Your search found 21 records
1 Pierret, Alain; Doussan, C.; Capowiez, Y.; Bastardie, F.; Pages, L. 2007. Root functional architecture: a framework for modeling the interplay between roots and soil. Vadose Zone Journal, 6(2):269-281. [doi: https://doi.org/10.2136/vzj2006.0067]
(Location: IWMI HQ Call no: e-copy only Record No: H033450)
(0.43 MB)
Soil ecosystems support a plethora of intertwined biophysical and biochemical processes. Soil structure plays a central role in the formation and maintenance of soil biological activity by providing a diversified habitat for soil organisms and determining the movement and transport of the resources on which they rely. At the same time, the formation and preservation of soil structure and fertility is also strongly linked to soil biological activity through feedback loops. In most soil ecosystems, soil biological activity and associated processes are concentrated in the soil located around living plant roots and influenced by root activity, an environment known as the rhizosphere. Consequently, among the wide array of soil life forms, plants play a dominant role in the regulation of many soil processes. In this paper, we illustrate the functional complexity of soil ecosystems using specific examples of root–soil interactions and associated processes. Through examples taken from the literature, we examine the origins and variations in soil physical, chemical, and biological properties and their impact on root growth. Next, we consider how the response of root systems to their environment affects resource acquisition by plants. Finally, we describe how the concept of root functional architecture can improve the integration of research advances from fields operating as independent disciplines and improve our understanding of soil ecosystems.
2 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.
3 Stockan, J. A.; Langan, S. J.; Young, M. R. 2012. Investigating riparian margins for vegetation patterns and plant–environment relationships in northeast Scotland. Journal of Environmental Quality, 41(2):364-372. [doi: https://doi.org/10.2134/jeq2010.0518]
Vegetation ; Riparian zones ; Water quality ; Watercourses ; Analytical methods ; Catchment areas ; Soil chemicophysical properties ; Plants ; Species ; Environmental effects / Scotland
(Location: IWMI HQ Call no: e-copy only Record No: H044744)
(0.67 MB)
4 International Union of Soil Sciences (IUSS); Institut de Recherche pour le Developpement (IRD); Thailand. Land Development Department (LDD); International Water Management Institute (IWMI); FAO. Regional Office for Asia and the Pacific (FAO RAP); Khon Kaen University. Faculty of Agriculture. 2005. Management of tropical sandy soils for sustainable agriculture: a holistic approach for sustainable development of problem soils in the tropics. Proceedings of the First Symposium on Management of Tropical Sandy Soils for Sustainable Ariculture, Khon Kaen, Thailand, 27 November – 2 December 2005. Bangkok, Thailand: FAO Regional Office for Asia and the Pacific (FAO RAP). 524p.
Soil management ; Sandy soils ; Tropical soils ; Semiarid soils ; Sustainable agriculture ; Poverty ; Food production ; Soil chemicophysical properties ; Planting ; Eucalyptus ; Savannas ; Groundnuts ; Rain ; Farmers ; Farming systems ; Irrigation methods ; Livestock ; Socioeconomic environment ; Clay minerals ; Fertilizers ; Paddy fields ; Water erosion ; Wind erosion ; Case studies ; Hydraulics ; Soil organic matter ; Agroecosystems ; Farm ponds ; Watersheds ; Coastal area ; Infiltration water / Asia / Southern Africa / Eastern Africa / Latin America / Sahel / Northern Burkina Faso / South Africa / West Africa / Cambodia / Vietnam / China / Australia / Malawi / Niger / Guam / Northeast Thailand / Southern Brazil / Ecuador / Hainan / Bình Thuan / Thua Thien Hue / Zululand / Mangodara
(Location: IWMI HQ Call no: 630 G000 INT Record No: H046693)
(16.90 MB) (16.9 MB)
5 Noble, Andrew D.; Berthelsen, S.; Mather, J. 2005. Changes in soil chemical properties under two contrasting plantation systems on the Zululand coastal plain, South Africa. In International Union of Soil Sciences (IUSS); Institut de Recherche pour le Developpement (IRD); Thailand. Land Development Department (LDD); International Water Management Institute (IWMI); FAO. Regional Office for Asia and the Pacific (FAO RAP); Khon Kaen University. Faculty of Agriculture. Management of tropical sandy soils for sustainable agriculture: a holistic approach for sustainable development of problem soils in the tropics. Proceedings of the First Symposium on Management of Tropical Sandy Soils for Sustainable Ariculture, Khon Kaen, Thailand, 27 November – 2 December 2005. Bangkok, Thailand: FAO Regional Office for Asia and the Pacific (FAO RAP). pp.93-100.
