Even in the times of excess water events, continued water conservation will be critical for the future of Utah agriculture.
IFA crop consultants can help make their growers’ irrigation dollar go further without sacrificing yield with the following irrigation solutions:
- Advanced water and soil tests
- Soil nutrition strategies involving gypsum
- High-tech block polymer soil surfactants and wetting agents
USDA Extension’s water balance equation treats the crop and soil as a box with inputs such as precipitation and irrigation water and outputs such as runoff, deep drainage, evaporation and transpiration.
Water Infiltration
Increasing water infiltration is the key to reducing runoff. This is especially important in sodic Western soils, which repel water because organic minerals found in the soil, oily coatings from crop residue and soil amendments inhibit water infiltration. In addition, carbonates from high-pH irrigation water wrap the soil particles, creating tight soil surface issues. Last, frequent wet-dry-wet cycles associated with intense irrigation and inconsistent irrigation patterns cause soil to become water-repellent or hydrophobic.
New Water and Soil Testing Methods
The usual water and soil tests used by most crop consultants and growers only tell part of the story. Standard water tests focus on water pH. Standard soil tests estimate what nutrients will be available to the crop during the growing season with rainwater as the source.
IFA now offers three advanced water and soil tests used successfully in the PNW and California to save water, improve plant nutrient uptake and increase ROI.
The Water pHc Test measures total dissolved solids and alkalinity. High carbonate levels in groundwater and some surface water sources create heavy soil crusting and sealing, resulting in excessive water use, salt buildup and increased soil pH. The Water pHc test identifies the concentration and nature of dissolved cations and anions in irrigation water. It characterizes irrigation water as either “dissolving,” which lowers soil pH, or “depositing,” which raises soil pH. It provides growers with more detailed information they need for effectively treating low-quality irrigation water. Effectively treating low-quality irrigation water will reduce water use and pumping and increase nutrient availability.
The Saturated Soil Analysis Test measures the immediately available crop nutrients in soil solution at a given time.
The Soil Organic Acid Reserve test employs a laboratory reagent to mimic plant root nutrient uptake based on organic acids emitted by the roots. These organic acids temporarily lower soil pH to make nutrients more available to the plant. Both tests are designed to measure nutrients readily available to the plant and predict release curves throughout the growing season. The tests enable IFA crop consultants to optimize nutrition programs to reduce cost and improve crop quality and yield.
Improved Soil Nutrition Strategies Involving Gypsum
Gypsum is an invaluable tool for improving water efficiency. Gypsum increases water infiltration for sodic western soils. It improves soil structure by providing needed calcium to flocculate clays in acid and alkaline soil. Gypsum provides vital sulfur to increase soil microbial populations and activity. It offers essential calcium for improved plant health and crop quality. In addition, it improves low-quality irrigation water and allows it to penetrate the soil more effectively.
Unlike pelletized gypsum, solution-grade gypsum can be applied year-round with pivot, drip, and micro-emitter irrigation systems. The best solution-grade gypsum is 97% pure and can pass through 325 mesh. Growers using it have decreased gypsum application rates by up to 4X compared to standard pelletized gypsum.
High Tech Block Polymer Surfactants and Wetting Agents
It's common to use four acre-feet of water in a season to produce three cuttings of alfalfa from just one acre of land. High-tech block polymer soil surfactants such as Aqua-Drive, in concert with soluble gypsum, are valuable tools in growers’ arsenals to increase water infiltration and, in many cases, reduce water needs by as much as 30%.
The new block polymer surfactants and wetting agents help growers use less water and reduce pumping costs. They increase the movement of crop nutrients and crop protection inputs throughout the soil profile. They absorb strongly onto soil particles to improve the wetting characteristics of treated water and offer residual control with good rewetting performance. They can be efficiently applied through pivot, drip or micro-emitters throughout the growing season.
For more information, contact your IFA crop advisor.
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Written by Mason Allred, Marketing Manager, Diamond K Gypsum, and originally published in the IFA Cooperator magazine (vol. 89, no. 4) Winter 2023.