Studies on the mineral nutrition and fertilization of Macroptilium atroporpureum, Galactia striata andGlycine wightii. II: nutritional requirements

Abstract

Macroptilium atvoporpureum (siratro), Galactia striata and Glycine wightii were grown in pots filled with two soil types of the State of S.Paulo, Brazil, namely, a Red Yellow Podzol from Araçatuba and a Distrophic Sand Quartz, according to the technique of diagnosis by subtraction; chemical analyses of the material provided information concerning both mineral requirements and nutrient levels in the tops destined to evaluate the nutritional status. One ton of dry matter contains the following quantities of macro (kg) and micronutrients (g) for the three species in the given order: N - 33; 22 and 29; Ca - 15; 17 and 22; P - 3.6; 1.9 and 2.6; Mg - 2 .1. ; 1.5 and 2.0; K - 54; 45 and 52; S - 2.4; 1.4 and 2.2; B - 16; 17 and 18; Mn - 642; 182 and 179; Cu - 13; 10 and 11; Zn - 57; 42 and 60; Fe - 558; 539 and 701. Maximum production of dry matter under the experimental conditions took place when the tops contained the following levels of macro (%) and micronutrients (ppm), data referring to the three species in the order already given: N - 3.39; 2.26; 3.20 Ca - 1.64; 1.76; 1.72 P - 0.33; 0.18; 0.28 Mg - 0.24; 0.16; 0.24 K - 5.60; 4.57; 5.35 S - 0.23; 0.14; 0.20 B - 18; 19; 20 Zn - 68; 59; 76 Cu - 10; 6; 9 Mn - 400; 397; 464 Fe - 539; 456; 563.