Your search found 17 records
1 de Datta, S. K.; Krupp, H. K.; Alverez, E. I.; Modgal, S. C. 1973. Water management practices in flooded tropical rice. In International Rice Research Institute, Water management in Philippine irrigation systems: Research and operations (pp. 1-18). Los Banos, Laguna, Philippines: International Rice Research Institute.
Water management ; Cropping systems ; Water use efficiency ; Clay ; Rice ; Weed control ; Pest control ; Furrow irrigation ; Puddling / Philippines
(Location: IWMI-HQ Call no: 631.7.6 G732 INT Record No: H06)
Experiments conducted for several cropping seasons on the montmorillonitic Maahas clay soil at the IRRI farm demonstrate that continual flooding is not essential for high grain yield but flooded rice can tolerate at least 15cmif the improved varieties are grown. Tall varieties like H-4 has less adaptability under wide range of water management conditions than semidwarfs like IR8. With adequate water supply, 5 to 7 cm of water is desirable on most soils for best weed and insect control with granular chemicals, forhigh nutrient availability, and for minimum losses of nutrients from fertilizer and soil. If rainfall does not provide supplemental water, irrigation intervalslonger than 8 days reduce grain yield under a rotational irrigation system. Varieties like IR5 that have a long growth duration were least sensitive to moisture stress imposed by long irrigation intervals. This is because IR5 will generally recover from high moisture stress for a short period or low moisture stress for a long period. An experiment with IR20 indicates that the furrow irrigation of nonpuddled soil does not provide more efficient water use in rice compared with rice grown on puddled lowland soil.
2 de Datta, S. K.; Abilay, W. P.; Kalwar, G. N. 1975. Water stress effects in flooded tropical rice. In International Rice Research Institute, Water management in Philippine irrigation systems: Research and operations (pp. 19-36). Los Banos,Laguna, Philippines: International Rice Research Institute.
(Location: IWMI-HQ Call no: 631.7.6 G732 INT Record No: H07)
Moisture stress often limits economical and stable yields of rainfed rice. On the montmorillonitic Maahas clay soil, grain yields of IR8 were less sensitive to growth stage at which moisture stress occurred and more sensitive to intensity and duration of moisture stress, while the tall variety, H-4,was sensitive to moisture stress during the reproductive and ripening stages as well as to intensity and duration of moisture stress. Our data indicate that moisture stress effects should be related to variety rather than to varietal type growth characteristics of rice varieties. The growth duration of rice varieties were increased with increased stress level and the relationships between moisture stress and stage of the crop may depend on growth duration of the variety among other factors. Current results indicate that soil moisture tension as low as 15 cb was enough to reduce grain yield of rainfed flooded (lowland) rice. Part of the reduction in grain yield due to the loss of nitrogen under alternately dry and wet conditions which prevailed in the plots subjected to various stress levels. The improved varieties, IR20, IR22, and IR24, consistently out yielded the traditional varieties Peta, Sigadis, and Intan, at all stress levels up to 33 cb. At most stress levels, however, the grain yields were higher with higher nitrogen levels, and more so with improved varieties than with traditional varieties.
3 Sudan. Ministry of Irrigation. Hydraulics Research Station. 1983. Proceedings of the Seminar on Expansive Clay Soil Problems in the Sudan, Wad Medani, 29-31 January 1983. Wad Medani, Sudan: Hydraulic Research Station. Ministry of Irrigation. 90p.
(Location: IWMI-PAK Call no: 631.7.2 G146 SUD Record No: H0870)
4 Yousaf, M.; Ali, O. M.; Rhoades, J. D. 1987. Clay dispersion and hydraulic conductivity of some salt-affected arid land soils. Soil Science Society of America Journal, 52(4):905-907.
(Location: IWMI-HQ Call no: P 4214 Record No: H018253)
5 Oster, D. J.; Shainberg, I.; Abrol, I. P. 1996. Reclamation of salt-affected soil. In Agassi, M. (Ed.), Soil erosion, conservation, and rehabilitation. New York, NY, USA: Marcel Dekker Inc. pp.315-352.
