Wednesday, May 27, 2015
Recharging the water supply
Over the last few weeks, we have received an abundant amount of rainfall. So much rain fell over southeastern Kansas last weekend that the Neosho River spilled out of its banks and flooded our pecan grove (photo above).
There are positive and negatives when it comes to flooding. On the plus side, a low level flood, like the one we are experiencing now, is serving to recharge the subsoil water supply. Every since the extreme droughts of 2011 and 2012, we have never received the surplus rains needed to completely recharge the system. This flood should get us back to full water supply.
The downside of flooding is a loss of soil nitrogen due to the actions of denitrifying bacterial that flourish in flooded soils. Based on predictions from the National Weather Service, this flood should last about five days. That's long enough to recharge the soil moisture supply but not long enough to throw our trees into nitrogen deficiency.
Update Friday May 29th: The National Weather Service operates River Forecast Centers all across the country. If your pecan grove is in a flood plain you should go to the NWS website and find the closest reporting site on your river. We use the data recorded just south of us on the Neosho River to predict how flooding will impact the Pecan Experiment Field. The data above is a screen shot from Friday, May 29th. Water covers the road to the Pecan Field when the river hits 18 feet. At 24 feet, we will have water in our buildings. The biggest flood I've lived through and the second highest in recorded history occurred in early July of 2007. On July 5th, the river crested at 29.25 feet and we had 5 feet of water in our workshop.
The rain received today will extend local flooding conditions (see chart above) and will cause some of our trees to be under water for more that a week's time. This will cause low nitrogen problems for trees in lowest lying areas. With a big crop set on the trees, I'll be adding more N fertilizer to several tree blocks once the flood recedes.