Matt Ruark, Dept. Soil Sci. Nav Ghimire, UWEX Green Lake County Joe Lauer, Dept. Agronomy. Thierno Diallo, Dept. Agronomy. CONTROLLED AND DELAYED RELEASE NITROGEN FERTILIZER TRIALS
Controlled-release Polymer-coated ESN® (Agrium) The polymer coating expands with heat, allowing water in to dissolve the urea. The soluble N then diffuses out of the porous coating. NITROGEN FERTILIZERS
Delayed release Contains a chemical that stops part of the N cycle Urease inhibitors Inhibits conversion of urea to ammonia NBPT Agrotain Nitrification inhibitors Inhibits conversion of ammonium to nitrate DCD SuperU (contains both NBPT and DCD, impregnated into the urea granule) NITROGEN FERTILIZER
Is there a reliable benefit to using PCU, urease inhibitors, or nitrification inhibitors in Wisconsin? These products come at a premium so there needs to be an economic benefit when using them. Greater yield at the same rate of N Same yield with lower rate of N QUESTION
Arlington, WI SuperU, ESN, and ammonium nitrate (AN) on corn Green Lake, WI SuperU, Agrotain, ESN, and urea on no-till corn N FERTILIZER TRIALS IN WISCONSIN
Part of long-term rotation and tillage study at Arlington, WI Rotation Corn following corn Corn following soybean Tillage Chisel plow No-till N applied at planting at a rate of 180 lb/ac TRIALS
Corn Yield Prev. Crop N Source Average bu/ac CornAN ESN SuperU SoybeanAN b ESN a SuperU b Chisel Plow systems
Corn Yield Prev. Crop N Source Average bu/ac CornAN ab ESN a SuperU b SoybeanAN a ESN a SuperU b No-till systems
Location: Green Lake County Two fields per farm Corn following corn (no-till) Corn following soybean (no-till) 2012 AND 2013 TRIALS
Fertilizers Urea Agrotain SuperU ESN Rate “recommended” vs. 20% reduction CC: 170 vs 135 CS: 150 vs 120 Controls (unreplicated) of 0 and 200 lb/ac N APPROACH
Assuming… Urea is $550/ton (~$0.60/lb-N) ESN is $750/ton (~$0.82/lb-N) If N application is 150 lb-N/ac and if corn is $4/bu, then need 8 bu/ac gain If corn is $5/bu, then need 6-7 bu/ac gain ECONOMICS
2012 CORN-CORN 135 VS. 170 LB-N/AC
2013 CORN-CORN 135 VS. 170 LB/AC
2013 CORN-SOYBEAN 120 VS. 150 LB-N/AC
These data show that yield gains when applying optimum N rates are not often nor consistently observed. The rainfall patterns of the season will create the situation where the product is valuable or not (i.e. early season intense rains). These products were applied at planting. Perhaps greater value if applied 2-3 weeks prior to planting (i.e. more time to protect). The products work, but need to be tested on your fields to find the benefit, mostly likely coming from reduced N rates. RESULTS
WHERE IS THE VALUE?
QUESTIONS? COMMENTS? CONCERNS?