Nutritional factors limiting legume growth in a red-yellow podzolic soil

• Autor(a) principal: Eira, Paulo Augusto da
• Data de Publicação: 2014
• Outros Autores: Almeida, Dejair Lopes de, Silva, Wanlou Coelho e
• Tipo de documento: Artigo
• Idioma: por
• Título da fonte: Pesquisa Agropecuária Brasileira (Online)
• Texto Completo: https://seer.sct.embrapa.br/index.php/pab/article/view/17401

In a greenhouse experiment fertility limitations of a red yellow podzolic soil were studied with three tropical forage legumes (Phaseolus atropurpureus DC., Glycine javanica and Stylosanthes gracilis). For Glycine javanica a 24 complete factorial design was used and for the two other legumes an incomplete factorial (+ PKCaM) with half the treatments necessary for the complete design. In the statistical analysis the data of G. javanica were analyzed as a complete factorial 24 and also as two incomplete blocks (+ PKCaM and - PKCaM). The two other legumes were analized only as incomplete factorials. The legume which showed the highest forage yield, best nodulation and highest protein content was Phaseolus atropurpureus, S. gracilis being intermediate and G. javanica the poorest of the three. The three legumes gave varying responses, confirming the importance of performing such experiments with several species. Phosphorus increased green and dry matter, nodulation and total nitrogen of all three legumes. Nitrogen percentage, however, was increased by phosphorus in P. atropurpureus, and decreased in the two other legumes. This seems to be another factor favoring the selection of the first of the legumes. Potassium increased the green matter of S. gracilis and nodule number and weight in G. javanica, while nitrogen percentage was reduced in the latter legume. Lime increased the nitrogen percentage of P. atropurpureus, and the total nitrogen of G. javanica. The mixture of minor elements (B, Mo, Fe, Cu, Zn) increased green and dry matter, nodule number and weight and total nitrogen in G. javanica. In P. atropurpureus, the minor elements increased green and dry matter and nitrogen percentage while in S. gracilis dry matter, and percentage and total nitrogen were increased. Comparing the three experimental designs used for G. javanica it became evident that both incomplete factorials were able to substitute for the complete factorial design.