Plant Analysis with Standardized Scores Combines DRIS and Sufficiency Range Approaches for Corn

Abstract

The Sufficiency Range (SR) system and the Diagnosis and Recommendation Integrated System (DRIS) represent two competing approaches to interpreting plant analyses. Our objectives were (i) to show that the two approaches are complementary and (ii) to introduce a new plant analysis system that combines them, called Plant Analysis with Standardized Scores (PASS). The SR provides discrete, easily computed independent nutrient indices (INI). The DRIS determines continuous, difficult to calculate, but easily interpreted dependent nutrient indices (DNI), plus an overall balance index and a ranking of the relative deficiencies. Those differences are complementary; that is, the strengths of the one are the weaknesses of the other, and vice versa. The PASS system combines the strengths of the SR and DRIS by including an INI section and a DNI section, in which both types of indices are on the convenient DRIS scale. When we compared the ability to diagnose deficiencies and sufficiencies in 24 corn (Zea mays L.) dry matter or grain yield comparisons, PASS had a higher efficiency rating (82%) than the SR (41%) and DRIS (33%). The PASS system had a significantly higher proportion of correct diagnoses of deficient nutrients than the DRIS and a significantly greater proportion of correct diagnoses of sufficient nutrients than the SR. Furthermore, the PASS overall index, but not the DRIS, was significantly correlated with relative corn grain yield in 10 comparisons showing a yield response.

Comparação de dois métodos DRIS para o diagnóstico de deficiências nutricionais do cafeeiro

“…Portanto, preconiza-se a utilização de métodos que favoreçam subsídios para um diagnóstico nutricional eficiente e prático, a partir de resultados analíticos das folhas de uma planta ou lavoura. O Sistema Integrado de Diagnose e Recomendação (DRIS) (Beaufils, 1973) incorpora o conceito de balanço nutricional, ou de equilíbrio entre os minerais nos tecidos das plantas (Baldock & Schulte, 1996;Lucena, 1997). Esta técnica baseia-se no cálculo de índices DRIS, para cada nutriente, avaliados pela relação entre as razões dos teores de cada elemento com os demais, obtidas de uma amostra com relações padrões, cuja composição mineral é proveniente de uma população de plantas altamente produtivas.…”

“…Índices DRIS positivo e negativo indi-cam, respectivamente, excesso ou deficiência de nutriente na planta. Desta forma, quanto mais próximo de zero estiver o índice, mais próximo do equilíbrio estará o elemento (Baldock & Schulte, 1996).…”

DRIS norms validation for sugarcane crop

“…Plant analysis can be a useful tool for correcting plant nutrient deficiencies and imbalances (Baldock & Schulte, 1996), optimizing crop production (Walworth et al, 1986), and for evaluating fertilizer requirements. The Diagnosis and Recommendation Integrated System (DRIS) is a recent approach to interpreting plant-tissue analysis.…”

“…The DRIS index scale that results from those calculations is continuous and easy to understand (Baldock & Schulte, 1996). This model is designed to determine when the nutrient contents of crops are excessive (positive indices), adequate (zero indices) or deficient (negative indices).…”

Norms establishment of the Diagnosis and Recommendation Integrated System (DRIS) for nutritional diagnosis of sugarcane

“…Negative DRIS index values indicate that the nutrient level is below optimum, consequently the more negative index, the more deficient the nutrient. Similarly, a positive DRIS index indicates that the nutrient level is above the optimum, and the more positive the index, the more excessive the nutrient is relative to normal, and DRIS index equal to zero indicates that the nutrient is at the optimum level (Baldock & Schulte, 1996). The DRIS also computes an overall index, which is the sum of the absolute values of the nutrient indices (Baldock & Schulte, 1996), called nutrient balance index (NBI) (Rathfon & Burger, 1991).…”