Ohio State University Extension
Department of Horticulture and Crop Science
2021 Coffey Road, Columbus, Ohio 43210-1044

Useful Tables: Adjustments and Conversions On Corn and Soybean Parameters

AGF-502-95

Expected Corn Yield Due to Various Planting Dates and Population Rates*

Planting Date	Plants per acre at Harvest
	12,000	14,000	16,000	18,000	20,000	22,500	25,000
	% of optimum yield
April 20	72	78	83	87	90	93	95
April 25	75	81	86	90	93	96	98
May 1	77	83	88	92	95	98	100
May 6	78	83	88	92	95	98	100
May 11	77	83	88	92	95	98	99
May 16	75	81	86	90	93	96	98
May 21	73	78	83	87	91	94	95
May 26	69	75	80	84	87	90	92
May 31	64	70	75	79	82	85	87
June 5	59	64	69	73	77	80	81
June 10	52	58	63	67	70	73	75

*Adapted from NCH-30. Yields are expressed as a % of optimum planting date and population yield (assumes plants are uniformly spaced within each row).

Seed Spacings to Achieve Various Corn Plant Populations

Seeds/ac	Inches between kernels						Final* Population
Seeds/ac	20"row	28"row	30"row	36"row	38"row	40"row	Final* Population
15,000	20.9	14.9	13.9	11.6	11.0	10.5	13,500
16,000	19.6	14.0	13.1	10.9	10.3	9.8	14,400
17,000	18.4	13.2	12.3	10.2	9.7	9.2	15,300
18,000	17.4	12.4	11.6	9.7	9.2	8.7	16,200
19,000	16.5	11.8	11.0	9.2	8.7	8.3	17,100
20,000	15.7	11.2	10.5	8.7	8.3	7.8	18,000
22,000	14.3	10.2	9.5	7.9	7.5	7.1	19,800
24,000	13.1	9.3	8.7	7.3	6.9	6.5	21,600
26,000	12.1	8.6	8.0	6.7	6.3	6.0	23,400
28,000	11.2	8.0	7.5	6.2	5.9	5.6	25,200
30,000	10.5	7.5	7.0	5.8	5.5	5.2	27,000
32,000	9.8	7.0	6.5	5.4	5.2	4.9	28,800

*Assuming 10% stand loss

Corn Moisture Corrections

Pounds Needed to Equal One Bushel of No. 2 Corn
Percent Moisture	Shell Corn	Ear Corn
10.0	52.58	63.49
11.0	53.17	64.25
12.0	53.77	65.06
12.5	54.08	65.50
13.0	54.39	65.95
13.5	54.71	66.42
14.0	55.02	66.89
14.5	55.35	67.39
15.0	55.67	67.89
15.5	56.00	68.40
16.0	56.33	68.94
16.5	56.67	69.51
17.0	57.01	70.09
17.5	57.36	70.69
18.0	57.71	71.31
18.5	58.06	71.95
19.0	58.42	72.60
19.5	58.78	73.27
20.0	59.15	73.96
20.5	59.52	74.60
21.0	59.90	75.36
21.5	60.28	76.07
22.0	60.67	76.79
22.5	61.06	77.53
23.0	61.45	78.25
23.5	61.86	79.01
24.0	62.26	79.76
24.5	62.68	80.50
25.0	63.09	81.25
25.5	63.52	82.03
26.0	63.95	82.82
26.5	64.38	83.50
27.0	64.82	84.19
27.5	65.27	84.90
28.0	65.72	85.62
28.5	66.18	86.32
29.0	66.65	87.04
29.5	67.12	87.76
30.0	67.60	88.50
31.0	68.58	89.94
32.0	69.59	91.43
33.0	70.63	92.85
34.0	71.70	94.28
35.0	72.80	95.71
36.0	73.94	97.17
37.0	75.11	98.64
38.0	76.32	100.13
39.0	77.57	101.63
40.0	78.87	103.16

Use the following formula to determine lbs. per bushel of shelled corn with moisture contents not found in the above chart:

lb/bu = 47.3 / (100 - % moisture) x 100

To convert lbs of a wet grain to pounds of a dry grain, use the following equation:
lbs dry = [(100% - wet%) / (100% - Dry %)] x lbs of wet grain

EXAMPLE: Convert 10,000 lbs of 25% moisture corn to 15.5% moisture:
[(100%-25%) / (100%-15.5%) x 10,000 lbs] = (25% / 84.5% x 10,000)
= 0.888 x 10,000 = 8,880 lbs @ 15.5%

USDA Grade Requirements for Shelled Corn

Grade	Minimum test weight/bushel	Cracked foreign material*	Maximum limits of damaged kernels
	Minimum test weight/bushel	Cracked foreign material*	Total	Heat
	(lb)	(%)	(%)
1	56	2	3	.1
2	54	3	5	.2
3	52	4	7	.5
4	49	5	10	1.0
5	46	7	15	3.0
*Broken corn, foreign material, and other grains

Sample grade shall include corn of the class Yellow Corn or White Corn, or Mixed Corn, which does not come within the requirements of any of the grades from No. 1 to No. 5, inclusive; or which contains stones and/or cinders; or which is musty, or sour, or heating, or which has and commercially objectionable foreign odor, or which is otherwise of distinctly low quality.