Soil properties ; Soil chemicophysical properties ; Soil profiles ; Plantations ; Species ; Eucalyptus grandis ; Pinus elliottii ; Podzols ; Organic carbon ; Coastal plains / South Africa / Zululand Coastal Plain
(Location: IWMI HQ Call no: 630 G000 INT Record No: H047324)
(0.39 MB) (16.9 MB)
Over the past 4 decades there has been considerable expansion in the plantation forestry along the eastern seaboard of South Africa. In particular there have been significant increases in eucalypt, and to a less extent, pine plantations on soils of a light sandy texture along the Zululand coastal plain. These soils are characteristically dominated by sands with low clay and organic matter contents, have low cation exchange capacity and water holding capacity. Pedogenesis and selected chemical attributes of a 49-year-old stand of Eucalyptus grandis and Pinus elliottii established on these sands were compared. Changes in soil pH, exchangeable cations, organic carbon, extractable Fe and Al and the surface charge characteristics were investigated. Evidence of the development of bleached A2e horizon within the surface 0-5 cm depth interval under E. grandis was confirmed through the development of surface charge fingerprints, changes in organic carbon and Fe and Al mobilization for each of the pedogenetically distinct horizons. Such development was not observed under the P. elliottii stand, suggesting that this pine species has had less impact on the soil. It is argued that the rate of A2e horizon development is not dissimilar to that observed under native forest ecosystems in Australia, although considerably slower that those observed under reclaimed sand mining operations. Whilst these systems appear to be relatively stable due to no clear felling and timber product extraction, this could drastically change with the introduction of short-term rotations of fast growing clonal plantations, questioning the long-term sustainability of these production systems on these light textured sands.
6 Soda, W.; Noble, Andrew D.; Suzuki, S.; Simmons, R.; Sindhusen, L.; Bhuthorndharaj, S. 2005. The co-composting of waste bentonites from the processing of vegetable oil and its affect on selected soil properties of a light textured sand. In International Union of Soil Sciences (IUSS); Institut de Recherche pour le Developpement (IRD); Thailand. Land Development Department (LDD); International Water Management Institute (IWMI); FAO. Regional Office for Asia and the Pacific (FAO RAP); Khon Kaen University. Faculty of Agriculture. Management of tropical sandy soils for sustainable agriculture: a holistic approach for sustainable development of problem soils in the tropics. Proceedings of the First Symposium on Management of Tropical Sandy Soils for Sustainable Ariculture, Khon Kaen, Thailand, 27 November – 2 December 2005. Bangkok, Thailand: FAO Regional Office for Asia and the Pacific (FAO RAP). pp.204-214.
Composting ; Bentonite ; Plant oils ; Waste treatment ; Bleaching ; Litter for animals ; Rice husks ; Soil properties ; Soil chemicophysical properties ; Acidity ; Porosity ; Pot experimentation / Thailand / Bangkok
(Location: IWMI HQ Call no: 630 G000 INT Record No: H047327)
(0.59 MB) (16.9 MB)
Waste acid bentonite is a byproduct from vegetable oil bleaching that is both acidic (pH <3.0) and water repellent (hydrophobic). These materials are currently disposed in landfills and are an environmental hazard due to the aforementioned properties. A study was undertaken using three different sources of waste oil bentonites collected from processing plants within the Bangkok metropolitan area. These wastes included soybean oil bentonite (SB), palm oil bentonite (PB) and rice bran oil bentonite (RB), each of which was co-composted with rice husk, rice husk ash, and chicken litter in order to eliminate their acid reactivity and hydrophobic nature. The chemical and physical characteristics of acid activated bentonites before and after bleaching and the co-composted materials after addition to a degraded light textured soil were assessed and are reported herein. The organic carbon (OC) content, pH, exchangeable cations and cation exchange capacity (CEC) of the waste oil bentonites increased significantly after the co-composting phase. In addition, the hydrophobic nature of these materials as measured using the Water Drop Penetration Test (WDPT) decreased from 10,800 seconds to 16-80 seconds after composting. Furthermore, when these composted materials were incorporated into a degraded light textured sandy soil positive impacts to soil physical attributes in terms of specific surface area, total porosity and available water content for crop growth were observed. The results from this study demonstrate the positive impact of the waste products when modified through composting on the physical and chemical properties of a light textured sandy soil.
7 Berthelsen, S.; Noble, Andrew D.; Ruaysoongnerm, S.; Webb, M.; Hengfu, H.; Jiexiang, Y. 2005. Addition of clay based soil ameliorants to light textured soils to reduce nutrient loss and increase crop productivity. In International Union of Soil Sciences (IUSS); Institut de Recherche pour le Developpement (IRD); Thailand. Land Development Department (LDD); International Water Management Institute (IWMI); FAO. Regional Office for Asia and the Pacific (FAO RAP); Khon Kaen University. Faculty of Agriculture. Management of tropical sandy soils for sustainable agriculture: a holistic approach for sustainable development of problem soils in the tropics. Proceedings of the First Symposium on Management of Tropical Sandy Soils for Sustainable Ariculture, Khon Kaen, Thailand, 27 November – 2 December 2005. Bangkok, Thailand: FAO Regional Office for Asia and the Pacific (FAO RAP). pp.373-382.
