Nutrient Management in Oil Crops
The new OSU Nutrient Management Guide for Peppermint is located here.
Meadowfoam nutrient requirements have been evaluated by many OSU-grower cooperative field trials. Information for other oil crops is derived from experience and information from other areas. Some oil crops require a low amount of spring N compared to winter wheat or grass seed crops.
Meadowfoam usually requires only modest amounts of spring applied nitrogen to produce top yield. Similar to fall seeded grain crops, fall fertilizer application is usually not necessary. Spring nitrogen generally is applied in February or early March prior to stem elongation. Spring nitrogen applications should not exceed 40 to 50 pounds N per acre. Over supply of nitrogen leads to excessive foliage, increased incidence of lodging and disease. No yield benefit has been observed from meadowfoam to application of phosphorus, potassium, sulfur, or micronutrients unless soils are deficient. Use a winter wheat soil test and recommendations to determine adequacy of these nutrients.
Brassica crops such as canola often benefit from boron application.