The Lower Rio Grande Valley farmers traditionally irrigate vegetable crops with furrow irrigation systems. To conserve water and mitigate the effects of droughts, there is a need to adopt more efficient irrigation and fertilization methods and practices in vegetable crops to increase crop production quality and profitability. Farmers that use furrow irrigation systems apply from 4 to 6 inches per irrigation depending on their furrow length and apply more than five irrigations during the vegetable growing season, and using between 20 inches (1.7 ac-ft) and 40 inches (3.3 ac-ft) of irrigation water in their fields. Vegetables have a shallow root system, so farmers must irrigate frequently to maintain good moisture levels during the growing season for optimum growth, possibly wasting water. We use image analysis derived from Unmanned Aerial Systems (UAS) and irrigation soil water sensors to provide management recommendations to schedule drip and surface irrigation to conserve additional amounts of water. We established replicated research experiments using subsurface drip irrigation and soil water sensors (watermark sensors) to irrigate watermelons and other vegetable crops. We grew plants under three different water levels to trigger irrigation (50, 75, and 100 cb). A drip irrigation system with plastic mulch was placed in the field, as well as soil-water sensors, to measure and monitor the soil moisture. After calculating the water used in the three water level treatments, the 50 cb treatment used 0.27 ac-ft, the 75 cb treatment used 0.24 cb and 0.22 ac-ft was used by the 100 cb treatment. According to our results, we could conserve up to 3.0 ac-ft with our recommendations. We concluded that watermelons could be managed when the soil-water sensor readings range between 50 and 75 CB and approximately 0.3 ac-ft of water using subsurface drip irrigation. We obtained an average yield of 53,536 lb/ac, when irrigated under the 50 cb treatment, 42,059 lb/ac at 75 cb, and 36,719 lb/ac at 100 cb.
