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Fertilizer Recommendation Tables - 2007 Revision

Author: Keith Reid - Soil Fertility Specialist/OMAFRA
Creation Date: October 2007
Last Reviewed: October 2007
2007 Revision

Potassium Requirement Table - Field Crops

Potash (K2O) required - kg/ha
  Soil Potassium (1M ammonium acetate extract) mg K L-1 of soil (ppm K)      Spring barley, mixed grain, spring wheat      Corn, sweet corn, sorghum, sunflower     Soybeans, peas, field beans, snap beans, lima beans,
0‑15 90 HR

170 HR

120 HR

16‑30 80 HR

160 HR

110 HR

31‑45 70 HR

140 HR

90 HR

46‑60 50 HR

110 HR

80 HR

61‑80 40 HR

80 MR

60 MR

81‑100 30 MR

50 MR

40 MR

101‑120 20 MR

30 MR

30 MR

121‑150 20 MR

0 LR

0 LR

151‑180 0 LR

0 RR

0 RR

181‑210 0 RR

0 RR

0 RR

211‑250 0 RR

0 RR

0 RR

250+ 0 NR*

0 NR*

0 NR*

* adding nutrients to soils with these levels of nutrients may reduce crop yields or quality by interfering with the uptake of other nutrients.



Potash (K2O) required - kg/ha
  Soil potassium (1M ammonium acetate extract) mg K L-1 of soil
(ppm K)
 Oats, spring rye, mustard, canola, fodder rape, kale, buckwheat, flax, millet, unimproved pasture  Winter wheat, winter barley, winter rye, or winter triticale with or without seeding down (at seeding) Spring cereals, seeded down, (oats, mixed grain barley, rye) direct seeding (at seeding). (See next column for fall application)    Established hay-pasture, fall application. New seedings (after harvest)
0‑15

70 HR

50 HR

90 HR

480 HR

16‑30

50 HR

40 HR

80 HR

400 HR

31‑45

40 HR

30 HR

70 HR

320 HR

46‑60

30 HR

20 HR

50 HR

270 HR

61‑80

20 MR

20 MR

40 HR

200 HR

81‑100

20 MR

20 MR

30 MR

130 HR

101‑120

0 LR

20 LR

20 MR

70 MR

121‑150

0 RR

0 RR

20 MR

20 MR

151‑180

0 RR

0 RR

0 LR

0 LR

181‑210

0 RR

0 RR

0 RR

0 LR

211‑250

0 RR

0 RR

0 RR

0 RR

250+

0 NR*

0 NR*

0 NR*

0 NR*

* adding nutrients to soils with these levels of nutrients may reduce crop yields or quality by interfering with the uptake of other nutrients.

 

The fertilizer rates in this table are designed to produce highest economic yields when accompanied by good or above average management. Research data show that higher rates will occasionally produce higher yields but that these increases in yield are likely to be small and uneconomic.

HR, MR, LR, RR, and NR denote, respectively, high, medium, low, rare and no probabilities of profitable crop response to applied nutrient.

 

Approved: Ontario Soil Management Research and Services Committee (June 2007).

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