Soil texture ; Soil fertility ; Soil chemicophysical properties ; Soil organic matter ; Clay soils ; Sandy soils ; Cation exchange capacity ; Bentonite ; Plant water relations ; Agricultural production ; Productivity ; Rice ; Yields ; Farmers ; Biomass / Northern Australia / Northeast Thailand / China / Hainan
(Location: IWMI HQ Call no: 630 G000 INT Record No: H047329)
(0.46 MB) (16.9 MB)
Productivity decline occurs in many agronomic systems due to loss of soil organic matter and a consequent decline in soil fertility. This is pronounced in light textured soils, which even in their pristine state can have low levels of fertility. High temperatures and leaching conditions in tropical environments further exacerbates this poor fertility. In order to facilitate agronomic production on these soils, significant amounts of organic or inorganic fertilizers are required to maintain economic yields. However, the inherent low cation exchange capacity (CEC) of these soils limits their ability to retain nutrients such as Ca2+, Mg2+ and K+. The addition of inorganic fertilizer is often beyond the means of resource poor farmers and has the potential negative impact on the environment due significant leaching losses associated with the high hydraulic conductivity of light textured sandy soils. This paper reviews results from field experiments designed to assess the efficacy of bentonite (high-activity clay with a high CEC) additions on improving crop productivity and reducing nutrient loss. A number of field trials were established on light-textured soils in Northern Australia, Northeast Thailand and Hainan Province in China. Treatments and crop species (including sugarcane and various forage crops) differed at each of the study locations and included a range of rates (from 10 to 60 t ha-1), different application methods (broadcast, banded and slotted), and in some trials a comparison with other commonly used field amendments (e.g. various organic materials and termite mound material). These field trials demonstrated significant increases in crop biomass and yields associated with clay additions. Additional glasshouse studies support the observed increases in biomass observed in the field trials, and suggest that the yield increases were due to a combination of increased water-holding capacity, nutrient availability and reduced nutrient loss. These results support the notion that degraded light textured soils can be highly productive if intrinsic properties are addressed through clay additions.
8 Garcia-Orenes, F.; Caravaca, F.; Morugan-Coronado, A.; Roldan, A. 2015. Prolonged irrigation with municipal wastewater promotes a persistent and active soil microbial community in a semiarid agroecosystem. Agricultural Water Management, 149:115-122. [doi: https://doi.org/10.1016/j.agwat.2014.10.030]
Wastewater irrigation ; Urban wastes ; Water reuse ; Agroecosystems ; Semiarid zones ; Freshwater ; Soil analysis ; Microbial activities ; Soil chemicophysical properties / Spain / Mediterranean region
(Location: IWMI HQ Call no: e-copy only Record No: H047499)
(1.01 MB)
The use of treated wastewater (WW) for irrigation is a common practice, especially in arid and semiarid agroecosystems. We aimed to evaluate the influence of long-term (up to 45 years) irrigation with WW on the soil microbial community structure, microbial activity and physicochemical properties, in comparison with soil irrigated with fresh water (FW), in a semiarid orange-tree orchard. Phospholipid fatty acid (PLFA) analysis was used to assess the shifts in the soil microbial community in response to the application of WW. Total organic carbon and available P increased significantly, by about 49% and 37%, respectively, due to WW irrigation. The urease, -glucosidase, alkaline phosphatase and dehydrogenase activities and aggregate stability were higher in the soil irrigated with WW than in that irrigated with FW. The PLFA analysis showed a significant increase in bacterial abundance, particularly in G+ bacteria. The relative abundances of fungi, G- bacteria and actinobacteria were similar in the two soils. Principal components analysis of the PLFAs showed discrimination between the FW-irrigated soil and the WW-irrigated soil, which was enriched in actinobacterial PLFA 10Me18:0. The prolonged use of treated WW for irrigation in a semiarid agroecosystem promoted the establishment of a specific and persistent microbial community that was functionally more active.
9 Adeba, D.; Kansal, M. L.; Sen, S. 2015. Assessment of water scarcity and its impacts on sustainable development in Awash Basin, Ethiopia. Sustainable Water Resources Management, 1(1):71-87. [doi: https://doi.org/10.1007/s40899-015-0006-7]
Water scarcity ; Water availability ; Water balance ; Water resources ; Water demand ; Water requirements ; Sustainable development ; Assessment ; Surface water ; Domestic water ; Industrial uses ; Livestock ; Models ; Soil chemicophysical properties ; Land use ; River basins ; Environmental effects ; Calibration / Ethiopia / Awash Basin
(Location: IWMI HQ Call no: e-copy only Record No: H047902)
(3.02 MB)
Equitable access and rational use of water resources is important to cope with water scarcity. The optimal allocation of limited water resources for various purposes is required for sustainable development. Awash river basin is one of the most utilized river basins in Ethiopia. There is increasing demand for water due to recent population growth in the basin because of Urbanization. Excessive water abstraction without properly assessing the available water resources in the basin contributes to water scarcity. The basin exhibits two extreme hydrological events, flooding and drought at different seasons of the year. This paper mainly focuses on surface water resources assessment of the Awash basin, and the temporal gap between water supply and demand. The paper also discusses the impacts of these gaps on sustainable development and suggested few recommendations to minimize it. Using SWAT model, the annual average surface water available is estimated around 4.64 Billion Cubic Meters (BCM) as compared to the estimated demand of about 4.67 BCM in the basin for 1980–2012. This shows that on an average, the demand exceeds the availability by 0.03 BCM during the study period. Seasonal water deficit is even serious. A detailed seasonal analysis for the last 2 years (2011–2012) shows that the demand exceeds supply by 1.27 and 2.82 BCM during December–April of 2011 and 2012, respectively. However, there is a surplus supply of 1.67 and 3.16 BCM during June–September months of the same year.
