The Effect of Land Cover Change on Soil Properties around Kibale National Park in South Western Uganda

The change from natural forest cover to tea and Eucalyptus is rampant in protected areas of western Uganda. The objectives were; to examine the trend in land-use /cover change and determine the effect of these changes on the physico-chemical properties of soils around Kibale National Park. The trend in land use/cover change was assessed by analyzing a series of landsat images. Focused group discussions and key informant interviews were used for land-use/cover reconstruction. Three major land uses were included; woodlot (Eucalyptus grandis; 5 years old) ), tea (57 years old) and natural forest used as a control. Each of these land-uses were selected at two different North facing landscape positions and were replicated three times. A total of 36 composite soil samples were taken at 0–15 and 15–30 cm depth from natural forest, Tea plantation and eucalyptus on three ridges. Results showed that small scale farming, tea and eucalyptus plantation and built up area have increased over time, to the expense of woodlot and forest cover. Tea and Eucalyptus have induced changes in: exchangeable Mg and Ca, available P, SOM, pH, and bulk density of sub soil (P<.05). Landscape positions within land use also significantly influenced most soil properties (P<.05). Similar findings were observed by Wang et al. (2006) in commercial tea plantations in China that received nitrogen fertilizers

LAND USE/COVER CHANGE PATTERNS IN HIGHLAND ECOSYSTEMS OF LAKE BUNYONYI CATCHMENT IN WESTERN UGANDA

Land use and cover changes influence the livelihood and degradation of fragile ecosystems. The extents of these changes in pattern were investigated in Lake Bunyonyi Catchment which lies in the South Western Highlands of Uganda. The dynamics and magnitude of land use and cover changes were assessed using Landsat (TM/ETM+) satellite images and collection of socio-economic data through interviews. The images were processed and analysed using the mean-shift image segmentation algorithm to cluster and quantify the land use and cover features. The study noted that in the assessment period 1987-2014, the small-scale farmlands, open water and grasslands remained quasi constant; while the woodlots followed a quadratic trend, with the lowest acreage experienced in 2000. The tropical high forests and wetlands cover types experienced significant decline over the years (P&lt;0.05). Patches of small-scale farmlands, woodlots, and wetland interchangeably lost or gained more land dependant on climate variability. Even though the tropical high forest lost more than it gained, it only gained and lost to small scale farmland and woodlots; while grassland mainly lost to small scale farmland and woodlots.L\u2019occupation du sol et les changements de couverture influencent la subsistance et la d\ue9gradation des \ue9cosyst\ue8mes fragiles. La tendance des niveaux de ces changements \ue9taient \ue9valu\ue9e dans le basin versant du lac Bunyonyi qui relie les r\ue9gions montagneuses du Sud-Ouest d\u2019Ouganda. Les dynamiques et l\u2019 envergure d\u2019utilisaton de la terre et les changements de couverture \ue9taient \ue9valu\ue9es en utilisant les images du satellite Landsat (TM/ETM+) et la collecte des donn\ue9es socio-\ue9conomiques \ue0 travers des interviews. Les images \ue9taient trait\ue9es et analy\ue9es en utilisant l\u2019algorithme de segmentation de passage-moyen-d\u2019image pour grouper et quantifier les occupations du sol et les caract\ue9ristiques de la couverture. L\u2019\ue9tude a montr\ue9 que dans la p\ue9riode d\u2019\ue9valuation de 1987-2014, la petite \ue9tendue de terres cultivables, l\u2019eau libre et les prairies sont demeur\ue9es quasi constantes; tandis que les terres bois\ue9es ont suivi une tendance quadratique, avec la plus petite superficie observ\ue9e en l\u2019an 2000. Les grandes for\ueats tropicales et les zones humides ont exp\ue9riment\ue9 un d\ue9clin significatif au cours des ann\ue9es (P&lt;0.05). Les petites parcelles de terres agricoles, les terres bois\ue9es, et les zones humides indistinctement ont perdu et gagn\ue9 plus de terres d\ue9pendamment de la variabilit\ue9 climatique. Bien que la grande for\ueat tropicale aie perdu plus qu\u2019elle en a gagn\ue9e; elle a seulement perdu de tr\ue8s petites \ue9tendues de terres agricoles et bois\ue9es; alors que les prairies ont principalement perdu de tr\ue8s petites \ue9tendues de terres agricoles et bois\ue9es

