Legume Cover Crops are More Beneficial than Natural Fallows in Minimally Tilled Ugandan Soils

It is important to establish the various effects of legume cover crops on soil physicochemical properties because they have been considered for use as improved fallows (with shorter rest periods) to enhance development and maintenance of soil productivity. Our objectives were to assess: (i) aboveground dry matter yields of legume cover crops; and (ii) cover crop effects on weed infestation and soil physicochemical properties in a minimum tillage management system. Trials were conducted for 2 yr at Kawanda Agricultural Research Institute and on farmers’ fields in Mbale and Pallisa districts, eastern Uganda. Th e experiment layout was a Randomized Complete Block Design (RCBD) in a split-plot arrangement with four replications. Natural and improved fallows were established in the second cropping season of 2004. Cover crops used in the improved fallows included mucuna [Mucuna pruriens (L.) DC.var. utiliz], Dolichos lablab (Lablab vulgaris Savi cv. Rongai), canavalia [Canavalia ensiformis (L.) DC.], and crotalaria (Crotalaria paulina Schrank). The fallows were reestablished in the same plots in the second cropping season of 2005 aft er maize (Zea mays L.). Canavalia yielded significantly more dry matter than the other fallows regardless of year or site. With an average yield of 169 kg N ha–1 canavalia accumulated significantly more N than the other fallows; all improved fallows produced significantly more N than the natural fallow. Canavalia also accumulated significantly more P than the other fallows; all improved fallows, with the exception of crotalaria, accumulated more P than the natural fallow. There was no significant change in soil physicochemical properties by the improved fallows. All effects considered, improved fallows were more beneficial than natural fallow. A significant improvement in soil physicochemical properties using legume cover crops might be possible, though it may require more than the two cropping cycles used in this study of degraded soils

Legume Cover Crops are More Beneficial than Natural Fallows in Minimally Tilled Ugandan Soils

It is important to establish the various effects of legume cover crops on soil physicochemical properties because they have been considered for use as improved fallows (with shorter rest periods) to enhance development and maintenance of soil productivity. Our objectives were to assess: (i) aboveground dry matter yields of legume cover crops; and (ii) cover crop effects on weed infestation and soil physicochemical properties in a minimum tillage management system. Trials were conducted for 2 yr at Kawanda Agricultural Research Institute and on farmers’ fields in Mbale and Pallisa districts, eastern Uganda. Th e experiment layout was a Randomized Complete Block Design (RCBD) in a split-plot arrangement with four replications. Natural and improved fallows were established in the second cropping season of 2004. Cover crops used in the improved fallows included mucuna [Mucuna pruriens (L.) DC.var. utiliz], Dolichos lablab (Lablab vulgaris Savi cv. Rongai), canavalia [Canavalia ensiformis (L.) DC.], and crotalaria (Crotalaria paulina Schrank). The fallows were reestablished in the same plots in the second cropping season of 2005 aft er maize (Zea mays L.). Canavalia yielded significantly more dry matter than the other fallows regardless of year or site. With an average yield of 169 kg N ha–1 canavalia accumulated significantly more N than the other fallows; all improved fallows produced significantly more N than the natural fallow. Canavalia also accumulated significantly more P than the other fallows; all improved fallows, with the exception of crotalaria, accumulated more P than the natural fallow. There was no significant change in soil physicochemical properties by the improved fallows. All effects considered, improved fallows were more beneficial than natural fallow. A significant improvement in soil physicochemical properties using legume cover crops might be possible, though it may require more than the two cropping cycles used in this study of degraded soils

Characterising agrometeorological climate risks and uncertainties: Crop production in Uganda

Uganda is vulnerable to climate change as most of its agriculture is rain-fed; agriculture is also the backbone of the economy, and the livelihoods of many people depend upon it. Variability in rainfall may be reflected in the productivity of agricultural systems and pronounced variability may result in adverse impacts on productivity. It is therefore imperative to generate agronomically relevant seasonal rainfall and temperature characteristics to guide decision-making. In this study, historical data sets of daily rainfall and temperature were analysed to generate seasonal characteristics based on monthly and annual timescales. The results show that variability in rainfall onset dates across Uganda is greater than the variability in withdrawal dates. Consequently, even when rains start late, withdrawal is timely, thus making the growing season shorter. During the March–May rainy season, the number of rainy days during this critical period of crop growth is decreasing, which possibly means that crops grown in this season are prone to climatic risks and therefore in need of appropriate adaptation measures. A time-series analysis of the maximum daily temperature clearly revealed an increase in temperature, with the lower limits of the ranges of daily maximums increasing faster than the upper limits. Finally, this study has generated information on seasonal rainfall characteristics that will be vital in exploiting the possibilities offered by climatic variability and also offers opportunities for adapting to seasonal distribution so as to improve and stabilise crop yields

