Alley cropping is practiced in a small portion of California orchards where annual cash crops are grown in orchards’ alleyways in years 1 and 2 when trees are small. Although alley cropping can increase land use efficiency and generate income when fruit trees are unproductive, possible competition of the cash crop for water and its effects on tree productivity is a concern for growers. Quantification of tree water status in the field can be challenging. Here we present a low-cost lysimeter that we have built to quantify the evapotranspiration of 2years almond (Prunus dulcis) trees in response to the ground covering with alfalfa (Medicago sativa) and white clover (Trifolium repens). The lysimeter is made of a 50G industrial trash can where the tree is planted in a customized soil mix with adequate fertilizers. About 5 cm bottom of the trash can is filled with gravel to maintain soil drainage. A 0.5” PVC pipe connects the bottom of the trash can to a small bucket that is installed outside of the can to catch the drainage. Inside the catch bucket, a water-leveling valve opens and closes the flow of water to the soil surface on top of the trashcan. When tree uses the entire water in the trash can and subsequently the catch bucket, valve allows water to run and irrigates the tree. Once the tree drainage reaches the bottom of the trashcan and runs into the catch container, the valve shuts the water off. A flowmeter records the cumulative water run through the system and applied to the tree. To avoid overwatering due to the slow water infiltration, irrigation is spread to several 15-minute events throughout the day. Details of the lysimeter, including the diagram and photos will be presented in the poster.