Your search found 14 records
1 Rumpel, C.; Chaplot, V.; Chabbi, A.; Largeau, C.; Valentin, Christian. 2008. Stabilisation of HF soluble and HCl resistant organic matter in sloping tropical soils under slash and burn agriculture. Geoderma, 145:347-354.
Sloping land ; Shifting cultivation ; Tropical soils ; Climatic soil types ; Erosion ; Soil profiles / Laos / Luang Prabang
(Location: IWMI HQ Call no: IWMI 631.4 G708 RUM Record No: H041554)
2 Gash, J. H. C.; Shuttleworth, W. J. (Comps.) 2007. Evaporation: selection, introduction and commentary. Wallingford, UK: International Association of Hydrological Sciences (IAHS). 521p. (IAHS Benchmark Papers in Hydrology 2)
Evaporation ; Evapotranspiration ; Measurement ; Lysimetry ; Water balance ; Stream flow ; Soil water movement ; Climate ; Models ; Photosynthesis ; Stomatal conductance ; Forests ; Transpiration ; Soil profiles ; Afforestation ; Vegetation ; Weather
(Location: IWMI HQ Call no: 551.572 G000 GAS Record No: H043494)
(0.40 MB)
3 Douxchamps, S.; Frossard, E.; Uehlinger, N.; Rao, I.; van der Hoek, R.; Mena, M.; Schmidt, A.; Oberson, A. 2011. Identifying factors limiting legume biomass production in a heterogeneous on-farm environment. Journal of Agricultural Science, 16p. (Online first). [doi: https://doi.org/10.1017/S0021859611000931]
Biomass ; Legumes ; Smallholders ; Crop production ; Farms ; Canavalia ; Maize ; Soil profiles ; Soil fertility ; Soil properties ; Rooting ; Sloping land ; Watersheds ; Environmental effects ; Landscape ; Statistical analysis / Nicaragua
(Location: IWMI HQ Call no: e-copy only Record No: H044796)
(0.45 MB)
Multipurpose legumes provide a wide range of benefits to smallholder production systems in the tropics. The degree of system improvement after legume introduction depends largely on legume biomass production, which in turn depends on the legumes’ adaptation to environmental conditions. For Canavalia brasiliensis (canavalia), an herbaceous legume that has been recently introduced in the Nicaraguan hillsides, different approaches were tested to define the biophysical factors limiting biomass production on-farm, by combining information from topsoil chemical and physical properties, topography and soil profiles.
Canavalia was planted in rotation with maize during two successive years on 72 plots distributed over six farms and at contrasting landscape positions. Above-ground biomass production was similar for both years and varied from 448 to 5357 kg/ha, with an average of 2117 kg/ha. Topsoil properties, mainly mineral nitrogen (N; ranging 25–142 mg/kg), total N (Ntot; 415–2967 mg/kg), soil organic carbon (SOC; 3–38 g/kg) and pH (5·3–7·1), significantly affected canavalia biomass production but explained only 0·45 of the variation. Topography alone explained 0·32 of the variation in canavalia biomass production. According to soil profiles descriptions, the best production was obtained on profiles with a root aggregation index close to randomness, i.e. with no major obstacles for root growth. When information from topsoil properties, topography and soil profiles was combined through a stepwise multiple regression, the model explained 0·61 of the variation in canavalia biomass (P<0·001) and included soil depth (0·5–1·70 m), slope position, amount of clay (19–696 kg/m2) and stones (7–727 kg/m2) in the whole profile, and SOC and N content in the topsoil. The linkages between topsoil properties, topography and soil profiles were further evaluated through a principal component analysis (PCA) to define the best landscape position for canavalia cultivation.
The three data sets generated and used in the present study were found to be complementary. The profile description demonstrated that studies documenting heterogeneity in soil fertility should also consider deeper soil layers, especially for deep-rooted plants such as canavalia. The combination of chemical and physical soil properties with soil profile and topographic properties resulted in a holistic understanding of soil fertility heterogeneity and shows that a landscape perspective must be considered when assessing the expected benefits from multipurpose legumes in hillside environments.