Soybean Moisture Conversions

% moisture	Pounds per bu
7.0	56.13
7.5	56.43
8.0	56.74
8.5	57.05
9.0	57.36
9.5	57.68
10.0	58.00
10.5	58.32
11.0	58.65
11.5	58.98
12.0	59.32
12.5	59.66
13.0	60.00
13.5	60.35
14.0	60.70
14.5	61.05
15.0	61.41
15.5	61.77
16.0	62.14
16.5	62.51
17.0	62.89
17.5	63.27
18.0	63.66
18.5	64.05
19.0	64.44
19.5	64.84
20.0	65.25

Use the following formula to determine pounds per bushel of samples with moisture contents not found in the above chart.

lb/bu = 52.2 / (100 - % moisture) x 100

To convert lbs of a wet grain to pounds of a dry grain, use the following equation: lbs dry = [(100% - wet%) / (100% - dry%)] x lbs of wet grain

EXAMPLE: Convert 3,000 lbs of 18% moisture beans to 13.0% moisture:
[(100%-18%) / (100%-13%)] x 3,000 lbs = 82/87 x 3,000 lbs
= 0.942 x 3,000 lbs = 2827.5 lbs @ 13%

Suggested Soybean Plant Populations and Seeding Rates at Various Row Widths

inches	plants/ft	plants/acre	seeds/ft	lbs/acre
Row width	Suggested number of plants /feet of row	Recommended total plant population	Required seeding rate at 90% germination and 90% emergence	Required #/acre at 2,500 seeds/#
36	7.0	101,640	8.6	50
30	6.0	104,540	7.4	52
20	5.0	130,680	6.2	64
18	4.5	130,680	5.6	64
16	4.0	130,680	5.0	64
14	3.5	130,680	4.3	64
12	3.0	130,680	3.7	64
10	2.8	143,750	3.4	71
8	2.5	163,350	3.1	81
7	2.2	168,020	2.8	83
6	2.0	174,240	2.5	86

Length of Row Equal to 1/1,000th Acre

Row width inches	Length of single row to equal 1/1,000th of an acre
Row width inches	Feet	Inches
6	87	1
7	74	8
8	65	4
10	52	3
15	34	10
20	26	2
28	18	8
30	17	5
32	16	4
36	14	6
38	13	9
40	13	1

Atomic Weights of Nutrients

Element		Atomic Weight
N	Nitrogen	14.01
P	Phosphorus	30.98
K	Potassium	39.10
Ca	Calcium	40.08
Mg	Magnesium	24.31
S	Sulfur	32.06
Cu	Copper	63.54
Fe	Iron	55.85
Mn	Manganese	54.94
Zn	Zinc	65.37
B	Boron	10.82
Cl	Chlorine	35.46
Mo	Molybdenum	95.94
O	Oxygen	16.00
C	Carbon	12.01
H	Hydrogen	1.01

Micronutrient Sources

BORON MATERIALS	PERCENTAGE:
Borax	11
Boron Frits	2-6
Boric Acid	17
Fertilizer Borate-46	14
Fertilizer Borate-65	21
Solubor	20
ZINC MATERIALS	PERCENTAGE:
Zinc Sulfate	35
Zinc Oxide	78-80
Organic Zinc Complexes	5-12
Zinc Chelates	9-14
Zinc Frits	Varies
MANGANESE MATERIALS	PERCENTAGE:
Manganese Sulfate	25-28
Organic Manganese Complexes	5-12
Manganese Chelate	5-12
Manganese Frits	10-25
IRON MATERIALS	PERCENTAGE:
Ferrous Sulfate	19-21
Ferric Sulfate	23-27
Iron Chelates	5-15
Organic Iron Complexes	5-12
Iron Frits	30-40
COPPER MATERIALS	PERCENTAGE:
Copper Sulfate	13-53
Cupric Oxide	75
Cuprous Oxide	89
Copper Chelate	9-13
Copper Frits	40-50
Organic Copper Complexes	5-7
MOLYBDENUM MATERIALS	PERCENTAGE:
Ammonium Molybdate	54
Sodium Molybdate	39
Molybdenum Frits	2-3

Number of Beans (Seeds) Damaged per Linear Foot of Row
to Result in Economic Loss*

Market Value	$5/bu				$6/bu
Treatment Cost	$7	$8	$9	$10	$7	$8	$9	$10
7	2.6	3.0	3.4	3.8	2.2	2.5	2.8	3.2
15	5.7	6.5	7.3	8.1	4.7	5.4	6.1	6.7
30	11.3	13.0	14.6	16.2	9.4	10.8	12.1	13.5
36	13.6	15.5	17.5	19.4	11.3	13.0	14.6	16.2
38	14.4	16.4	18.5	20.5	12.0	13.7	15.4	17.1
40	15.1	17.3	19.4	21.6	12.6	14.4	16.2	18.0
Market Value	$7/bu				$8/bu
Treatment Cost	$7	$8	$9	$10	$7	$8	$9	$10
7	1.9	2.2	2.4	2.7	1.7	1.9	2.1	2.4
15	4.1	4.6	5.2	5.8	3.5	4.1	4.6	5.1
30	8.1	9.3	10.4	11.6	7.1	8.1	9.1	10.1
36	9.7	11.1	12.5	13.9	8.5	9.7	10.9	12.1
38	10.3	11.7	13.2	14.6	9.0	10.3	11.5	12.8
40	10.8	12.3	13.9	15.4	9.4	10.8	12.1	13.5

*Based on average of 141,000 beans per bushel.

Prepared by:
Extension Agronomy

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Ohio State University Extension Department of Horticulture and Crop Science 2021 Coffey Road, Columbus, Ohio 43210-1044