I suspect the foremost decision-making factors in moving towards a new crop season this year are input prices and the resulting return on your investment. As I check the futures market, I am comforted by the fact that cotton and soybean prices are very good and corn, slightly above average, while Georgia’s peanut price per ton appears to hang in the $475-$500 range. All of this points to opportunities to shift some acreage to capture a good return on the investment even under rapidly rising costs. None of us like the fact that rising input costs are the results of the cost of raw products used in manufacturing, lingering affects of COVID, a screwed-up supply chain, inflation and, yes, the fact that commodities prices to the farm are rising and everyone wants a piece of it.
For corn growers, one of the largest input prices is fertilizer. We all have witnessed over the last two years, prices increases of 200% to 400% on the farm. In fact, we are less than a month away in south Georgia and it is difficult at best to get a price. Pricing is simply done on delivery. So how do we manage our inputs when you only can get a price when it is delivered at that time? I suggest with any commodity that we take a closer look at our soil test results and plan to apply that which is needed for our year to year average yield. Reduce it down to what you expect to yield (not hope) given average conditions and fertilize accordingly.
If you are using a private lab, I expect that you are receiving, based on a yield goal, a recommendation that in reality is high for your yield expectation. It tends to build soil levels over the years and is likely to overestimate the off-take. How do we confidently reduce our fertilizer applications while having confidence that we are doing no harm to our expected average yield? I suggest take your private lab data and plug in into the UGFertex program: https://aesl.ces.uga.edu/calculators/ugfertex/ . It will cost you nothing but a little time. This program is designed to allow you to use data provided by most labs in the state and place them into the program to obtain fertilizer recommendations on any crop.
Here is a sample taken from a field that has had poultry litter applied for several yields. The soil is a heavier textured soil and the field is irrigated. In this case, the grower requested a yield of 300 bushels per acre.
|Target pH||Soil pH||Buffer ph||Phos||Potass||Mag||Cal||Zn||Mn||Lime tons/ac|
The nitrogen recommendation from the private lab was 390 lbs N per acre while the UGFertex was 360 lbs N per acre. UGFertex also has a calculation for manure and will recalculate your recommendations based on the type and amount of manure you use. This grower could input the data and place the expected average yield in the appropriate box and, most likely, reduce his fertilizer bill.
While similar in some cases, UGA’s lab does use crop coefficient curves that provide probabilities of response to soil test values and crop yield. Their values reflect crop uptake and usage. One thing I will say for most recommendations from any lab is that they do NOT reflect the improving nitrogen use efficiency of many modern-day hybrids. As I reviewed N studies across the country, it is noticeable that the yield response to nitrogen is closer to 1 lb N per bushel per acre on average in the corn belt. In Georgia and South Carolina, where the majority of corn is planted on sandy to sandy loam soils, N recommendations average 1.2 lbs N per bushel per acre. On deep sandy soils, we often recommend 1.3 lbs N per bushel per acre. This helps you manage nitrogen throughout the year as nitrogen is very mobile and easily leaches in our soil. In wet years, our fields are prone to N loss. This year, with nitrogen prices being as much as 300% higher than last year, I suggest that you look at your field yield acreage and supply nitrogen at 1 lb N per average bushel yield obtained over the last several years. Since most corn is irrigated, nitrogen can be injected through the irrigation system or applied via airplane if more N is needed due to wet weather. Managing your fertilizer cost to obtain your yield average given the extraordinary cost this year, is a wise step that reduces your risk.
Many growers will be relying on manure this year for much of their phosphorus and potassium and other nutrients. A lot of growers generally don’t reduce their inorganic N supply in corn fertilizer with the nitrogen in the manure but you should. Poultry manure (broiler) is 2.5 to 3% N per ton. That amounts to 50 to 60 lbs N per ton. Of that, you can expect the availability to range from 50 to 60% or 25 to 36 lbs N per acre per ton. Of that, roughly half will be available quickly. In addition, studies show, depending on the litter and how it is stored or how long it weathers, the availability of P and K ranges from 70 to 85%. I would certainly account for these and other nutrients this year if I were using manure to reduce my commercial fertilizer cost.
Another cost that you may well consider modifying is seed cost. I see many farmers only getting 7 to 8 bushels per acre per thousand kernels. For example, if you plant 34,000 kernels per acre and average 225 to 230 bushel per acre, I would drop my planting rate to 30,000 kernels. In lots of our yield trials, the average yield per thousand kernels per acre is 8.5 bushels per thousand kernels. Given the math, 30 K could easily average 255. Before you say wait a minute, just know that under high yielding, well managed environments, I have seen yields of 10 to 12 bushels per thousand kernels but that is the exception. Reduce your seed cost within reason and focus your attention on getting every seed up as quickly as possible near the same time. This way, you will have very few plants dominating the other. Rapid, even emergence is a benefit to obtaining better yield.
It appears that as pencils get shorter, planting time is nearer and budgets become clearer. Cost this year, are much higher and prices good but not great. I was talking a grower lately and he said that counting everything (and he meant every cost), he was looking at ~$1,000.00 – $1200.00 input cost per acre on irrigated corn. He certainly averages above 200 bushels per acre BUT the rapid math is not hard to do ($6.00 breakeven). On his farm, I expect he averages nearer 240 bu ac which is nearer $5.00 per bushel. Ouch. I encourage every corn grower…..focus on producing the best yield that you have more confidence in obtaining with your equipment, skills, etc; pay attention to the details during the year, walk your fields and respond to crop stress and mitigate it as quickly as possible. You do this, and you would have done your best.