Soil reclamation ; Soil degradation ; Soil Salinity ; Sodic soils ; Clay ; Soil properties ; Infiltration ; Irrigation water ; Sprinkler irrigation ; Groundwater ; Water quality ; Alkaline soils ; Crop production / USA / Israel / India / California
(Location: IWMI-HQ Call no: P 4218 Record No: H018257)
6 Cofie, Olufunke; Pleysier, J. 2004. Ion exchange involving calcium-potasium (Ca-K) and calcium-magnesium (Ca-Mg) in soil and organic matter fractions. Communications in Soil Science and Plant Analysis, 35(17-18):2417-2431.
Ion exchange ; Soil properties ; Soil organic matter ; Clay ; Fractionation ; Calcium ; Magnesium ; Potassium / Nigeria
(Location: IWMI-HQ Call no: IWMI 631.4 G000 COF Record No: H035917)
The chemical characteristics of two soil types, an Alfisol and an Ultisol, were studied in the humid tropical zone of southern Nigeria. The objective was to investigate the contribution of soil organic matter (SOM) to nutrient retention characteristics and identify those SOM pools that contribute most to the ion exchange properties of the soils. Ion exchange studies involving K-Ca and Mg-Ca systems in whole soil, organic fraction (53-250 mm) and clay fraction (<2 mm ) showed a preference for Ca relative to K in the soil and organic fraction. For the clay fraction in Alfisol, the isotherm in K-Ca system suggested a preference for K at low K saturation, but from about 50% K saturation, the isotherm inferred a preference for Ca. However, the overall selectivity at constant temperature and pressure as expressed by Gibb’s free energy change suggested a stronger binding of K than Ca by the fraction.
7 Ruaysoongnern, Sawaeng; Noble, Andrew. 2005. Using clay based materials as a soil improvement strategy. SEAWatch, 11:2-3.
(Location: IWMI-HQ Call no: IWMI 631.4 G750 RUA Record No: H038079)
8 Al-Omran, A. M.; Sheta, A. S.; Falatah, A. M.; Al-Harbi, A. R. 2005. Effect of drip irrigation on squash (Cucurbita pepo) yield and water-use efficiency in sandy calcareous soils amended with clay deposits. Agricultural Water Management, 73(1):43-55.
(Location: IWMI-HQ Call no: PER Record No: H036813)
9 International Water Management Institute (IWMI). 2010. Improving soils and boosting yields in Thailand. Colombo, Sri Lanka: International Water Management Institute (IWMI). 2p. (IWMI Success Stories 002) [doi: https://doi.org/10.5337/2011.0031]
(Location: IWMI HQ Call no: e-copy only Record No: H043316)
(310.20 KB)
10 Nikiema, Josiane; Cofie, Olufunke; Impraim, Robert; Drechsel, Pay. 2012. Fortified excreta pellets for agriculture. Paper presented at the Second International Faecal Sludge Management Conference, Durban, South Africa, 29 October - 1 November 2012. 5p.
Excreta ; Agricultural production ; Fertilizers ; Composts ; Faeces ; Irradiation ; Pellets ; Starch crops ; Cassava ; Clay ; Moisture content / Ghana
(Location: IWMI HQ Call no: e-copy only Record No: H045351)
https://publications.iwmi.org/pdf/H045351.pdf
http://www.susana.org/docs_ccbk/susana_download/2-1624-nikiema.pdf
http://www.susana.org/docs_ccbk/susana_download/2-1624-nikiema.pdf
(0.34 MB)
This paper describes the pelletization process of fecal sludge-based fertilizers. The equipment used for the process was fabricated locally in Ghana. Each fertilizer product was individually used for the production of cylindrical pellets. From the current study, the binding material type (cassava starch, either pregelatinized or pretreated by gamma irradiation, or kaolin clay) and concentration (0 to 10 % in mass) as well as moisture content (20-47%) appeared to be the most critical factors during pellets production. It was noticed that the higher the binder concentration, the higher the stability of pellets. This study confirmed that cassava starch is a preferred binding material and that fixing its concentration at 1-3 % could be enough during the pelletization process. The pellets produced in this project had 7.5 to 7.7 mm in diameter, but their length distribution varied depending on the material used.
