By Chris Hicks, County Director, – UT Extension Smith County
Last week we looked at how fertilizer prices have risen by over 2.5X what they were last year, and how soil testing could help in deciding where to allocate our fertility dollars. This week, let’s look at some specific things farmers can do to both decrease their dependance on commercial fertilizer, and to get the most out of the fertilizer they do apply.
Anytime you grow a crop and remove it from a given field, you are taking nutrients away as well. This “nutrient removal rate” is different for each crop. Take pasture and hay for example. The nutrient removal for a cow/calf pair is 10-7-1, while the nutrient removal for hay is much higher at 35-18-50 per ton of tall fescue hay.
Being intentional about where and how hay is fed is one way to manage fertility. If you have the ability to feed hay on your hay fields doing so will put some of those nutrients back where they came from. Also, if you buy hay, you have the advantage of bringing nutrients from someone else’s farm. The nutrient value in a 900 lb fescue bale in the fall of 2020 was $21. In December of 2021, the nutrients in that same roll were worth $49. Some hay is still being sold too cheap so take advantage of that if you can.
How you feed hay will determine how nutrients are distributed around the farm. Animals won’t stray far from a hay ring during cold weather. Moving hay rings around the farm or unrolling hay every day is a great way to improve nutrient distribution and put nutrients where you want them. Feed hay on pastures with low soil test values first.
Rotational grazing is another management tool that is important anytime, but especially when fertilizer prices are so high. Manure and urine contain nutrients, and research consistently shows that the higher your rotation frequency is, the more evenly distributed these nutrients will be.
Some folks have had success finding good sources of manure or litter to use instead of commercial fertilizer. While this can be a good option, prices on these materials have also gone up, and there is significant variation in their nutrient analysis. Be sure to request an analysis so you know what you are buying and compare it on a price per nutrient basis. Remember to take full advantage of the manure off your own farm first.
Adding legumes to your pasture or hayfields can give you a cheaper dose of nitrogen than relying on commercial fertilizer. This time of year is the perfect time to add 2 lbs. of white clover and 4 lbs. of red clover per acre. While you won’t get the quick boost from clovers that you will from adding urea, over the course of the growing season yield from a good tall fescue/clover mixture will be comparable to adding 60 lbs. of nitrogen.
Speaking of urea, this particular nitrogen source is prone to volatilization losses. Losses can range from 0 to 50%, but on average are about 25%. Losing 25% of a product you paid $990/ton for is a significant waste. Unless you are growing a crop where you can till it into the soil, or can reasonably expect 1” of water from either rain or irrigation within the next 3 days, Urea should be coated with a nitrogen stabilizer like Agrotain to reduce N loss from volatilization.
When prices jump like they have there is no easy solution, but farmers have a way of being innovative and resilient. Hopefully some of these tips will be useful. You might also want to checkout the first two editions of our Forage Webinar Series which dealt with managing fertilizer prices and adding legumes. They can be found at tiny.utk.edu/youtubesmith.