Conservation Farming and Changing Climate: More Beneficial Than Conventional Methods for Degraded Ugandan Soils

The extent of land affected by degradation in Uganda ranges from 20% in relatively flat and vegetation-covered areas to 90% in the eastern and southwestern highlands. Land degradation has adversely affected smallholder agro-ecosystems including direct damage and loss of critical ecosystem services such as agricultural land/soil and biodiversity. This study evaluated the extent of bare grounds in Nakasongola, one of the districts in the Cattle Corridor of Uganda and the yield responses of maize (Zea mays) and common bean (Phaseolus vulgaris L.) to different tillage methods in the district. Bare ground was determined by a supervised multi-band satellite image classification using the Maximum Likelihood Classifier (MLC). Field trials on maize and bean grain yield responses to tillage practices used a randomized complete block design with three replications, evaluating conventional farmer practice (CFP); permanent planting basins (PPB); and rip lines, with or without fertilizer in maize and bean rotations. Bare ground coverage in the Nakasongola District was 187 km2 (11%) of the 1741 km2 of arable land due to extreme cases of soil compaction. All practices, whether conventional or the newly introduced conservation farming practices in combination with fertilizer increased bean and maize grain yields, albeit with minimal statistical significance in some cases. The newly introduced conservation farming tillage practices increased the bean grain yield relative to conventional practices by 41% in PPBs and 43% in rip lines. In maize, the newly introduced conservation farming tillage practices increased the grain yield by 78% on average, relative to conventional practices. Apparently, conservation farming tillage methods proved beneficial relative to conventional methods on degraded soils, with the short-term benefit of increasing land productivity leading to better harvests and food security

Conservation Farming and Changing Climate: More Beneficial than Conventional Methods for Degraded Ugandan Soils

The extent of land affected by degradation in Uganda ranges from 20% in relatively flat and vegetation-covered areas to 90% in the eastern and southwestern highlands. Land degradation has adversely affected smallholder agro-ecosystems including direct damage and loss of critical ecosystem services such as agricultural land/soil and biodiversity. This study evaluated the extent of bare grounds in Nakasongola, one of the districts in the Cattle Corridor of Uganda and the yield responses of maize (Zea mays) and common bean (Phaseolus vulgaris L.) to different tillage methods in the district. Bare ground was determined by a supervised multi-band satellite image classification using the Maximum Likelihood Classifier (MLC). Field trials on maize and bean grain yield responses to tillage practices used a randomized complete block design with three replications, evaluating conventional farmer practice (CFP); permanent planting basins (PPB); and rip lines, with or without fertilizer in maize and bean rotations. Bare ground coverage in the Nakasongola District was 187 km2 (11%) of the 1741 km2 of arable land due to extreme cases of soil compaction. All practices, whether conventional or the newly introduced conservation farming practices in combination with fertilizer increased bean and maize grain yields, albeit with minimal statistical significance in some cases. The newly introduced conservation farming tillage practices increased the bean grain yield relative to conventional practices by 41% in PPBs and 43% in rip lines. In maize, the newly introduced conservation farming tillage practices increased the grain yield by 78% on average, relative to conventional practices. Apparently, conservation farming tillage methods proved beneficial relative to conventional methods on degraded soils, with the short-term benefit of increasing land productivity leading to better harvests and food security

Detecting level of wetland encroachment for urban agriculture in Uganda using hyper-temporal remote sensing - Land_stat_1996

