At the production site of open-field vegetables, stable production and stable supply corresponding to contract cultivation for processing and business demand has occupied the majority of vegetable consumption of the people. In addition, technological development is also necessary to contribute in strengthening competitiveness in response to the increase in imported fresh vegetables. On the other hand, the frequent occurrence of unusual and abnormal weather conditions induces a volatility in the price and quantity of production which remains a risk for stakeholders and consumers of the food industry. Therefore more stable production is required. Further there is also a need for technology development that responds to the needs of introducing open-field vegetables in large-scale land-use agriculture. We are pursuing research to cope with the open-field vegetables off-crop season and to ensure stable supply of raw materials for leafy vegetables in the domestic processing business. We are pursuing research on the (1) development of stable production technology utilizing the Farm Oriented Enhancing Aquatic System (FOEAS), a groundwater level control system and the Optimum Surface Irrigation System (OPSIS), an underground irrigation system for upland fields, and the (2) development of off-crop season production technology and high-quality production technology to cope with demand for processing and business as well as to counter imported vegetables. These innovations will eventually facilitate the stabilization and maintenance of high-yielding production of open field vegetables to meet the market demand.