11 Ratnayake, R. (Comp.) 2008. River sand mining - boon or bane?: a synopsis of a series of national, provincial and local level dialogues on unregulated/illicit river sand mining. Colombo, Sri Lanka: Sri Lanka Water Partnership (SLWP). 14p.
(Location: IWMI HQ Call no: 622.3622 G744 RAT Record No: H045613)
(3.68 MB)
12 Nikiema, Josiane; Cofie, Olufunke; Asante-Bekoe, Barbara; Otoo, Miriam; Adamtey, N. 2014. Potential of locally available products for use as binders in producing fecal compost pellets in Ghana. Environmental Progress and Sustainable Energy, 33(2):504-511. [doi: https://doi.org/10.1002/ep.11790]
Faeces ; Composts ; Fertilizers ; Binders ; Crops ; Cassava ; Soil fertility ; Costs ; Pelleting ; Clay ; Beeswax ; Classification ; Water holding capacity ; Environmental effects ; Risks / Ghana
(Location: IWMI HQ Call no: e-copy only Record No: H046137)
(1.81 MB)
Market studies in Ghana have revealed a potential for composted or cocomposted fecal matter as nutrient source inputs for agricultural production. To increase the marketability of such products, high nutrient value and easier handling/transporting options are among the significant factors which drive demand. Pelletization is seen as a potentially interesting option to address these challenges. To preserve form stability of the pellet products, the addition of a binding material during the pelletization process is crucial. In Ghana, water, beeswax, clay, and cassava starch have been identified as locally available binding materials. A comparative assessment of these materials as a premier binder suitable for pelletization was performed based on predefined criteria. Quantitative criteria considered included the total amounts available, the seasonal variation during the year and cost. Qualitative criteria such as handling and storage conditions, ease of use during pelletization, and the binding ability were also evaluated. Based on this assessment, clay and cassava-based starch were selected as the most promising binding agents. Currently, clay is abundant in Ghana and this may suggest a guarantee for consistent and stable supply over coming years. However, from the perspective of cassava-based starch, this situation depicts limited production of starch and competition on the local markets.
13 Lanka Jalani; Capacity Building Network, Sri Lanka (CapNet); Network of Women Professionals, Sri Lanka (NetWWater) 2006. Proceedings of the National Dialogue on River Sand and Clay Mining, Sri Lanka Foundation Institute, Colombo, Sri Lanka, 24 April 2006. Colombo, Sri Lanka: Lanka Jalani; Capacity Building Network, Sri Lanka (CapNet); Network of Women Professionals, Sri Lanka (NetWWater). 53p.
Rivers ; Sand ; Clay ; Mining ; Economic aspects ; Costs ; Labour costs ; Environmental effects ; Social aspects ; Sustainability ; Governmental interrelations ; Living standards ; Legal aspects / Sri Lanka / Maha Oya
(Location: IWMI HQ Call no: 622.3622 G744 LAN Record No: H046178)
(0.48 MB)
14 Pereira, K.; Ratnayake, R. 2013. Water integrity in action: curbing illegal sand mining in Sri Lanka. Berlin, Germany: Water Integrity Network (WIN). 36p.
