Forage Density | Whatcom CD

Forage Density Determination

Field cover is an important consideration for application of manure. Application to bare or sparsely vegetated fields (<50% cover) will have a much greater risk of runoff than dense fields. Vegetation works to reduce overland flow, help water infiltrate into the soil, reduce surface compaction, and take up nutrients. Only established, dense (>70% cover) grass or cover/relay crops grown for harvest are effective at reducing the runoff potential from fields. Fields with sparse vegetation (<50% cover) should not be applied to during the wet season.

Grass Field

The following pictures show differing forage densities. You can determine your forage density visually, or by grid evaluation. To conduct a grid evaluation, frame out a representative 1 foot by 1 foot block of your field. Determine how much (%) of the area is not covered by forage (i.e., bare ground) and subtract from 100%. Repeat in at least three other locations to get an average for the field.
Forage density less than 50% is not permitted for application due to the elevated potential for runoff.

grass

100% Density

95% Density

90% Density

85% Density

80% Density

75% Density

60% Density

<50% Density

Rocky, <50% Density

Saturated, <50% Density

Moss Covered, <50% Density

Cover Crop

Manure can be applied to a cover crop field in the spring if it is agronomic and that crop is going to be harvested. Cover crops that will be killed or tilled under may not be applied to as it is not agronomic.

cover

Cover dense enough to evaluate for application.

Cover NOT dense enough for application.

Application would not be permittedon these fields prior to March 15 per the Manure Ordinance (16.28).

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Forage Density Determination

Grass Field

Cover Crop