10 Amoah, Philip; Adamtey, N.; Cofie, Olufunke. 2017. Effect of urine, poultry manure, and dewatered faecal sludge on agronomic characteristics of cabbage in Accra, Ghana. Resources, 6(2):1-14. [doi: https://doi.org/10.3390/resources6020019]
Soil chemicophysical properties ; Soil analysis ; Chemical analysis ; Fertilizer application ; pH ; Urine ; Poultry droppings ; Organic fertilizers ; Faecal sludge ; Agronomic characters ; Nutrient uptake ; Urban agriculture ; Cabbages ; Nitrogen fertilizers ; Wet season ; Farmers ; Environmental pollution ; Water pollution / Ghana / Accra
(Location: IWMI HQ Call no: e-copy only Record No: H048132)
(1.39 MB)
The study was to assess the: (i) effect of human urine and other organic inputs on cabbage growth, yield, nutrient uptake, N-use efficiency, and soil chemical characteristics; (ii) economic returns of the use of urine and/or other organic inputs as a source of fertiliser for cabbage production. To meet these objectives, participatory field trials were conducted at Dzorwulu, Accra. Four different treatments (Urine alone, Urine + dewatered faecal sludge (DFS), Urine + poultry droppings (PD), NPK (15-15-15) + PD) were applied in a Randomised Complete Block Design (RCBD) with soil alone as control. Each treatment was applied at a rate of 121 kg·N·ha-1 corresponding to the Nitrogen requirement of cabbage in Ghana. Growth and yield parameters, plant nutrient uptake, and soil chemical characteristics were determined using standard protocols. There were no significant differences between treatments for cabbage head weight, or total and marketable yields. However, unmarketable yield from NPK + PD was 1 to 2 times higher (p < 0.05) than those from Urine + PD, Urine + DFS, and Urine alone. Seasonal effect on yields was also pronounced with higher (p < 0.001) cabbage head weight (0.95 kg) and marketable yields (12.7 kg·ha-1) in the dry season than the rainy season (0.42 kg and 6.27 kg·ha-1). There was higher (p < 0.005) phosphorous uptake in cabbage from Urine + PD treated soil than those from other treatments. Nitrogen (N), phosphorous (P), and potassium (K) uptake in the dry season was significantly higher than the rainy season. Soils treated with Urine + DFS and Urine + PD were high in total N content. Urine + PD and Urine + DFS treated soils gave fairly high yield than PD + NPK with a net gain of US$1452.0 and US$1663.5, respectively. The application of urine in combination with poultry droppings has the potential to improve cabbage yields, nutrient uptake, and soil nitrogen and phosphorous content.
11 Hishe, S.; Lyimo, J.; Bewket, W. 2017. Soil and water conservation effects on soil properties in the Middle Silluh Valley, northern Ethiopia. International Soil and Water Conservation Research, 5(3):231-240. [doi: https://doi.org/10.1016/j.iswcr.2017.06.005]
Soil conservation ; Water conservation ; Land degradation ; Soil chemicophysical properties ; Soil density ; Soil texture ; Soil organic matter ; Nitrogen ; Phosphorus ; Cation exchange capacity ; Valleys / Ethiopia / Middle Silluh Valley
(Location: IWMI HQ Call no: e-copy only Record No: H048336)
http://www.sciencedirect.com/science/article/pii/S2095633917300679/pdfft?md5=555c872c6770f549b14171beeee2810d&pid=1-s2.0-S2095633917300679-main.pdf
https://vlibrary.iwmi.org/pdf/H048336.pdf
https://vlibrary.iwmi.org/pdf/H048336.pdf
(1.94 MB) (1.94 MB)
Community-based Soil and Water Conservation (SWC) practices have been adopted in the Tigray region since 1991 for restoration of the degraded landscape. The effects of those conservation measures on physico-chemical properties of soil were limitedly studied. Thus, this study evaluated the effects of SWC on selected soil properties in the Middle Silluh Valley, Tigray region, Northern Ethiopia. The study considered conserved landscapes (terraced hillside, terraced farmland and exclosure area) and non-conserved landscapes (non-terraced hillside, non-terraced farmland and open grazing land) for comparison using a one-way analysis of variance (ANOVA). A total of 24 samples were collected from each landscape at a depth of 10–30 cm. The results indicated that mean bulk density (BD) was low on terraced hillside, non-terraced hillside and exclosure area. Sand and clay content were significantly different at P <0.05 for the six landscape categories. Higher mean organic matter was observed in the conserved landscape, as compared with the corresponding non-conserved landscape. Pearson's correlation between Soil Organic Matter (SOM) and clay content, SOM and Total Nitrogen (TN) showed strong positive relationships. Overall, the results show that SWC had significantly positive effects on soil's physical and chemical properties in the study area.
