Is organic fertilizer application a viable alternative to synthetic fertilizer for Piatã grass?

Organic fertilizer in many cases can replace mineral fertilizers and in consequence reduce production costs and improve soil quality. Thus, the aim of this work was to evaluate productive, morphogenic and structural characteristics of Piatã grass (Urochloa brizantha) fertilized with urea, organic compost and biofertilizer throughout a year. The trial design was a block split-plot in time (seasons) design with 4 treatments (fertilizing with urea, organic compost, biofertilizer and Control) and 6 repetitions. The evaluated parameters were: dry matter production (DMP), leaf elongation rate (LER), leaf appearance rate (LAR), phyllochron (PHYL), leaf lifespan (LLS), pseudostem elongation rate (SER), final leaf length (FLL), number of live leaves (NLL) and number of tillers (NT). The highest LAR values were observed during summer and spring for the treatment with urea, which also produced the highest LER values. No difference was found in SER among the fertilizer treatments but all fertilized treatments were superior to Control. NT and DMP values were highest (P<0.05) in the treatment with urea, followed by biofertilizer, organic compost and Control. In conclusion, while the use of urea provided greatest forage production, applying biofertilizer gave superior yields to organic compost. Other benefits of organic fertilizers should be assessed as well as combinations of organic and inorganic fertilizers.