This project evaluated the impact of varying compost application rates on bell pepper yield and nitrogen status. A grower-cooperator, who produces compost, has been applying three to ten tons of compost (along with other nitrogen inputs like cover crops, feather meal, and sodium nitrate) for the past two years to meet the nitrogen requirements of their pepper crops. However, compost-derived nitrogen has proven insufficient to elevate soil nitrogen levels adequately for optimal crop nutrition.

This study assessed the effect of different compost application rates on the nitrogen status and yield of bell peppers in a commercial setting. The objectives were:

1. To establish a plot to evaluate the effectiveness of various compost application rates on pepper crops in meeting the crop’s nitrogen requirements.

2. To monitor soil and pepper petiole nitrogen levels throughout the season to assess the sufficiency of applied nitrogen. Yield evaluations were also conducted.

3. To analyze yield, soil, and tissue evaluation data to gain insights into compost dynamics in soil enrichment and nitrogen provision for a long-season, high-nitrogen demanding crop like bell pepper.

Considering the plot fertilization throughout the season, drawing definitive conclusions about nitrogen release from compost and its beneficial effect on pepper yield is limited. However, observations included: 1) no significant release of nitrate-nitrogen, even from the 24 T/A compost treatment; 2) a substantial release of ammonium both early and late in the season across all compost treatments; and 3) significant increases in microbial biomass, even 157 days post-application, with as little as 6 T/A of compost.