Sand ; Sand dunes ; Clay ; Mining ; Legal aspects ; Rivers ; Water supply ; Erosion ; Riverbank protection ; Environmental effects / Sri Lanka / Deduru Oya / Maha Oya
(Location: IWMI HQ Call no: 622.3622 G744 PER Record No: H046318)
http://www.waterintegritynetwork.net/index.php?option=com_mtree&task=att_download&link_id=174&cf_id=61
https://vlibrary.iwmi.org/pdf/H046318.pdf
https://vlibrary.iwmi.org/pdf/H046318.pdf
(5.66 MB) (5.66 MB)
15 Natarajan, Rajmohan; Prathapar, Sanmugam A.; Jayaprakash, M.; Nagarajan, R. 2014. Vertical distribution of heavy metals in soil profile in a seasonally waterlogging agriculture field in eastern Ganges Basin. Environmental Monitoring and Assessment, 186(9):5411-5427. [doi: https://doi.org/10.1007/s10661-014-3790-x]
Soil profiles ; Heavy metals ; Waterlogging ; Soil pollution ; Sediment ; Contamination ; Clay ; Sandy soils / India / Bihar / Ganges River
(Location: IWMI Call no: e-copy only Record No: H046446)
(0.59 MB)
The accumulation of heavy metals in soil and water is a serious concern due to their persistence and toxicity. This study investigated the vertical distribution of heavy metals, possible sources and their relation with soil texture in a soil profile from seasonally waterlogged agriculture fields of Eastern Ganges basin. Fifteen samples were collected at ~0.90-m interval during drilling of 13.11 mbgl and analysed for physical parameters (moisture content and grain size parameters: sand, silt, clay ratio) and heavy metals (Fe, Mn, Cr, Cu, Pb, Zn, Co, Ni and Cd). The average metal content was in the decreasing order of Fe>Mn>Cr>Zn>Ni>Cu>Co>Pb>Cd. Vertical distribution of Fe, Mn, Zn and Ni shows more or less similar trends, and clay zone records high concentration of heavy metals. The enrichment of heavy metals in clay zone with alkaline pH strongly implies that the heavy metal distributions in the study site are effectively regulated by soil texture and reductive dissolution of Fe and Mn oxy-hydroxides. Correlation coefficient analysis indicates that most of the metals correlate with Fe, Mn and soil texture (clay and silt). Soil quality assessment was carried out using geoaccumulation index (Igeo), enrichment factor (EF) and contamination factor (CF). The enrichment factor values were ranged between 0.66 (Mn) and 2.34 (Co) for the studied metals, and the contamination factor values varied between 0.79 (Mn) and 2.55 (Co). Results suggest that the elements such as Cu and Co are categorized as moderate to moderately severe contamination, which are further confirmed by Igeo values (0.69 for Cu and 0.78 for Co). The concentration of Ni exceeded the effects-range median values, and the biological adverse effect of this metal is 87 %. The average concentration of heavy metals was compared with published data such as concentration of heavy metals in Ganga River sediments, Ganga Delta sediments and upper continental crust (UCC), which apparently revealed that heavy metals such as Fe, Mn, Cr, Pb, Zn and Cd are influenced by the dynamic nature of flood plain deposits. Agricultural practice and domestic sewage are also influenced on the heavy metal content in the study area.
