Comparison of value of ecosystem services in conventional and wheat and potato organic farms in Fariman city

Valuation and quantifying of different services for agro-ecosystems is one of the main effective factors for increased attention to these services and for adopting suitable approaches to sustainability of these services. In fact, economic valuation reflects the value of some ecosystem functions, goods and services, and helps social and economic planners and managers to plan the conservation and sustainable exploitation of resources. A solution for achieving sustainability on farms is the use of the natural services in agricultural lands through the replacement of off-farm inputs such as pesticides and chemical fertilizers.
In the study, the value of agro-ecosystem services was evaluated under two different management systems, including conventional and organic for wheat and potato crops in Fariman city. The agroecosystem services studied included primary and secondary production as market services and pest control, soil production, carbon sequestration, supply of nutrients from the soil and soil fertility as non-market services. The main products included the two products (tubers and seeds for cultivation and harvest-to-send to the market in the following year), which farmers purchase and sell. The economic value of secondary production was the price of wheat and potato residual on the farm and this residual was considered as a secondary production. Other ecosystem services included non-market values. The market and non-market value of the ecosystem services in conventional and organic farms were calculated. These values were evaluated according to three different scenarios on the total acreage of wheat (10000 hectares) and potato (800 hectares) in the Fariman region. In this scenario it was assumed that 10, 25 and 50 percent of the total area of conventional wheat and potato farms would be replaces by an organic system. Finally, the differences between the scenarios were compared with the condition where the total area was under the conventional management.
The results showed the conventional potato system had a higher market value than the organic system, but the value of non-market services in the conventional was less than in the organic. Market and non-market values for wheat organic farms was higher than conventional farms, so that the total value of ecosystem services in organic farms was equal to 9.75 million RS ha-1 year-1 and this value for conventional systems gained about 7.84 million RS ha-1 year-1. The results of the evaluated scenarios illustrated that the value of non-market services increased with an increasing cultivated area of potato and wheat in the Fariman region so that, when 50% from total cultivated area of potato and wheat will be managed as organic, the total non-market value will be increased by 861 million RS year-1 and 6998 million RS year-1, respectively. Other studies also showed that ecosystem services, especially non-market services, have more value in organic agriculture than in conventional and intensive agriculture (Takatsuka et al., 2005). Sandhu et al. (2008) showed that the value of ecosystem services were 4600 and 3600 US $ per hectare per year in organic and conventional systems, respectively. Grandy and Robertson (2007) indicated that the total value of ecosystem services in organic agriculture is more than in conventional agriculture.
This study showed that organic management systems of potato and wheat farms provide more ecosystem services, especially non-market services, in comparison with conventional systems. However, in some cases, loss of yield and market value reduced the total value of organic agricultural services, but it should be noted that the movement towards organic and sustainable farming provides both -market services as well as market services such as environmental protection and healthy food production.