Advanced Crop Advisers Workshop, Feb , Fargo, ND

Transcription

1 Advanced Crop Advisers Workshop, Feb , Fargo, ND

2 Definition - UNL the placement of small quantities of nutrients in a concentrated zone in close proximity to the point of seed placement at the time of planting. - Small Quantities? Can be fairly large with P on corn- (2x2) - On top of row on soil surface? not work well for immobile nutrients. - Close? I consider within 2 inches - Pop-up - starter in seed furrow

3 Wheat - a given Soybean not that responsive to starter applications and very sensitive to fert salts. Sugarbeets from 2013 survey, almost 90% of growers use and estimate average of gross return of $17 /acre. Corn will limit my comments to this crop.

4 Nutrients often applied N small amounts comes with P, sands may respond P this is the biggie, immobile, most response from K if soil tests low, can t put much on with seed S- lower soil tests, sands, low OM, no-till Zn if lower soil tests

5 What considered a P starter response Any response to P over and above broadcast application of P Or any response to P when soil P tests are very high.

6 75 sites sites were from 80 s and 90 s Most used 2 x 2 placement or close variation 13 were with seed 21 no-till 40 tillage 14 not identified

7 Starter yield response over check ranged from +35 to -31 bu/a - Most had small amount of N, all had P (25-40 lbs P 2 O 5 ), about 10 had K and small number with other nutrients - P response? Assumed most were.

8 Range of Response (starter over check) for 75 sites B u / a

9 Early Growth Response from Starters

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11 Adv. of starter, early growth response. of 71 sites of 47 that had early growth response

12 /71 sites with no early growth response % of sites with response /24 of these has sign. yield response 5 0

13 Were frequency of yield responses related to soil test P? 3 sites from ppm. 1 site at 30 ppm

14 Magnitude of sign. response by soil test P level

15 Average significant starter response Frequency response x magnitude = Ave. Resp. VL or L M H VH 0.42 x 10 bu/a = 4.2 bu/a 0.28 x 15 bu/a = 4.2 bu/a 0.33 x 12 bu/a = 4.0 bu/a 0.16 x 17 bu/a = 2.7 bu/a

16 What about starter placement? Ave yield resp. 2 x 2 (33 sites) = 4.2 bu/a With seed (9 sites) = 6.2 bu/a

17 Photo Credit: Iowa State

18 Photo Credit: Purdue Univ.

19 Influence of phosphorus placement on P uptake at tassel and grain yield of irrigated corn, Pierre, SD. Ave. 3 years. P2O5 * P uptake Yield Placement g/shoot bu/a with seed 0.26 a 197 a 2 x bc 197 a surface bandover row 0.22 c 189 b After Riedell et al. (2000) * 20 lbs/a P2O5/a as P soil test = 6 (Low),

20 Influence of distance of P fertilizer from seed on V6 corn weight, Brookings, grams NO P 2x10" 2x6" 2x4" 2x2" seed 3" below No yield response to P, low -med soil test.

21 What about tillage and starter response? System Frequency (%) Yield inc. No-Till 9/21 = 43% 8.5 bu/a Till 10/39 = 26% 4.7 bu/a

22 Influence of P rate and placement on V11 height SE Farm, 2009 height, inches lb/a P2O5 till-seed notill-seed till-bct notill-bct

23 What about starter rates? Rate Gal/ac Yield Bu/ac *Conventional tillage *Soil : 124 lb N/acre prior to planting; 5 ppm (L) P (Olsen) No difference in plant stand among fertilizer rates P. Hendrickson

24 Wheat 100 bu/a x 0.45 lb P 2 O 5 /a = 45 lb P 2 O 5 /a Soybean 60 bu/a x 0.61 lb P 2 O 5 /a = 37 lb P 2 O 5 /a Corn 180 bu/a x 0.27 lb P 2 O 5 /a = 49 lb/a P 2 O 5 /a SD values M. Nathan, U of MO

25 Placement and rate of phosphorus (MAP) on no-till corn yield, two year mean, Watertown, SD broadcast 157 band bu/a P 2 O 5, lb/a

26 Influence of P rate and placement on corn yields, SE Farm 1, SDSU, Year check Starter --- Broadcast Rate of P 2 O 5 /a bu/a yr- mean Low P soil test

27 Lit review of 38 sites/studies (upper midwest) yields All responsive to phosphorus 60% of the time band > broadcast

28 Corn Yield Response in Nebraska to Different Sources of P fertilizer Phosphorus Source P2O5 rate (lb/ac) Polyphosphate Orthophosphate Corn yield, bu/ac *after Mengel & Ruiz, data from UNL

29 17 Crop Consultants Most NE SD Frequency Starter Liquid In-furrow % - Number out of 16 respondents Range

30 benefits of early growth and yield > response to no till Rate of lbs P2O5/a probably sufficient many cases will need to broadcast as well - Banded P application > efficient than broadcast - However, over time need to apply at least removal rates IF want to maintain soil test levels

31 Phone