1. Compare the price of turkey litter to commercial fertilizers or to other products producers are using.
Turkey litter and broiler litter have similar content of N, P2O5 and K2O. Variability of nutrient content can be quite large between samples so it is always a good idea to get a lab test showing the nutrient content. A rule of thumb is that about 40 to 50 percent of the N in poultry litter is lost or is unavailable to crops when the litter is surface applied so that must be factored in for fertilizer application. If the litter is incorporated, little N loss can be expected. Another important point is to know what current soil fertility levels are in fields where litter is to be applied. Even though the combined value of N, P, and K in litter can be as much as $80/ton (as shown in Graph 1.1) that value is less if soil test levels of P and K are high. In soils with high P and K levels, no crop response would be expected from additional P and K so then the value of litter would only be for the nitrogen content. Table 1.1 shows the nutrient content of various fertilizer materials.
2. What are the best ways to manage high fertilizer costs this year?
Soil test as much as possible and determine where legumes can be grown effectively to reduce N fertilizer need.
Use rotational grazing to improve utilization of forage and to increase nutrient cycling through deposition of manure and urine across pastures instead of near water and shade.
Lime where recommended by soil test to improve fertilizer efficiency and to improve legumes establishment potential.
Compare fertilizer sources according to the price per pound of nutrient and not by the price per ton of fertilizer. For example, in Graph 1.1 ammonium nitrate sells for $450/ton but ammonium sulfate sells for $334/ton. However, ammonium nitrate is cheaper because the cost per pound of nitrogen is $0.66 compared to $0.80 for ammonium sulfate.
Apply fertilizer according to forage species, season, and need. Often producers apply all the fertilizer at one time of year which often causes rapid forage growth that cattle cannot utilize leading to wasted forage and fertilizer. By applying fertilizer to only enough acres in spring summer and fall to provide the needed forage each season, the fertilizer is used more efficiently with less wasted forage.
Fertilize in late summer for stockpiling bermudagrass or fescue for fall and winter grazing. Stockpiled forages greatly reduce hay need during winter and are much less expensive than either growing or buying hay for winter feed.
To see a pro versus con list of fertilizers compiled by Jennings visit our website at www.ozarksfn.com and click 'Extended Stories: Best Nitrogen.'
John Jennings is a forage specialist and instructor with the University of Arkansas extension.
