April and May are traditionally dry periods for farming in North Florida. Unfortunately, this coincides with rapidly increasing water requirements by the crops we grow. Corn is particularly challenging this time of year with rapidly increasing plant water demand and large yield impacts of drought stress. The warm dry conditions throughout May have done little to assist farmers keeping up with requirements, which can reach 0.30″ of water per day. This is in conjunction with sandy soils that only have an allowable water depletion of 0.7″ in the top 2 feet root zone. One local farm got their irrigation schedule one day out of sequence to allow aerial application of fungicide and I saw the corn was already in severe stress. Other farms are dealing with breakdowns of equipment and no rainfall to buffer the downtime.
I laughed when a local farmer contacted me this week and said I have a “center pivot for sale.” He was trying to throw some humor into the challenging situation of keeping 20 year old irrigation systems running to meet the water requirements of his corn crop. Reviewing local conditions, I see we received 0.27″ of rain from April 21 to May 18 at the Live Oak FAWN station. That is why farmers and their irrigation systems have been running hard to keep up. Rainfall of 0.84″ on May 19 finally settled the dust in Suwannee County, but most of southern Columbia County is still without a decent rain.
As we approach and continue through tassel, pollination, and grainfill, it is important irrigators consider water requirements and yield loss to stress. Attached are a few diagrams I share in our local irrigation clinics. As farmers address cost-benefit analysis of each input, I think they will find meeting the water requirements at this time of year offer a return second only to actually planting the seed. There are many inputs I would forgo before withholding water during pollination.