Promoting Tropical Cover Crop Mulch Systems for Minimum-Till Crop Production in the U.S. Virgin Islands


Stuart A. Weiss


The tropical environment poses specific challenges for the management of soil fertility, agricultural pests, and water resources. Virgin Island’s farmers have limited options to address these management concerns. Soil fertility and pest management create unique challenges to USVI farmers in that imported fertilizers and pesticides are 2-to 3-times the cost of inputs in the continental USA and they require costly specialized application equipment to which USVI’s farmers have little or no access.  

Minimum- till, mechanical-kill systems for cover crops have proven to be cost efficient, all while improving soil organic matter and providing weed suppression (Curran et al., 2010). Our project includes fabrication of a research and demonstration roller-crimper (a.k.a knife roller) implement for use by the Agriculture Experiment Station and the Cooperative Extension Service, which local farmers can test, copy, and fabricate, for their own on-farm use. (link to Roller Crimper PPT or PDF)


  • To construct a roller-crimper from locally available recycled materials for use in on-farm research and to demonstrate the effectiveness of the roller crimper to kill tropical cover crops to produce surface sheet mulch.
  • To evaluate the biomass production of 6 different tropical cover crop species.
  • To evaluate the effectiveness of the roller-crimper to successfully kill 6 different cover crop species and provide suitable surface sheet mulch for soil quality enhancement and weed suppression in subsequent vegetable crop production systems.  
  • To determine cover crop re-growth and weed suppression capability in cover crop surface sheet mulch (6 species) post termination with a roller-crimper.  


  • Evaluate cover crop regrowth and weed suppression capabilities of 6 cover crop species
  • Evaluate cover crop plant tissue nutrient values
  • Identify biomass production of 6 different tropical cover crop species


Anticipated Outcomes and Benefits

This project tests the response of mechanically killed tropical cover crops using a roller-crimper where the cover crop residue is utilized as surface sheet mulch in minimum-till vegetable crop production systems.  Research will determine biomass production of 6 different tropical cover crop species, cover crop plant tissue nutrient levels, and post termination cover crop re-growth and weed suppression capability.  Expected benefits of this cultural practice include the creation of nutrient-rich mulch that will last until the harvest of the following crop and thereby, shade the soil and reduce water loss from evaporation, protect the soil against erosion, reduce weed germination and development, and serve as an organic soil amendment to increase soil fertility.


  • Southern Sustainable Agriculture Research and Education (SARE) On-Farm Grant (SARE)

University of the Virgin Islands
Agricultural Experiment Station
RR 1 Box 10,000
Kingshill, VI 00850
Telephone: (340) 692-4020 Fax: (340) 692-4035