The effect of tillage systems and mulching on soil microclimate, growth and yield of yellow yam (Dioscorea cayenensis) in Midwestern Nigeria

Yellow yam (Dioscorea cayenensis) is one of the major varieties of yam produced in Midwestern Nigeria mainly by traditional farmers. Most of these traditional farmers employ zero tillage system and mulching after planting. But, is this the best practice for optimising yield? This paper examines the effect of tillage systems and mulching on soil microclimatic conditions, growth and yield of yellow yam. To generate the needed data, the physiological approach was employed. An experimental farm that measured 35 x 47 m was established at Agbor, Delta State, Nigeria, for two planting seasons 1997/98and 1998/99. The microclimatic parameters monitored include air and soil temperatures and relative humidity while the physiological parameters measured were emergence, growth rate, leaf areaaccumulation and yield. Time series, multiple correlations, chi-square, ANOVA, least square range test and stepwise regression analysis were the statistical tools employed in analysing the data. The resultsshowed that soil moisture at 0-15 cm depth was significantly higher in zero tillage (40 g/g), followed by ridge (30 g/g) and mound (24 g/g) but the reverse was the case with soil temperature where moundtillage (34.2°C) had the highest temperature followed by ridge (31.4°C) and zero (29.5°C). Mulching also significantly influenced the soil microclimatic condition. While soil moisture enhanced yam emergence,soil temperatures favoured the growth, leaf area accumulation and yield. Mound tillage significantly gave the highest yam tuber yield (12.0 t/ha-1), followed by ridge (8.8 t/ha-1) and zero (5.0 t/ha-1). Partiallymulched treatment significantly produced the highest yam tubers (10.3 t/ha-1), followed by the unmulched (8.1 t/ha-1) and mulched (7.4 t/ha-1) treatments. The best practice recommended for theproduction of ware yams is mound tillage that is partially mulched. This recommended practice yielded more than the local practice by 44.6%

The Impact Of Climate Change On Water Resources: Global And Nigerian Analysis

This paper investigates the impact of climate change on global and regional water resources. Primary climatic data (Rainfall and Temperature) for Nigeria were collected from the Nigeria Meteorological Station, Lagos between 1960 and 2002. Changes in Lake Chad waters were collected from the National Centre for Remote Sensing (NCRS), Jos. World temperature and water resources data were collected from different sources. The data were analysed using percentages and time series among others. The result shows that the atmospheric concentration of most greenhouse gases (GHGs) is increasing and this has resulted to changing global climate with increasing temperature. The rise in global average temperatures since 1860 now exceeds 0.6OC. The effect of the GHGs concentration on global warming as at 2100 is estimated by three scenarios to be 1.5OC (Low), 2.5OC (Middle) and 4.5OC (High). In Nigeria, while rainfall has decreased by 92 mm, temperature increased by 0.8OC since 1960. This has led to increasing evapotranspiration and water stress resulting in the drying up of rivers and lakes. For example, Lake Chad has reduced in size from 22902 km2 in 1963 to 16884 km2 in 1972 and 304 km2 in 2000. While climate change will make some countries to experience increase in water resources, majority will face serious water stress. Based on projection, by the 2080s, most countries in the Middle East, around Mediterranean, part of Europe, North and South Africa will face acute water stress while Southern and Eastern Asia, U.S.A. and Alaska. will experience reduction in water stress. By the 2020, 2050, 2080s the total population that will face increasing water stress due to climate change will be 2.3, 3.2 and 3.7 billion respectively. Some recommendations were made to reverse this ugly situation

The effect of tillage types on microclimatic condition and yield of inter-cropped vegetables in Mid Western Nigeria

No Abstract. Global Journal of Agricultural Sciences Vol. 5(1) 2006: 77-8

Geospatial approach to spatio-temporal pattern of urban growth in Benin City, Nigeria

This study examines the spatio-temporal pattern of urban growth in Benin City, Nigeria for a period of 26 years (1987-2013) using remote sensing data and geographic information systems techniques. It also analysed the factors driving the observed pattern of growth in the city. The results show that Benin City is growing more towards the north, east and south along the major transportation routes. The land use pattern in Benin City is compact and radial from the city centre while the growth pattern makes Benin City a monocentric city. The settlement expanded from 220 km2 in 1987 to 359 km2 in 2013 with a mean annual growth rate of 1.5%. The growth of Benin City is observed to be influenced by the siting of public institutions such as schools, hospitals, government offices and industries. While this study demonstrates the importance of using geospatial technology in the acquisition of data for urban planning and management, the results highlight the influence of infrastructure development on urban growth pattern.Key words: Urban growth, spatial analysis, monocentric, remote sensing, geographic information systems (GIS), Nigeria