Your search found 25 records
1 Dalgliesh, N.; Foale, M. 1998. Soil matters: Monitoring soil water and nutrients in dryland farming. Queensland, Australia: Agricultural Production Systems Research Unit. viii, 122p.: col. ill.; 31 cm.
(Location: IWMI-SEA Call no: 631.47 G922 DAL Record No: BKK-134)
2 Karimov, Akmal; Noble, Andrew; Kurbantaev, R.; Solieva, N. 2008. Stability of soil aggregates in Arys Turkestan Canal Command Zone. Paper presented at the International Conference on Agro-technologies for Soil and Water Conservation in Uzbekistan, Uzbek Research Institute of Cotton Growing, Tashkent, Uzbekistan, 5 December 2008. 14p.
Soil structural units ; Soil properties ; Soil sampling ; Saline soils ; Irrigated soils / Kazakhstan / Turkestan Canal Command Zone
(Location: IWMI HQ Call no: e-copy only Record No: H041910)
(0.17 MB)
3 Amoah, Philip. 2008. Irrigated urban vegetable production in Ghana: sources of pathogen contamination and risk elimination. In Parrot, L.; Njoya, A.; Temple, L.; Assogba-Komlan, F.; Kahane, R.; Ba Diao, M.; Havard, M. (Eds.). Agriculture and urban development in Sub-Saharan Africa: environment and health issues. Paris, France: L'Harmattan. pp.123-132. (Collection Ethique Economique)
Irrigated farming ; Vegetables ; Lettuces ; Irrigation water ; Water quality ; Pathogens ; Water pollution ; Health hazards ; Urban agriculture ; Periurban areas ; Soil sampling / Ghana / Kumasi / Accra
(Location: IWMI HQ Call no: e-copy only Record No: H041924)
(0.10 MB)
4 Murtaza, G.; Ghafoor, A.; Owens, G.; Qadir, Manzoor; Kahlon, U. Z. 2009. Environmental and economic benefits of saline-sodic soil reclamation using low-quality water and soil amendments in conjunction with a rice-wheat cropping system. Journal of Agronomy and Crop Science, 195:124-136. [doi: https://doi.org/10.1111/j.1439-037X.2008.00350.x]
Cropping systems ; Crop rotation ; Crop management ; Rice ; Wheat ; Plant growth ; Saline sodic soils ; Soil reclamation ; Soil management ; Soil sampling ; Soil properties ; Leaching ; Irrigation water ; Water quality ; Infiltration ; Experiments ; Irrigated farming / Pakistan / Indus Basin
(Location: IWMI HQ Call no: e-copy only Record No: H042131)
(0.36 MB)
A combination of appropriate crop rotation(s) and management interventions has the potential to transform saline-sodic soil and water resources from an environmental burden into an economic asset. We carried out 2-year field studies in the Indus Basin of Pakistan to evaluate different irrigation and soil management options of using saline-sodic waters (SSW) and soils for reclamation and for growing salt-tolerant cultivars of rice (SSRI-8) and wheat (SIS-32). These soils have variable levels of salinity and sodicity (ECe 9–44 dS m)1 and SAR 83–319). The treatments on both the sites were the same and consisted of: (1) Irrigation with SSW, (2) Irrigation with freshwater (FW), (3) Soil application of gypsum at 100 % gypsum requirement of soil + SSW (G + SSW), (4) G + one irrigation with SSW and one with FW (G + 1SSW + 1FW), (5) G + two irrigations with SSW and one with FW (G + 2SSW + 1FW), (6) Farm manure at 25 Mg ha)1 each year before rice + one irrigation with SSW and one with (FW FM + 1SSW + 1FW) and (7) FM + two irrigations with SSW and one with FW (FM + 2SSW + 1FW). Rice was grown as the first crop. After harvesting final wheat crop (fourth in sequence), maximum decrease in bulk density and increase in infiltration rate was observed with G + 1SSW + 1FW while FM + 1SSW + 1FW treatment showed higher decrease in pHs and ECe. Significantly the highest decrease in SAR occurred at both sites with G + 1SSW + 1FW. Maximum yields of rice and wheat were generally observed with G + 1SSW + 1FW. The crop yield and economic benefits with treatments showed a positive correlation with that of improvement in soil physical and chemical properties. Overall, the greatest net benefit was obtained from G + 1SSW + 1FW treatment. We also found that the farmers’ management skills were crucial in the overall success in improving crop yields during reclamation of saline-sodic soils. Based on the results of this study, we propose that SSW could be used to reclaim saline-sodic soils by using a rice–wheat rotation and a site-specific combination of soil amendments and water application strategies.
