Nutrient Management Research Database

A single fall planting of a leguminous cover crop of vetch/pea mixture increased fruit yields of processing tomatoes by 5 to 13%. Nitrogen benefit from the leguminous cover crop appeared limited.Effects on soluble solids fruit quality were inconsistent between years. Rainfall run-off during the early spring was reduced up to 70% compared to the conventional, weed-free bed approach. Some growers have since adopted the planting of a leguminous mix of cover crops ahead of cropping to tomatoes. The yield increases occurred only when grown succeeding tomatoes in the crop rotation. In our Meridian-located test, when tomatoes followed rice in the rotation, we observed no yield benefit from the cover crop program.

• Fall plantings of a common vetch-pea mix were established in 1998, 1999, 2000, drilled into dry beds in the fallow period between 2 consecutive rotations of tomatoes.
• Strips were planted along the trial sites to evaluate rainfall run-off. Greenhouse-grown tomato plants were transplanted between March and April.
• The experiment was a randomized complete block design with 6 replications , with each plot 3 beds wide by 100 ft. long.
• 2 factors were evaluated:
  • fallow vs. cover cropping with a vetch-pea mix,
  • and spring-applied sidedress N rates of 0, 50, 100, or 150 lbs N/acre.
• N status of the tomato plants was monitored throughout the season.
• In 1998, the cover crop was desiccated with herbicide and incorporated with conventional equipment in mid March.
• In 1999 and 2000 a bed mulcher was designed to incorporate the cover crop.

• Tomato yields declined when grown solely on the N fixed by the vetch-pea cover crops and without benefits of supplemental applied N.
• An estimated 100 lbs of N was fixed by the cover crop in 1998 with over 200 lbs of N fixed in 1999 and 2000.
• Yield increases of 5-13% were recorded in the cover crop treatment when compared to the fallow-bed treatment.
• Soluble solids also increased from 4.7 to 4.9% Average seasonal runoff for the final two years was reduced by 50% with the use of cover-crops when compared to the fallow-bed treatment.

sprinklers were used to establish transplants, furrow irrigation was used thereafter. Cost of the cover cropping practices was estimated at $75 per acre. A 2-ton tomato gain would pay for the added expense.