ISHS Acta Horticulturae 777: IX International Rubus and Ribes Symposium
SUSTAINABLE NITROGEN MANAGEMENT IN BRITISH COLUMBIA RASPBERRY CROPS |
| Authors: | M. Jeffries, G. Hughes-Games, M. Sweeney, C. Mouritzen |
| Keywords: | raspberry, nitrogen, aquifer |
| Abstract:
In south coastal BC ground water was found to contain elevated levels of nitrates believed to be due in part to application of commercial fertilizers and manure to raspberry crops. A four year program was undertaken to assess, demonstrate and encourage production practices which would minimize nitrate leaching while still maintaining viable, high yielding raspberry production. From 2000 to 2003, a survey of raspberry fields showed post-harvest nitrate values ranging from 6.25 to 115 ppm. In 72% of fields where manure and commercial sources of nitrogen were used, post-harvest nitrate levels were over 55 ppm, a level presenting a high risk of aquifer contamination. Of fields that used commercial nitrogen only (no manure), only 24% had nitrate levels over 55 ppm. Several initiatives were undertaken to encourage improved nutrient and crop management. A nitrogen credit calculator was developed to help growers estimate crop requirement, account for all sources and determine the rate of nitrogen fertilizer to apply. Seeding a cereal cover crop after harvest to capture residual nitrates was promoted - in the years of the program, cover cropping increased from 24% to 40% of raspberry fields. | |
Download Adobe Acrobat Reader (free software to read PDF files) | |
