Preliminary DRIS Norms for Alfalfa in the Southeastern United States and a Comparison with Midwestern Norms¹

Abstract

Foliar tissue norms were developed for 'Apollo' alfalfa (Medicago sativa L.) grown on two highly weathered soils in the Georgia Piedmont for use in the diagnosis and recommendation integrated systems (DRIS). These norms were generated from a data bank comprised of tissue nutrient composition and plant yield and consisting of 3915 field observations. A yield of 3.5 Mg ha-• per cut was used to divide high yielding from low yielding members. Norms were generated by averaging values from the high yielding segment for all possible ratios of N, P, K, Ca, Mg, Zn, Cu, B, and dry matter (DM) and compared to those previously calculated from midwestern data. Values from Georgia were generally similar to those from the Midwest, except for Mg, which was lower, and B, which was higher. Differences in Mg norms were attributed to soil conditions. Norms generated in Georgia correctly diagnosed nutrient requirements of plants grown in Georgia, but differences between the two sets of norms indicate some regionality in DRIS norms for alfalfa. The DM index was demonstrated to adequately separate nutrients present in sufficient and insufficient quantities for recommendation purposes.

Faixas normais de nutrientes em cana-de-açúcar pelos métodos ChM, DRIS e CND e nível crítico pela distribuição normal reduzida

“…: A/B ou B/A). Para cada par de nutrientes, a forma de expressão do quociente entre eles que forneceu a maior razão de variância entre o grupo de baixa produtividade e de referência foi selecionada para ser usada no DRIS, conforme descrito por Walworth et al (1986) e Hartz et al (1998). As funções intermediárias para geração dos índices DRIS foram calculadas pela fórmula de Beaufils (1971), simplificada por Jones (1981):…”

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 system makes multiple two-way comparisons between the levels of various plant nutrients and integrates these comparisons into a series of nutrient indices (Walworth et al, 1986). The DRIS index scale that results from those calculations is continuous and easy to understand (Baldock & Schulte, 1996).…”

“…Several authors have affirmed that, after being developed for a plant species, the DRIS norms can be used irrespective of the cultivar grown or local conditions (Sumner, 1979;Walworth & Sumner, 1987;Payne et al, 1990), but others found that locally developed DRIS norms are more accurate than the broad based norms in their nutrient diagnoses (Dara et al, 1992;Jones Junior, 1993). This demonstrates that DRIS norms, calculated on the basis of finite sets of field data, must be tested to insure validity and accuracy (Walworth & Sumner, 1987).…”

Élaboration de normes DRIS provisoires pour des transplants de céleri

“…(Vigier et al 1989) et la tomate {Lycopersicon esculentum L.) (Caron et Parent 1989). La proposition de normes provisoires (Evanylo et al 1987 ;Hockman et al 1989;Savoy et Robinson 1989;Sumner 1977;Walworth et al 1986) présente un intérêt certain puisque le gain de précision est de plus en plus faible à mesure que s'ajoutent les informations dans la banque de données (Letzsch et Sumner 1984).…”