Nutritional reference values for Opuntia ficus‐indica determined by means of the boundary‐line approach

Optimum concentrations and/or sufficiency ranges of nutrients are useful for a correct diagnosis and improvement of nutrient status of cultivated plants. To develop boundary‐line approach (BLA) standards for Opuntia ficus‐indica L., a database of N, P, K, Ca, and Mg concentrations in 1‐year‐old cladodes and cladodes fresh‐matter yield was used. The BLA optimum concentrations (associated with estimated maximum yield) for O. ficus‐indica were: N = 13.1 g kg –1 , P = 3.2 g kg –1 , K = 44.4 g kg –1 , Ca = 38.1 g kg –1 , and Mg = 17.3 g kg –1 . The BLA sufficiency ranges at 95% yield were 8.4–20.3 g kg –1 for N, 2.4–4.2 g kg –1 for P, 38.2–50.8 g kg –1 K, 31.8–45.2 g kg –1 for Ca, and 14.3–20.9 g kg –1 for Mg. The BLA standards are comparable to those obtained in a previous study using compositional‐nutrient‐diagnosis (CND) approach.