More Crop per Drop

OPTIMIZE IRRIGATION WATER USE

The primary agricultural irrigation system in Texas is the center pivot irrigation system. Approximately 23,000 center pivot systems are located across the state, mainly below the Fall Line. Drip irrigation is also utilized in vegetable and orchard production statewide. Other forms of irrigation that are not as common include solid set sprinklers and traveling guns.

Some of the practices described below, such as remote control and irrigation scheduling, apply to any type of irrigation system. The other practices, such as retrofits and variable rate irrigation, are more specific to center pivot irrigation.

ENHANCE ON-FARM EFFICIENCY

Smart Irrigation tools range from simple and free to complex and costly. The best management practices described below are available to farmers in Texas. Each practice includes a brief description, examples, an estimated cost, and approximate gains in water use efficiency or water savings. Note: water use efficiency refers to the amount of water pumped that is utilized by the crop (more crop per drop), and water savings refers to actual water conserved from reduction in groundwater withdrawal. The estimates below are not necessarily additive as each efficiency and savings scenario is dependent on individual field conditions and management decisions.

RETROFITS

CONVERT HIGH PRESSURE SPRINKLERS TO LOW PRESSURE

Irrigation Retrofits

EVOLUTION OF EFFICIENCY

Farmers began implementing center pivot irrigation systems in Texas in the 1970’s, and the conventional models operated at high pressure with impact sprinklers spraying water from the top of the pivot mainline. Converting these systems from high to low pressure with spray-type sprinklers on drop hoses generates considerable water and energy savings. By applying water at a lower pressure more directly to the soil surface, the low pressure system significantly reduces evaporation and wind drift losses.

Today’s low pressure spray-type sprinklers are designed to produce a very uniform application of water droplets over the field. In combination with drop hoses, these sprinklers help to reduce losses to wind drift and evaporation by applying water closer to the crop in larger droplets. High pressure impact sprinklers, in comparison, spray the water much higher in the air with smaller droplets. Also, low pressure spray-type sprinklers are unique in the fact that they operate between 10 to 30 pounds per square inch (psi) allowing them to have a lower energy requirement.

A center pivot irrigation system with high pressure sprinklers. (Calvin Perry/UGA)

A center pivot irrigation sprinkler with low pressure drop-nozzle sprinklers. (Casey Cox)

EFFICIENCY

The high pressure system has an average efficiency of 60%, due to water losses from evaporation, wind, and drift. Combined with the installation of end-gun controls to keep irrigation inside the field boundary and the repairing of leaks in the system, retrofitting a pivot may increase water use efficiency to 80 - 90%.

ESTIMATED COST

Converting an existing system from high pressure to low pressure costs range from approximately $2,500 to $5,000. Most new center pivot systems are equipped with low pressure drop hose sprinklers.

REMOTE CONTROL

MANAGE IRRIGATION FROM ANYWHERE

Remote Irrigation Control

MONITOR IRRIGATION FROM PHONE OR WEB

Farmers have spent countless hours and tanks of gas at all times of the day and night driving back and forth to fields to check irrigation systems. With this remote control technology, a farmer can now save time and fuel with the ability to remotely monitor and control irrigation systems from their phone or computer.

This technology controls multiple aspects of the system remotely: turn on, turn off, change direction, set a timer for the system to start, control the end-gun sprinkler with precision by degree, check the position of the system, set the stop for a precise angle, and even speed control variable rate irrigation on certain systems. All systems enabled with this technology are available on a singular dashboard and even connected with some soil moisture sensor systems transmitting real-time data from the field.

This technology is available for both center pivot and drip irrigation systems.

ESTIMATED COST

Remote pivot control systems vary by product but generally range from $2,000 - $5,000 per system with an annual subscription fee in the $300 range.

EFFICIENCY

No official studies have been done to approximate the efficiency of remote control technology for irrigation systems. Any increase in efficiency is highly subjective by field and producer. The ability to stop the system at precise angles, control the end-gun by degree, and set automatic timers to start and stop the system take limitations on timing out of irrigation management (e.g. if the farmer is unable to arrive at a system at the precise moment it needs to be stopped).

IRRIGATION SCHEDULING

KNOW WHEN AND HOW MUCH TO IRRIGATE

WHAT IS IRRIGATION SCHEDULING?

ANALYZING REAL-TIME FIELD DATA TO OPTIMIZE IRRIGATION APPLICATION DECISIONS

Irrigation scheduling helps determine when to irrigate and how much water to apply.

Irrigation scheduling can optimize plant growth, crop yield, crop quality, nutrient management, root zone health, and irrigation decisions.

SMART IRRIGATION APPS

A screenshot of the Smart Irrigation app developed by UGA & UF

The University of Texas and University of Florida have collaborated on a project to develop Smart Irrigation apps for both iOS and Android for several different agricultural crops. Currently available apps include Cotton, Soybean, Citrus, Strawberry, and Avocado. Corn, Peach, and Blueberry are in the development/field validation process and will be publicly released in the next couple of years.

Each app generates irrigation recommendations for its specific crop according to the particular characteristics and phenology of that crop. The concept of Smart Irrigation Apps is to keep a simple range of inputs (that producers can reasonably answer) that will then be used to run a Soil Water Balance model based on estimated water loss (Evapotranspiration), crop and region specific coefficients (KC) and observed and forecasted weather data (from Weather Stations, National Weather Data Grid, and more recently for some apps (Cotton and Soybean) Automated Rain Sensors).

One of the most useful features of the app is the ability to receive notifications when irrigation is needed, rain events are observed in the field area, and approaching phenological stages.

While the project started supporting only Florida and Texas producers (due to the availability of automated weather stations networks (Texas Automated Environmental Monitoring Network (GAEMN) and Florida Automated Weather Network (FAWN) ), a few of them are now expanding to other producing regions in the United States by using National Weather Data Grid sources.