Wednesday, November 15, 2006

Effect of AirJection™ Irrigation on Crop Yield and Soil Properties.

Dave Goorahoo1, Diganta Adhikari1, David Zoldoske1, Angelo Mazzei2, and Richard Fanucchi2. (1) CIT - CSUF, 5370 N. Chestnut Ave. M/s Of18, 5370 N. Chestnut Ave. M/s Of18, Fresno, CA 93740-8021, United States of America, (2) Mazzei Injector Corporation, 500 Rooster Drive, Bakersfield, CA 93307

The concept of aerating the sub surface drip irrigation (SDI) water- referred to as Air-jection® increases the potential for the air to travel with water movement within the root zone.  Physical, chemical, and biological soil characteristics that influence crop growth and yield depend on the relative proportions of the liquid and gas phases within the root zone.  The findings of a pilot study conducted in 2000 at the Center for Irrigation Technology (CIT) in California, in which air was injected into the root zone of bell peppers via the subsurface drip irrigation (SDI) system justified follow-up fieldwork on larger plots approaching commercial scale. In this presentation, we review the current research aimed at evaluating the technical and economic feasibility of air injection into a SDI as a best management practice for fresh-market tomato, melon, bell pepper and broccoli production. Since the 2000 small scale study, we have been working with commercial vegetable growers in evaluating the feasibility of Air-jection® in crop production.  In Fall 2003, in comparative tests between air injection and water only treated melons (honey dews) on 13acres plots with a drip tape run length of over 400m there was a 14% increase in the number of melons and, a 16% increase in the weight of melons harvested due to air injection. These figures translate into a projected increase of $260 to $350 per acre for the farmer depending on the wholesale price of melons, which can range from $3 to $4 per box.  In Summer 2004, for cantaloupes grown on 20-acre plots, there was a 13% increase in the number of melons and, a 18% increase in the weight of melons harvested due to air injection. So far, we have found that Air-jection® Irrigation increased root zone aeration and can add value to grower investments in SDI.