Browsing by Author "Opoku A."

Now showing 1 - 2 of 2
  • No Thumbnail Available
    Item
    Contributions of Rhizobium Inoculants and Phosphorus Fertilizer to Biological Nitrogen Fixation, Growth and Grain Yield of Three Soybean Varieties on a Fluvic Luvisol
    (American Journal of Experimental Agriculture, 2015) . Aziz A. L. A.; Ahiabor B. D. K; Opoku A.; Abaidoo R. C
    An experiment to identify an efficient strategy to optimize biological nitrogen fixation (BNF) in three soybean varieties {Jenguma (TGx1448-2E), Anidaso and Quarshie (TGx1445-2E)} was conducted in the experimental field of the CSIR-Savanna Agricultural Research Institute, Nyankpala, Northern Region, Ghana. The experiment had a split-split plot design with three replications and interactions tested were inoculation rate (0, 50 and 100% inoculation) (main plot), soybean variety (sub-plot) and phosphorus rate (0, 22.5 and 45.0 kg P2O5/ha) (sub-sub plot) using maize as a reference crop. The soybean was sown at two seeds per hill at a spacing of 50 cm x 10 cm. The results showed that inoculating soybean with the commercial inoculant Legumefix (Bradyrhizobium strain 532c) had no effect on plant height, nodule number, nodule dry weight, shoot dry weight, pod number, grain yield and 100-seed weight. However, the soybean varieties showed significant differences in pod number, 100-seed weight and phosphorus uptake efficiency (PUE). The amount of N2 fixed (measured by Total Nitrogen Difference method) ranged between 52.3-71.0 kg N/ha. Phosphorus applications of 22.5 and 45.0 kg P2O5/ha increased grain yield by 35.4 and 33.9%, respectively and also increased N2 fixation by 49.39 and 69.82%, respectively over the unfertilized control. The interactions among these treatments did not significantly influence the parameters measured except PUE for which there were significant differences among the soybean varieties and the phosphorus rates. Inoculation did not therefore increase nodulation and BNF of the three soybean varieties but phosphorus application increased the growth and grain yield of the soybeans.
  • No Thumbnail Available
    Item
    Mechanism(s) Underlying Interactions Between Cattle Manure and Mineral Fertilizer in a Maize Field Soil in Ghana
    (Agricultural and Food Science Journal of Ghana, 2021) Brempong M.B.; Opoku A.; Ewusi-Mensah N.; Abaidoo R. C; 0000-0002-1235-2252
    A 70-day laboratory incubation study was conducted to unravel the mechanism(s) underlying synergistic interactions between organic and inorganic nutrient inputs to the soil. Soil from a maize farmer's field at Kpongu in the Upper West Region of Ghana was amended with a factorial combination of 0, 50% and 100% levels of the recommended rates (RR) of inorganic fertilizer and cattle manure and incubated at room temperature in plastic cups. Deionized water was added to maintain soil moisture at 70% field capacity throughout the incubation period. Cups were covered with gas-permeable parafilm. Soil sampling was done at 7, 28, 42, 56 and 70 days after incubation. The soil was analyzed for available phosphorus, organic carbon, microbial biomass carbon, nitrates, ammonium, soil urease activity, iron, and copper at each sampling. The addition of 100% RR NPK + 50% RR manure often results in higher amounts of the measured parameters,synergistic interactions and supply of nutrients to the soil, with longer residual effects. While all the under-studied mechanisms (improved nutrient synchrony, priming effects, general fertility improvement fertility) contribute to synergistic interactions, the improved nutrient synchrony mechanism is the most prominent. Farmers can therefore manage the timing of the nutrient inputs well to capitalize on this mechanism for improved soil fertility.