Agriculture is the world’s single largest consumer of fresh water, making the water shortages expected over the next 10 years in at least 40 states -- Mississippi included -- critically important.

The Nature Conservancy estimates 70% of the planet’s fresh water withdrawals annually are for agriculture. In the U.S., irrigation accounts for more than 80% of total water use.

“Each year, Mississippi growers add 40,000 to 50,000 more acres of irrigation,” said Jason Krutz, director of the Mississippi Water Resources Research Institute, or MWRRI, at Mississippi State University.

Although Mississippi has one of the highest precipitation rates in the country, much of that rain falls outside the growing season. Crops are watered using two main methods: pivot irrigation, where water is sprayed from overhead sprinkler systems; or furrow irrigation, where water is released in large quantities to flow down furrows between crop rows.

Promoting water conservation

Through the water institute and the National Center for Alluvial Aquifer Research, MSU is heavily invested in promoting water conservation and irrigation efficiency while maintaining farm yields. Since 2012, the university has dedicated extensive research efforts and countless manhours finding best irrigation practices and extending that information to the agricultural producers of the state.

“We are looking at the technology, tools and approaches to irrigation to make it as effective and efficient as possible,” Krutz said.

MSU efforts primarily focus on the adoption and correct use of soil moisture sensors, which make it possible to schedule irrigation efficiently, and the use of computerized hole selection and surge valves so water in furrow irrigation is dispersed at the appropriate rate.

Water conservation and financial savings are equally important, said Dave Spencer, an Extension pivot irrigation specialist.

“We have shown water savings up to 40% and yield improvement up to 5% when these technologies are properly implemented,” Spencer said.

Slight improvements

That means growers who adopted water efficiency tools and practices reduced water use by up to 40% and still saw slight improvements in crop yields.

Soil moisture sensors are key tools in irrigation efficiency.

These sensors are strategically placed underground to measure the amount of moisture in the soil at the plant’s root zone. Knowing how much water is actually available to the plant allows the grower to postpone irrigation even if the top of the ground is very dry.

Soil moisture data also allows growers to accurately predict how many days remain before water is needed, allowing them to postpone irrigation if rain is likely in the forecast, Spencer said.

Adoption rate

Mississippi has a 20% adoption rate for soil moisture sensors, a close second to Nebraska. The regional and national average is less than 2% adoption. These tools are not enough unless the grower knows how to interpret the data and make decisions based upon it.

“There’s still 80% that we can work with,” Spencer said. “We’re looking at production systems holistically and evaluating production systems to see how to use the irrigation technologies with the greatest efficiency.”

Jeremey Jack, owner of Silent Shade Planting Co. in Belzoni, has adopted irrigation efficiency tools, including the scheduling of irrigation.

“We have the mindset of conservation,” Jack said. “Last year on row rice, we had wells come on and off automatically. We treated rice like a golf course where irrigation was on a schedule, and we would adjust that from our phone if it was going to rain. We would go by every couple of days to make sure the well was working.”

Jack said his farm does not focus on just one tool, but constantly learns new strategies and methods that can increase profitability through higher yields while conserving resources.

“So many things have improved through the practices we’ve been able to implement through technology,” he said.

Source: Mississippi State University Extension Service