Stacia Davis and Naveen Adusumilli  

Irrigation of agricultural crops in Louisiana has contributed to the state’s economic growth, and it is anticipated that the number of irrigated acres will continue to increase. Irrigated acres of major row crops increased 21 percent from 2011 to 2014 (Figure 1). This increase in irrigated acres, however, has also increased the need for water withdrawals to supplement crop water requirements. Total water withdrawals for irrigation of feed grain crops, soybeans, cotton, wheat, other vegetable crops and rice exceed 900 million gallons per day. With growing populations, declining groundwater levels, irregular precipitation patterns, and an anticipated increase in irrigated acreage fueled mostly by high crop prices, demand for water will further increase, putting additional pressure on the state’s already stressed water resources. Insufficient irrigation water and inefficient irrigation in agriculture were the highest-ranked natural resource concerns for Louisiana in 2014 by the U.S. Department of Agriculture Natural Resources Conservation Service. Such anticipated effects warrant growers to make sound decisions focused on better crop water management strategies to protect the continued productivity of irrigated agriculture in the state.

The LSU AgCenter’s approach to addressing agricultural water challenges in the state include education and outreach about conservation and efficiency. One such conservation effort aids in irrigation scheduling using crop soil moisture monitoring techniques, commonly referred to as smart technologies. Smart Technologies for Agricultural Management and Production (STAMP), a research and extension program, was initiated in 2014 at the Red River Research Station in Bossier City. The STAMP program aims to find answers to questions like when and how much to irrigate, plant response to irrigation at critical growth stages to maximize yield, impact of excessive irrigation on crop yield and net returns, and measuring water needs to regulate irrigation and to prevent leaching of nutrients and erosion of topsoil. The program is based on the premise that efficient irrigation water applications have the potential to address concerns over diminishing water resources, environmental regulation and rising costs of irrigated agriculture. Because it is not likely that new water sources will be found to satisfy current and future irrigation needs, water conservation through proper irrigation management strategies is critical.

Smart technologies have become popular methods to aid producers in making irrigation decisions. Prevalent among the smart technologies is soil moisture irrigation technology, typically involving sensors buried in the crop root zone that estimate the amount of soil moisture available for the crop. The soil moisture data provided by the sensors can aid the producer in deciding when to irrigate. Some sensors equipped with realtime monitoring capability can also provide information to the producer on when to stop irrigation based on soil moisture conditions achieved (Figure 2). The STAMP program is focused on field testing of the various soil moisture sensors in different crops. As a part of the research and extension program, workshops will be held for local producers to provide hands-on training. Economic analyses associated with using smart technologies will include estimation of potential reduction in pumping costs, change in crop yields, change in net returns, and payback period. Although the program is initiated in 0 200,000 400,000 600,000 800,000 1,000,000 2011 2012 Louisiana’s northwest region, it will extend across the state. The STAMP program will initially focus on row crops and will expand to include vegetable crops, pasture production, nursery plantations, and residential lawn management.

Specific objectives of the STAMP program include:
• Evaluation – Not all technologies work for every situation and for every farmer. Variable soil types, installation restrictions, technological competency and economic factors are just some of the factors that can affect the success of implementation. Research will focus on developing recommendations appropriate to Louisiana.
•Conservation – With strong competition for Louisiana’s natural resources and changing climatic conditions, the ultimate goal is to improve irrigation efficiency, which has been shown to also improve yield, boost nutrient use efficiency, reduce sediment losses and reduce energy costs. Helping irrigators measure their water, energy and economic savings achieved by using smart technologies can direct agricultural practices toward becoming increasingly sustainable.
• Demonstration – With so many commercially available technologies, it can be overwhelming for irrigators to start from scratch without having educational opportunities. Knowledge will be gained by researchers and specialists during evaluation that can be translated to the irrigators through extension programs. The distribution of knowledge will occur in various ways, including workshops, field days and educational materials.

Stacia Davis is an irrigation engineer, and Naveen Adusumilli is an agricultural economist, both at the Red River Research Station, Bossier City, La.

This article was published in the winter 2015 issue of Louisiana Agriculture Magazine.