Issue link: http://read.dmtmag.com/i/437957
IRRIGATION GOES IRRIGATION GOES included water conservation, lower flow rates to irrigate more acres at one time, and less weed control required in the vineyard due to just a small wetted area beneath the vines where water is applied. GOING UNDERGROUND Even so, there was still the feel- ing by some innovators that drip rip irrigation was revolution- ary when it was introduced in the 1970s and 1980s. As equipment was improved with refinements such as pressure com- pensation, in-line emitter tubing and highly uniform emitter perfor- mance, growers readily adopted the technology. Prior to that, sprin- klers, flood irrigation and dry-land farming were mostly how vineyards were managed for water. Each had various problems, and is no longer widely used today. Drip irrigation allowed a way to deliver water in a precise and con- trolled method that seemed perfect for grape vines, given the design of a vineyard (trellis systems to hang drip hoses from, vines that are long and narrow in shape) and where roots can effectively forage for applied water directly beneath the vines. D r i p i r r i g a t i o n a l s o a l l o w e d vineyards to be planted in loca- tions and soils that formerly would have been problematic to irrigate: hillsides, soils with slow infiltra- tion rates, soils with poor water holding capacities, and soils with considerable rock and gravel (but good rooting depth). With drip irri- gation, it became possible to man- age water to keep vines at ideal soil moisture content. Added benefits BY GLENN MCGOURTY + Drip irrigation was revo- lutionary when it was first introduced. + A new "deep water irriga- tor" is designed to connect a Woodpecker-type emitter to a conventional above- ground drip system. + It combines the benefits of delivering water below ground, right into the vine's root zone, with the conve- nience of an above-ground water distribution system. + Vineyard trials are ongoing. AT A GLANCE irrigation could be improved. Buried drip irrigation has been successfully used in landscape, vegetable crops and even perennial crops such as alfalfa. The benefits include less evaporation loss, putting water pre- cisely where it is needed, and the ability to also place nutrients in the root zone for those who fertigate. Water conservation and improved plant growth are the outcomes when these systems work well. There are some definite draw- backs to buried drip systems in a vineyard. First, you need to have drip hose with in-line emitters, since the system is usually shanked into the ground with a special appli- cator behind a tractor. These kinds of drip systems require high preci- sion in planting so that the emitters end up close to the vines, especial- ly in the first year when vine roots are limited. Second, you can't really see the system, so you need to have effec- tive ways of monitoring it as it is operating. This requires pressure gauges, flow gauges and constant vigilance. Gophers can wreak havoc on these systems, and leak repairs are awkward when required. Any tillage across the system is also a problem, as the lines have to be deep enough to avoid damage. Root intrusion can also become UNDERGROUND UNDERGROUND UNDERGROUND A fresh look at vineyard subsurface irrigation 7 6 V I N E YA R D & W I N E RY M A N A G E M E N T | J a n - F e b 2 015 w w w. v w m m e d i a . c o m