12 Sinore, T.; Kissi, E.; Aticho, A. 2018. The effects of biological soil conservation practices and community perception toward these practices in the Lemo district of southern Ethiopia. International Soil and Water Conservation Research, 6(2):123-130. [doi: https://doi.org/10.1016/j.iswcr.2018.01.004]
Soil conservation ; Biological activity in soil ; Erosion ; Water conservation ; Soil analysis ; Soil chemicophysical properties ; Communities ; Farmers attitudes ; Regression analysis ; Sesbania ; Pennisetum purpureum / Ethiopia / Lemo
(Location: IWMI HQ Call no: e-copy only Record No: H048777)
https://www.sciencedirect.com/science/article/pii/S2095633917300060/pdfft?md5=21b77777bef1f3b3b74a0a22c71de7fc&pid=1-s2.0-S2095633917300060-main.pdf
https://vlibrary.iwmi.org/pdf/H048777.pdf
https://vlibrary.iwmi.org/pdf/H048777.pdf
(1.28 MB) (1.28 MB)
Land degradation is the critical ecological and agricultural challenges in Ethiopia. To combat this, the government and local farmers’ have undertaken soil and water conservation measures (physical, biological and integrated) across the country since 1970's. This study investigate effect of elephant grass (P. purpureum) and sesbania sesban (S. sesban) used as biological land rehabilitation practices on soil properties and farmers’ perception on the practices. Composite soil samples (0–30 cm) were randomly collected from lands treated with sesbania, elephant grass, and adjacent degraded grazing land, and a structured questionnaire was used to assess farmers’ perceptions. Statistical results showed that elephant grass and sesbania were significantly (P o .05) improves degraded land soil bulk density, pH, CEC, OC, TN, Av.P, K, Na, Ca, Mg and clay characteristics. Moreover, there was a significant (P o .05) difference between farmers’ perception of the effectiveness of physical, biological and integration of the two practices to control soil erosion. 48% of the farmers perceived that using both biological methods and the integration of biological with physical structures was more successful for controlling erosion and improving soil fertility. Logistic regression analysis revealed strong association (R2 ¼ 0.84) between farmers’ perception on elephant grass and sesbanias' roles in soil conservation and groups of explanatory variables. Among the variables age, education and extension service significantly (P o .05) influenced farmers’ perception on the practices. Generally, elephant grass and sesbania are effective biological practices for rehabilitating lands and improving soil properties through minimizing erosion.
13 Araya, A.; Prasad, P. V. V.; Gowda, P. H.; Afewerk, A.; Abadi, B.; Foster, A. J. 2019. Modeling irrigation and nitrogen management of wheat in northern Ethiopia. Agricultural Water Management, 216:264-272. [doi: https://doi.org/10.1016/j.agwat.2019.01.014]
Irrigation management ; Fertilizer application ; Nitrogen ; Crop production ; Wheat ; Crop yield ; Water productivity ; Soil chemicophysical properties ; Biomass ; Models ; Strategies / Ethiopia / Mekelle
(Location: IWMI HQ Call no: e-copy only Record No: H049197)
(1.10 MB)
Wheat (Triticum aestivum) is one of the most important staple food crops in Ethiopia. However, its production is limited by moisture and nutrient stresses. A field experiment was conducted in northern Ethiopia to: (i) evaluate the effects of irrigation and nitrogen (N) and phosphorus (P) fertilizer application rates on yield, biomass and irrigation water productivity (IWP) of wheat; (ii) calibrate and validate a crop model for simulating yield and biomass of wheat under different levels of nitrogen and irrigation applications; (iii) evaluate consecutive aboveground biomass accumulation as affected by different combinations of irrigation and N fertilizer rates. The Decision Support for Agro technology Transfer Cropping System Model (DSSAT-CSM) was calibrated and validated with experimental data. The calibrated and validated DSSAT-CSM was used to simulate wheat biomass, yield, and irrigation water productivity under rainfed and three irrigation scenarios: I0, rainfed; DI1, two irrigations from heading to flowering; DI2, four irrigations from heading to early grain filling; and DI3, six irrigations from heading to mid grain filling period in combination with nine N rates (0, 16, 32, 64, 80, 96, 112, 128 and 160 kg/ha). Simulation results showed that both irrigation and nitrogen applications positively affected wheat yield, biomass and IWP. Much of the increase in biomass and yield was due to increased N than to increased irrigation. Yield increased with increase in N application rates, however, at a diminishing rate yielding a curvilinear relationship. Four irrigation (DI2) starting from heading to early grain filling stage resulted in a yield similar to DI3, six irrigation applications from heading to mid grain filling stage. Simulations showed that two irrigation applications strategy (DI1) yielded relatively higher IWP (1.8 kg/m3 ) at the highest application rate of 160 kg N/ha. Further economic analysis would help to identify most efficient practices for wheat production in northern Ethiopia.
14 Beyene, A. A.; Verhoest, N. E. C.; Tilahun, S.; Alamirew, T.; Adgo, E.; Nyssen, J. 2019. Irrigation efficiency and shallow groundwater in anisotropic floodplain soils near Lake Tana, Ethiopia. Irrigation and Drainage, 68(2):365-378. [doi: https://doi.org/10.1002/ird.2320]
Irrigation schemes ; Irrigation efficiency ; Floodplains ; Groundwater table ; Groundwater recharge ; Water levels ; Surface water ; Soil chemicophysical properties ; Soil moisture ; Evapotranspiration / Ethiopia / Lake Tana
(Location: IWMI HQ Call no: e-copy only Record No: H049344)
(0.81 MB)
Field experiments were conducted (December 2014 to May 2015) in a small irrigation scheme (60 ha) to study the effect of flood irrigation on anisotropic soils with shallow groundwater in the Lake Tana floodplains of Ethiopia. Irrigation (470 ± 33 mm) was measured using V-notches; rainfall did not occur, and the groundwater table was monitored daily using piezometers to estimate recharge from irrigated onion fields using the groundwater table fluctuation method. Recharge was influenced by applied irrigation amount, groundwater table depth, seasonal temperature variations, irrigation application efficiency and crop growth stages. The decreased deep percolation during the hottest periods and peak growth stages negatively influenced the reduction in groundwater decline caused by irrigation. The soil anisotropy also played a major role in the recharge amount: despite clay dominance in the topsoils, rapid groundwater table rises (0.02–0.56 m) were due to the presence of granular and blocky structures. Recharge was also influenced by irrigation efficiency, indicating higher recharge during periods of lower efficiency. The seasonal recharge was 34–46% of applied irrigation and there is much room for improving irrigation efficiency which is only 46 (±12) to 51 (±17)%.
