PROCEEDINGS 2017 Crop Pest Management Short Course & Minnesota Crop Production Retailers Association Trade Show

Transcription

1 PROCEEDINGS 217 Crop Pest Management Short Course & Minnesota Crop Production Retailers Association Trade Show Institute for Ag Professionals Do not reproduce or redistribute without the written consent of author(s).

2 Nitrogen on Soybeans: Yes, No, or Maybe? 217 University of Minnesota and Minnesota Crop Protection Retailers CPM Short Course, Minneapolis, December 12-14, 217 Emerson Nafziger Crop Sciences University of Illinois

3 Why fertilize soybeans with N? Yields keep going up, with field yields in the 8s almost routine in some areas. There s been some contention that soybeans can t fix all the N they need and make high yields as well too much energy used in fixing N? Soybean yield contest winners use N fertilizer, some repeatedly, so it must be necessary Some consultants suggest (or push) this

4 7 Illinois soybean yields, Bushels per acre bu/a/yr Rate of increase:.57 bu/acre/year = 16 bu/acre over 28 years

5 6 5 Minnesota soybean yields, Yield, bu/acre y =.4264x R² =

6

7 More response to N with high soybean yields? These are ONLY the sites in which N gave a yield increase ( about half of the 6+ sites) Salvagiotti et al., 28)

8 From Pioneer Crop Insight by John Schmidt adapted from Salvagiotti

9 If you accept that N fixation is limited (here, to 3 lb/acre) and the soil N supply is capped (1 lb/acre) you come up with this gap between requirement and supply Fluid J. Fall 216

10 How much N do soybeans take up? Yield average =82 bu/acre N in plants at maturity Yield level Seed Stover Total bu/acre lb. N per acre Source: Gaspar et al., Crop Science 57: (217) lb. N/acre 9

11 Yield, bu/acre Urbana Non-irr-N Non-irr+N Irr-N Irr+N Avg

12 Yield, bu/acre Urbana Non-irr-N Non-irr+N Irr-N Irr+N Avg

13 Yield response to N, bu/acre Urbana 28-1, Non-irrigated y =.2447x R² =.994 Irrigated y = x R² = Yield level, bu/acre

14 Yield response to in-season N, bu/acre Illinois trials, Trial average yield, bu/acre

15 Yield, bu/acre N on Soybean Urbana B B B B B 8.5 Control Planting R1 R3 R5 Pl+R1+R3+R5 Application of 1 lb urea/acre + No effect of foliar N A

16 Chillicothe, NS B B A Yield, bu/acre Control Nitrogen Sulfur 1 Irrigated Dryland

17 Chillicothe 9/2/215 Loam (not sandy loam) soil at ~2% OM

18 Yield, bu/acre N on soybeans, Urbana b c ab ab b a a bc bc N application, 1 lb N/acre

19 N in top 2 ft., lb/acre Soil N, Urbana 215 With crop, no N With crop, N at planting No crop, no N No crop, N at planting Planting R1 R3 R5 R6 R8 Sampling stage

20 Total N recovered, lb. N/acre In plant In soil Urbana R1 R3 R5 R6 R8 R1 R3 R5 R6 R8 R3 R5 R6 R8 R6 R8 No N N at planting N at R1 N 4X N treatment and sampling stage

21 Yield, bu/acre N on Soybeans, Chillicothe (irr.) bc a b b b b a c Application of 1 lb N/acre

22 N in top 2 ft., lb./acre Chillicothe, 215 With crop, no N With crop, N at planting No crop, no N No crop, N at planting Planting R1 R3 R5 R6 R8 Sampling stage

23 Total N recovered, lb./acre In plant In soil Chillicothe, R1 R3 R5 R6 R8 R1 R3 R5 R6 R8 R3 R5 R6 R8 R6 R8 No N N at planting N at R1 N 4X N treatment and sampling stage

24 Soybean yield, bu/acre Yield and Plant N, 215 Chillicothe Urbana N in plants at R6, lb N/acre

25 Yield, bu/acre N on soybean Monmouth bc b bc bc bc c a d Treatment, 1 lb N each time

26 Yield, bu/acre N on soybean Brownstown (SC IL) bc c bc a ab ab c bc 1 lb N application

27 Yield, bu/acre N on irrigated soybean at Chillicothe, D AB C C C A BC 1 No N Planting R1 R3 R5 4X: Planting, R1, R3, R5 Application of 1 lb urea/46 lb N AMS at R3

28 lb N per acre Chillicothe 216 Soil N at R6 Plant N at R N application

29 Yield, bu/acre Chillicothe, Plant N at R6, lbs/acre

30 Yield, bu/acre Irrigated soybeans, Chillicothe, 216 y = -.29x x R² =.9991 Not only did N increase yield more N increased it more N applied as urea at planting, lb. N/acre

31 SDS or NDVI (x1) Chillicothe soybeans, 216 SDS NDVI x 1 N-fertilized soybean had less SDS why/how? lb N as urea applied at planting

32 Yield, bu/acre No N N on soybean at Urbana, lb urea at planting 1 lb urea at R1 1 lb urea at R3 1 lb urea at R No significant differences in yield X: planting, R1, R3, R lbs N as AMS, R3

33 N recovered at R6, lb N/acre Plant N at R6 Soil N at R6 Urbana UTC PT1U R1 R3 R5 4X AMS N application - 1 lb urea per acre

34 Yield, bu/acre Soy N Study, Urbana, Plant N at R6, lbs N/acre

35 Yield, bu/acre Orr Center N on soybean, Optimum y = -.2x x R² = N rate, lb N/acre applied as urea

36 N on soybean, Urbana, Yield, bu/acre B AB B AB AB A AB Nitrogen treatment, 1 lb urea each time

37 Yield, bu/acre Chillicothe, Irrigated loam, B B B B B A B No N Pl R1 R3 R5 4X AMS R3 N treatment

38 Soybean yield, bu/acre Monmouth N x rotation, 28 yr N rate on previous corn crop

39 Following 12 years of continuous corn: Urbana soybean input trial 215, 15 rows no N +N* Untreated check Fungicide + insecticide 2x All with Fung+Ins 2X Without With Fish-Seaweed extr Chicken litter Gypsum *Urea/AT + ESN 75+75

40 Soy mgt study, Urbana, 217 What worked; and what paid? Fungicide increased yield, but didn t pay Micro N (2X) Fungicide Insecticide Yield n n n n 74.3 bcd n n n y 75.3 abcd n n y n 73.8 bcd n n y y 78.5 a n y n n 76.5 abc n y n y 73.6 bcd n y y n 75.5 abcd n y y y 73.2 cd y n n n 73.4 bcd y n n y 74.8 abcd y n y n 77.4 ab y n y y 76.1 abc y y n n 71.8 d y y n y 73.4 Bcd y y y n 74.2 bcd y y y y 76.5 abc

41 N on soybeans: yes, no, maybe? We still typically see, in most Illinois soils, little or no response of soybeans to in-season fertilizer N There is no indication that higher-yielding soybeans might respond more to N We have evidence that planting-time N can increase soybean yield on lighter, lower-om soils We can often force higher yields by applying N 4 times; this is interesting, but not profitable

42 N on soybeans: yes, no, maybe? As a general practice, N fertilizer on soybean is unlikely to pay for itself, and some of it might end up in tile lines While yield contestants routinely include use of N, often along with fungicide and other stuff, there has been no indication that any of this increases yield It s possible that stimulating a lot of growth by using N under rainfed conditions can increase water use and limit yield So, the answer is NO, at least in most fields for now; MAYBE in lower-om soils but we have no idea when or if N will pay on ANY field

43 THANK YOU