Canavalia was planted in rotation with maize during two successive years on 72 plots distributed over six farms and at contrasting landscape positions. Above-ground biomass production was similar for both years and varied from 448 to 5357 kg/ha, with an average of 2117 kg/ha. Topsoil properties, mainly mineral nitrogen (N; ranging 25–142 mg/kg), total N (Ntot; 415–2967 mg/kg), soil organic carbon (SOC; 3–38 g/kg) and pH (5·3–7·1), significantly affected canavalia biomass production but explained only 0·45 of the variation. Topography alone explained 0·32 of the variation in canavalia biomass production. According to soil profiles descriptions, the best production was obtained on profiles with a root aggregation index close to randomness, i.e. with no major obstacles for root growth. When information from topsoil properties, topography and soil profiles was combined through a stepwise multiple regression, the model explained 0·61 of the variation in canavalia biomass (P<0·001) and included soil depth (0·5–1·70 m), slope position, amount of clay (19–696 kg/m2) and stones (7–727 kg/m2) in the whole profile, and SOC and N content in the topsoil. The linkages between topsoil properties, topography and soil profiles were further evaluated through a principal component analysis (PCA) to define the best landscape position for canavalia cultivation.
The three data sets generated and used in the present study were found to be complementary. The profile description demonstrated that studies documenting heterogeneity in soil fertility should also consider deeper soil layers, especially for deep-rooted plants such as canavalia. The combination of chemical and physical soil properties with soil profile and topographic properties resulted in a holistic understanding of soil fertility heterogeneity and shows that a landscape perspective must be considered when assessing the expected benefits from multipurpose legumes in hillside environments.
4 Qureshi, Asad Sarwar; Ahmad, Waqas; Ahmad, A-F. A. 2013. Optimum groundwater table depth and irrigation schedules for controlling soil salinity in Central Iraq. Irrigation and Drainage, 62(4):414-424. [doi: https://doi.org/10.1002/ird.1746]
Groundwater table ; Depth ; Irrigation management ; Irrigation scheduling ; Soil salinity ; Soil profiles ; Crop production ; Wheat ; Maize ; Simulation models ; Calibration ; Water balance / Central Iraq
(Location: IWMI HQ Call no: PER Record No: H045915)
(0.78 MB)
Excessive irrigation and poor drainage conditions are the major factors contributing to rising groundwater tables and soil salinity in the irrigated areas of Central Iraq. Therefore calculations of precise irrigation requirements are necessary to optimize crop production and keep the groundwater table below the root zone to avoid soil salinization. In this study, the soil–water–atmosphere–plant (SWAP) model is used to determine optimal groundwater table depth and irrigation amounts for the study area. SWAP was calibrated using field data from the study area during the wheat and maize season of 2011–2012. The modelling results reveal that under current irrigation practices (600mm to wheat and 1000mm to maize), more than 30% water is lost as deep percolation. This causes a rise in the groundwater table and reduction in crop yields. The model simulations suggest that a groundwater table depth of 200 cm together with an irrigation application of 500mm to wheat and 600mm to maize will be the best combination to attain optimal yields. Therefore a drainage system in these areas should be installed to maintain groundwater table depth around 200 cm. Maintaining adeeper groundwater table will not be suitable as costs will increase and crop responses negligible. For long-term sustainability, rehabilitation of existing drainage systems to evacuate excessive salts from the root zone will be imperative.
5 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.
6 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.
7 Armour, J. D.; Berthelsen, S.; Ruaysoongnern, S.; Moody, P. W.; Noble, Andrew D. 2005. Remediation of soil acidification by form of nitrogen fertilizer on grass swards of Australia and Thailand. 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.135-139.
