Take 10 steps to save money on fertilizer
Are you taking all of the following steps to make the best use of applied nitrogen?
1. Take credit for carryover soil nitrate. The 2-foot soil nitrate test can accurately measure the carryover amount. This is very important this year.
2. Take credit for legumes. The recommended credit for soybeans is 40 pounds per acre regardless of previous bean yield.
3. Take credit for manure applications. Sample manure for both organic and inorganic N so accurate credits can be taken. Manure with significant inorganic N content should be knifed below the soil surface or immediately incorporated to prevent volatilization losses of ammonia. Accurate spreading is also a must.
4. Take credit for N applied with phosphorus and other N-containing fertilizers. Sixty pounds of P applied as DAP supplies almost 25 pounds of N.
5. Do not apply N in the fall until soil temperatures fall below 50 degrees F to prevent conversion to nitrate and possible leaching from snowmelt and early spring rains. Soils across central South Dakota usually reach that temperature about Oct. 15. Since some microbial activity still occurs at that temperature, colder soils would be better.
6. Do not apply N in the fall on sandy or any coarse-textured soil.
7. Sidedress N on corn to minimize early-season leaching or denitrification losses. This is especially important for sandy soil, irrigated land or areas that may pond water after heavy rains.
8. Incorporate urea within two weeks of applications to minimize volatilization losses if there is no rainfall. Avoid winter urea since studies show significant volatilization losses can occur.
9. Set reasonable yield goals. Setting goals that may be reached only one or two years out of 10 will result in over-application of N the other eight or nine years. Make sure phosphorus, potassium and zinc levels are adequate for the yield goal. If these levels are too low, adding more N may have little benefit.
Source: Paul O. Johnson, South Dakota State University Extension agronomy field specialist, Watertown, S.D.
This article published in the January, 2013 edition of DAKOTA FARMER.