Comments From: Wes Porter, UGA Extension Irrigation Specialist
Once the peanut crop is in the ground it’s time to start considering how to manage it, and specifically how to manage irrigation. The simplest method is the UGA Checkbook in Figure 1 below. Peanuts typically do not require a lot of water in the first month after planting as exhibited by the yellow box and water use curve below. However, if it gets hot and dry you may need to apply a few small irrigation applications. The yellow box below represents the first five weeks after planting of peanut water requirements. Keep a track of rainfall and temperature, and make irrigation applications accordingly. Your irrigation efficiency is typically around 65-70% for high pressure systems and 80-90% for low pressure systems. You can test your pivot for uniformity if you think you may have a problem reach out to your county agent.
Keep in mind that the water requirement below is irrigation plus rainfall, and the weekly water requirement recommendation was developed based on a historical average of evapotranspiration. So your actual water/irrigation requirement may vary slightly based on weather conditions and rainfall during the growing season.
There are many irrigation scheduling tools available to producers from Checkbook methods, to computer models and soil moisture sensors. Depending on your operation and what your irrigation capabilities are one of these methods may be a better fit than another.
UGA Extension has developed a quick and easy irrigation scheduling guide that is laminated and contains the four major row crops grown in Georgia. The guide can be downloaded at https://extension.uga.edu/publications/detail.html?number=C1189.