Soil profiles ; Acidification ; Grasses ; Pastures ; Species ; Cropping systems ; Nitrogen fertilizers ; Soil pH ; Alkalinity ; Acrisols / Australia / Thailand / Mareeba / Tully / Chiang Yuen
(Location: IWMI HQ Call no: 630 G000 INT Record No: H047325)
(0.36 MB) (16.9 MB)
Acidification of soil profiles from legume and N fertilized crops is a serious sustainability threat. Under tropical conditions of Northeast Thailand and Northern Australia, acidification to >90 cm has been recorded in Stylosanthes and Leucaena based pasture systems. Acidification has also been measured in other Australian cropping systems fertilized with urea or ammonium forms of N. The major processes contributing to what could be termed anthropogenic acidification are removal of base cations in the harvested product and leaching below the root zone of nitrate from ammonium and urea N fertiliser or legumes resulting in an accumulation of protons in surfaces horizons. If prophylactic applications of lime are not undertaken, acid generation in surface horizons will progressively move down the profile inducing subsoil acidification. Subsoil acidity is often difficult to correct using conventional applications of liming products. Field experiments with pastures on Acrisols in Northeast Australia (two sites) and Northeast Thailand (one site) compared the rates of alkalisation or acidification from N applied as nitrate or as urea (Australia) or ammonium sulphate (Thailand). Soil pH increased where N was applied as nitrate and decreased where N was applied as urea or ammonium sulphate. At one of the sites in Australia, regular applications of N as nitrate at 350 kg N ha-1 year-1 were made to irrigated Digitaria melanjiana cv Jarra. This significantly increased soil pH (1:5 0.01 M CaCl2) by up to 0.5 units to a depth of 0.90 m over a period of 4 years when compared to bare soil. The alkalisation of the profile was equivalent to 2.7 t/ha of calcium carbonate distributed evenly down the profile. Urea at the same rate of N decreased soil pH at 20-50 cm by 0.2 units. Similar but smaller changes were measured at the other Australian site (Brachiaria decumbens) and the site in Thailand (Andropogon gayanus cv Carimagua (Gamba grass). Treatment effects at these sites were restricted by time (1 year) or seasonal conditions that limited the number of N applications that could be applied (290 kg N/ha over 3 years) at the Thai site. The research has clearly demonstrated that nitrate N fertilizer can rapidly correct soil acidity down the soil profile to 0.9 m and this is attributed to the release of alkali from roots as nitrate is taken up. Such a strategy may be an effective approach to addressing subsoil acidification where surface applications of lime are ineffective and profile modification is cost prohibitive.
8 Tubeileh, A.; Bruggeman, A.; Turkelboom, F. 2016. Water-harvesting designs for fruit tree production in dry environments. Agricultural Water Management, 165:190-197. [doi: https://doi.org/10.1016/j.agwat.2015.11.006]
Water harvesting ; Fruit trees ; Crop production ; Olives ; Water storage ; Arid zones ; Soil profiles ; Soil moisture ; Moisture content ; Sloping land ; Precipitation ; Rain ; Catchment areas / Syria / Mediterranean Region
(Location: IWMI HQ Call no: e-copy only Record No: H047630)
(0.70 MB)
Water scarcity and increasing demand coupled with climate change require maximizing the use of available resources. Water harvesting (WH) systems are currently being used in many areas to sustain crops and increase water productivity. This study investigated the effect of three treatments (S15: 50-m2 catchment area with 15% slope, S8: 50-m2 catchment area with 8% slope, and L8: 70-m2 catchment area with 8% slope) on the amount of water harvested in tree basin for young olive (Olea europaea L.) trees from November 2002 to July 2003. Soil moisture was monitored weekly during the rainy season and bi-weekly afterwards. To determine moisture changes in the catchment and target areas and amount of water harvested (in liters) for each tree, volumetric soil moisture content was measured at three or four points along the slope using a neutron probe down to a maximum depth of 120 cm, as soil depth allowed. WH structures increased soil moisture content in the rootzone compared to the catchment area. The rainfall threshold for runoff generation was less than 15 mm. Land slope was more important than micro-catchment size for increasing the amount of water harvested. Compared to the 8% slope, the 15% slope resulted in larger harvested amounts for small storms, but the two were comparable when storms were large. The large micro-catchment size resulted in higher amounts of harvested water only in the presence of storms greater than 26 mm. After adding the amounts lost by evapotranspiration, the net amount of water harvested in the tree basin of each tree for the 2002–2003 rainy season reached 722 and 688 l (or 361 and 344 mm) for treatments S15 and S8, respectively. Deeper soil profiles (i.e., >90 cm) were important to ensure longer storage periods. By early July, soil moisture content in the tree basin for treatments S15, L8 and S8 was still higher by 38, 13, and 5% respectively, than the levels recorded at the onset of the experiment. WH increased soil moisture content during the spring and early summer, a critical period for olive production.