5 Simmons, R. W.; Ahmad, Waqas; Noble, Andrew; Blummel, M.; Evans, Alexandra; Weckenbrock, P. 2009. Effect of long-term un-treated domestic wastewater re-use on soil quality, wheat grain and straw yields and attributes of fodder quality. Irrigation and Drainage Systems, 24(1-2):95-112. (Special issue with contributions by IWMI authors) [doi: https://doi.org/10.1007/s10795-009-9085-7]
Water reuse ; Domestic water ; Wastewater irrigation ; Water quality ; Soil sampling ; Irrigation effects ; Wheat ; Fodder / Pakistan / Punjab Province / Faisalabad / Chakera / Kehala
(Location: IWMI HQ Call no: PER Record No: H042570)
http://www.springerlink.com/content/w2772vq200k01212/fulltext.pdf
https://vlibrary.iwmi.org/pdf/H042570.pdf
https://vlibrary.iwmi.org/pdf/H042570.pdf
(0.25 MB)
In 2006 a comprehensive sampling program was undertaken in two pre-selected peri-urban villages in Faisalabad, Pakistan to evaluate the soil and agronomic impacts of long-term (25–30 years) untreated wastewater re-use on wheat grain and straw yields and attributes of wheat straw fodder quality. Soil SAR, ESP, RSC and ECe were 63%, 37%, 31%, and 50% higher under wastewater (WW) as compared with canal water (CW) irrigated plots. Further, 2.7 and 6.65 fold increases in soil NO3- + NO2 - - N and Olsen-P were observed in WW as compared with CW irrigated plots. However, no significant differences in grain yield, wheat straw biomass, or fodder quality attributes were observed between WW and CW irrigated plots. In addition, for both CW and WW irrigated plots wheat straw, Cd and Pb concentrations were orders of magnitude below the EC Maximum permissible levels for Pb and Cd in feed materials and thus pose no threat to the fodderlivestock food chain. Further, elevated soil N associated with WW irrigated plots has a significant (p<0.01) positive influence on fodder quality by increasing the N content. Factorial ANOVA with covariance indicates that effective management of the elevated soil ECe in WW irrigated plots would increase grain yield and wheat straw biomass by 853 kg ha-1 (19.5%) and 819 kg ha-1 (18.6%) respectively as compared with CW irrigated plots. In Faisalabad, if managed appropriately to address emerging salinity issues the contribution of wastewater irrigation to the achievement of MDGs 1 and 7 could be significant if adverse impacts remain as marginal as found in this study.
6 Bezborodov, G. A.; Shadmanov, D. K.; Mirhashimov, R. T.; Yuldashev, T.; Qureshi, Asad Sarwar; Noble, Andrew; Qadir, Manzoor. 2010. Mulching and water quality effects on soil salinity and sodicity dynamics and cotton productivity in Central Asia. Agriculture, Ecosystems and Environment, 138(1-2):95-102. [doi: https://doi.org/10.1016/j.agee.2010.04.005]
Water scarcity ; Water quality ; Salinity ; Irrigation water ; Mulching ; Soil analysis ; Soil sampling ; Soil salinity ; Water productivity ; Cotton ; Yields ; Water conservation / Central Asia / Uzbekistan / Syr-Darya River Basin
(Location: IWMI HQ Call no: e-copy only Record No: H043366)
(0.66 MB)
Water scarcity and the predicted impact of climate change will necessitate the use of alternate available water resources in agriculture, such as saline water, to narrow the gap between demand and supply of freshwater. Saline water, in combination with freshwater or alone, is used to irrigate cotton (Gossypium hirsutum L.) in Central Asia in summer when there are often severe freshwater shortages. The use of saline water without appropriate management can result in the accumulation of salts in the root zone with associated negative impacts on crop productivity. The accumulation of salts in surface soil layers can be managed by reducing evaporation from the soil surface. A 3-year field study on a saline soil (ECe = 13.9 dSm-1; SAR = 3.1) in the Syr-Darya River Basin of Uzbekistan was undertaken to evaluate the effects of wheat straw mulching on alternate irrigation furrows (1.5 t ha-1) and different levels of irrigation water salinity (4.0, 6.2, and 8.3 dSm-1) on soil salinity and sodicity dynamics, cotton yield, and crop water productivity. Compared to the pre-experiment status in 2005, the average increase in salinity in the upper 0.15mlayer of post-cotton 2007 soil under mulching treatments was significantly less than the non-mulching treatments. On average, there was a 20% increase in surface soil salinity of the nonmulching treatments compared to the mulching treatments. These treatment differences were less with increasing soil depth. Similar trends were observed with respect to changes in soil SAR in the top soil and across the soil profile. Cotton yield and water productivity under mulching treatments were significantly greater than non-mulched treatments at a given irrigation water salinity level. In addition, cotton yields were up to 800 kg ha-1 higher and crop water productivity (lint + seed) up to 0.47 kgm-3 greater in the mulching treatments than the farmers’ managed fields with conventional practices in the same region. These results suggest that by using appropriate combinations of water quality and mulching, there could be substantial increase in crop yield and water productivity resulting in water savings of up to 0.5m3 for each kg of cotton produced. When translated on a broader scale, such water savings are significant in a region where freshwater supplies are constrained and salt-induced water quality deterioration is widespread.