15 Akpoti, K.; Kabo-bah, A. T.; Dossou-Yovo, E. R.; Groen, T. A.; Zwart, Sander J. 2020. Mapping suitability for rice production in inland valley landscapes in Benin and Togo using environmental niche modeling. Science of the Total Environment, 709:136165. [doi: https://doi.org/10.1016/j.scitotenv.2019.136165]
Land suitability ; Rice ; Agricultural production ; Environmental modelling ; Linear models ; Forecasting ; Uncertainty ; Water productivity ; Soil water content ; Rainfed farming ; Climatic data ; Soil chemicophysical properties ; Socioeconomic environment ; Valleys / Benin / Togo
(Location: IWMI HQ Call no: e-copy only Record No: H049495)
(5.47 MB)
Inland valleys (IVs) in Africa are important landscapes for rice cultivation and are targeted by national governments to attain self-sufficiency. Yet, there is limited information on the spatial distribution of IVs suitability at the national scale. In the present study, we developed an ensemble model approach to characterize the IVs suitability for rainfed lowland rice using 4 machine learning algorithms based on environmental niche modeling (ENM) with presence-only data and background sample, namely Boosted Regression Tree (BRT), Generalized Linear Model (GLM), Maximum Entropy (MAXNT) and Random Forest (RF). We used a set of predictors that were grouped under climatic variables, agricultural water productivity and soil water content, soil chemical properties, soil physical properties, vegetation cover, and socio-economic variables. The Area Under the Curves (AUC) evaluation metrics for both training and testing were respectively 0.999 and 0.873 for BRT, 0.866 and 0.816 for GLM, 0.948 and 0.861 for MAXENT and 0.911 and 0.878 for RF. Results showed that proximity of inland valleys to roads and urban centers, elevation, soil water holding capacity, bulk density, vegetation index, gross biomass water productivity, precipitation of the wettest quarter, isothermality, annual precipitation, and total phosphorus among others were major predictors of IVs suitability for rainfed lowland rice. Suitable IVs areas were estimated at 155,000–225,000 Ha in Togo and 351,000–406,000 Ha in Benin. We estimated that 53.8% of the suitable IVs area is needed in Togo to attain self-sufficiency in rice while 60.1% of the suitable IVs area is needed in Benin to attain self-sufficiency in rice. These results demonstrated the effectiveness of an ensemble environmental niche modeling approach that combines the strengths of several models.
16 Phogat, V.; Mallants, D.; Cox, J. W.; Simunek, J.; Oliver, D. P.; Pitt, T.; Petrie, P. R. 2020. Impact of long-term recycled water irrigation on crop yield and soil chemical properties. Agricultural Water Management, 237:106167. (Online first) [doi: https://doi.org/10.1016/j.agwat.2020.106167]
Irrigation water ; Water reuse ; Recycling ; Crop production ; Crop yield ; Soil chemicophysical properties ; Water quality ; Horticultural crops ; Soil salinity ; Models / Australia / Northern Adelaide Plains
(Location: IWMI HQ Call no: e-copy only Record No: H049635)
(1.88 MB)
The variably-saturated flow and multi-component transport module UNSATCHEM of HYDRUS-1D was used to evaluate the impact of the long-term (2018-2050) application of recycled water (RCW) for irrigating perennial horticulture (almonds, pistachios), viticulture (grapevines), annual horticulture (carrot, onion, and potato), and pasture crops in representative soils from the Northern Adelaide Plains (NAP), South Australia. The input parameters for soil hydraulic, soil solution, and cation exchange data were determined for 14 soil profiles from the NAP region. For a warm-up period from 1970 to 2017, the model used historical climate data and low-salinity irrigation water. In the subsequent period (2018-2050), irrigation continued with RCW and projected meteorological conditions were obtained by considering expected future climate change. The average soil water salinity (ECsw) at the end of the simulation period ranged from 2.9-10.5 dS/m across all soils and crops. Potential yields of salt-sensitive crops such as annual horticulture and almonds were reduced by 4-32% due to increased salinity in the soil. Similarly, the model predicted that the sodium adsorption ratio (SAR) and exchangeable sodium percentage (ESP) would increase above threshold values, typically considered as indicative of poor growing conditions for most crops. Relationships between SAR and ESP were developed for four representative soils, providing the threshold soil SAR that corresponds to a critical ESP (>6), which would lead to adverse soil health and crop growth impacts. Threshold SARs were derived for calcareous (SAR = 4), hard red-brown (SAR = 3.5), sand over clay (SAR = 6), and deep uniform to gradational (SAR = 3) soils. An increase in SAR and ESP in soils adversely affects soil structural stability and soil water movement, which can severely impact the sustainable crop production in the NAP region. Relationships such as those between SAR and ESP help in identifying critical soil constraints and assist in devising better guidelines for the sustainable use of recycled water for irrigated agriculture.
