Faculty of Science

Permanent URI for this communityhttp://erepository.kibu.ac.ke/handle/123456789/111

Browse

Browsing Faculty of Science by Author "Chemining’wa, G.N."

Filter results by typing the first few letters
Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    Effects of N and K fertilization of sugarcane (Saccharum oficinarum) on acrisols in western Kenya
    (Elixirpublishers : Agriculture, 2014-01-01) Mutonyi, J.; Shibairo, Solomon .I.; Chemining’wa, G.N.; Olubayo, F.O.; Nyongesa, Hillary; Konje, Martha
    Sugarcane fertilization in Kenyan plantations is largely concentrated on Nitrogen and Phosphorus. Use of Potassium, secondary nutrients and micronutrients is altogether missing. Recent soil analysis results indicate that soils in the Mumias Sugar zone of western Kenya that accounts for 50-60 % of national production are K- deficient. In examining the quality factor in sugarcane payment systems as envisaged in recent legislation, adoption of balanced nutrition by inclusion of K would help improve sugar cane productivity and enhance sugar recovery. This paper reports the effect of K, N and their interaction on sugarcane yield and juice quality on acrisols. Four experiments were established in several locations from 2009-2011. The treatments included a factorial combination of four rates of K at 0, 60, 120 and 180 kg/ha K2O and four rates of N at 0, 46, 92 and 138 kg/ha N. Recommended basal phosphate was included in every plot at 92 kg/ha P2O5. Each experiment was harvested after 18 months of growth. Results showed significant responses to K and N. Agronomic efficiency was higher in plots supplied with K along with N. Nitrogen and K2O application rates that produced optimum cane yields were: N = 46kg/ha and K2O = 60 kg/ha; however, economically profitable rates were N = 46-92 kg/ha and K2O at 60 kg/ha. Productivity gains did not offset costs when rates were higher than 120 kg/ha of K2O and 138 kg/ha of N. The results imply that the inclusion of K in the sugar cane fertilization regime at Mumias will be beneficial. An initial rate of 60kg/ha K2O (2 bags of 50 kg muriate of potash is recommended on soils with K-deficiency. There were strong indications that with K fertilization the current N recommendation of 120 – 150 kg N/h
  • Thumbnail Image
    Item
    Sugarcane response to liming, manuring and inorganic fertilizers on acid acrisols in Western Kenya
    (International Journal of Recent Scientific Research, 2014-01-01) Mutonyi, J.; Shibairo, Solomon .I.; Chemining’wa, G.N.; Olubayo, F.M.; Kenya, N.C.O.; Nyongesa, Hillary
    Effects of agricultural lime, organic manure and selected inorganic fertilizers on sugarcane growth, yield and quality were determined in four trials conducted from 2009-2011 on acid acrisols in western Kenya. Predominantly grown sugarcane variety CO 945 was used in all experiments that were laid out in a randomized complete block design with three replications. The treatments comprised absolute control (no manure, no fertilizer), compost (18 t/ha), compost (18 t/ha+100 kg/ha diammonium phosphate (DAP) + 100 kg/ha Urea), standard practice (200 kg DAP + 200 kg Urea), agricultural lime (3 t/ha + 200 kg/ha DAP + 200 kg/ha Urea), agricultural lime (3 t/ha + 100 kg/ha DAP + 100 kg/ha Urea), Mavuno NPK (350 kg/ha + 200 kg/ha Urea) and Single Super Phosphate (SSP 450 kg/ha + 200 kg/ha Urea). Soil analysis results generally indicated low levels of pH, total nitrogen, phosphorus, potassium, calcium, magnesium, organic carbon and C.E.C in all sites. The soils were classified as acrisols with sandy clay, clay loam and sandy clay loam texture and high bulk density in all sites. Emergence, tillering, stalk number, height, inter-node length, cane and sugar yields differed significantly (p < 0.05) among the treatments in all locations. Higher cane and sugar yields were consistently recorded in treatments where agricultural lime and compost were included. There was no difference in yield between treatments that received full or half dose of the recommended Nor P along with the lime and compost amendments. Juice quality was highest in the SSP+Urea treatment ranging from 13.58 - 14.43 % Pol and lowest in the compost treatment ranging from 11.43- 13.37 % Pol. Smut incidence was notable in the compost and control treatments. Agronomic efficiency was highest in treatments where compost and agricultural lime were included, ranging from 90.3 to 481.5 kg sugarcane/kg nutrient. Highest net returns and value cost ratios were also recorded in treatments with compost and agricultural lime. Results of this study clearly demonstrated that utilization of agricultural lime and organic compost along with inorganic fertilizers improved sugarcane yield with potential benefits of reduced dosage of N and P to 50% of the local recommendation.