7 Dutta, S. K.; Singh, D.; Sood, Aditya. 2011. Effect of soil chemical and physical properties on sorption and desorption behavior of lead in different soils of India. Soil and Sediment Contamination, 20(3):249-260. [doi: https://doi.org/10.1080/15320383.2011.560979]
Soil chemicophysical properties ; Sorption ; Desorption ; Lead ; Statistical methods ; Analytical methods ; Multiple regression analysis ; Models ; Soil sampling ; Chemical composition / India
(Location: IWMI HQ Call no: e-copy only Record No: H043832)
(0.25 MB)
Lead (Pb) is a non-biodegradable contaminant, present in the environment, especially near lead-based industrial sites, agricultural lands, and roadside soils. Bioavailability of Pb in the soil is controlled by the sorption and desorption behavior of Pb, which are further controlled by the soil chemical and physical properties. In this study, sorption and desorption amounts of Pb in soil were compared with soil physical (sand, silt, clay content) and chemical (pH; electrical conductivity, EC; percent organic carbon, (%OC);cation exchange capacity, CEC) properties. Twenty-six surface soils (0–5cm), expected to vary in physical and chemical properties, were collected from different parts of India and were treated with known concentration of Pb solution (40 µg/L). The amount of Pb sorbed and desorbed were measured and correlated with soil properties using simple linear regressions. Sorption was significantly (p = 0.05) and positively correlated with pH, and %OC; desorption was significantly (p = 0.05) negatively correlated with the same two factors. Stepwise multiple regressions were performed for better correlations. Predicted sorption and desorption amounts, based on multiple regression equations, showed reasonably good fit (R2 = 0.79 and 0.83, respectively) with observed values. This regression model can be used for estimation of sorption and desorption amounts at contaminated sites.
8 Mekuria, Wolde. 2013. Conversion of communal grazing lands into exclosures restored soil properties in the semi-arid lowlands of northern Ethiopia. Arid Land Research and Management, 27(2):153-166. [doi: https://doi.org/10.1080/15324982.2012.721858]
Grazing lands ; Common lands ; Soil properties ; Soil organic matter ; Soil sampling ; Soil conservation ; Lowland ; Vegetation ; Biomass ; Climate change / Northern Ethiopia / Raya-azebo District / Alemata District / Tanqua-abergele District
(Location: IWMI HQ Call no: e-copy only Record No: H045710)
(0.41 MB)
In the semi-arid tropics, communal grazing lands provide a livelihood for millions of people.However, it is highly threatened by overgrazing and continuous land degradation and, as a result, proper management is important to improve the livelihood of the people. This study investigated the effectiveness of exclosures established on communal grazing lands to restore soil properties and identified the relationship among soil properties, site and vegetation characteristics, and exclosure age. A space-for-time substitution approach to detect changes in soil properties following the establishment of exclosures on communal grazing lands was used. Replicated (n¼3) 5-, 10-, and 15-year-old exclosures were selected and paired, each exclosure with an adjacent communal grazing land. All exclosures showed higher soil organic matter (OM), total soil nitrogen (N), available phosphorus (P), and cation exchange capacity (CEC) than the adjacent grazing lands. The increases in soil properties between exclosures and grazing lands in the 0- to 0.2-m depth varied between 58 and 101% for OM, from 54 to 108% for N, from 26 to 128% for P, and from 18 to 28% for CEC over the grazing lands. Soil properties in exclosures and grazing lands showed significant (p<0.05) correlations with biomass and vegetation cover indicating that vegetation restoration is a key to restore degraded soils through exclosure establishment. Establishing exclosures on communal grazing lands can be effective in restoring the degraded soils in the semi-arid lowlands of Ethiopia. However, further studies are required on the ecological and economic benefits of future exclosures, as expansion of exclosure could cause grazing pressure on the remaining communal grazing lands.