17 Pradhan, Surendra K.; Cofie, Olufunke; Nikiema, Josiane; Heinonen-Tanski, H. 2019. Fecal sludge derived products as fertilizer for lettuce cultivation in urban agriculture. Sustainability, 11(24):7101. [doi: https://doi.org/10.3390/su11247101]
Faecal sludge ; Organic fertilizers ; Urban agriculture ; Lettuces ; Cultivation ; Fertilization ; Soil fertility ; Greenhouse crops ; Sustainable products ; Crop yield ; Nutrients ; Waste management ; Waste treatment ; Composting ; Pellets ; Sludge dewatering ; Enrichment ; Hygiene ; Faecal coliforms ; Soil chemicophysical properties ; Poultry manure / Ghana / Accra
(Location: IWMI HQ Call no: e-copy only Record No: H049661)
(0.27 MB) (272 KB)
Fecal sludge (FS) contains a significant amount of plant nutrients. FS (treated/untreated) has been used as soil ameliorant in several countries. Use of FS-based compost on lettuce may meet reservations due to possible microbiological contamination. The objectives of this research are: (1) To determine the fertilizer value of different formulations of sawdust and fecal sludge compost (SDFS) pellets, and (2) to compare the effect of these SDFS formulations with poultry manure, commercial compost, mineral fertilizer, and non-fertilization on lettuce cultivation. The SDFS products were made by enriching, and pelletized with ammonium sulphate, mineral-NPK, or ammonium sulphate + muriate of potash + triple superphosphate. Lettuce was cultivated in a greenhouse and an open field. The result showed that the saleable fresh weight lettuce yield obtained from all SDFS pellets with/without enrichments were higher than those obtained from commercial compost, poultry manure, mineral fertilizer, or no fertilizer. Cultivation in the open field gave higher yields than those in the greenhouse. No helminth eggs were detected in composts or lettuces. Some fecal coliforms were detected in lettuces fertilized with almost all fertilizers tested, including NPK and non-fertilized control. A properly treated fecal sludge-based fertilizer can be a sustainable solution for lettuce production, which helps urban and peri-urban agriculture.
18 Mwinuka, P. R.; Mbilinyi, B. P.; Mbungu, W. B.; Mourice, S. K.; Mahoo, H. F.; Schmitter, Petra. 2021. Optimizing water and nitrogen application for neglected horticultural species in tropical sub-humid climate areas: a case of African eggplant (Solanum aethiopicum L.). Scientia Horticulturae, 276:109756. [doi: https://doi.org/10.1016/j.scienta.2020.109756]
Water use efficiency ; Nitrogen fertilizers ; Fertilizer application ; Fruit vegetables ; Eggplants ; Horticulture ; Solanum aethiopicum ; Crop water use ; Water requirements ; Drip irrigation ; Crop growth stage ; Crop yield ; Performance indexes ; Subhumid climate ; Soil chemicophysical properties / Africa / United Republic of Tanzania / Rudewa
(Location: IWMI HQ Call no: e-copy only Record No: H050012)
https://www.sciencedirect.com/science/article/pii/S0304423820305847/pdfft?md5=f79f2516a52f7afe55f8cb9d3fb8a4d2&pid=1-s2.0-S0304423820305847-main.pdf
https://vlibrary.iwmi.org/pdf/H050012.pdf
https://vlibrary.iwmi.org/pdf/H050012.pdf
(2.42 MB) (2.42 MB)
African eggplant, a traditional and important nutrient-dense crop to Tanzania’s nutrition and food security. However, yields remain low as a result of sub-optimal irrigation and fertilizer practices. To reduce the yield gap, a randomized split-plot design set up with irrigation as a main and nitrogen (N) treatments as a sub-factor. The irrigation regimes were 100 % (I100), 80 % (I80) and 60 % (I60) of crop water requirements whilst nitrogen levels were 250 kg N/ha (F100), 187 kg N/ha (F75), 125 kg N/ha (F50) and 0 kgN/ha (F0). The study evaluated the effect of irrigation water and N on crop growth variables and yield, fruit quality, WUE and NUE. The study showed the importance of combining different irrigation performance indicators which responds to different levels of water and nitrogen to evaluate and assess suitable irrigation and fertilizer strategies for African eggplant. The crop growth variables (plant height and LAI) had a good correlation with fruit yield (R2 = 0.6 and 0.8). The fruit quality was best performed by 100 % water in combination with 75 % N treatment. The best WUE and NUE was attained at 80 % and 100 % levels of water in combination with 75 % N. However, minimizing trade-offs between the various indicators, the optimal application for African eggplant would likely be around 80 % of the total irrigation requirement and 75 % of the N requirement in sandy clay loam soils under tropical sub-humid conditions.
