Water is essential to crop production though too much water can lead to erosion, nutrient leaching, plant diseases, and anaerobic soils. Plants also suffer in drought conditions. In dryland production systems, those that are not irrigated, water availability relies on what is stored in the soil or provided by rainfall. Irrigated systems benefit from the ability to control soil moisture more precisely, though rainfall can still enhance or hamper yields. Even in high rainfall western Washington irrigation is required in many cropping systems, since the majority of the precipitation occurs in winter and summers are dry. There are many irrigation strategies are some are more efficient than others.
Soil moisture and irrigation
Practical Use of Soil Moisture Sensors and Their Data for Irrigation Scheduling, 2013, Washington State University, by Troy Peters, Kefyalew Desta, and Leigh Nelson. This publication provides practical recommendations for using soil moisture sensors and interpreting their measurements for more profitable crop production.
Drip Irrigation for the Yard and Garden, 2011, Washington State University Extension, by Troy Peters. This publication provides an overview of drip irrigation systems, including the benefits and costs, the various components, and the basics of design and operation of such systems.
Managing Wheel-Lines and Hand-Lines for High Profitability, 2011, Washington State University Extension, by Troy Peters. The focus of this publication is on providing background information to assist managers of wheel- or hand-lines in understanding soil water management and on offering some best management practices that lead to higher profitability and improved environmental water quality.
Managing Irrigation Water for Different Soil Types in the Same Field, 2012, Washington State University Extension, by Troy Peters and Joan Davenport. Highly variable soils make irrigation water management difficult. This publication provides some practical suggestions for irrigation managers who maintain fields with highly variable soils.
Irrigating with Booms vs. Big Guns in Northwestern Washington, 2010, Washington State University Extension, by Troy Peters and Don McMoran. Traveling, or reel big gun systems of irrigation are effective at supplying water to crops but they do so inefficiently. High pressures are required to propel the water long distances, making it highly vulnerable to wind drift and evaporation. Tests show that big gun systems also have poor distribution uniformity compared to other irrigation systems.
Water Quality
Managing Irrigation Water Quality for Crop production in the Pacific Northwest, 2007, Pacific Northwest Extension, by Bryan Hopkins, Donald Horneck, Robert Stevens, Jason Ellsworth, and Dan Sullivan. Water quality is a concern to everyone who uses water. How to manage water in a specific situation can be both a practical and financial challenge. This publication focuses on analyses used for typical agricultural irrigation water sources. Water originating from an industrial, livestock, or municipal source may require additional analyses and care.
Water Rights
Washington Water Rights for Agricultural Producers, 2009, Washington State University, by Troy Peters. In most cases, only farms that have water rights can use surface or ground water to irrigate their farms, and use is limited to the quantity established in the right. A water right is not necessary in Washington State if the water will be pumped from groundwater to water stock, irrigate a half acre or less of non-commercial lawn and/or garden, or if 5,000 gallons per day or less are used for domestic or industrial use. The Surface Water Code that governs water rights was established in 1917. The code states that existing water rights would be protected and that new beneficial uses of water would need a water right.