Nutrient Management Research Database

A burgeoning wine industry could benefit from organic production techniques; however, their effects on vine growth and grape quality have not been explored in New Mexico. Alternative vineyard floor management systems were evaluated for organic grape production at the Alcalde Sustainable Agriculture Science Center in Alcalde, NM, from 2003 to 2006. Grape yield and vegetative biomass were compared between plants grown with and without compost and cover crop. Soil and leaf tissue analyses were performed yearly to monitor changes in soil fertility and chemistry. Addition of compost to vineyard soils provided adequate mineral nutrition, with the exception of plant available potassium; though vegetative growth may have been excessive. A combination of cover cropping and compost addition supported adequate grape yield; however, soil and plant mineral nutrition were varied. The use of cover crops in vineyards must be carefully managed to avoid mineral nutrition competition and to obtain consistent effects.

• Own rooted Leon Millot hybrids were planted at the New Mexico State University Sustainable Agricultural Science Center.
• Four treatment plots were identified for applications of organic compost to the rooting zone and cover crops treatments for the vineyard floor.
• The four treatments were:
  • compost/with cover crop;
  • without compost/without cover crop;
  • with compost/with cover crop;
  • without compost/with cover crop.
• New Zealand white clover was seeded in May at 15 lbs per acre.
• Compost was 30% horse manure and 70% chopped alfalfa, applied in May and November at 4.345 tons per acre per application.
• Yield, plant growth, and leaf nutrient analysis, as well as soil nutrient tests, were conducted on each plot.

• No significant differences in yield were recorded among the four treatments
  • the addition of compost and cover crops did maintain an adequate grape yield.
• Compost additions provided plant available nitrogen and were a significant source of phosphorus.
• Potassium remained deficient in all treatments, although the compost applications did increase potassium contents.
• The addition of compost did support excessive vegetative growth.
• Increasing soil organic matter through compost and cover crop treatments can increase soil water holding capacity and increase water infiltration rates to decrease surface water runoff.
• Cover crops, when used without additional soil nutrition were not able to significantly increase soil organic matter or provide the necessary plant nutrition.