9 Ruffeis, D.; Loiskandl, W.; Spendlingwimmer, R.; Schonerklee-Grasser, M.; Awulachew, Seleshi Bekele; Boelee, Eline; Wallner, K. 2010. Assessment of potential environmental impacts of two large scale irrigation schemes in Ethiopia. Ethiopian Journal of Development Research, 32(2):63-105.
Irrigation development ; Irrigation schemes ; Irrigation water ; Environmental effects ; Environmental policy ; Satellite surveys ; Groundwater ; Hydrology ; Sugar crops ; Soil sampling ; Ecosystems ; Valleys ; Erosion / Ethiopia
(Location: IWMI HQ Call no: IWMI Record No: H045761)
(3.11 MB)
This article presents the findings of a study undertaken to assess environmental impacts of two selected large scale irrigation schemes on natural resources in Ethiopia. The study puts special emphasis on linkages and implications of the utilized water source, ground water hydrology and soil characteristics, on the sustainability of the selected 5chemes. In addition, potential interference of irrigation projects with woodland ecosystems is highlighted. For this purpose primary soil and water data and data from research reports from Wonji/Shoa Sugar Plantation and Finchaa Valley Sugar Estate were collected and analysed using a "before-after" and "with or without" type of analysis. Rising oj groundwater table, water logged within the root zone of the cultivated sugar cane and elevated EC values within 1m of soil depth indicate the· risk of secondary alinization at Wonji/Shoa Sugar Plantation. Unfavourable EC, SAR and RNa values ofthe utilized irrigation source in combination with the CEC ofsoil and ongoing soil erosion processes suggests that irrigation might lead to long-term infiltration problems and destruction of the soil structure at Fincha Sugar Estate. The establishment of the scheme and migration tendencies increased the pressure on the eco-system ofthe valleys and led to clearing of wood and grass lands. To guarantee long-term sustainability, proper study and continuous research of aLready implemented and planned large s.cale irrigation projects is necessary, so that the positive roles of irrigation could be enhanced and timely mitigation measures taken for the negative impacts.
10 Lennartz, B.; Janssen, M.; Tiemeyer, B. 2011. Effects of artificial drainage on water regime and solute transport at different spatial scales. In Shukla, M. K. (Ed.) Soil hydrology, land use and agriculture: measurement and modelling. Wallingford, UK: CABI. pp.266-290.
Drainage ; Soil transport processes ; Soil properties ; Soil sampling ; Nitrates ; Nitrogen ; Catchment areas ; Groundwater table ; Drinking water ; Water quality / Germany
(Location: IWMI HQ Call no: e-copy SF Record No: H045784)
11 Brindha, Karthikeyan; Elango, L. 2015. Cross comparison of five popular groundwater pollution vulnerability index approaches. Journal of Hydrology, 524:597-613. [doi: https://doi.org/10.1016/j.jhydrol.2015.03.003]
Groundwater pollution ; Groundwater recharge ; Water levels ; Water table ; Aquifers ; Sustainability ; Pesticides ; Nitrogen assimilation ; Land use ; Contamination ; Monsoon climate ; Rain ; Soil sampling / India
(Location: IWMI HQ Call no: e-copy only Record No: H046948)
(1.78 MB)
Identification of a suitable overlay and index method to map vulnerable zones for pollution in weathered rock aquifers was carried out in this study. DRASTIC and four models derived from it, namely Pesticide DRASTIC, modified DRASTIC, modified Pesticide DRASTIC and Susceptibility Index (SI) were compared by applying them to a weathered rock aquifer in southern India. The results were validated with the measured geochemical data. This study also introduces the use of temporal variation in the groundwater level and nitrate concentration in groundwater as input and for validation respectively to obtain more reliable and meaningful results. Sensitivity analysis of the vulnerability index maps highlight the importance of one parameter over another for a given hydrogeological setting, which will help to plan the field investigations based on the most or the least influential parameter. It is recommended to use modified Pesticide DRASTIC for weathered rock regions with irrigation practises and shallow aquifers (<20 m bgl). The crucial input due to land use should not be neglected and to be considered in any hydrogeological setting. It is better to estimate the specific vulnerability wherever possible rather than the intrinsic vulnerability as overlay and index methods are more suited for this purpose. It is also necessary to consider the maximum and minimum values of input parameters measured during a normal year in the models used for decision making.