9 Tamene, L.; Adimassu, Zenebe; Aynekulu, E.; Yaekob, T. 2017. Estimating landscape susceptibility to soil erosion using a GIS-based approach in northern Ethiopia. International Soil and Water Conservation Research, 5(3):221-230. [doi: https://doi.org/10.1016/j.iswcr.2017.05.002]
Soil profiles ; Soil conservation ; Erosion ; Geographical information systems ; Landscape conservation ; Land degradation ; Sediment transport ; Sedimentation ; Watersheds ; Catchment areas ; Rain ; Reservoir storage / Ethiopia
(Location: IWMI HQ Call no: e-copy only Record No: H048139)
http://www.sciencedirect.com/science/article/pii/S209563391630137X/pdfft?md5=f2cd5081ebf0f23056b3f7a851d98187&pid=1-s2.0-S209563391630137X-main.pdf
https://vlibrary.iwmi.org/pdf/H048139.pdf
https://vlibrary.iwmi.org/pdf/H048139.pdf
(1.29 MB)
Soil erosion is a very critical form of land degradation resulting in the loss of soil nutrients and downstream sedimentation of water storages in the highlands of Ethiopia. As it is technically and financially impossible to conserve all landscapes affected by erosion, identification of priority areas of intervention is necessary. Spatially distributed erosion models can help map landscape susceptibility to erosion and identify high erosion risk areas. Integration of erosion models with geographic information systems (GIS) enables assessing evaluate the spatial variability of soil erosion and plan implementing conservation measures at landscape levels. In this study, the Revised Universal Soil Loss Equation adjusted for sediment delivery ratio was used in a GIS system to assess landscape sensitivity to erosion and identify hotspots. The approach was applied in three catchments with size being 10–20 km2 and results were compared against quantitative and semi-quantitative data. The model estimated mean soil loss rates of about 45 t ha-1 y-1 with an average variability of 30% between catchments. The estimated soil loss rate is above the tolerable limit of 10 t ha-1 y-1. The model predicted high soil loss rates at steep slopes and shoulder positions as well as along gullies. The results of the study demonstrate that knowledge of spatial patterns of high soil loss risk areas can help deploy site-specific conservation measures.
10 Adimassu, Zenebe; Mul, Marloes; Owusu, Afua; Barron, Jennie; Kadyampakeni, Davie; Cofie, Olufunke O. 2016. Smallholder irrigation productivity for sustainable intensification: water balances for high value crops in northern Ghana. Ibadan, Nigeria: International Institute of Tropical Agriculture (IITA). 35p.
