Browsing by Author "Badu, Mavis"

Now showing 1 - 1 of 1
  • Thumbnail Image
    Item
    Evaluation of interactive effects from combined cattle manure and mineral fertilizer application in sole maize cropping system
    (2015-02-24) Badu, Mavis
    A field experiment and a laboratory incubation study were conducted at Kpongu in the Upper west region of Ghana (Guinea Savannah Agro - ecological zone) and the Soil Science Laboratory of KNUST respectively to determine the added benefits in maize grain yield from the combined application of different rates of manure and mineral fertilizer and the mechanisms for interactive effects from combined applications. Nine treatments (three levels of mineral fertilizer at 0, 50 and 100 % of the 60-40-40 NPK kg / ha recommended rate (RR) by three levels of manure at 0, 50, 100 % of 5 t / ha RR) were applied on the field in a factorial experiment arranged in Randomized Complete Block Design (RCBD) with three replications. The same treatments were applied to 207 g of the field soil on mass basis in the incubation study over a 70 day period to determine the mechanism(s) causing added benefits, be it the improved nutrient synchrony, priming effect or the general fertility improvement mechanisms. The use of 60: 40: 40 kg / ha NPK + 5 t manure gave the largest stem girth (5.11 cm at 4 WAP, 6.51 cm at 6 WAP and 7.05 cm at 8 WAP) and highest grain yield of 4678 kg / ha. Synergistic interaction resulting in appreciable added benefits in grain yield were observed from 30: 20: 20 kg / ha NPK + 5 t manure (1305 kg / ha), 60: 40: 40 kg / ha NPK + 2.5 t manure (1122 kg / ha) and 60: 40: 40 kg / ha NPK + 5 t manure (1371 kg / ha) while an antagonistic interaction (- 44 kg / ha) was realized from 30: 20: 20 kg / ha NPK + 2.5 t manure on the field. Soil analysis after harvest showed that N stock had increased by 66 and 33 % for 60:40:40 kg / ha NPK + 5 t manure and 30: 20: 20 kg / ha NPK + 2.5 t manure respectively. The use of 30:20:20 kg / ha NPK + 2.5 t increased soil P by 3.71 % while 30:20:20 kg / ha NPK + 5 t increased soil P by 0.60 %. The value cost ratio iii analysis showed that 30: 20: 20 kg / ha NPK + 5 t manure and 60: 40: 40 kg / ha NPK + 2.5 t manure were the most economically viable combined treatment. The laboratory incubation study showed that combined application of manure and mineral fertilizer improved the synchrony between crop nitrogen demand and soil nitrogen release. This was confirmed by a principal component analysis (PCA) which gave the improved nutrient synchrony mechanism a higher percentage cumulatively (45.72 %). The next most contributing mechanism to the manure-mineral fertilizer interaction observed was the priming mechanism which dominated 43.15 % of the principal components while the least was general fertility improvement (11.13 %). It is therefore recommended that resource poor farmers could cut the cost of mineral fertilizer by 50 % and supplement it with good quality cattle manure without compromising on maize yield and profitability.