Water is often the limiting factor for corn production. The lack of water during key growth stages or an overabundance in stages when the plant doesn’t require as much, or both, can be problematic.
The best idea is to employ some method to plan and optimize irrigation scheduling. The use of volumetric soil moisture probes is becoming popular in Florida’s Suwannee River Basin. These tools are not inexpensive, but they can help growers optimize the amount of water to match corn needs. Talk to your local UF/IFAS Extension agent about the loaner soil moisture sensor program, or contact Suwannee River Water Management District for cost-share information on probes.
Double check to make sure irrigation systems are applying water uniformly from one end to the other. This is especially important since pivot irrigation systems are being used in most cases to apply the nitrogen budgeted for the crop. More uniformity of nitrogen application will increase overall crop health and provide better consistency in yield outcomes. Take advantage of agency cost-share programs to get Mobile Irrigation Lab Evaluations done, and plan to retrofit systems showing less than 80% distribution uniformity.
Select optimum plant populations for your soil type, which in Florida is mostly sand, and for the amount of irrigation you can reasonably apply during peak corn water use.
In many cases in North Florida, corn may still be planted too thick. There is the potential to yield profitable 250 plus bushels of corn per acre with around 32,000 plants per acre as a field average. Think carefully about variety selection with your situation in mind, but also remember severe thunderstorms later in the season. High plant populations and certain varieties are at risk to lodge from the high winds that are common with storms that time of year.
Conduct soil tests and/or sample on a grid to use precision application of nutrients. Variable-rate fertilizer and lime applications based on a grid-sampled soil test will save the farmer money and reduce wasted fertilizer.
The soil pH for grain and silage corn should be between 6 to 6.5. Above and below that mark could bring about plant absorption inefficiencies that lead to yield reductions.
If you are applying poultry litter or cow manure, get it tested by the UF Waste Testing Lab or one of the area private labs. Make sure you know what you are getting from the litter source. This will be helpful to account for the expected nutrient content within the litter when developing your target rates of each nutrient.
Apply starter fertilizer by the row to get corn plants growing quickly and developing a good, deep root system. Healthy, deep roots should use all nutrients that have been applied more efficiently. Too much water while the plants are young will limit root expansion and impact plant health later.
Conduct frequent tissue sampling to determine the status of all nutrients in the corn as it moves through vegetative stages and early reproductive stages. This will aid you in making the best nutrient management decisions for your crop throughout the season.
Apply a nematicide to control root knot, stubby root and sting nematodes. With short rotations, or in some cases no rotation, and sandy soils, this should be a priority. Because of these factors, one should assume these nematode species have the potential to hurt root development, which reduces fertilizer and water uptake within the plant.
Try to keep corn healthy all the way to black layer. This means optimizing irrigation, and scout for plant diseases. Soil moisture sensors will show declining moisture use of the corn plant after its peak. Monitor the crop regularly for disease and apply fungicides if needed, from before tassel to brown silk. Later-planted corn will be at higher risk for disease and insect damage.
Good luck with this year’s upcoming season, and contact your local agriculture Extension agent with questions or concerns. CS