Early assessment of corn and soybean stands can help to identify potential crop concerns early in the season. Once seedlings emerge, stand counts and inspection of the plants can help to identify problems from planting, insects and/or diseases. Two common methods for taking stand counts are outlined below. The 1/1000th acre method is widely used for corn and wide-row soybeans. The hoop method is often used for drilled beans.

When evaluating a corn or soybean stand, only count plants that have a good chance of survival. Keep in mind that while corn plant populations are a critical component of yield, soybean plants are better able to compensate for low plant populations.

1/1000TH ACRE METHOD

One way to evaluate corn stands is to count the number of plants in a length of row equal to 1/1,000th of an acre, based on row width (Table 1). Multiply the number of plants by 1,000 to calculate the plants per acre. Repeat the process five times per 10 ha (25 acres) in separate parts of the field.

Table 1. Length of row to measure for stand count evaluations based on row width using the 1/1,000th of an acre technique.
Row Width Row Length Required for 1/1,000th Acre
Centimeters Inches Meters Feet
51 20 8.0 26 ft. 1 in.
76 30 5.3 17 ft. 5 in.
91 36 4.4 14 ft. 6 in.
97 38 4.2 13 ft. 9 in.

HOOP METHOD

The circular-hoop method (Table 2) is often used for solid seeded or drilled beans. Throw the hoop and count the number of plants that it encircles. Plants per hoop can be converted to plants per hectare (or acre) by using the multiplication factors in the table.
Table 2. Stand count conversions based on the circular-hoop method for solid-seeded soybeans.
Hoop Diameter cm (inches) Area M2 (Ft2) Multiplication Factor to Get:
Plants per Hectare Plants per Acre
91 (36) 0.65 (7.0) 15,385 6,165
84 (33) 0.55 (6.0) 18,182 7,334
76 (30) 0.45 (4.9) 22,222 8,874
69 (27) 0.37 (4.0) 27,027 10,956
61 (24) 0.29 (3.2) 34,483 13,865