Water News Archive

Water Optimizer Tool

The Water Optimizer tool evaluates single fields for several crop options. Irrigated crops include: corn, soybeans, sorghum, wheat, alfalfa, edible beans, sunflowers, and sugar beets. Dryland crops include: corn, soybeans, sorghum, sunflowers, alfalfa and wheat in continuous, summer fallow and eco-fallow rotations.

Economics & Costs

The University of Nebraska's Bureau of Business Research conducted a study in 2003 to determine the impact of irrigated agriculture on Nebraska 's economy. The net total economic impact was computed by comparing impacts with irrigation to what would have resulted without irrigation. The research examined actual 2003 impacts and what would have occurred if average precipitation had occurred. For normal precipitation the total impact of irrigation would have been just over $3.6 billion per year. Since 2003 was a drought year, the actual economic impact was more than $4.5 billion.

The evapotranspiration (ET) process is a key variable in many disciplines including irrigation management, crop growth, hydrologic cycle, plant physiology, soil-plant-water-atmosphere relationships, microclimate and surface interactions, and drainage studies.

Application Uniformity of In-Canopy Sprinklers, G1712
PDF version
Use of in-canopy sprinklers can reduce application uniformity and increase runoff. Learn how to evaluate the efficiency of in-canopy sprinklers.

Irrigation Management Publications from Nebraska Extension

Harvesting Crop Residues, NebGuide G1846
Issues of crop residue harvest, including nutrient removal and effects on erosion, soil quality, water loss, and yield are discussed in this NebGuide.

Reduce Need for Irrigation by Maintaining Crop Residue and Reducing Soil Tillage

Leaving higher levels of crop residue and doing less tillage can increase the soil water balance by increasing the amount of water that infiltrates the soil from irrigation or precipitation, and decreasing the amount of water that runs off the soil surface. More residue and less tillage also reduce the rate of evaporation of water from the soil. Maintaining residue on the soil surface and doing less tillage can significantly reduce the amount of irrigation water needed to grow a crop.

Precipitation Patterns

Another major factor in irrigation scheduling is making use of precipitation, both during the growing season and in the off season. Shown below is a map detailing the average net irrigation requirement for corn for the State of Nebraska.

The net irrigation requirement is based on precipitation patterns and soils. In wet years less water is needed and in dry years more water will be needed.

Soil Water

Irrigation scheduling needs to begin with a discussion on soil and soil water. This is the basis of irrigation scheduling.

Coarse soils, such as sands and gravels, have relatively large pores. However the number of pores is small when compared to a finer textured soil. Fine soils, like clays or clay loams, have relatively small pores. Having many small pores means that a fine textured soil can hold more water than a coarse textured soil.

Why Manage Irrigation?

The goal of irrigation management is to use water in the most profitable way at sustainable production levels. For production agriculture this generally means supplementing precipitation with irrigation.

In recent years we have seen declines in groundwater levels, almost statewide. Much of the State of Nebraska is considered fully or over-appropriated. This means that in those over-appropriated areas there will be no new development of irrigated acres.

Furrow Irrigation

Advantages to furrow irrigation include lower initial investment of equipment and lower pumping costs per acre-inch of water pumped. Disadvantages include greater labor costs and lower application efficiency compared to sprinkler and subsurface drip irrigation. The number of furrow irrigated acres in Nebraska has decreased from 2.4 million to approximately 1.5 million acres in the past 10 years.