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?