16 Mekuria, Wolde; Noble, Andrew; Sengtaheuanghoung, O.; Hoanh, Chu Thai; Bossio, D.; Sipaseuth, N.; McCartney, Matthew; Langan, Simon. 2014. Organic and clay-based soil amendments increase maize yield, total nutrient uptake, and soil properties in Lao PDR. Agroecology and Sustainable Food Systems, 38:936-961. [doi: https://doi.org/10.1080/21683565.2014.917144]
Soil amendments ; Soil properties ; soil organic matter ; Maize ; Rice husks ; Clay ; Nutrients ; Food security ; Food production ; Agricultural production ; Smallholders ; Bentonite ; Composts ; Biomass ; Land degradation / Lao People's Democratic Republic / Veunkham / Naphok
(Location: IWMI HQ Call no: e-copy only Record No: H046584)
(0.29 MB)
In the Lao People’s Democratic Republic (PDR), increasing food security remains a challenge since smallholder agricultural systems, which are the main source of food production, are under serious threat due to poor soil fertility and climate variability. This study was undertaken in Lao PDR to investigate the impacts of organic and clay-based soil amendments on maize yield, total nutrient uptake, and soil properties. Structured field experiments were established over two consecutive years (2011 and 2012) with maize as the test crop at the Veunkham and Naphok sites. Ten treatments were applied in a randomized complete block design with three replications. The treatments were control, rice husk biochar (applied at a rate of 10 t ha-1), bentonite clay (10 t ha-1), compost (4 t ha-1), clay-manure compost (10 t ha-1), rice husk biochar compost (10 t ha-1), and their combinations. All treatments were applied in 2011. Significant (p < 0.05) treatment effects in maize grain yields, total nutrient uptake, and soil properties were observed. At Veunkham, differences between the control and amended soils in yield ranged from 0.9 to 3.3 t ha-1 in 2011 and from 0.2 to 1.3 t ha-1 in 2012, whereas differences at Naphok varied between 0.2 and 2.2 t ha-1 in 2011 and from 0.2 to 1.7 t ha-1 in 2012. At both sites, in most of the treatments, yields in 2012 were significantly (p < 0.05) lower than 2011; this was attributed to a late season drought. Differences between the control and amended soils in yield can be attributed to the improvements in total N and P uptake, soil pH, exchangeable Ca++ and Mg++, and cation-exchange capacity following the application of soil amendments. The results of this study confirm that the soil amendments under consideration can be effective in improving agricultural productivity, while improving key soil properties indicating that soil amendments could be an option for intensification of agricultural productivity.
17 Ghosal, U.; Sikdar, P. K.; McArthur, J. M. 2015. Palaeosol control of arsenic pollution: the Bengal Basin in West Bengal, India. Groundwater, 53(4):588-599. [doi: https://doi.org/10.1111/gwat.12251]
Groundwater ; Arsenic ; Contamination ; Water pollution ; Water quality ; Palaeosols ; Sand ; Clay ; Aquifers ; Manganese ; Health hazards ; Hydrogeology ; Models ; Wells ; Drilling / India / West Bengal / Bengal Basin
(Location: IWMI HQ Call no: e-copy only Record No: H047963)
http://onlinelibrary.wiley.com/doi/10.1111/gwat.12251/epdf
https://vlibrary.iwmi.org/pdf/H047963.pdf
https://vlibrary.iwmi.org/pdf/H047963.pdf
(2.35 MB) (2.35 MB)
Groundwater in the Bengal Basin is badly polluted by arsenic (As) which adversely affects human health. To provide low-As groundwater for As mitigation, it was sought across 235 km2 of central West Bengal, in the western part of the basin. By drilling 76 boreholes and chemical analysis of 535 water wells, groundwater with <10 µg/L As in shallow aquifers was found under one-third of a study area. The groundwater is in late Pleistocene palaeo-interfluvial aquifers of weathered brown sand that are capped by a palaeosol of red clay. The aquifers form two N-S trending lineaments that are bounded on the east by an As-polluted deep palaeo-channel aquifer and separated by a shallower palaeo-channel aquifer. The depth to the top of the palaeo-interfluvial aquifers is mostly between 35 and 38 m below ground level (mbgl). The palaeo-interfluvial aquifers are overlain by shallow palaeo-channel aquifers of gray sand in which groundwater is usually As-polluted. The palaeosol now protects the palaeo-interfluvial aquifers from downward migration of As-polluted groundwater in overlying shallow palaeo-channel aquifers. The depth to the palaeo-interfluvial aquifers of 35 to 38 mbgl makes the cost of their exploitation affordable to most of the rural poor of West Bengal, who can install a well cheaply to depths up to 60 mbgl. The protection against pollution afforded by the palaeosol means that the palaeo-interfluvial aquifers will provide a long-term source of low-As groundwater to mitigate As pollution of groundwater in the shallower, heavily used, palaeo-channel aquifers. This option for mitigation is cheap to employ and instantly available.
Powered by DB/Text WebPublisher, from