12 Bellwood-Howard, I.; Haring, V.; Karg, Hanna; Roessler, R.; Schlesinger, J.; Shakya, M. 2015. Characteristics of urban and peri-urban agriculture in West Africa: results of an exploratory survey conducted in Tamale (Ghana) and Ouagadougou (Burkina Faso) Colombo, Sri Lanka: International Water Management Institute (IWMI) 38p. (IWMI Working Paper 163) [doi: https://doi.org/10.5337/2015.214]
Urban agriculture ; Peri-urban agriculture ; Farming systems ; Farmers ; Seasonal cropping ; Cultivation ; Soil sampling ; Soil fertility ; Households ; Livestock ; Landownership ; Water availability ; Wastewater ; Irrigation ; Market prices ; Leaf vegetables ; Inorganic fertilizers ; Organic fertilizers ; Villages ; Surveys / West Africa / Ghana / Burkina Faso / Tamale / Ouagadougou
(Location: IWMI HQ Call no: IWMI Record No: H047216)
(2 MB)
The report summarizes key results from surveys carried out on urban and peri-urban agriculture (UPA) in Tamale (Ghana) and Ouagadougou (Burkina Faso) in 2013. The aim was to provide a broad overview of the state of UPA in the study cities and a basis for future research endeavors. The randomized sampling approach used aerial photography to identify 10 sites in different categories of farm in each city. Farmers provided information on their cropping and livestock-rearing activities. There were similarities between the cities, but the differences in the expression of UPA in Tamale and Ouagadougou were more intriguing, as in farm sizes, crops grown and livestock ownership. Farmers were particularly concerned about diminishing access to land in Tamale, where sales by chiefs to private investors were accelerating. In Ouagadougou, formal reallocation of land to homeowners by the state had similarly decreased available farmland. Water availability was a universal concern, and the quality of water used for irrigation was potentially more questionable in Ouagadougou than in Tamale. The results point to the need for further work on uncontaminated, perennial water sources and soil fertility management, alongside focuses on commercialization of animal production, and the legal, political and institutional context of UPA in different West African cities.
13 Schmitter, Petra; Haileslassie, Amare; Nakawuka, Prossie; Gebregziabher, Gebrehaweria; Tesema, M.; Tegegne, D.; Abdela, M.; Yilak, D. L.; Tilahun, S.; Ayana, M.; Langan, Simon. 2016. The importance of Ethiopian soils in irrigation and overall watershed management [Abstract only] Paper presented at the Strategic Forum on Sustainable development in Africa: Opportunities and Pitfalls for Universities and NGO’s, Heverlee, Belgium, 15 January 2016. 1p.
Watershed management ; Irrigation methods ; Surface irrigation ; Groundwater irrigation ; Irrigation water ; Water quality ; Water management ; Soil sampling ; Soil moisture ; Agronomic practices ; Crop production ; Tillage / Ethiopia
(Location: IWMI HQ Call no: e-copy only Record No: H047383)
(0.01 MB)
Irrigation has a large potential to increase agricultural output and yield per unit area. However, the long term sustainability increased production, together with degradation of the soils (and associated water bodies) in irrigated areas may be irreparably damaged by inappropriate watering schedules. In Ethiopia, surface and groundwater irrigation has been promoted intensively throughout the country. While many projects focus on individual or scheme level water access, very little is known about the sustainability of irrigation in Ethiopia. Aside, from water quantity the quality of irrigation water has a significant impact on soil stability and its chemical properties. In the Ziway, a very important irrigation area in Oromia, soils are increasingly becoming sodic due to the large irrigation quantities and the poor water quality. The International Water Management Institute focusses through various research for development projects on improving irrigation water management, increasing groundwater recharge and assessing the environmental impact of irrigation for various soils throughout the Amhara, Oromia and SNNPR region. Irrigation scheduling tools have been introduced at individual and scheme based small holder farms for the irrigation of high value horticultural and fodder crops to improve water and crop productivity and reduce nutrient leaching. Simultaneously groundwater recharge experiments were carried out using deep tillage and soil & water conservation practices in the rainy season. In these studies, soils are sampled, irrigation quantified, soil moisture measured and standard agronomic practices monitored. Additionally, socio-economic data are being collected on household composition, land holding, labor involved in as well as income generated by the various technologies. Preliminary results showed that crop productivity was not effect while reducing water between 18-35% as function of the prevailing soil types. For the groundwater recharge studies lowest runoff values and highest crop productivity values were observed in the deep tillage plots compared to zero and normal tillage. The socio-economic as well as biophysical data are used in field as well as watershed models to assess the environmental and economic impact of various irrigation scenarios throughout the agro-ecological zones.
