A new report released by the Wisconsin Department of Natural Resources (Feb 12,2013) stated that power generation and municipal uses account for 85% of total state water use compared with 4% by agriculture. Even in Portage, Adams and Waushara (among the highest use counties), municipal withdraws were higher (42%) than agricultural irrigation (33%). These counties “comprise much of the central sands area of the state known as a globally significant vegetable production region” according to the DNR report; production and processing of specialty crops, which are concentrated in the region, contribute $6.4 billion in economic return to the state and generate almost 35,000 jobs.
In recent years, concern over water use and availability in the region has sparked debate over the impact of climate, irrigation, and municipalities on groundwater resources. While climate is an impact that local growers have no control over, they do have the ability to impact the efficiency of irrigation, especially during the peak use in July and August when crops require the most water. Mike Copas, field manager from Russet Potato Exchange, explains the importance of his irrigation strategy as “a complete approach to conserving the resource by supplying only what the crop needs. We understand the importance of managing our water resources wisely and are utilizing the most advanced technologies to be the most efficient in our usage for our potato and vegetable rotations”.
The majority of growers use center pivot overhead irrigation systems, which are monitored continuously to ensure uniform water distribution, precisely control the amount of water applied, and operated during off peak hours whenever possible to conserve energy demand on the system. To increase the efficiency of these systems, growers are adopting a range of cutting edge technologies including variable-rate precision irrigation, deficit irrigation and drip irrigation. Sophisticated irrigation scheduling programs have been developed and used to precisely match water applied to crop need and thus eliminate waste. However, growers are now pushing the envelope further by mapping the varying soil types and their ability to retain water across fields; water is applied at variable rates according to crop need in a new technology termed, “variable-rate, precision irrigation,” which has been shown to not only save water but increase crop quality.
Additional technologies are also being tested in research funded by the WPVGA that include crop varieties and landscapes that require less water, withholding water during non-critical growth stages (deficit irrigation), and drip irrigation. Together, these innovative approaches make a difference. As Mike Copas concludes, “water management is a complex task, and we use all our tools to manage it as effectively as possible. As a grower and land manager, I want people to know that we are working hard to maintain our water resources. They are an integral part of our farming operation, and to maintain it for the long-term, we will utilize our water correctly”.