determining the cropping pattern with emphesize on reducing fertilizer and water consumption policies in mazandaran province (case study: behshahr county)

abstract:background and objectivesenvironmental is one of the most important components of global macro policies, therefore, one of the main prerequisite of many activities in macro level is compatibility with environment. environmental pollution is one of the most significant challenges that is faced by human society in 21st century. agriculture sector compare to the other other sectors of economy is more closely related with environment. environment from one hand provide main factors such as soil and water which are needed for production of agricultural crops and on the other hand its affected by pollution resulted from production activities of agricultural sector especially pollution due to over consumption of chemical fertilizers and pesticides. in recent decades consumption of chemical fertilizers have had undesired effects and outcomes such as soil and water pollution which in turn resulted in health condition of human beings as well as rest of living creatures. the aim of this study is to investigate the effect of reducing the consumption of fertilizer and water to cultivated area of crops in behshahr county.materials and methods: in this study with application of positive mathematical programing (pmp) effects of policies reduction of water and fertilizers consumption on cropping pattern of agricultural products of agronomy sub sector of behshahr county of mazandaran province. required data are gathered through jahad-e-agriculture organization and regional water organization of study area and statistical center of iran. information regarding cost of production and farmers income were gathered through direct interviews with farmers of behshahar county. in this research simple random sampling methods is used thus 133 farmers were interviewed. results:the results show that implementing the policy of reduction the amount of fertilizer used by 49 percent, will reduce cultivated area of all crops and the most part of reduction will occurs in the area under rainfed rapeseed, if the policy of fertilizer reduction of 56 percent comparing to current level of consumption of fertilizer is implemented the area under cultivation of agricultural crops will reduce and most of this reduction will ensue in the area under the cultivation of rainfed wheat. under the policy of reducing the amount of irrigation water by 13.93 percent, cultivated area of all irrigated crops decrease and rainfed crops (rainfed wheat, rainfed barley and rainfed rapeseed) will increase. conclusion:as it is obvious from the results reduction in the consumption of chemical fertilizers has more effects on rainfed crops, it is suggested that reduction in level of fertilizer consumption in the areas which contain rainfed crops is performed cautiously. thus, noting to the results of this research work it is suggested that in order to prevent the reduction in the area under the cultivation of irrigated crops it is required to improve irrigation efficiency by usage of under pressure irrigation so that production of irrigated agricultural crops do not get effect by reduction of consumption of irrigation water.