Smallholders ; Irrigation systems ; Water productivity ; Sustainability ; Intensification ; Water balance ; Estimation ; Rain ; Dry season ; Dry spells ; Rainfed farming ; Water management ; Crops ; Plant developmental stages ; Maize ; Vegetables ; Yield response functions ; Soil profiles ; Soil types ; Models / Ghana / Navrongo
(Location: IWMI HQ Call no: e-copy only Record No: H049041)
https://cgspace.cgiar.org/bitstream/handle/10568/83313/AR_WA_water_balance_dec2016.pdf?sequence=1&isAllowed=y
https://vlibrary.iwmi.org/pdf/H049041.pdf
https://vlibrary.iwmi.org/pdf/H049041.pdf
(1.63 MB) (1.63 MB)
11 Ibrakhimov, M.; Awan, U. K.; Sultanov, M.; Akramkhanov, A.; Djumaboev, Kakhramon; Conrad, C.; Lamers, J. 2019. Combining remote sensing and modeling approaches to assess soil salinity in irrigated areas of the Aral Sea Basin. Central Asian Journal of Water Research, 5(2):100-116. [doi: https://doi.org/10.29258/CAJWR/2019-R1.v5-2/64-81eng]
Soil salinization ; Irrigated land ; Remote sensing ; Modelling ; Forecasting ; Techniques ; Soil profiles ; Groundwater ; Irrigated farming ; Cotton ; Case studies / Uzbekistan / Aral Sea Basin / Khorezm
(Location: IWMI HQ Call no: e-copy only Record No: H049745)
(1.14 MB) (1.14 MB)
Accurate assessment of the soil salinization is an important step for mitigation of agricultural land degradation. Remote sensing (RS) is widely used for salinity assessment, but knowledge on prediction precision is lacking. A RS-based salinity assessment in Khorezm allows for modest reliable prediction with weak (R2=0.15–0.29) relationship of the salinity maps produced with RS and interpolation of electromagnetic EM38 during growth periods and more reliable (R2=0.35–0.56) beyond irrigation periods. Modeling with HYDRUS-1D at slightly, moderately and highly saline sites at various depths showed that irrigation forces salts to move to deeper layers: salts reappear in the upper profile during dry periods. Beyond irrigation events, salts gradually accumulated in the upper soil layers without fluctuations. Coupling RS techniques with numerical modeling provided better insight into salinity dynamics than any of these approaches alone. This should be of interest to farmers and policy makers since the combination of methods will allow for better planning and management.
12 Traore, K.; Traore, B.; Diallo, A.; Synnevag, G.; Aune, J. B. 2022. Farmer participatory evaluation of sorghum varieties in flood recession agriculture systems in North-Western Mali. Agronomy, 12(6):1379. [doi: https://doi.org/10.3390/agronomy12061379]
Farmer participation ; Participatory approaches ; Sorghum ; Varieties ; Breeding ; Farming systems ; Crop yield ; Floodplains ; Soil profiles ; Food security ; Villages ; Households / Mali / Kayes / Yelimane
(Location: IWMI HQ Call no: e-copy only Record No: H051182)
https://www.mdpi.com/2073-4395/12/6/1379/pdf?version=1654674736
https://vlibrary.iwmi.org/pdf/H051182.pdf
https://vlibrary.iwmi.org/pdf/H051182.pdf
(4.08 MB) (4.08 MB)
Flood recession farming is an important cropping system for ensuring food security in western Mali. The present study identified sorghum varieties adapted to this farming system. In the first year, numerous varieties were tested in the fields of 12 farmers. The 22 best-performing varieties, based on farmers’ scores using a preference index (PI), were further studied the following year. In the third year, the four varieties with the highest PI scores were tested against the local variety, Samé. The best-performing varieties were given the names Yélimané 1, Yélimané 2, Yélimané 3, and Yélimané 4. Across the three years, the best-performing variety, Yélimané 1, showed a 60.2% and 55.3% greater grain and stover yield, respectively, compared to the local Samé variety. The four improved varieties also reached maturity 30 days sooner than the local variety. A survey involving 101 farmers showed that the improved varieties, combined with higher plant density, seed priming and microdosing of mineral fertilizer, reduced the number of food-insecure months by 3.59 months. These varieties combined with improved agronomic practices have the potential to improve food security in flood recession areas in West Africa
