都市周邊地區為介於都市與鄉村之間的過渡地帶，直接受到都市成長與土地開發需求等衝擊。農業生產利潤較其他非農部門低，農民預期都市周圍的農地會變更為非農業使用，不僅會減少對農業的投資，甚至持有土地以享漲價之利。農地除具備生產價值外，更具備其他外部環境價值，包括氣候調節、固碳作用、調節洪水逕流、環境景觀保護與鄉村地區就業等。他國經驗不受生產補貼限制的綠色措施，可直接將農地環境效益貨幣化補貼予農民，得促進農地維持農用或至少不變更為他用。故本文嘗試從部分較易量測的農地環境價值項目進行推估，進而將估算所得的環境價值與農地轉用價值比較分析，初探農地環境價值內部化政策對於轉用減緩可能性。研究結果顯示，水田環境價值中以氣候調節環境價值最高，其次為淨化空氣與防洪減災，惟依本研究推估之農地環境價值相對農地轉用增值為低，是以單以環境價值補貼可能對農地轉用之抑制或誘因略為不足。未來除考量農地環境價值外，其他如農地糧食生產價值、農民就業、休耕補貼等綜合計算，以有效達到抑制農地轉用之效果。

Urban growth and land developments lead to rapid changes in the peri-urban areas between urban and rural areas. Crop production generally has lower benefits than non-agricultural sectors, and the expectation of land use change not only decreases agricultural investments, but also encourages farmers to retain farm land for future land price increment. Aside from food provisions, external environmental values of farmland include climate adjustments, carbon sequestration, flood regulatory capability, environmental landscape protection and employment in rural areas. Unlimited support in the form of green box policies can directly monetize environmental benefits and subsidize farmers, and thus encourage farmland for farming usage. This study attempts to evaluate some measurable environmental benefits, and compares these with the value of farmland use change. The purpose is to perform a preliminary exploration on the mitigation of farmland use change by the amount of monetized environmental benefits. Analytical results reveal that the climate adjustment is the strongest environmental benefit, followed by air purification and flood retention. However, the rational level of subsidy is lower than the value of farmland use change. Therefore, the monetized environmental benefits may not encourage farmers to minimize farmland use change. Other benefits, such as food production and employment, should considered when estimating farmland subsidy in order to mitigate farmland use change.