Background: Urbanization is an important indicator of economic growth and social change but is associated with environmental degradation, which threatens sustainable growth of African cities. One of the most vulnerable ecosystems in urban areas are wetlands. In Uganda, wetlands cover an area of 11% of the country's land area. Half of the wetland areas in Ugandan cities have been converted to industry and residential areas, and urban agriculture. There is limited information on the extent of wetland conversion or utilization for urban agriculture. The objective of this study was to investigate the extent of wetlands lost in two Ugandan cities, Wakiso and Kampala, in the last 30 years. Secondly, we demonstrate a simple methodology to monitor agriculture on encroached wetlands. Methods: Using a field survey and free remote sensing data from Landsat TM 1986 and Landsat ETM 2016 we classified the rate of wetland loss and encroachment in the last 30 years. Using MODIS NDVI 16-day composites at 500-meter spatial resolution, we generated distinctive crops and crop mixtures in the encroached wetlands for urban agriculture using the ISODATA clustering algorithm. Results: Over a 30-year period, 72,828 ha (73%) of the Wakiso-Kampala wetlands have been lost. Agriculture area on the other hand doubled. Of the new cultivation area, 16,488 ha (23%) were reclaimed from wetlands. All cultivated agriculture in Kampala was in the wetlands while in Wakiso, 73% of crop agriculture was in the wetlands. The major crops grown in these urban wetlands were banana (20%), sugarcane (22%), maize (17%), Eucalyptus trees (12%), sweet potatoes (10%), while ornamental nurseries, pine trees, vegetables and passion fruits were each at 5%. Conclusions: Current wetland exploitation for food security for urban dwellers may be a trade-off between the provision of food in the short-term and the loss of important ecosystems services in the long-term

Detecting level of wetland encroachment for urban agriculture in Uganda using hyper-temporal remote sensing -Gapmark2016

Background: Urbanization is an important indicator of economic growth and social change but is associated with environmental degradation, which threatens sustainable growth of African cities. One of the most vulnerable ecosystems in urban areas are wetlands. In Uganda, wetlands cover an area of 11% of the country's land area. Half of the wetland areas in Ugandan cities have been converted to industry and residential areas, and urban agriculture. There is limited information on the extent of wetland conversion or utilization for urban agriculture. The objective of this study was to investigate the extent of wetlands lost in two Ugandan cities, Wakiso and Kampala, in the last 30 years. Secondly, we demonstrate a simple methodology to monitor agriculture on encroached wetlands. Methods: Using a field survey and free remote sensing data from Landsat TM 1986 and Landsat ETM 2016 we classified the rate of wetland loss and encroachment in the last 30 years. Using MODIS NDVI 16-day composites at 500-meter spatial resolution, we generated distinctive crops and crop mixtures in the encroached wetlands for urban agriculture using the ISODATA clustering algorithm. Results: Over a 30-year period, 72,828 ha (73%) of the Wakiso-Kampala wetlands have been lost. Agriculture area on the other hand doubled. Of the new cultivation area, 16,488 ha (23%) were reclaimed from wetlands. All cultivated agriculture in Kampala was in the wetlands while in Wakiso, 73% of crop agriculture was in the wetlands. The major crops grown in these urban wetlands were banana (20%), sugarcane (22%), maize (17%), Eucalyptus trees (12%), sweet potatoes (10%), while ornamental nurseries, pine trees, vegetables and passion fruits were each at 5%. Conclusions: Current wetland exploitation for food security for urban dwellers may be a trade-off between the provision of food in the short-term and the loss of important ecosystems services in the long-term

Detecting level of wetland encroachment for urban agriculture in Uganda using hyper-temporal remote sensing - classifiedlandstat2016

Background: Urbanization is an important indicator of economic growth and social change but is associated with environmental degradation, which threatens sustainable growth of African cities. One of the most vulnerable ecosystems in urban areas are wetlands. In Uganda, wetlands cover an area of 11% of the country's land area. Half of the wetland areas in Ugandan cities have been converted to industry and residential areas, and urban agriculture. There is limited information on the extent of wetland conversion or utilization for urban agriculture. The objective of this study was to investigate the extent of wetlands lost in two Ugandan cities, Wakiso and Kampala, in the last 30 years. Secondly, we demonstrate a simple methodology to monitor agriculture on encroached wetlands. Methods: Using a field survey and free remote sensing data from Landsat TM 1986 and Landsat ETM 2016 we classified the rate of wetland loss and encroachment in the last 30 years. Using MODIS NDVI 16-day composites at 500-meter spatial resolution, we generated distinctive crops and crop mixtures in the encroached wetlands for urban agriculture using the ISODATA clustering algorithm. Results: Over a 30-year period, 72,828 ha (73%) of the Wakiso-Kampala wetlands have been lost. Agriculture area on the other hand doubled. Of the new cultivation area, 16,488 ha (23%) were reclaimed from wetlands. All cultivated agriculture in Kampala was in the wetlands while in Wakiso, 73% of crop agriculture was in the wetlands. The major crops grown in these urban wetlands were banana (20%), sugarcane (22%), maize (17%), Eucalyptus trees (12%), sweet potatoes (10%), while ornamental nurseries, pine trees, vegetables and passion fruits were each at 5%. Conclusions: Current wetland exploitation for food security for urban dwellers may be a trade-off between the provision of food in the short-term and the loss of important ecosystems services in the long-term

