One thing a drought does is confuse the fertilizer issue for the coming year’s crops. We know the proper amount of fertilizer was applied last spring to produce normal row crop yields. Nobody had normal crops. What happened to the fertilizer that was not utilized? Can it be used next year?


One thing a drought does is confuse the fertilizer issue for the coming year’s crops. We know the proper amount of fertilizer was applied last spring to produce normal row crop yields. Nobody had normal crops. What happened to the fertilizer that was not utilized? Can it be used next year?
Most crop producers do not test for residual nitrogen even though we suspect there is some out there. As dry as it is, it would be very difficult to get a soil probe down into the subsoil today. However, should we get enough moisture to soften up the soil up to where a probe can go down 14-16 inches, it would provide very valuable information about the residual nitrogen levels.
If we can reduce the normal nitrogen rate by 25 percent, for example only, how many dollars would that save per acre next spring? Saving 50 percent of a normal N rate would be a huge cost saving strategy.
Let’s say we applied 100 units of nitrogen for corn last spring, and our corn made only 10 bushels per acre. That would mean that we hauled about 10 units of nitrogen to town and perhaps 25-30 got used for the stover. That leaves about 55-60 units of nitrogen to be accounted for. Some units are lost forever (leaching, denitrification, volatilization), some get tied up in the organic portion of the soil (immobilization), and some just lay there waiting to be consumed by the next crop. The big question is this: how much is just laying there as free nitrogen that we can count on for next year?
Phosphorous is probably not as critical an issue. Plants normally use only about one-third of the phosphorous that is applied each year. The other two thirds goes into the phosphorous pool and is gradually utilized over several years. Therefore, phosphorous application rates are fairly constant regardless of a one year drought.
Other nutrients are not adjusted due to a drought. Potash, sulfur, chloride, and zinc are typically applied at similar rates to a normal rainfall year.
Custom rate projections
One of our most requested publications at the Extension office has been the Kansas Custom Rate Guide published by the State Board of Agriculture. However, since funding for this publication has been cut, K-State has developed an estimate of what current custom rates might be based upon 2009 data adjusted for inflated costs. Those 2009 figures came from a survey of about 1,400 custom operators, farmers, co-ops and elevators.
  The information can be found at www.AgManager.info. Select  Farm Management in the left-hand column, then Machinery, and then Farm Machinery Papers.
  The custom rates projections are intended to be a guide to help custom operators and farmers reach mutual agreements. The prices reported should not be taken as official or established rates. Prices given cover machine, power, fuel and operator labor only, except haying which covers twine.
Remember, there are large variations in jobs, thus variations in rates for specific jobs. For many items, the state or district rate may not be typical of a special locale.
Some farmers may charge lower rates for neighbors, relatives, or close friends. Soil condition, field size, efficiency of equipment, power required, timeliness of operation, and many other important factors move the rates up and down from the averages.
A fair custom rate can usually be calculated by estimating six factors: depreciation, interest, repairs, insurance, fuel and operator labor on a per acre basis. We typically estimate these items on an annual basis, and then divide those totals by the number of acres gone over in a typical year.
Point of interest: it is generally accepted that most farmers are willing to do custom tillage work for less than their actual costs.
Therefore, most tillage operation rates given in this bulletin are thought to be less than the true cost of operation.

Dale Ladd is the agriculture extension agent for the McPherson County K-State Extension Service office. He can be reached by calling 241-1523.