Water use efficiency of maize (Zea mays L.) crop under selected soil and water conservation practices along the slope gradient in Ruzizi watershed, eastern D.R. Congo

Open Access Journal; Published online: 18 Oct 2022Maize (Zea mays L.) productivity is constrained by water shortages in the predominantly rainfed agriculture of the tropical semi-arid Ruzizi Plain, in the eastern Democratic Republic of Congo (DRC). The region is characterized by a high seasonal and inter-annual rainfall variability and a frequent occurrence of consecutive dry days within growing seasons. Consequently, planning water utilization in rainfed agriculture has become complex, as appropriate soil water conservation (SWC) practices are lacking among most smallholder farmers. Identifying practices that increase water use efficiency (WUE) along the slope gradient is crucial for supporting maize production in the region. In this study, we assessed, for three growing seasons, the effectiveness of two SWC practices (tied ridges and Zai pits) in improving the WUE of two maize varieties along three slope gradients (0–2, 2–8, and 8–15%) in the tropical semi-arid Ruzizi Plain. In this area, rainfall amounts (142–289 mm) were consistently below the evapotranspiration demands (356–533 mm) across the three growing seasons. Tied ridges recorded the highest grain yield (2.16 t ha−1) and WUE (15.23 kg mm−1), especially at low slopes, when compared to Zai pits and conventional tillage. For all SWC practices, WUE decreased with the slope gradient (p < 0.01). Furthermore, a decrease in stored soil water (SWS) at silking and maturity stages (milk, dough, and dent stages) negatively affected the WUE. The variety had no significant effect on grain yield and WUE. Root biomass (RBM), shoot biomass (SBM), and leaf area index (LAI) at the flowering stage were the most associated with the WUE (R2 = 58.5%). In conclusion, tied ridges showed potential for improving maize WUE and yield in the water-deficient conditions that characterize the Ruzizi Plain, and could be promoted to improve the maize productivity among smallholder farmers

Characterization of Historical Seasonal and Annual Rainfall and Temperature Trends in Selected Climatological Homogenous Rainfall Zones of Uganda

There is general lack of scientific consensus on the trend and distribution of annual and seasonal rainfall and temperature in Uganda. This study used both observational and AgMerra rainfall and temperature data for the period 1980-2010 to characterize the trend and variability in seasonal and annual rainfall, maximum and minimum temperatures across 12 different rainfall homogenous zones (K, H, ME, L, J, F, MW, D, E, A1, A2, and I) of Uganda. Trends analysis was done using regression method, while coefficient of variation and ANOVA techniques were used to analyze variability. The results show statistically significant increasing trends (P ≤ 0.05) in annual rainfall amount in zone A1 and a declining trend for zone K (P<0.05)

Principles, design and processes of integrated agricultural research for development: experiences and lessons from LKPLS under the SSACP

With increasing recognition holding the promise of overcoming the outstanding problems faced byAfrican agriculture, IAR4D faces the danger of being ‘blurred’ by past approaches and falling short of its potential to deliver the desired impacts in diverse multi-stakeholder, biophysical, socio- economic, cultural, technological and market contexts unless its actualisation and working is clearly understood. In this paper, we present the conceptualisation and principles of and knowledge-based experiences and lessons from the implementation of the sub-Saharan Africa Challenge Programme (SSACP) in the Lake Kivu Pilot Learning Site (LKPLS). The presentation covers the formation and facilitation of IPs for the actualisation of IAR4D to evolve mechanisms for the early recognition of interlinked issues in natural resource management, productivity and value addition technologies, markets, gender and policy arrangements. These have autonomously triggered flexible, locally directed interactions to innovate options from within or outside their environment for resolving the challenges, and have moved along a new institutional and technological change trajectory. Emerging lessons point to the endowment of IP members with selfhelp knowledge interactions, training in IAR4D, quality of facilitation and research to be key determinants of the power behind of self-regulating mechanisms

Runoff, Soil and Nutrient Losses from Major Agricultural Land-use Practices in the Lake Victoria Basin, Uganda

