Reference values for nutritional diagnosis of ‘Gigante’ cactus pear by DRIS and BIK methods

Abstract

ABSTRACT The equilibrium and nutritional balance of plants are known to be of utmost importance to evaluate their yield potential and to comprehend the dynamics of nutrients in the soil-plant system. Hence, the present study determined the reference values for evaluating the nutritional status of ‘Gigante’ cactus pear cultivated with organic fertilization in semiarid conditions by Diagnosis and Recommendation Integrated System (DRIS) and Balanced Indexes of Kenworthy (BIK) methods. The cladodes nutrients contents and dry matter yield of 72 plots were employed. The database was classified into a high-yield and low-yield population, above and below 19.93 Mg ha-1 cycle-1, respectively. The five ranges of nutrient contents in cladodes were defined based on the standard deviation range(s) of the DRIS indexes of the high-yield population. Furthermore, the fixed BIK values made it possible to ascertain the lower and the upper limit of the reference values of nutrient contents in the cladodes. The reference values for all nutrients determined by the DRIS and BIK methods varied from each other and those reported in the literature. These methods were efficient in identifying the limiting nutrients for ‘Gigante’ cactus pear, with differences in the hierarchical order of limitation, due to lack or excess, and nutrients not limiting to productivity.