چكيده لاتين :
Introduction
Agricultural development in response to the growing demand for food is inevitable. Besides that, undesirable implications occur for human life and the environment that are requirements for problem- solving and change. Pollution of surface waters and ground waters includes the most important undesirable implications for agricultural development (Ongley, 2003). Chemical pesticides and fertilizers consist about 15 percent of water pollution. Chemical pesticides directly affect water quality. But chemical fertilizers affect water quality when large quantities of them enter the soil, so that its surplus enters rivers and lakes by outlet water and drainage and by providing food for algae causes their rapid growth. These materials consume the oxygen of water and cause the death of aquatic organisms (Ali Hosseini, 2011). Also, shedding liquids such as urban sewage, industrial sewage and domestic sewage on agricultural land particularly and the legal or illegal excretion of them in the water resources and failure or overflow of the sewage system cause water pollution. Since farmers are partners in the creation of water pollution, to reduce the environmental undesirable effects of polluted water we should examine farmers’ behavior, until finally we become able to modify or reduce the undesirable environmental effects. For this reason, this study tried to examine farmers’ financial participation to specifically reduce the undesirable environmental effects of polluted water in Kashaf- Rood basin .
Materials and methods
In order to examine farmersʹ financial participation (willingness to pay), the Contingent Valuation approach was used. In this approach, willingness to pay (WTP) to maintain the present situation and to make positive changes in the environment and willingness to accept (WTA) to compensate loss of profit or increase a loss of Environment (Pearce & Turner, 1990) were examined. In this study, for extracting the value of the goods or service in the contingent valuation approach, Open End technique was used, because the farmers who were questioned, were aware of the undesirable environmental effects of polluted water and the cost of reducing these effects. Tobit model by Heckmanʹs two stages was the model used in this study. Failure of Logit and Robit models in the distinction between the factors affecting the decision and the factors affecting the level of activity were the main reasons for using this model (Darijani, 1999; Tobin, 1958). To achieve the desired sample proportion with the study objectives, simple random sampling was used, because of the homogeneity of the studied population. To determine the number of samples the Cochrane relationship and so were used. 100 questionnaires were collected from farmers of Kashaf- Rood Basin in the city of Mashhad in 2014. For estimation of Tobit model Shazam software version 11 was used.
Results and discussion
The results showed that variables of age, farmers agreement with rural and urban sewage inflow into Kashaf-Rood river index, total amount of annual consumption of chemical pesticides and variables of sex, total cultivated land area, farmers agreement with benefits of preventing soil washing index, farmers agreement with desirable quality of available soil and water index and farmers agreement with investments to protect the soil and water index, experience in the use of soil and water conservation practices had significant positive and negative impacts on farmersʹ decisions to financially participate in reducing the undesirable environmental effects of polluted water, respectively. Also, variables of age, type of agricultural activity, crops under cultivation, the total amount of annual chemical fertilizer consumption per year, the total amount of annual chemical pesticides consumption, farmers agreement with rural and urban sewage inflow into Kashaf- Rood river index and variables of net savings of agriculture, land ownership status, experience in the use of soil and water conservation practices, total cultivated land area, farmers agreement with desirable quality of available soil and water index, and sex had significant positive and negative impacts on the amount of farmersʹ financial participation to reduce the undesirable environmental effects of polluted water, respectively. The results indicated that the maximum amount of farmers’ financial participation for reducing the undesirable environmental effects of polluted water per hectare in five scenarios were 134500, 179500, 225500, 271000 and 354500 rials, respectively.
References
Ongley, E. 2003. Control of water pollution from agriculture. FAO Irrigation and Drainage 55: 101 pp.
Pearce, D., and Turner, R.K. 1990. Economics of Natural Resources and the Environment. Johns Hopkins University, Baltimore.
Ali Hosseini, M. 2011. The risks posed by pesticides and fertilizers. Geomorphology Page. Available at Web site http://geologist63.blogfa.com.
Darijani, A. 1999. A survey of depositorsʹ view and factors affecting the amount of household bank deposits. MSc Dissertation, University of Tehran, Iran. (In Persian with English Summary)
Pearce, D., and Turner, R.K. 1990. Economic of Natural Resources and the Environment. Johns Hopkins University, Baltimore.
Tobin, J. 1958. Estimation of relationships for limited dependent variables. Econometrica 26: 29-36.