13 Adimassu, Zenebe; Mul, Marloes; Owusu, Afua. 2023. Intra-seasonal rainfall variability and crop yield in the Upper East Region of Ghana. Environment, Development and Sustainability, 20p. (Online first) [doi: https://doi.org/10.1007/s10668-023-03861-2]
Rainfall patterns ; Seasonal variation ; Crop yield ; Water requirements ; Dry spells ; Rainfed farming ; Maize ; Millets ; Sorghum ; Sowing date ; Water deficit ; Water management ; Climatic data ; Soil profiles ; Models / West Africa / Ghana / Navrongo / Zuarungu
(Location: IWMI HQ Call no: e-copy only Record No: H052251)
(1.07 MB)
Occurrence of frequent dryspell is affecting agriculture; productivity in the semi-arid areas of West Africa such as northern Ghana. The objective of this study was to analyze the effects of dryspells on rainfed maize (early and late maturing), millet, and sorghum yields in a savanna agro-ecosystem in northern Ghana, and suggest management options for reducing their impacts. Long-term dryspell analyses were carried out using INSTAT + v3.37 on climatic data collected over a 30- to 50-year period. The probabilities of dryspells exceeding 7, 10, 14 and 21 days were calculated for crop types during different physiological growth stages and growing seasons of varying lengths. CROPWAT 8.0 was used to determine effective rainfall, crop water requirement, crop water deficit, and changes in yield. The results showed that 80% of the rains begin between the second week of May and the third week of June in the Upper East Region of Ghana. The result also revealed that more dryspells occurred after the initial growth stage of crops. During mid and late stages of crop growth there was a 50% probability of dryspells greater than seven days for early maturing maize and millet and of > 70% for sorghum. Late maturing maize experienced higher crop water deficit than early maturing maize. The result also showed that significant yield reduction (36% reduction in late maturing maize at both Navrongo and Zuarungu) occurs if planting is done before May 21. Similarly, 25 and 23% yield losses, were observed in sorghum at Navrongo and Zuarungu, respectively. We therefore recommend (i) early maturing crop varieties, (ii) adjusting sowing dates based on seasonal climate information, and (iii) improving water management.
14 Singh, J.; Angadi, S.; Begna, S.; VanLeeuwen, D.; Idowu, O. J.; Singh, P.; Trostle, C.; Gowda, P.; Brewer, C. 2024. Deficit irrigation strategy to sustain available water resources using guar. Industrial Crops and Products, 211:118272. (Online first) [doi: https://doi.org/10.1016/j.indcrop.2024.118272]
Water resources ; Water availability ; Irrigation water ; Rainfall ; Drought stress ; Irrigation management ; Biomass production ; Crop yield ; Aquifers ; Soil profiles
(Location: IWMI HQ Call no: e-copy only Record No: H052630)
(4.30 MB)
The gradual depletion of irrigation water is a major threat to the agricultural economy in the arid and semi-arid regions of the world. Drought–tolerant crops and improved irrigation management practices may help the sustainability of agriculture in the region. A three–year field experiment (2018–2020) was conducted to assess the effects of pre–and in–season irrigations on the physiology, biomass production, yield, and yield components of two diverse guar (Cyamopsis tetragonoloba) cultivars. A split-split plot design was used, where the main plot was pre–irrigation, subplots consisted of in–season irrigation treatments, and sub-sub plots were cultivars. Each treatment was replicated four times each year. Pre–irrigation improved the averaged final seed yield by 32% compared to plots with no pre–irrigation. Seed yield was significantly affected by in–season growth stage based irrigation treatments. Averaged over the years, full irrigation achieved the highest seed yield, although not significantly different from no irrigation during the vegetative growth stage in any study year. Cultivar Kinman performed better than Monument in biomass production and seed yield. Overall, pre–irrigation improves guar growth and development, leading to greater seed yield and biomass production. The most sustainable strategy to utilize the available water resources will be to grow guar with restricted irrigation during the vegetative growth stage, save 22% of water, and maintain a similar seed yield to plots that received irrigation throughout the crop season.
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