Precision Irrigation for Hops

2021 Idaho Hops Virtual Field Day

PRECISION WATER MANAGEMENT FOR AGRONOMIC, ECONOMIC, AND ENVIRONMENTAL SUSTAINABILITY OF IDAHO HOP PRODUCTION

OBJECTIVES:

Objective 1. To evaluate the efficacy of using generalized hop crop coefficients and the existing Irrigation Scheduler for guiding water application for hops in Idaho.

Objective 2. Compare the ET-based irrigation water management with a typical time-based water application strategy currently used by the Idaho hop growers. The analysis will include agronomic, economic, and environmental assessment.

Objective 3. To assess what climatological, soil, and plant-derived measurements collected throughout the season (alone and in combination) are most useful in improving the accuracy of the ET-based irrigation recommendations for hops produced in Idaho.

Idaho Hops. Source: Boise State Public Radio.

RESEARCH & EXTENSION TEAM:

• Dr. Olga Walsh, Research Associate Professor, Extension Specialist, Cropping Systems Agronomy, University of Idaho, Parma R&E Center
• Dr. Howard Neibling, Associate Professor, Extension Specialist - Water Management Engineer, University of Idaho, Kimberly R&E Center
• Dr. Patrick Hatzenbuehler, Assistant Professor, Extension Specialist, Crops Economics, University of Idaho, Twin Falls R&E Center

• Idaho hop industry lacks the ability to make robust predictions regarding water management because very limited information is available on water requirements for hop production in Idaho’s unique climatic conditions. The Idaho Hop Commission, hop producers, and University of Idaho researchers will collaborate on this project focused on improving the efficiency of water use in hop production. Olga Walsh’s Cropping Systems team at Parma Research and Extension Center, Howard Neibling’s Water Management team, and Patrick Hatzenbuehler, an Agricultural Economist, will conduct trials and economic analysis for 2 years. Trials will assess and compare the agronomic, economic, and environmental aspects of hops grown under 1) traditional time-based water management currently practiced by the Idaho growers, and 2) a water management system based on the estimated hop crop evapotranspiration (ET) and other crop irrigation best practices.
• An efficient sensor-based water application methodology will be developed based on a comprehensive climatological, soil, and plant – related measurements collected throughout the season. The study will serve as a needed starting point for development of a more comprehensive hop grower guide detailing the water and nutrient management for hop varieties commonly grown in Idaho. Extension education will be conducted to encourage the adoption of efficient water management strategies by the Idaho hop producers and will discuss the estimated economic implications of such adoption.

• The first hop yard in southern Idaho was established in 1934. The hop industry has come a long way since then, and has grown tremendously in the past decade, becoming a vital part within the Idaho agricultural sector. Idaho acres planted to hops have increased from 2017 by more than 1,200 acres in 2018, bringing the total acreage under hops to 8,220 – an increase of almost 20%. Idaho is now 2nd in the nation in hop production (considering both acreage and production amount) after Washington. In 2018, U.S. hop production increased by 4% to a record 55,340 acres (108 million pounds, $583 million value). Since 2012 (6 years) U.S. hop acreage has increased 95%, from 29,685 to 57,770 acres. Idaho hop acres have been rapidly expanding in the recent years in large part to satisfy the soaring demand for aroma hops from the brewing industry. In 2017, Idaho hop growers produced 13.7 million pounds of hops, with average yields of 1,970 pounds per acre. In 2018, Idaho hop production represented over $86 million, up 22.4 % from 2017. U.S. exports of hops increased 12.36 percent from $169.93 million to $190.94 million in 2018. Nationally, the craft brewing industry’s utilization of aroma hops has exploded from 6 million pounds in 2007 to 33 million pounds in 2016.

• Irrigating hops requires a sizable upfront investment. Surface drip irrigation systems used by the majority of hop growers costs at least $4,150 per acre ($2,650 per acre represent the cost of materials, plus $1,500 per acre installation cost). Furthermore, the annual water charge is at least $95 per acre for a typical hop yard. Although drip irrigation is relatively efficient for water delivery, the effectiveness of the system is not fully realized because there is not yet a research-based methodology to guide the amount and timing of water application throughout the season.
• The majority of Idaho hops are intended for craft brewing (approximately 80%, compared to about 20% for alpha-based market). Recently, growers have faced substantial increases in the cost of production, driven in large part by investments that allow for expansion of harvesting and production capacity to handle the rapid growth in acreage over the past 6 years, in addition to updating equipment, increased labor costs, and rising costs of other production inputs. Administrative and operating costs associated with best management practices to comply with strict food safety regulations have also increased.
• We expect that with efficient irrigation water management, the hop yield can increase, and quality can be improved while decreasing the total amount of water applied and distributing the water more appropriately throughout the growing season. A similar management approach in wheat in Idaho has enabled growers to decrease water application by 25%, which, in addition to cost and water savings, also reduced lodging and improved wheat grain quality. Applying less water to hops 1) would cut down on fertilizer applications (less water flushing through the plant/soil system would result in minimized nutrient loss), 2) minimize hop disease occurrence and severity a) crown-and-root rot of hop (referred to as black root rot) - the disease is most damaging in poorly drained soils and areas with high water tables; b) powdery mildew (typically exacerbated by excessive fertility and high soil moisture).
• Although the water allocations have been steady for Idaho hop growers in the recent years, minimizing water application would substantially lower their water management costs, especially by lowering the water pumping costs and reducing the need for re-application of fertilizers. Furthermore, reducing both water and fertilizer application would minimize concerns related to water quality associated with crop production in Idaho, including hops.