Air Injection and Potato Performance Under Subsurface Drip Irrigation.

Subsurface drip irrigation can substantially reduce the amount of irrigation water needed for potato production. However, tuber yield and quality need to be improved to offset the initial cost of drip installation. A field study was conducted at the San Luis Valley Research Center, Colorado State University, to evaluate the effect of air injection in subsurface drip irrigation on the performance of Rio Grande Russet Potato. Treatments included subsurface drip irrigation with and without air injection. Stem number and tuber set were increased from 4 to 5 and 7 to 8, respectively, when drip irrigation water was aerated with atmospheric air. Tuber bulking was faster, and terminated earlier under the air-injected drip system, than in the drip system without air injection. Root, stem, and tuber dry mass were observed to be higher under the air-injected drip system than under the drip that did not have air injection. Leaf Area Index increased by 1.9 for plants grown under aerated drip irrigation during the tuber bulking phase. Air injection increased total tuber yield by 8%. For tuber size distribution, the 170 to 340, 170 to 398, and 170 to 454 g tuber yields were increased by 19, 21, and 19%, respectively, when Rio Grande Russet potatoes were grown under subsurface drip irrigation with air injection. Tubers were observed to be bulkier in the air-injected drip treatment.  Air injection of subsurface drip irrigation produced 14% more tubers with 5 to 10 cm tuber diameter, compared to the drip treatment that did not have air injection. Data from this study indicate that potato tuber yield and quality can be improved under subsurface drip irrigation if the drip water is aerated by atmospheric air injection.