Soybean Irrigation Developments and Tools
Current production inputs should be monitored frequently to ensure their cost effectiveness. Plus, new ideas and technologies about irrigating soybeans are constantly forthcoming, and these should be evaluated objectively to determine their worth. Thus, midsouthern U.S. soybean producers who irrigate will likely find the following subjects interesting and informative.
IRRIGATION WATER PUMPING COSTS. The contents of an article titled “Irrigation Water Pumping Costs in the Mid-South“ by Dr. Brad Watkins of the Univ. of Arkansas provide estimates of the pumping costs associated with applying 10.5 acre-inches of water to soybeans in the midsouthern U.S. The water source used for the estimates is the Miss. River Valley Alluvial Aquifer [MRVAA], and the data in Table 1 of the article show estimates that are based on using either a diesel or electric power source and a Total Dynamic Head [TDH–depth to water plus drawdown and discharge pressures] that ranges from 40 to 130. As stated in the article, pumping costs will vary greatly based on location and water availability. Miss. State Univ. personnel have provided Publication 3889 titled “How to Calculate Irrigation Pumping Costs with MITOOL” that gives a step-by-step procedure that can be used to estimate these costs for irrigated Delta crops.
WEATHER STATIONS. The concentration of weather stations in rural vs. urban areas is diminished, and this presents a challenge to irrigators in rural areas because of the resulting gaps in rainfall data. These gaps can and often do lead to inefficient irrigation because of the lack of rainfall data that is precise for a particular irrigated field–i.e., there is often a lack of locally-specific rainfall data, and this can lead to either over- or under-irrigation of a field that is irrigated. Thus, rainfall data from localized weather stations can be used in conjunction with other irrigation tools–e.g. Lindsey’s FieldNET Advisor–to optimize irrigation water use and improve irrigation efficiency.
DROUGHT TOLERANT CROPS. Soybean producers who irrigate their crop often rotate their soybeans with another crop. For soybean irrigators that may be subject to water allocations either now or in the future, incorporating a drought-tolerant crop [e.g. grain sorghum] into the rotation scheme may be necessary if irrigation water is limited to the soybean year. In an article titled “Researchers Look at Roots for Insight into Drought-tolerant Wheat”, information about how Univ. of Nebraska scientists are assessing how wheat’s root system and its surrounding environment may affect its drought tolerance. In an article titled “Drought-Tolerant Corn Hybrids: Yield Benefits” by Kansas State Univ. researchers, corn hybrids for water-limited environments have been assessed and found to be beneficial for use where water is limited. Midsouth soybean producers who irrigate should be aware of these developments so they are prepared to adapt to a future where water for irrigation may become limited and allocated to only the soybean crop.
WATER VAPOR MEASUREMENT. The contents of this article rely on the same principle as that of having a weather station in each irrigated field–i.e. measurement of the evapotranspiration [ET] that occurs at a specific irrigated site is a precise way of determining just how much water is being lost from that site. This localized measurement of ET will likely provide the most accurate information when used in concert with soil moisture sensors and a rain gauge. The value of ET measurement for crop irrigators is addressed here.
Click here for an Irrigation White Paper and here for the Mississippi Soybean Irrigation Guide, both on this website.
Composed by Larry G. Heatherly, Oct. 2024, larryh91746@gmail.com