This page contains images regarding various field tests of compost on crops. To use an image, click on the thumbnail and you can view and download the full-size file. Images are intended for educational use only, not for commercial use. No permission is needed to use these, but please provide a credit to “WSU” or the “CERWA project.” More details are on the main page for this site.
The effect of a compost application two years prior to this canola crop can be seen in the “waves”, with the low spots being those without compost. Barley was grown the first year after application. Pullman, WA.
Compost field plots at Pullman, WA. No visual differences are apparent.
WSU Greenhouse Tomato Study showing the effect of compost rates from 0-40% in the potting mix, using water only.
WSU Greenhouse Tomato Study showing the effect of compost rates from 0-40% in the potting mix, using a nutrient solution instead of water.
A single application of biosolids (dark green stripes) to this field of dryland wheat in Washington State led to 10-15% yield increases.
Wheat without biosolids, fertilized with nitrogen; Mansfield, WA. Note the soil probe for scale.
Wheat with biosolids, but no nitrogen fertilizer. Note the difference in canopy compared to the adjacent strip pictured above; Mansfield, WA. Note the soil probe for scale.
The grass on the left was fertilized with biosolids, the right side was unfertilized; western Washington.
Conifer tree growth in western Washington was dramatically increased where biosolids were added to the soil before planting (far side of road) compared to the control (foreground).
Effect of dairy manure compost on soil organic matter in southern Idaho.
Yield response of potatoes to a dairy manure compost in southern Idaho.
Yield response of dryland wheat to a dairy manure compost in Utah.
Yield response of potatoes to cull potato comopst in Maine.
Effect of biosolids compost on yields of chile pepper in New Mexico.
Effect of biosolids compost on suppression of damping-off disease in chile peppers; New
