Timing fertilizer application is important to ensure that money spent on fertilizer actually gets into the tree. I use two key pieces of information to time the spring fertilizer application: bud development and the weather forecast.
Outer scale split also marks the time when pecan tree roots enter their springtime flush of new growth. Fertilizer is most readily absorbed by actively growing roots, so waiting until outer scale split ensures that the nutrients applied today will be taken up immediately.
The second factor in decided to fertilizer today was the weather. The Neosho River is still at very low levels and the chances of a springtime flood seems remote (at least for the next several weeks). Later this week, we are expecting a wintery mix of light rain, sleet, and light snow. This kind of light precipitation will be prefect for moving fertilizer nutrients down into the rooting zone of our pecan trees.