Effect of Fertilizer Level and Harvesting Date on Yield and Nutritive Value of Desho Grass (Pennisetum pedicellatum) in Hula and Bule districts of the Southern Region of Ethiopia

Abstract

A study was conducted to investigate the effect of fertilizer level and harvesting date on agronomic traits, biomass yield and chemical composition of Desho grass (Pennisetum pedicellatum) at Hula and Bule districts of Sidama and Gedeo zones, respectively, Southern Nations, Nationalities and Peoples` Region of Ethiopia. A factorial arrangement was employed using a randomized complete block design with 3 level of nitrogen fertilizer (0, 41 and 73 kg N/ha) and 3 harvesting dates (112, 133 and 154 days). Plant height, number of tillers per plant, leaf length and leaf to stem ratio were determined. The ash, crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), acid detergent lignin (ADL) contents were analyzed. In vitro organic matter digestibility (IVOMD), dry matter yield (DMY) and CP yield were also quantified. Data were analyzed using the general linear model procedures of the Statistical Analysis System. Plant height was greater (P<0.05) at 154 days of harvesting than at the other two harvesting dates and when 73 kg N/ha was applied compared to application of 41 kg N/ha or no fertilizer. The tiller number was lower (P<0.05) when harvested at 112 days after planting compared to those harvested at 133 and 154 days with no significant differences between the latter two harvesting dates. Tiller number was higher (P<0.05) at the application of 73 kg N/ha than no fertilization application (0 kg N/ha). The leaf length was greater (P<0.05) when 73 kg N/ha was applied compared to the other two N fertilization levels. The leaf: stem ratio decreased (P<0.05) with increasing harvesting date. The CP content was higher (P<0.05) when 41 and 73 kg N/ha was applied compared to the unfertilized treatment (0 kg N/ha). Ash and CP contents were higher (P<0.05) at 154 days than at 112 days of harvesting. The NDF, ADF and ADL contents increased (P<0.05) with increasing harvesting date but showed a decreasing trend with increasing N fertilization level. The IVOMD was higher (P<0.05) at early (112 days) harvesting date than at the intermediate (133 days) and late (154 days) harvesting date. The DMY and CP yield increased (P<0.05) with increasing harvesting date and N fertilizer level. In conclusion, higher yield could be obtained at later harvesting date (154 days) with application of 73 kg N/ha, without affecting quality attributes. However, further study is needed to verify the cost benefit and environmental impact of increased fertilizer level.