Soil degradation by water erosion is recognized to be a major agTicultural and environmental probkm in the Lake Victoria basin. The objective of this study was to quantifY runoff, soil and nutrient losses from major agricultural land-use types (Annual crops, banana, coffee and degraded rangelands) and assess the efficiency of contour bunds ·in reducing these losses in two selected micro-catchments of the Lake Victoria Basin. The experiment was conducted on 13 runoiT plots or 15 by 10 m. Each land-usc type was replicated three times, except banana. Contour bunds were hand constructed I wo years after establishment of runoff plots, at 20-m spacing interval. Before the establishment of contour bunds, the average annual runoff ranged between 3 I 5. 47 and 2438.92 m3 ha' 1/yr, with relatively higher amount of rainfall water loss on rangelands compared to banana and colfee (p=0.022). The avarage annual soil loss ranged from 27.7 to 86.7 t/ha/yr, with higher soil loss on annuals compared to banana and coffee (p=0.038). Seasonal soil losses contributed for more than 75% of the annual losses for all agriculrural land-use. while seasonal runoff contributed the same proportion only for banana and rangelands (p&lt;0.05). Eroded sediments had relatively high nutrient concentrations than the remaining soils, and varied with land-use and /or seasons (p&lt;0.05). The amount ofN, P, K and organic matter (OM) lost through erosion was relatively high, and varied with seasons (p&lt;0.05). The establishment of contour bunds increased OM, Ca and Na content in eroded sediments. while it decreased total OM, TN losses for all land-use types except on rangelands where they increased one year afler. These exports from agricultural land play a major role in the nutrient enrichment of rivers and open bodies. •Key words: Pollution, Sustainability, Farming system, Land-use, Soil nutrient losses

Changes in water infiltration along a catena prior to mechanised clearing operations and after two cropping seasons

Maintenance of water infiltration into sloped agricultural lands is an important mechanism for both moisture supply to crops and erosion control. Changes in water infiltration of a typic Kandiudult (Rhodic Nitisols) with a 21% slope were measured in the upper-, middle- and lower-backslope segments of 9 m by 40 m run-off plots located at Makerere University Agricultural Research Institute, Kabanyolo, Uganda. Cumulative infiltration was computed for the Green-Ampt, Philips, and Kostiakov models from infiltrometer measurements taken prior to mechanised land clearing and during maize (Zea mays) cropping. Kay et al. (1994) model was used to predict the time of 50% reduction in infiltration rate. The infiltration behaviour was best described by the Kostiakov model. Changes in infiltration rate were dependent on slope position with greatest alterations recorded on the upper and middle positions. Mean cumulative infiltration after 60 minutes was highest prior to land clearing with values of 150, 97 and 97 cm for the upper-, middle- and lower-slope segments, respectively. The Kay et al. model predicted significant (

Effect of applying low rates of lime and manure on bean growth and yield on Ferralsols of Lake Victoria crescent agro-ecological Zone-Central Uganda

An experiment was conducted to determine the effect of applying low rates of lime and chicken manure on bean (var. NABE 15) growth and yield on Ferralsols. Using split plot factorial randomized complete block design, lime (0.0, 0.5, 1.0, 1.5 and 2.0 t ha-1) as the main plot and chicken manure (0.0, 1.0, 2.0 and 3.0 t ha-1) as sub plot, were replicated three times. The experiment was conducted for three rainy seasons, two seasons’ on-station and one season on-farm using promising combinations from the on-station experiments. In Mukono, increased grain yield of 117% over the control was observed at 2.0 t ha-1 lime with 1.0 t ha-1 manure. Applying 1.5 t ha-1 lime with 2.0 or 3.0 t ha-1 manure resulted in a yield increase of 81.1 and 103.6% over the control respectively. Applying 0.5 t ha-1 lime or 1.0 and 2.0 t ha-1 manure alone caused minimal yields. In Masaka 0.5 t ha-1 lime with 3.0 t ha-1 manure, resulted in 95% yield increase over the control. The control and 0.5 t ha-1 lime yielded the least. All the BCRs were less than one; there was net gain in nutrients (N . P . K) for the subsequent crop.This article is published as Kabango, F., Byalebeka, J., Semalulu, O., Lenssen, A. W., Majaliwa, M. J. G., & Kyebogola, S. (2022). Effect of applying low rates of lime and manure on bean growth and yield on Ferralsols of Lake Victoria crescent agro-ecological Zone-Central Uganda. African Journal of Agricultural Research, 18(12), 1110-1120. doi:10.5897/AJAR2022.16176. Posted with permission.Author(s) agree that this article remain permanently open access under the terms of the Creative Commons Attribution License 4.0 International License</a