The study aims to (1) build a linear programming model and determine the optimal volume of dam water that maximizes farmers' income based on plant types and field area for two growing seasons; (2) modify the linear programming model by incorporating marginal land, (3) test model sensitivity to obtain information about farmers' income when the government program "planting corn and harvesting cows" is implemented. The research was conducted in Fatuketi Village, which is the only area irrigated by Rotiklot Dam for agricultural purposes, with a land area of 159 ha in 2021. Agricultural commodities cultivated by the farmers consist of rice and corn. The data analysis is based upon a linear programming model for income maximization and its simulation with 300 ha of marginal land having the potential to be managed into new agricultural land, as well as testing the sensitivity of corn cultivation models covering 10%, 20%, 25%, and 50% of the area. The model analysis suggests that maximum income can be achieved when farmers cultivate only rice on the land, with a total income of Rp.1,270,070,000. The model also recommends planting rice on all marginal lands (300 ha) so that the total income increases to Rp.3,666,428,000. The sensitivity analysis suggests that cultivating maize on 10%, 20%, 25% and 50% of the 159-ha land will result in income decrease,