Browsing by Author "Laryea, K.B."
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Item Characterisation of seasonal rainfall for cropping schedules(Ecological Laboratory, University of Ghana, 2011) Mawunya, F.D.; Adiku, S.G.K.; Laryea, K.B.; Yangyuoru, M.; Atika, E.El Nino-South Oscillation (ENSO) phenomenon occurs in the Equatorial Eastern Pacific Ocean and has been noted to account significantly for rainfall variability in many parts of the world, particularly tropical regions. This variability is very important in rainfed crop production and needs to be well understood. Thirty years of daily rainfall data (1976–2006 excluding 1991) from the Akatsi District in the Volta Region of Ghana were analysed to observe the variation of rainfall characteristics such as onset and cessation dates, seasonal rainfall amount and their temporal distribution with ENSO phase, namely El Nino, La Nina and Neutral. Using rainfall reference evapotranspiration relationships, the onset of rainfall during La Nina and Neutral seasons occurred within the same period, March 11–20, but about a month late (April 11–20) during El Nino. Without regards to ENSO phase, the long-term mean onset date of the rainy season occurred from March 11–20. Annual and major season (March–July) rainfall amounts decreased in the order of these ENSO phases; La Nina, Neutral and El Nino but showed an opposite decreasing order of El Nino, Neutral and La Nina during the minor seasons (September-November). The trend of variability of rainfall distribution during the major season was observed to be highest during El Nino years and least during Neutral years. The study also showed that the optimum planting periods on 10-day time scales during La Nina, Neutral and El Nino years were found to be March 13–22; March, 17–26 and April 20–29, with March 16–25 for the long-term situation. These observations seem to reveal that long-term or climatological observations alone are no longer sufficient for seasonal rainfall prediction to aid cropping schedules.Item Effect of N-enriched co-compost on transpiration efficiency and water use efficiency of maize (zea mays L) under controlled irrigation(Agricultural Water Management, 2010) Ofosu-Budu, G.K.; Adamtey, N.; Cofie, O.; Ofosu-Anim, J.; Laryea, K.B.; Dionys, F.Population growth, urban expansion and economic development are increasing competition for water use between agriculture and other users. In addition, the high rate of soil degradation and declining soil moisture in the Sub-Saharan African Region have called for several crop production management and irrigation options to improve soil fertility, reduce water use by crops and produce more crops per drop of water. Notwithstanding, this, considerable variations exist in the literature on water use efficiency. WUFewu (economic yield per water used) for maize (Zea mays L) across climates and soil management practices. Different views have been expressed on the effect of different rates of nitrogen (N) application on transpiration efficiency. TE (biomass product per unit of water transpired). The objectives of the study were to assess the effect of different rate of N -enriched municipal waste co-compost and its derivative on TE, WUEewu and yield of maize (Z mays L) in comparison to inorganic waste fertiliser. The green house put experiment was conducted in Accra, Ghana a study loam soil (Ferric Lisisol) using a split plot design. The main plot treatments were soil (S) dewatered focal study (DES) municipal solid water compost ( C) co-compost from municipal solid waste and dewatered focal study (Co) compost enriched with (NH4)2SO4. The sub-plot treatments were different rates of application of nitrogen fertilizer applied at the rate at 91, 150 and 210 kg n ha-1 respectively …Item Influence of method of residue application and moisture content on water soluble nitrogen in a rhodickandiustalf amended with different fallow plant materials(West African Journal of Applied Ecology, 2019-10-05) Darko, D.A.; Nartey, E.K.; Adiku, S.; Laryea, K.B.Use of plant residues as nutrient sources presents a viable option to resource poor farmers who sparsely use mineral fertilizer in crop production. A study was conducted to gain an insight into how different application methods of residues from different fallow management systems under two moisture regimes would affect soluble N release in a Rhodic Kandiustalf. Three residue types viz, elephant grass from a natural fallow (T1) and another as a fallow following a previously fertilized maize (T2) and a fallow legume (T3) were