Proper fertilizer applications will help to maximize yield. However, this year has seen an extremely fast rise in the price of fertilizers, and, with increased prices, profit margins become even smaller. Dr. Lenny Wells has a good article speaking on ways to try and offset these costs.
The earliest predictions for the 2021 Georgia pecan crop was to be between 75 and 80 million pounds. The top and bottom of that number would most likely be determined by scab pressure. By Thanksgiving, it appeared that the 75-80 million pound estimate would fall very short, possibly below 50 million pounds. Recent reports from assessments show that 2021 is going to end up close to 75 million pounds after all. I believe this can be attributed almost completely to trees under 40 years of age, including many orchards planted in the last ten years that are coming into production in Georgia.
We can expect older trees to produce greater swings in production following Hurricane Michael. This means 2022 will likely be an on-year, and crop load management is needed to break this cycle. During production meetings, I’ve discussed the high cost of inputs. How can we cut costs without cutting corners? In terms of fertilizer, these are our best options:
How much nitrogen (N) do pecans need? The old rule of thumb has been 10 pounds of N for every 100 pounds of crop. This “rule” was in place before we knew much about how pecan trees use N. All studies in the past 100 years in the Southeast demonstrate that pecans do not need more than 100-125 pounds of N, and this would only be in years of a heavy crop. For 2022, we need to put out about 50-75 percent of our total N in April. Evaluate your crop in June to determine if you need any more N.
How much N do we get from clover in our middles? For growers managing clover in the middles, a little nitrogen in the spring is still a good idea because the N fixed by clover is not available to the trees until later in the season. A good stand of clover can account for the late season N needs of the tree.
What about chicken litter as a fertilizer source? Chicken litter is a great source of nitrogen, phosphorus, potassium, and even zinc for our orchards. It does appear the demand for chicken litter is high. If you use chicken litter to meet fertility needs, it should be applied before the end of May to assure there are no contamination issues. Do we need phosphorus (P)? You don’t necessarily need a maintenance application of P if your soil P levels are above 30 pounds and leaf tissue is at or about 0.12 percent. This will save about $36.00 per acre. If soil levels are 30 pounds and leaf tissue samples are below 0.12 percent, you have an uptake issue that WILL NOT be corrected by broadcasting P. This requires a concentrated, narrow band application within the herbicide strip in the area wetted by irrigation emitters.
Do we need to apply potassium (K)? You should apply K annually on sandy soils, especially when a heavy crop is expected. On more loamy-clay soils, maintenance K applications may not be as necessary. On these soils, if soil K levels are above 100 pounds and leaf tissue samples are above 1.1 percent, you should be fine. This will save about $38.00 per acre. Like P, if soil K is 100 pounds or above but leaf tissue is below 1.1 percent, then band K.
Do we need to apply zinc (Zn)? We do not need to broadcast Zn if our soils levels are at or above 15 pounds per acre. This will save about $24 per acre. If Zn levels are above 15 pounds but there are visible signs of Zn deficiency or leaf Zn is less than 50 ppm, then apply Zinc EDTA through the irrigation.