to achieving more efficiency in agricultural sector caused bad environmental effects. So in present research, calculating Iran agricultural productivity growth with respect to environmental effect in 1991- 2011 period has been considered. In this study, input-oriented Malmquist index with using the distance function and environmental adjusted productivity index (EAP) has been used. Results show that the growth of environmental productivity is 3.7 percent and the growth of typical productivity is 3.2 percent. In fact, the growth of computed environmental productivity was estimated more than the growth of typical productivity. These results show that in survey of environmental productivity, in addition to calculate productivity of products with market value also agriculture sector attempts to control of pollutant also has been considered. So suggest that in order to avoid overestimating productivity, always negative environmental effects of agricultural activities in the computing productivity must be considered.
Also the findings express a reduction of the growth rate of the agricultural sector. This is due to the higher growth rate of capital stock relative to the growth rate of products in the agricultural sector. One ways to increase this rate is prevention of the capital exiting from the agricultural sector and prioritize investments aimed at increasing productivity.

The input-oriented Data Envelopment Analysis was used to measure the water use efficiency and productivity indices of Tehran over the period 2005-13. Meanwhile, the correlation between water uses and regional economic activities was examined using the gross regional domestic product index. The results indicated that the total productivity was improved 1.8% and 1.68% aspect of technical efficiency change and scale efficiency change respectively. Furthermore, it was improved 12.32% aspect of technology change due to accumulation and treatment of waste water and applying water use management to increase annual water storage since 2011. The mentioned indices confirmed that a 22 million cubic meters decrease is possible in water uses without decreasing in the level of gross products related to Tehran.

Always, one of the expert subjects has been being the low irrigation efficiency and water utilization in agriculture for the surface flows. To investigate this issue, basin of Dasht-Sefidrud which only use the surface water, was selected as the study pattern. Then, based on the region's major product, it was sampled the transmission efficiency, water use efficiency and water utility in the field. Results showed that the transmission efficiency in irrigation networks with concrete cover was between 75 to 92 percent whereas, if the canal has been terrestrial and long, the irrigation efficiency would have reduced to 37/7 percent. Water use efficiency in farms under pressure of drip and sprinkler irrigations is more than 90 percent, but if the system is not be managed well, the efficiency will be reduced and reached to 63 percent. Water use efficiency in gravity irrigation is very variable, so that rice fields in which irrigation is as water flooding, the irrigation efficiency will come to 57 to 76 percent, respectively. If the management and plot size and dimensions are not appropriated, the irrigation efficiency will be greatly reduced and reached to 29 percent. Irrigation efficiency is obtained by multiplying the transmission efficiency in application efficiency. The minimum measured efficiency has been 14.2 percent and its maximum in pressure irrigation system was 95/1 percent, that the average of those will be about 57/7 percent. High level of irrigation efficiency caused the farmers recognize the importance of water and water management in recent years, and increase the irrigation efficiency in their farms and gardens.