surface applied and incorporated in a Rhodic Kandiustalf at both field capacity (FC) and 60% field capacity over a sixteen-week period. Incorporation of mucuna residues and elephant grass from previously fertilized maize fallow released similar soluble N levels which were higher than levels from the natural elephant grass amendments. At 60% FC, both mucuna and elephant grass from the fertilized maize fields that were surface applied had slower N releases than the grass from the natural fallow, suggesting the elephant grass from the natural fallow field could be used as an N source amidst light watering to avoid leaching in the dry season.Item Short-term effects of crop rotation, residue management, and soil water on carbon mineralization in a tropical cropping system(Plant and Soil, 2008-10) Adiku, S.G.K.; Narh, S.; Jones, J.W.; Laryea, K.B.; Dowuona, G.N.The purpose of this study was to investigate the short-term effects of maize (Zea mays)-fallow rotation, residue management, and soil water on carbon mineralization in a tropical cropping system in Ghana. After 15 months of the trial, maize-legume rotation treatments had significantly (P < 0.001) higher levels of potentially mineralizable carbon, C 0 (μg CO 2-C g-1) than maize-elephant grass (Pennisetum purpureum) rotations. The C 0 for maize-grass rotation treatments was significantly related to the biomass input (r = 0.95; P = 0.05), but that for the maize-legume rotation was not. The soil carbon mineralization rate constant, k (per day), was also significantly related to the rotation treatments (P < 0.001). The k values for maize-grass and maize-legume rotation treatments were 0.025 and 0.036 day-1 respectively. The initial carbon mineralization rate, m 0 (μg CO2-C g-1 day -1), was significantly (P < 0.001) related to the soil water content, θ. The m 0 ranged from 3.88 to 18.67 and from 2.30 to 15.35 μg CO2-C g-1 day-1 for maize-legume and maize-grass rotation treatments, respectively, when the soil water varied from 28% to 95% field capacity (FC). A simple soil water content (θ)-based factor, f w, formulated as: fw = [θ-θd/ θFC-θd], where θ d and θ FC were the air-dry and field capacity soil water content, respectively, adequately described the variation of the m 0 with respect to soil water (R 2 = 0.91; RMSE = 1.6). Such a simple relationship could be useful for SOC modeling under variable soil water conditions. © 2008 Springer Science+Business Media B.V.Item Test and Application of the DSSAT Model to Assess Rice Productivity in the Accra Plains of Ghana(University of Ghana, 2001-09) Ferdinand, M.D.; Laryea, K.B.; University of Ghana, College of Basic and Applied Sciences, School of Agriculture, Department of Soil ScienceField studies on the growth and development of the rice variety TOX 3107 were conducted at the Agricultural Research Station (A.R.S,) Kpong with the aim of calibrating and validating the CERES-RICE model of DSSAT (version 3.5). Rice was grown for two seasons namely 1999 minor cropping season (August to December) and 2000 major cropping season (April to August). In the 1999 minor season experiment, rice was grown under rainfall with supplementary irrigation. There were two simultaneous experiments in the 2000 major cropping season. In one experiment, rice was grown under rainfall with supplementary irrigation and in the second, rice was grown under solely rainfed conditions. Three levels of nitrogen fertilization namely 0-, 45- and 90 kg N ha-1 were used in all experiments. There was a basal application of 45 kg P ha-1 and 35 kg K ha-1 in each case. Randomised complete block design was used with four replications. The growth of the irrigated rice crop in the 2000 major season was better than the irrigated crop in the 1999 minor season. The irrigated rice crop in both seasons performed better than the rice grown under rainfed conditions in the 2000 major season. The durations of the phenological growth stages of rice grown in the minor season were shorter than those in the major season under both irrigated and rainfed conditions. Crop, soil, weather and field management data from the 1999 minor season experiment were used to calibrate the CERES-RICE model. The calibrated model failed to predict crop growth and development well for the 2000 major season experiment and for an independent data. The goodness of fit for simulations of the calibrated model did not give an indication of a high predictive capability. This constrained its application to assess the output of different nutrient levels, management or weather scenarios.