Effects of fertilizer type and harvesting age on species composition, yield and chemical composition of natural pasture in the highlands of Ethiopia

Abstract

Abstract. Yalew S, Asmare B, Mekuriaw Y. 2020. Effects of fertilizer type and harvesting age on species composition, yield, and chemical composition of natural pasture in the highlands of Ethiopia. Biodiversitas 21: 4999-5007. The experiment was conducted to evaluate the effects of fertilizer type and harvesting age on species composition, yield, and chemical composition of natural pasture in the highlands of Ethiopia. The experiment was laid out in randomized complete block design with factorial arrangement of two factors (fertilizer and harvesting age) with five replications. The data collected from the current study were forage species composition, dry matter yield, and chemical composition of natural pasture at different ages of harvesting. Forage species composition was determined by taking representative samples and identifying species from each sampling site. The samples of natural pasture were harvested at 90 and 120 days of age, weighed, dried, and then ground after that subsamples were taken for analyses of dry matter (DM), crude protein (CP), ash, acid detergent fiber (ADF), neutral detergent fiber (NDF) and acid detergent lignin (ADL). All the collected data were subjected to GLM ANOVA procedures of SAS version 9.0. The result indicated that all species composition and dry matter yield were significantly affected (P<0.001) by fertilizer type and harvesting ages. Higher forbs (0.66%) were found in control plot at 90 days of harvesting age. Natural pasture harvested at 120 days of harvesting and urea fertilizer application results the highest dry matter yield (DMY) (8.26 t/ha) while the lowest level (3.20 t/ha) from unfertilized plot at 90 and 120 days of harvesting. The relative proportion of legumes in the natural pasture attained its climax stage at 90 days while grass attained at 120 days of harvesting. The highest mean DMY (6.24 tone/ha) was obtained at 120 days of harvesting and the lowest (4.71 ton/ha) at 90 days of harvesting. Among the chemical composition parameters, DM, ash and CP were significantly affected (P<0.001) by both fertilizer type and harvesting age. The content of CP and ash were increased with manure fertilizer at early harvest age and were decreased with delayed harvest age. The application of fertilizer type did not significantly affect (P>0.05) NDF content of the natural pasture rather affected by stage of harvesting (P<0.001). Regardless of DM yield, better quality pasture was recorded for early (90 days) harvesting age and use of compost recommended for future natural pasture improvements as use of chemical fertilizer is relatively expensive for the majority of smallholder farmers in the highlands.

Biomass Yield, Quality, and Soil Nutrients of Pasture Influenced by Farmyard Manure and Enrichment Planting

“…Nemera et al (2017) reported a higher proportion of legumes under cattle manure and wood ash, which contradicts our finding. Similar to our study, Atsbha et al (2020) and Yalew et al (2020) reported a higher proportion of forbs in the unfertilized (control) treatment group. The higher proportion of grasses and the lower proportion of legumes in the second yr (see Fig.…”

“…This might be associated with variation in soil properties, climate, and the nature of the treatments used in the experiment. Conversely, other authors ( Zewudu et al 2010 ;Yalew et al 2020 ) reported comparable dry matter yield and CP content with application of organic and inorganic fertilizers under similar agroecology. The 16.7% increase in biomass yield in the control plots was likely caused by fencing to prevent animal incursion.…”

Assessment of fodder resources in Ethiopia: Biomass production and nutritional value

“…Similarly, natural pasture harvested during rainy season contained higher CP and lower NDF, ADF, and ADL than during dry season (Berhe, 2012; Dahir, 2016). In addition, the natural pasture harvested at an early stage of harvesting (60 d) contained higher CP and lower NDF and ADF than intermediate harvesting stages (90 d) which in turn contained higher CP and lower NDF and ADF value than late harvesting stage (120 d) (Tessema et al., 2010; Yalew, 2019).…”

Effect of Management Practices and Harvesting Stage on Botanical Composition, Biomass Yield, and Nutritional Value of Natural Pasture Under Traditional Livestock Production System in the Central Highlands of Ethiopia

“…Urea application resulted in a large proportion of grass and legumes (Tessema et al, 2010). The application of urea can increase total biomass yield, which can favor grass species over other herbaceous species due to the better response of grasses to nitrogen fertilizer (You et al, 2017;Yalew et al, 2020). The low biomass yield recorded under seasonal grazing management could be due to higher proportions of legume, sedge, and forb species than in semi-intensive pastureland management (Figure 3).…”