Nitrogen sources for pangola grass (Digitaria decumbens)

Abstract

In a greenhouse experiment with gray hydromorphic soil different legumes were compared with mineral nitrogen and Beijerinckia inoculation as nitrogen sources for pangola grass (Digitaria decumbens Stent). Nodulation of perennial soybean (Glycine javanica) was poorer than that of Centrosema pubescens, Pueraria javanica or Phaseolus atropurpureus. For two cuttings it was observed that P. atropurpureus was the only legume that increased the growth of the grass. Protein (total N) yield of C. pubescens with pangola grass was equivalent to protein yield of pangola grass with mineral nitrogen (120 kg/ha) and protein yield of pangola grass with P. atropurpureus was significantly higher than all other treatments. Protein yield of pangola grass with the remaining legumes was equivalent to grass alone. Extrapolating the results for kg/ha of N it was apparent that P. atropurpureus mixed with pangola grass, fixed 150 kg N in 78 days when compared with the check and exceeded nitrogen production of the treatment with mineral nitrogen by 61 kg. Inoculation with Beijerinckia spp. had no effect on nitrogen production of pangola grass alone or in association with C. pubescens.