14 Woldetsadik, D.; Drechsel, Pay; Keraita, B.; Marschner, B.; Itanna, F.; Gebrekidan, H. 2016. Effects of biochar and alkaline amendments on cadmium immobilization, selected nutrient and cadmium concentrations of lettuce (Lactuca sativa) in two contrasting soils. SpringerPlus, 5:1-16. [doi: https://doi.org/10.1186/s40064-016-2019-6]
Alkalinity ; Cadmium ; Immobilization ; Nutrients ; Cadmium ; Leaf vegetables ; Lettuces ; Soil sampling ; pH ; Faecal coliforms ; Nitrates ; Carbon ; Heavy metals ; Waste treatment
(Location: IWMI HQ Call no: e-copy only Record No: H047506)
(0.85 MB)
To assess the efficiency of seven treatments including biochars produced from dried faecal matter and manures as stabilizing agents of cadmium (Cd)-spiked soils, lettuce was grown in glasshouse on two contrasting soils. The soils used were moderately fertile silty loam and less fertile sandy loam and the applied treatments were 7 % w/w. The reduction of bioavailable Cd (ammonium nitrate extractable) and its phytoavailability for lettuce were used as assessment criteria in the evaluation of stabilization performance of each treatment. Moreover, the agronomic values of the treatments were also investigated. Ammonium nitrate extraction results indicated that faecal matter biochar, cow manure biochar and lime significantly reduced bioavailable Cd by 84–87, 65–68 and 82–91 %, respectively, as compared to the spiked controls. Unpredictably, coffee husk biochar induced significant increment of Cd in NH4NO3 extracts. The immobilization potential of faecal matter biochar and lime were superior than the other treatments. However, lime and egg shell promoted statistically lower yield and P, K and Zn concentrations response of lettuce plants compared to the biochar treatments. The lowest Cd and highest P tissue concentrations of lettuce plants were induced by faecal matter and cow manure biochar treatments in both soils. Additionally, the greatest Cd phytoavailability reduction for lettuce was induced by poultry litter and cow manure biochars in the silty loam soil. Our results indicate that faecal matter and animal manure biochars have shown great potential to promote Cd immobilization and lettuce growth response in heavily contaminated agricultural fields.
15 Mekuria, Wolde; Langan, Simon; Noble, A.; Johnston, Robyn. 2017. Soil restoration after seven years of exclosure management in northwestern Ethiopia. Land Degradation and Development, 28(4):1287-1297. [doi: https://doi.org/10.1002/ldr.2527]
Soil fertility ; Soil properties ; Soil moisture ; Soil organic matter ; Soil sampling ; Soil management ; Ecology ; Ecosystem services ; Land degradation ; pH ; Grazing lands ; Carbon ; Environmental degradation ; Watershed management ; Vegetation / Ethiopia
(Location: IWMI HQ Call no: e-copy only Record No: H047539)
(0.32 MB)
Ecological restoration through exclosure establishment has become an increasingly important approach to reversing degraded ecosystems in rangelands worldwide. The present study was conducted in northwestern Ethiopia where policy programs are aiming to restore degraded lands. Changes in soil properties following establishing exclosures on communal grazing lands were investigated. A space-for-time substitution approach was used to monitor changes in soil properties after conversion of communal grazing lands to exclosures with ages of establishment ranging from 1 to 7-years. Significant differences in soil pH, exchangeable cations, cation exchange capacity, soil moisture content, and bulk density were observed within exclosures and between exclosures and communal grazing land. Communal grazing land displayed significantly higher soil total nitrogen, phosphorus and potassium compared to exclosures. Exclosures did not display significantly higher soil organic matter content when compared to the communal grazing land. The results confirm that more than 7 years after the establishment of exclosures is required to detect significant improvements in most of the investigated soil properties. Prohibition of the practice of grass harvesting during the first 3 to 5 years following the establishment of exclosure, and decreasing the amount of grass harvest with exclosure age could support to increase easily decomposable organic inputs to the soil and improve soil properties in relatively short period of time.
