Cultivation of ruziziensis grass (Urochloa ruziziensis) using swine liquid manure fertilization

The objective of this study was to evaluate the use of liquid swine manure (LSM) as fertilization in the implantation of Urochloa ruziziensis. The experimental design was randomized blocks with five treatments and four replications, with the treatments being four doses of LSM (0; 100; 200 and 300 m3 ha-1) and one dose of mineral fertilization. Seven cuts were carried out uniformly, after which plant height (PH), total dry mass yield (TDMY), crude protein content (CP), neutral detergent fiber (NDF) and acid detergent fiber (ADF), macromineral extraction (N, P, K, Ca, Mg and S) and microminerals (Fe, Zn, Mn and Cu) of plants were evaluated every 30 days. Mineral fertilization provided higher PH, CP content and extraction of N and S, but lower NDF content. For ADF variable, there was no difference between treatments. The results of dry mass yield (DMY) and extractions of P, K, Ca and Mn showed that the effect of 300 m3 ha-1 LSM was statistically equal to mineral fertilization. For extractions of Mg, Fe, Zn and Cu doses of 200 and 300 m3 ha-1 did not differ statistically from mineral fertilization. Among the doses of LSM, there was increasing linear effect, with increases in the variables DMY (30.89%), PH (14.94%), CP (17%), N (53.01%), P (40.79%), K (27.84%), Ca (35.17%), Mg (29.6%), S (47.13%), Fe (31.2%), Zn (31.6%) and Mn (23.04%). For Cu extraction, there was a quadratic effect with the highest extraction in the dose of 26.36 m3, obtaining an increase of 19.94% in relation to treatment without application. It is important to study different LSM dosages to avoid risk of heavy metal toxicity. The LSM is an alternative in place of mineral fertilization for Urochloa ruziziensis grass.