Influences of different types of fertilizers on the agronomic characteristics of Chloris gayana forage in a selected area of Tanzania

Abstract

A study was undertaken from January to April 2021 in a commercial dairy farm in Iringa, Tanzania, to determine the effects of applying different types of fertilizers on the agronomic characteristics of Chloris gayana (Rhodes grass). Four types of fertilizers, namely cattle farm yard manure (CFYM), blended Nitrogen, Phosphorus, Sulphur, and Zinc (NPSZn), Sulphate of Ammonium (SA), and Urea, were applied in experimental plots using six different combinations in a Completely Randomized Design (CRD). The combinations were control (T1) with no fertilizer, CFYM alone (T2), CFYM and NPSZn (T3), NPSZn alone (T4), NPSZn with SA (T5), as well as NPSZn with Urea (T6) allocated in four replications per treatment. The physical and chemical properties of the soil in the experimental plots and the CFYM were also determined. The application of the fertilizers followed the protocols of the manufacturers. The seeds of C. gayana were broadcasted in all the experimental plots at a rate of 20 kg/ha. On the 90th day, forages in their respective sub-plots were clipped to obtain representative samples for the determination of the agronomic characteristics. Parameters considered were plant population (PP), number of tillers per plant (NTPP), stem height (SH), number of leaves per plant (NLPP), leaf length per plant (LLPP), leaf width per plant (LWPP) and stem diameter (SD). Results showed that the soil texture was primarily sandy clay loam. The soil and manure contained total N (%) of 0.15 and 1.76 respectively. The amounts of extractable P (mg/kg) in soil and manure were 3.38 and 40.35, respectively. The study showed that the plots fertilized by a combination of NPSZn and Urea (T6) produced the highest (p<0.05) mean values of PP (85.7 plants/m2), NTPP (24.5), SH (136.6 cm), NLPP (6.9), LLPP (40.9 cm), LWPP (1.5) and SD (3.1 mm) compared with other fertilizers. The control treatment (T1) with no fertilizer application had the least (p>0.05) mean values of PP (27.6 plants/m2), NTPP (5.3), SH (53.9 cm), NLPP (3.7), LLPP (23.4 cm) LWPP (0.5) and SD (1.5 mm). It is concluded that a mixture of blended NPSZn and Urea could improve the soil fertility and hence promote the growth parameters of C. gayana. Further studies to determine biomass yield and quality of the forage fertilized with different fertilizers under similar soil and environmental conditions are recommended.