RESUMO
Desho grass (Pennisetum glaucifolium Trin) an important fodder grass. However, information on its production is lacking. This study was carried out to evaluate the forage dry matter yield and nutritive value of Desho grass harvested at different cutting heights (CH), under rain-fed conditions in two different sites in central highlands of Ethiopia for two years. The treatments (T1-T8) were: 50, 60, 70, 80, 90, 100, 110, and 120 cm cutting heights, distributed in a randomized complete block design with three replications. The root splits of the grass were planted in a 3 m × 4 m (12 m2) plot size with 0.5 m × 0.25 m inter and intra-row spacing. In the two locations, over the years, significant differences were observed among cutting heights. The interaction of cutting heights by locations, and location by years were also significant. The interaction among cutting height, location, and year was insignificant. The highest (number of leaves per plant) NLPP was attained as the plant height advance, while the number of tillers per plant (NTPP) showed non-significant differene in different treatments. The dry matter yield (DMY) increased linearly with an increase in CH (ranging from 12.2 to 20.1 t ha-1 at Holetta, and 4.2 to 11.4 t ha-1at Kulumsa). The grass's ash and crude protein (CP) contents decreased as the cutting height increased. An increase in CH increased the fiber content Neutral detergent fiber (NDF), acid detergent fiber (ADF), and Acid detergent lignin (ADL), resulting decrease in in-vitro dry matter digestibility (IVDMD). We recommend that desho grass be managed at 80-90 cm height resulting in optimum dry matter yield and nutritive value for use in smallholder farmers and market-oriented livestock producers of the central highlands of Ethiopia and major growing areas.
RESUMO
Organic dye contamination of water is a contributing factor to environmental pollution and has a negative impact on aquatic ecology. In this study, unsupported NiO and kaolin-supported NiO composites were synthesized by a one-step wet impregnation-precipitation method through the precipitation of nickel hydroxide onto locally accessible, inexpensive, and easily treated kaolin surfaces by using sodium hydroxide as a precipitating agent. The product was calcined at 500 °C and used for the catalytic oxidative degradation of methylene blue (MB) dye in an aqueous solution. The morphology, structure, and interactions of the synthesized materials were explored by SEM, XRD, and FT-IR spectroscopy. The characterization results revealed the fabrication and the growth of NiO on the kaolin surface. To determine the catalytic oxidative degradation performance of the catalyst, many experiments have been performed using the MB dye as a model dye. The catalytic degradation tests confirmed the importance of NiO and the high catalytic activity of the synthesized NiO/kaolin composite toward MB dye degradation. The oxidative degradation results showed that the optimized precursor amount on the kaolin surface could efficiently enhance the removal of MB dye. The kinetic investigation of the catalytic degradation of MB dye fitted the pseudo-first-order kinetic model. High removal efficiency was observed after eight reuse cycles, proving the exceptional stability and reusability of the composite. The catalytic process also proceeded with a low activation energy of 30.5 kJ/mol. In conclusion, the kaolin-supported NiO composite was established to be a favorable catalyst to degrade a model dye (MB) from an aqueous solution in the presence of inexpensive and easily available NaOCl with a catalytic efficiency of the material higher than 99% of the 20.3 mg catalyst within 6 min with an apparent rate constant, kapp, higher than 0.44625 min-1, which is far better than that of the unsupported catalyst with a kapp of 0.0926 min-1 at 10 mg dose in 20 min.
