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New Mexico State University

Determining Amounts of Fertilizer for Small Areas

Guide H-119

Esteban Herrera, Extension Horticulturist

College of Agriculture, Consumer and Environmental Sciences New Mexico State University

This publication is scheduled to be updated and reissued 5/06.

A home gardener knows that a good fertilization program will result in optimum yields from vegetable crops. A complete fertilizer is one that includes nitrogen, phosphorous and potassium, and it should supply the plants' nutrition requirements from planting to harvest.

Unfortunately, the recommended rates of commercial fertilizers are often given on the per-acre basis.  Using the following tables, you can easily convert per-acre rates into amounts for small areas.

Conversion of fertilizer rates from per-acre basis to 
amounts for smaller areas.
Rate per Acre 
100 Sq Ft
1000 Sq Ft
lb
lb
lb
100
200
400
500
600
800
1,000
2,000
1/4
1/2
1
1-1/5
1-1/2
1-4/5
2-2/3
4-1/2
2-1/3
4-2/3
9-1/4
11-1/2
14
18-2/5
23
46

Use the table below to convert per-acre amounts of fertilizer into rates for 10 feet of row at different row spacings.


 
Conversion of fertilizer rates from pounds per-acre basis 
to ounces per 10 feet of row, at three different spacings.
Distance Between Rows 
Rates per Acre
One Foot
Two  Feet
Three Feet
lb
oz.
oz.
oz.
100
200
400
500
600
800
1,000
2,000
1/3
3/4
1-1/2
1-3/4
2-1/4
3
3-3/4
7-1/2
3/4
1-1/2
3
3-2/3
4-1/2
6
7-1/2
15
1-1/8
2-1/4
4-1/2
5-1/4
6-3/4
9
11-1/4
22-1/2

When individual plants are established and the recommended fertilizer rate has been determined on the per-acre basis, use the following table to find the amount of fertilizer needed per plant.

Conversion of fertilizer rates from pounds-per-acre 
basis to ounces per plant, at various spacings.
Distance Between Plants
Rates per Acre
5 x 5 ft
2-1/4  x  2-1/4 ft
2 x 1-1/2 ft
lb
100
200
400
500
600
800
1,000
2,000
oz.
1
2
3-3/4
4-3/4
5-3/4
7-1/2
9-3/4
18-1/2
oz.
1/4
1/2
1
1-1/4
1-1/2
2
2-1/3
4-2/3
oz.
1/8
1/4
1/2
2/3
3/4
1
1-1/4
2-1/4

New Mexico State University is an equal opportunity/affirmative action employer and educator. NMSU and the U.S. Department of Agriculture cooperating.

Reprinted May 2001
Electronic Distribution July 2001