Via Wesley Porter, Extension Irrigation Specialist;
There is about a month before everyone begins to get serious about getting their peanuts planted. Thus, now is the best time to do routine and preventative maintenance on equipment, specifically irrigation systems to ensure they are top shape once the crop is planted. Once the crop is planted the irrigation systems will be needed and a lot of them will run near continuously during times of no rainfall. There are two important factors that need to be considered before you get your peanuts planted. One is an overall irrigation system check and the other is specifically focusing on uniformity and distribution of your system. First go through a check list that includes all main components on your irrigation system to ensure they are working properly. Some of these components can include but do not have to be limited to the power units, pumping system, intake line, pipes and drains, electrical system, system alignment, safeties, tires, gear boxes and drive shafts and lines, and the switches on the auto stop feature. Once you have checked all of these components now it is time to start the system and finish checking components. Start up the pump and check the line pressure, flow, sprinklers, end gun and booster pump, regulators, drain valves, check for visible leaks, and test the auto stop and reverse features. The system flowrate and application rate are represented in Figure 1. It is important to remember due to increasing travel speed as we move to the end of the pivot the system flow rate will go up, but the application depth should remain consistent. This is achieved with properly sized sprinkler packages.
Figure 1. Application rate and depth across a pivot tower.
It is important to note that it can be very difficult to detect differences between individual sprinklers and banks of sprinklers on a pivot visually so it is strongly recommended that an application uniformity test be performed on the center pivot to detect any discrepancies along the tower length. A UGA Factsheet titled Evaluating and Interpreting Application Uniformity of Center Pivot Irrigation Systems is a very good step by step guide to completing this process. By following these suggestions you should have a properly operating pivot ready to go for the upcoming production season.