Some shortages in nutrients can be clearly identified in lucerne stands, as described below. Generally, nutrient deficiencies come back to poor inoculation, too less P/K-fertilizer or low soil quality.
Nitrogen deficiency – yellowish/light-green colored plants, stunted growth. This indicates a lack of active Rhizobium in the soil, which might come from using untreated seeds, a low soil-pH or Molybdenum-deficiency.
Phosphorus deficiency – stunted growth, plants are stiff and upright. Leaves tend to curl and purple coloration. Occurs mostly in spring, when soil temperature is low.
Potassium deficiency – small white spots on the older leaves, on leaf margins. Later turning yellow. Occurs more often after the 1st cut and K-deficient stands can show more winterdamaga.
Magnesium deficiency – younger leaves start yellowing, margins initially stay green. Might be identified as K-deficiency too.