SOLID INDUSTRIAL GELATIN WASTE AS A SOURCE OF NITROGEN FERTILIZATION IN MASSAI GRASS

Resumo

This study aimed to evaluate the effect of gelatin sludge as a source of nitrogen fertilization in Massai grass. The experiment was developed in the greenhouse of the Federal University of Mato Grosso, with three doses of sludge (DGS: 0, 200, 300 m³ ha^-1), an organomineral dose and an of mineral fertilizer and 6 repetitions. Sowing was performed directly in pots. The uniformity cut occurred 30 days after sowing. The variables evaluated were: number of tillers, number of leaves, plant and stem height, chlorophyll index, dry mass (leaves, roots and residue), crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), macronutrients and micronutrients contents. Root mass and SPAD value were not influenced by the doses of sludge compared to mineral fertilizer. There was no difference (P>0.05) in the contents of NDF, ADF and iNDF in all treatments. The organomineral fertilizer, recorded the highest number of tillers. The dose of 300 m³ ha^-1, promoted the highest number of green leaves and leaves per tiller. Leaf dry mass and dry mass production were influenced (P<0.05) by the nitrogen fertilization. The average contents of K, B, Cu, Fe, Mn and Zn in the leaf tissue, were not affected (P>0.05). Different doses of gelatin sludge alter the structural characteristics, nutritive value and yield of Massai grass. Besides influencing the stem height, number of leaves and chlorophyll index, being more responsive the dose of 300 m³ ha^-1.