ABSTRACT Nitrogen (N) is the critical plant nutrient. Low maize (Zea mays L.) yields in smallholder farms of Malawi are attributable to declining N fertility, aggravated by the ever increasing price of fertilizer. Maize, the country’s staple, has a high nitrogen demand. Little effort has been made to establish the best nitrogen rate in a maize- cowpea and maize-bean intercrop under variable soil conditions as a way of improving production, and was the objective of the current study. Field ...
ABSTRACT Soil physical and hydraulic properties determine soil productivity. Tillage alters the structure and composition of a soil consequently influencing important soil processes such as water, air, heat flux, resistance to root penetration and nutrient availability. Soil layers have distinct physical properties which influence water movement in a profile. This study investigated long term effects of conventional, conservation and no tillage systems with or without initial subsoiling on so...
ABSTRACT Soil fertility decline, due to soil loss by erosion, nutrient mining and sub optimal fertilizer use, is the major constraint in cabbage production in the volcanic highland region of Rwanda. The objective of the study was to assess the effect of mulch type and NPK (17-17-17) fertilizer rates on growth, nutrient uptake, yield of cabbage (Brassica oleracea var. capitata) and soil nutrient content in the volcanic highland region of Rwanda. Field experiments were conducted in two cropping...
ABSTRACT In an attempt to replicate the successful Japanese Satoyama watershed management model in the African agro-ecosystems, sawah rice cultivation technology has been introduced to West Africa in the last two decades. This study was conducted in inland valley at two different locations (Akaeze and Ikwo), to evaluate the effects of sawah water management systems on soil properties and rice grain yield. A split-split-plot in a randomized complete block design was used to evaluate these th...
ABSTRACT The use of plant growth promoting rhizobacteria offers an alternative to the use of chemical fertilizers. The quality and efficacy of inoculants is critical to realize the benefits of inoculation. The objectives of this study were; 1) to test the quality of 3 inoculants (Legumefix, Biofix for soybean and Biofix for common bean) and evaluate the response of soybean and common bean to inoculation; 2) to test the effect of soil fertility on inoculation response of soybean and common bea...
ABSTRACT Continuous land cultivation without adequate soil nutrients replenishment causes soil fertility decline leading to reduced crop productivity. Significant research on external fertility inputs application rates and type have been carried out under researcher designed and managed conditions in Kenya. But little research on the same has been carried out to evaluate their performances under on-farm smallholder farmers’ conditions. Hence, the study evaluated the decomposition rates (goa...
ABSTRACT Water insufficiency due to scarcity, poor distribution and high variability of rainfall in the Central Highlands of Kenya (CHK) and a decline in soil fertility have contributed to a continuous decrease in water productivity. To increase food production to match the growing population, soil management practices that ensure improved water productivity should be embraced. The study, therefore, sought to characterize rainfall and to establish the effects of selected soil management pract...
Abstract The Size-density relationship may be a valuable tool to reveal the extent of competition and mechanisms for distribution patterns, structure and functioning of woody species in savanna vegetation types. A study on the relationship between size and density of Acacia mellifera in the highland savanna of Namibia was carried out to try to facilitate an understanding of the development of stand density in relation to size (height) of A. mellifera. Data was collected at Neudamm farm in thr...
ABSTRACT This study reports investigation of the biodiversity of bradyrhizobia isolates that nodulate cowpea in Ghanaian soils. As a prelude, some components of nitrogen fixation of cowpea in the various soils were examined through: (1) assessment of the natural nodulation of 45 cowpea cultivars in 20 soils sampled from 5 ecozones (coastal savanna, tain forest, semi deciduous forest, forest savanna transition and guinea savanna), (2) determination of the numbers of bradyrhizobial isolates in ...
ABSTRACT Biochar prepared from cocoa pod, sawdust, rice straw and husk wastes may provide new low cost technology for environmental management with emphasis on P removal from waste water to minimize eutrophication and to enhance P availability in tropical soils. To achieve this, the sorption characteristics of the biochar types would have to be understood. In this study, laboratory experiments were conducted to investigate the P adsorptive characteristics on four biochar types derived...
ABSTRACT Soils of the semi-deciduous forest zone of Ghana are known to be moderately acid and very low in plant available phosphorus (P). These soils need to be fertilised to improve their potential for crop production. However high cost of commercial, water soluble fertilizers makes them beyond the reach of local farmers. Instead of expensive superphosphates, the use of less expensive phosphate rocks such as Togo rock phosphate (TRP), Gafsa rock phosphate (GRP) and 50% partially acidulated r...
ABSTRACT This study evaluated pedological differences in three soil profiles of the Amo series following cessation of seasonal flooding due to the construction of the Volta Dam. Three Pedons were used in this study. Pedon 1 is a modal profile; Pedon 2 is sited about 500m downslope from an oyster shell deposit site while Pedon 3 is on the oyster shell site. Soil properties determined include particle size distribution, hydraulic conductivity, pH, organic carbon, available and total phosphorus...
ABSTRACT The association between leguminous plants and rhizobia helps to meet the limiting nitrogen in the soil by producing about 40 to 60 million metric tons (Mt) per hectare per year of nitrogen. However, the focus of legume-Rhizobium symbiosis has been on biomass productivity, nodulation and nitrogen fixation of the major and domesticated food legumes whereas little research has been conducted on the indigenous legumes which hold promise in retaining agricultural diversity and achieving f...
Abstract Carbon is a major constituent of all living things and the cycling o f carbon between the atmosphere and the biosphere is one of the bases for life on earth. However, as a result of m an’s exploitative activities such as deforestation, automobile emission and power generation to increase productivity to m eet energy demands, the quality of the natural environment has and continues to deteriorate in many parts o f the world at a time when the human population is growing at an accele...
Nitrogen (N) is known to be a major limiting crop nutrient which is required in large amounts as compared with other major nutrients. In rice (Oryza sativa L.) cropping, urea is the main source of N which is applied to the crop because of its relatively low cost and its high N concentration (46%). However, low N use efficiency is always associated with urea application under paddy fields because of its high N loss, mostly through ammonia (NH3) volatilization. The split application of pri...