Keeping Up With Corn Water Demand

To say it has gotten dry in the area would be an understatement. Looking at the Live Oak FAWN weather station, we have recorded 0.34″ of rain in the last 29 days. The weather forecast has a chance of rain everyday for the foreseeable future, so maybe we will soon get some help. In the meantime our corn crop is pulling through the most critical period in terms of peak water demand and yield loss associated with water stress. The UGA Corn Production Guide shows peak water demand of about 0.33″ per day at the stage of pollination and the following 14 days. Research by Claasen and Shaw (1970) showed that moisture stress for four days during pollination resulted in as much as 50% yield loss compared to well irrigated conditions. I have heard of many pump failures  and pivots flipping over at corn pollination and the impacts on corn yield are pretty consistent with those yield losses. I cooperate with a network of farmers using soil moisture devices and rain gauges on their farms. We access this information via cell phone modems and a web page. I can see looking at this instrumentation, that water use is very high. I have attached a sample showing water content at 4″ and 12″ depths. You can see in this example that we have lost our subsoil moisture and the pivot is just keeping us going with irrigation on the soil surface. Hopefully we can get a rain here to recharge the subsoil. I always encourage farmers to take a shovel or posthole diggers to the field and dig deeper.  Sometimes you can learn much more than just kicking the top several inches of soil. 4 Days of Corn stressUGA Estimated water use of corn in GA

Soil moisture trend graph showing volumetric water content at 4" and 12" depth

Soil moisture trend graph showing volumetric water content at 4″ and 12″ depth








Leave a Reply

Your email address will not be published. Required fields are marked *