**3.2 Species composition**

Species composition of the study was presented in **Table 1**. Higher grasses species composition was obtained for combined application of urea and NPS than urea alone. Species composition was being higher for fertilizer application in both levels than control. The difference in species composition of the natural pastureland recorded in this trial is a desirable attribute in terms of pasture quality, quantity and persistence. Hence, the presence of various fodder species in this study would indicate the degree of persistence of some species against recurrent drought, frost and high pasture pressure consistent with the harshness of the prevailing climatic and biotic factors. Application of nitrogen and phosphorus activated growth and development of grasses, legumes and other pastures. Thus, the composition pastures in this study significantly higher in fertilized plots than in control (**Figure 4**). A total of 15 grass species recorded in 9 families with Polygonaceae and Asteraceae taking the highest record and others like Apiaceae the least. Some species like *Bidens macroptera* (Sch.Bip.ex Chiov.) was being very importantly chosen by women of the area for lactating cows. This result invites further immediate investigation of the particular grass species correlation with the milk production and quality. Natural


#### **Table 1.**

*Species' composition identified in the study area, 2017.*

*Top Dressing of Fertilizers: A Way Forward for Boosting Productivity and Economic Viability… DOI: http://dx.doi.org/10.5772/intechopen.99094*

#### **Figure 4.**

*Response of grass lands on species composition to fertilizer application.*

grasslands rich in species composition [24] and fertilizing improves the growth and development of dominated species that higher species composition across all the treatments including the urea applied plots. It was also reported that use of fertilizers increasing plant biomass production and biodiversity in semi-arid grasslands [14]. The average legume proportion was higher in the unfertilized plots than in the fertilized plots and this may indicate nitrogen fertilizer had an indirect suppressing effect on the proportion of legumes by inducing luxuriant growth and hence dominance of the grasses.

#### **3.3 Cost benefit analysis**

The partial budget analysis presented in **Table 2** conducted as cost of variable entities was calculated based on cost of fertilizers (Urea and NPS). However, the cost of management like fencing, harvesting, transporting and different activities


**Table 2.** *Partial budget analysis.* disposed for pasture was not included in calculation of variable costs. The price of one ton in the local area was 29.5 USD. Dry matter yield was increasing from control to different fertilizer application and each ton increment in yield influencing the income driving from the production. Net revenue is higher in nitrogen alone application than nitrogen and phosphorus. Therefore, this report verifies better marginal rate of return (MRR = 828%) recorded in Urea application for pastureland improvement in Gamo Gofa highland areas.
