The Influences of Production Factors with Profit on Agricultural Heritage Systems: A Case Study of the Rice-Fish System

With the mobility and off-farm employment of rural villagers, agricultural production has been influenced by the absence of labor force in the past few years. In particular, the inadequate assignment of resources has threatened the sustainability of some Globally Important Agricultural Heritage Systems due to their low profit. In this paper, the influences of labor force and capital on agricultural heritage systems are analyzed, taking the Qingtian Rice-Fish Culture System (QRFCS) as an example, so as to maximize profit along with the sustainability of agricultural heritage. The Cobb-Douglas Production Function is applied to examine the impacts of these major factors on agricultural productivity based on a survey held among 32 households in Longxian Village, Qingtian County, China. Subsequently, the profit maximization problem can be solved by a marginal rate of technical substitution under production standard. We come to the conclusion that the output elasticity coefficients of labor and capital are 0.6 and 0.4. Our results also indicate that the maximum yield of rice and field-fish is 0.84 kg under the level of 9 Yuan RMB and 0.24 man-days per square meter. The net profit can hit 24.8 Yuan RMB regardless of human resource cost. In contrast, the demand of 218,800 m(2) paddy fields exceeds the human resources available for the Rice-Fish system in QRFCS, thereby it is necessary to promote the refluence of skilled farmers.