19 Mekonnen, M.; Abeje, T.; Addisu, S. 2021. Integrated watershed management on soil quality, crop productivity and climate change adaptation, dry highland of northeast Ethiopia. Agricultural Systems, 186:102964. [doi: https://doi.org/10.1016/j.agsy.2020.102964]
Watershed management ; Integrated management ; Soil quality ; Agricultural productivity ; Climate change adaptation ; Highlands ; Arid climate ; Soil conservation ; Water conservation ; Carbon stock assessments ; Soil organic carbon ; Sustainable Development Goals ; Soil chemicophysical properties ; Crop yield ; Land degradation ; Erosion ; Farmers / Ethiopia / Miyo-Hadi Watershed
(Location: IWMI HQ Call no: e-copy only Record No: H050104)
(4.32 MB)
Miyo-Hadi watershed in the northeast dry highland of Ethiopia is known for the excessive degradation of natural resources and recurrent drought. To avert the problem soil and water conservation practices (SWCPs) were exhaustively implemented by governmental and non-governmental organizations based on the integrated watershed management approach. Although many studies have been conducted in the wet highlands of Ethiopia to assess the role of SWCPs on soil physical and chemical properties, carbon stock and grain yield, studies in the dry highlands of northeast Ethiopia are limited. Thus, this research is aimed to (i) investigate the impacts of SWCPs on soil physical and chemical properties, (ii) quantify the carbon stock trapped by the SWCPs, (iii) assess barley grain yield and (iv) evaluate farmers' perception on climate change adaptive strategies. Field experiment, observation, socio-economic survey were conducted for data collection. SPSS was used for data analysis. The result shows that soil and water conservation practices positively influenced the physico-chemical properties of the soil and barley grain yield. The quality of soil physico-chemical properties and barley grain yield in the treated farms/fields were better than the untreated farms. Similarly, the quality of soil physico-chemical properties and barley grain yield were found to be high in farms with lower slope gradients than the higher slope gradients. Almost all of the interviewed households (93%) perceived the existence of climate change in the area; and recurrent drought, pest and disease were among the events. About 65% of the households perceived that the implemented strategies (SWCPs, infrastructure, credit & saving, and capacity building) were helpful to adapt climate related shocks. Therefore, it can be concluded that integrated watershed management as a holistic approach, and SWCPs as specific technologies have meaningful roles in terms of minimizing land degradation, improving soil quality, increasing barley yield, and reducing climate change.
20 Fenta, H. M; Hussein, M. A.; Tilahun, S. A.; Nakawuka, Prossie; Steenhuis, T. S.; Barron, Jennie; Adie, A.; Blummel, M.; Schmitter, Petra. 2022. Berken plow and intercropping with pigeon pea ameliorate degraded soils with a hardpan in the Ethiopian highlands. Geoderma, 407:115523. [doi: https://doi.org/10.1016/j.geoderma.2021.115523]
Agricultural production ; Intercropping ; Maize ; Pigeon peas ; Soil penetration resistance ; Soil degradation ; Soil analysis ; Hardpans ; Soil moisture ; Tillage ; Rainfed farming ; Runoff ; Water storage ; Highlands ; Smallholders ; Farmers ; Economic analysis ; Crop yield ; Soil chemicophysical properties ; Infiltration ; Sediment ; Watersheds / Ethiopia / Amhara / Robit Bata Watershed
(Location: IWMI HQ Call no: e-copy only Record No: H050790)
https://www.sciencedirect.com/science/article/pii/S0016706121006030/pdfft?md5=1a75bfbda044c2e453917450c6e20dab&pid=1-s2.0-S0016706121006030-main.pdf
https://vlibrary.iwmi.org/pdf/H050790.pdf
https://vlibrary.iwmi.org/pdf/H050790.pdf
(8.62 MB) (8.62 MB)
Closing the yield gap and enhancing efficiency in rainfed maize production systems in Ethiopia requires urgent action in increasing the productivity of degraded agricultural land. The degradation of land through continuous compaction and decline in the organic matter has resulted in a wide-spread formation of a hardpan that restricts deep percolation, prevents plant root development, and, ultimately can lead to increased erosion. Studies exploring practical low-cost solutions to break the hardpan are limited in Ethiopia. The main objective was to evaluate soil mechanical (i.e. modified plow or Berken plow) or biological intervention (i.e. intercropping with pigeon pea) effectiveness to enhance soil water management and crop yield of rainfed maize systems whilst reducing soil erosion and runoff. Five farm fields, each including four plots with different tillage treatments, were monitored during two rainy seasons in 2016 and 2017. The treatments were: (i) farmers practice under conventional (CT) tillage; plots tilled three times using an oxen driven local plow Maresha, (ii) no-till (NT), (iii) Berken tillage (BT), plots tilled three times using an oxen pulled Berken plow, and (iv) biological (CT + Bio), taprooted pigeon pea intercropped with maize on plots conventionally tilled. Results showed that mean tillage depth was significantly deeper in the BT (28 cm) treatment compared to CT and CT + Bio (18 cm) treatments. Measured soil penetration resistance significantly decreased up to 40 cm depth under BT and maize roots reached 1.5 times deeper compared to roots measured in the CT treatment. Under BT, the estimated water storage in the root zone was estimated at 556 mm, 1.86 times higher compared to CT, 3.11 times higher compared to NT and 0.89 times higher compared to CT + Bio. The positive effects on increased water storage and root development resulted in an average increase in maize grain (i.e. 15%, 0.95 t ha- 1 ) and residual above ground biomass (0.3%, 6.4 t ha- 1 ) leading to a positive net benefit of 138 USD ha- 1 for the BT treatment compared to the CT treatment. The negative net benefit obtained under CT and CT+Bio was mainly related to the high labor cost related to plowing, weeding, planting, and fertilizer application whilst in the NT this was related to the significantly lower maize yields. The positive effects in the BT treatment, and to some extent the CT+Bio treatment show great potential for smallholder rainfed maize systems where degraded soils with hardpans and high variability in rainfall prevail.
Powered by DB/Text WebPublisher, from