16 Amoah, Philip; Nartey, E. G.; Schrecongost, A. 2016. Performance evaluation of biofil toilet waste digester technologies in Ghana: the efficacy of effluent treatment options. Environmental Technology, 37(23):3002-3013. [doi: https://doi.org/10.1080/09593330.2016.1173116]
Performance evaluation ; Waste treatment ; Wastewater treatment ; Water table ; Water pollution ; Excreta ; Latrines ; Digesters ; Sanitation ; Escherichia coli ; Faecal coliforms ; Nutrients ; Soil sampling ; Pathogens / Ghana / Accra
(Location: IWMI HQ Call no: e-copy only Record No: H047835)
The study was carried out to assess the efficacy of a standard Biofil toilet digester with regard to its effluent quality and to evaluate the performance of new effluent polishing options being developed by BiofilCom. Infuent and effluent were collected from 18 standard Biofil digesters connected to full- flush toilets. Effluent from five pilot installations with improved effluent polishing options were also taken for analyses. Ten other Biofil installations were selected to assess the impact of digester effluent discharge on the surrounding soil. Pollutant concentrations in the Biofil effluent exceeded both Ghana EPA and WHO standards for discharge though pollutant removal efficiencies were high: 84% for biochemical oxygen demand, 86.1% for chemical oxygen demand and 82.4% for total suspended solids. Escherichia coli and total coliform levels were signi cantly reduced by 63% and 95.6%, respectively, and nutrients were the least removed from effluents. Generally, effluents from the majority of the pilot polishing options met most of the discharge standards. E. coli were present in the soil at all study sites, except one. Biofil digester effluent is discharged subsurface but comparing their effluent quality with standards for discharge into water courses is relevant especially in areas of frequent flooding and high water tables.
17 Negussie, A.; Achten, W. M. J.; Norgrove, L.; Mekuria, Wolde; Hadgu, K. M.; De Both, G.; Leroy, B.; Hermy, M.; Muys, B. 2016. Initial effects of fertilization and canopy management on flowering and seed and oil yields of Jatropha curcas L. in Malawi. BioEnergy Research, 9:1231-1240. [doi: https://doi.org/10.1007/s12155-016-9767-6]
Fertilizer application ; Fertilization ; Nitrogen fertilizers ; Inorganic fertilizers ; Canopy ; Flowering ; Seed production ; Oilseeds ; Jatropha curcas ; Biofuels ; Bioenergy ; Agronomy ; Agronomic practices ; Pruning implements ; Planting ; Spacing ; Soil sampling / Malawi
(Location: IWMI HQ Call no: e-copy only Record No: H047879)
Appropriate canopy management, including planting density and pruning, and application of fertilizer may increase flowering success and seed and oil yields of Jatropha curcasL.Twofieldexperimentswereperformedfrom2009to 2011 in Balaka, Malawi, to assess the effect of planting density and pruning regime and single fertilizer application (N, P, and K) on male and female flower number and seed and oil yields of J. curcas. Planting density influenced flower sex ratio and female flower number. Branch pruning treatments did not influence the flower sex ratio but reduced seed and final oil yield by 55 % in the following year. It is claimed that J.curcas can be grown on soils with low nutrient content, but this study revealed that yield was low for non-fertilized trees. WeobservedhigherseedandoilyieldsathigherNapplication rates(upto203±42%seedand204±45%oilyieldincrease) compared with the non-fertilized control. The study suggests thatcurrentlyusedheavypruningpracticeisnotrecommended for J.curcas cultivation, although it needs further longer term investigation. Applying nitrogen fertilizer is effective in increasing yield.
18 Ribolzi, O.; Evrard, O.; Huon, S.; de Rouw, A.; Silvera, N.; Latsachack, K. O.; Soulileuth, B.; Lefevre, I.; Pierret, A.; Lacombe, Guillaume; Sengtaheuanghoung, O.; Valentin, C. 2017. From shifting cultivation to teak plantation: effect on overland flow and sediment yield in a montane tropical catchment. Scientific Reports, 7:1-12. [doi: https://doi.org/10.1038/s41598-017-04385-2]
Teak ; Plantations ; Sediment ; Shifting cultivation ; Overland flow ; Erosion ; Slopes ; Land use ; Land management ; Flow discharge ; Vegetation ; Catchment areas ; Rainfall-runoff relationships ; Infiltration ; Soil sampling / Southeastern Asia
(Location: IWMI HQ Call no: e-copy only Record No: H048176)
(2.73 MB)
Soil erosion supplies large quantities of sediments to rivers of Southeastern Asia. It reduces soil fertility of agro-ecosystems located on hillslopes, and it degrades, downstream, water resource quality and leads to the siltation of reservoirs. An increase in the surface area covered with commercial perennial monocultures such as teak plantations is currently observed at the expanse of traditional slash-andburn cultivation systems in steep montane environments of these regions. The impacts of land-use change on the hydrological response and sediment yields have been investigated in a representative catchment of Laos monitored for 13 years. After the gradual conversion of rice-based shifting cultivation to teak plantation-based systems, overland flow contribution to stream flow increased from 16 to 31% and sediment yield raised from 98 to 609 Mg km-2. This result is explained by the higher kinetic energy of raindrops falling from the canopy, the virtual absence of understorey vegetation cover to dissipate drop energy and the formation of an impermeable surface crust accelerating the formation and concentration of overland flow. The 25-to-50% lower 137Cs activities measured in soils collected under mature teak plantations compared to soils under other land uses illustrate the severity of soil erosion processes occurring in teak plantations.