Detecting level of wetland encroachment for urban agriculture in Uganda using hyper-temporal remote sensing

Background: Urbanization is an important indicator of economic growth and social change but is associated with environmental degradation, which threatens sustainable growth of African cities. One of the most vulnerable ecosystems in urban areas are wetlands. In Uganda, wetlands cover an area of 11% of the country's land area. Half of the wetland areas in Ugandan cities have been converted to industry and residential areas, and urban agriculture. There is limited information on the extent of wetland conversion or utilization for urban agriculture. The objective of this study was to investigate the extent of wetlands lost in two Ugandan cities, Wakiso and Kampala, in the last 30 years. Secondly, we demonstrate a simple methodology to monitor agriculture on encroached wetlands. Methods: Using a field survey and free remote sensing data from Landsat TM 1986 and Landsat ETM 2016 we classified the rate of wetland loss and encroachment in the last 30 years. Using MODIS NDVI 16-day composites at 500-meter spatial resolution, we generated distinctive crops and crop mixtures in the encroached wetlands for urban agriculture using the ISODATA clustering algorithm. Results: Over a 30-year period, 72,828 ha (73%) of the Wakiso-Kampala wetlands have been lost. Agriculture area on the other hand doubled. Of the new cultivation area, 16,488 ha (23%) were reclaimed from wetlands. All cultivated agriculture in Kampala was in the wetlands while in Wakiso, 73% of crop agriculture was in the wetlands. The major crops grown in these urban wetlands were banana (20%), sugarcane (22%), maize (17%), Eucalyptus trees (12%), sweet potatoes (10%), while ornamental nurseries, pine trees, vegetables and passion fruits were each at 5%. Conclusions: The Kampala-Wakiso wetlands have been disappearing at a rate of 2500 ha annually for the last 30 years, implying that at this rate, there will be no wetlands left by 2029. Policy implications are that, ecosystem services by of urban wetlands have been lost, a large population of urban poor are using wetlands for survival and yet Poverty eradication policies are in conflict with wetland conservation policies. Policy recommendations we endorse are, the Government of Uganda needs to promote wetland reclamation programs so as to restore and reconstruct lost and fragmented wetlands. Secondly, ministries mandated to food security and poverty eradication need to convene with ministries regulating wetlands to merge these conflicting policies. Thirdly, there is need for the development of polices that are inclusive of challenges faced by the urban poor while at the same time minimize the pressures on urban environments

Detecting level of wetland encroachment for urban agriculture in Uganda using hyper-temporal remote sensing - ground truth points of wakla

Background: Urbanization is an important indicator of economic growth and social change but is associated with environmental degradation, which threatens sustainable growth of African cities. One of the most vulnerable ecosystems in urban areas are wetlands. In Uganda, wetlands cover an area of 11% of the country's land area. Half of the wetland areas in Ugandan cities have been converted to industry and residential areas, and urban agriculture. There is limited information on the extent of wetland conversion or utilization for urban agriculture. The objective of this study was to investigate the extent of wetlands lost in two Ugandan cities, Wakiso and Kampala, in the last 30 years. Secondly, we demonstrate a simple methodology to monitor agriculture on encroached wetlands. Methods: Using a field survey and free remote sensing data from Landsat TM 1986 and Landsat ETM 2016 we classified the rate of wetland loss and encroachment in the last 30 years. Using MODIS NDVI 16-day composites at 500-meter spatial resolution, we generated distinctive crops and crop mixtures in the encroached wetlands for urban agriculture using the ISODATA clustering algorithm. Results: Over a 30-year period, 72,828 ha (73%) of the Wakiso-Kampala wetlands have been lost. Agriculture area on the other hand doubled. Of the new cultivation area, 16,488 ha (23%) were reclaimed from wetlands. All cultivated agriculture in Kampala was in the wetlands while in Wakiso, 73% of crop agriculture was in the wetlands. The major crops grown in these urban wetlands were banana (20%), sugarcane (22%), maize (17%), Eucalyptus trees (12%), sweet potatoes (10%), while ornamental nurseries, pine trees, vegetables and passion fruits were each at 5%. Conclusions: Current wetland exploitation for food security for urban dwellers may be a trade-off between the provision of food in the short-term and the loss of important ecosystems services in the long-term