Resposta da Brachiaria brizantha cv. Xaraés à adubação recomendada de fósforo e potássio e diferentes doses de nitrogênio no desenvolvimento inicial

Abstract

The increased use of pasture for ruminant production have been increasingly frequent. To achieve high productivity animal fertilizer is needed for pastures training and maintenance, and the choice of forage grasses that have potential for forage production with good nutritional value. Most of the pasture areas from Brazil were formed more than 20 years and are in some stage of degradation. As forages differ in their requirement in fertility, stress tolerance, and metabolism as a whole, it is essential to the establishment, fertilization, and proper plants management, determining their persistence and productivity. The objective of this study was to evaluate the answer Brachiaria brizantha cv. Xaraés to the recommended fertilizer phosphorus and potassium and different nitrogen levels in early development. For this, we collected soil layer 0-20 cm depth, air dried and passed in a 4 mm sieve to remove plant debris and coarser lumps. The experimental design was blocks by the random with five treatments with four replicates each, totaling twenty cups all with the lime correction. The treatments were: T1 - natural soil, T2 – Soil + Phosphorus + Potassium , T3 – Soil + N₁PK, T4 – Soil + N₂PK and T5 – Soil + N₃PK. The parameters evaluated were: shoots length, tillers number and leaves number. As a result, variables for number of tillers and length of plants, the treatments one, two, three and four, by variances analysis, the results were the same, no difference was observed for each treatment. In the analysis related to the leaves number, two treatment, phosphorus and potassium, which was get worse results compared to other treatments by variance analysis. Comparing to other treatments, where N rates were used, the average were the same, or be it, no significant difference. Therefore, the nitrogen application, phosphorus and potassium, according to the technical recommendation for the culture, there are significant results, however, when it is only 26 days after sowing, and tilling the soil and a consequent microorganisms activation to carry out the mineralization matter organic , this soil meets the initial the plants needs.