19 Manivanh, L.; Pierret, A.; Rattanavong, S.; Kounnavongsa, O.; Buisson, Y.; Elliott, I; Maeght, J. -L.; Xayyathip, K.; Silisouk, J.; Vongsouvath, M.; Phetsouvanh, R.; Newton, P. N.; Lacombe, Guillaume; Ribolzi, O.; Rochelle-Newall, E.; Dance, D. A. B. 2017. Burkholderia pseudomallei in a lowland rice paddy: seasonal changes and influence of soil depth and physico-chemical properties. Scientific Reports, 7:1-11. [doi: https://doi.org/10.1038/s41598-017-02946-z]
Pseudomonas pseudomallei ; Rice ; Soil properties ; Soil sampling ; Soil water characteristics ; Soil depth ; Chemicophysical properties ; Bacteria ; Melioidosis / Lao People's Democratic Republic
(Location: IWMI HQ Call no: e-copy only Record No: H048174)
(1.85 MB)
Melioidosis, a severe infection with the environmental bacterium Burkholderia pseudomallei, is being recognised increasingly frequently. What determines its uneven distribution within endemic areas is poorly understood. We cultured soil from a rice field in Laos for B. pseudomallei at different depths on 4 occasions over a 13-month period. We also measured physical and chemical parameters in order to identify associated characteristics. Overall, 195 of 653 samples (29.7%) yielded B. pseudomallei. A higher prevalence of B. pseudomallei was found at soil depths greater than the 30 cm currently recommended for B. pseudomallei environmental sampling. B. pseudomallei was associated with a high soil water content and low total nitrogen, carbon and organic matter content. Our results suggested that a sampling grid of 25 five metre square quadrats (i.e. 25 × 25 m) should be sufficient to detect B. pseudomallei at a given location if samples are taken at a soil depth of at least 60 cm. However, culture of B. pseudomallei in environmental samples is difficult and liable to variation. Future studies should both rely on molecular approaches and address the micro-heterogeneity of soil when investigating physico-chemical associations with the presence of B. pseudomallei.
20 Kadyampakeni, Davie M.; Mul, Marloes L.; Obuobie, E.; Appoh, Richard; Owusu, Afua; Ghansah, Benjamin; Boakye-Acheampong, Enoch; Barron, Jennie. 2017. Agro-climatic and hydrological characterization of selected watersheds in northern Ghana. Colombo, Sri Lanka: International Water Management Institute (IWMI). 40p. (IWMI Working Paper 173) [doi: https://doi.org/10.5337/2017.209]
Watersheds ; Agricultural production ; Intensification ; Agroclimatology ; Hydrology ; Analytical method ; Agronomic practices ; Water balance ; Water quality ; Water management ; Water deficit ; Climatic factors ; pH ; Electrical conductivity ; Soil texture ; Soil quality ; Soil sampling ; Soil fertility ; Land cover mapping ; Land use ; Rain ; Temperature ; Evapotranspiration ; Farmers ; Wet season ; Dry season ; Reservoir storage ; Wells ; Rivers ; Irrigation schemes ; Catchment areas ; Cropping systems ; Crop production ; Meteorological stations ; Cation exchange capacity / Ghana
(Location: IWMI HQ Call no: IWMI Record No: H048209)
(1 MB)
This paper provides the climatic and biophysical context of three watersheds in northern Ghana. The objective of the study is to describe the agro-climatic and hydrological features of the watersheds from a landscape perspective. The analyses show that water surplus occurs about 3 months in a year, with only one month providing a significant surplus. Small-scale irrigation is, therefore, carried out in the dry months between November and June. The quality of water used for irrigation from wells, reservoirs and rivers is good for irrigation and domestic purposes. The soil chemical parameters across the study sites show that the soils are suitable for irrigation and crop system intensification, although it requires substantial fertilizer inputs. The paper concludes that there are opportunities from both a soil quality and water availability perspective to enhance sustainable intensification through small- and medium-scale irrigation in the selected watersheds.
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