Your search found 12 records
1 Vyshpolsky, F.; Qadir, Manzoor; Karimov, Akmal; Mukhamedjanov, K.; Bekbaev, U.; Paroda, R.; Aw-Hassan, A.; Karajeh, F. 2008. Enhancing the productivity of high-magnesium soil and water resources in Central Asia through the application of phosphogypsum. Land Degradation and Development, 19: 45–56.
Soil degradation ; Soil amendments ; Soil properties ; Soil salinity ; Water quality ; Cotton ; Yields ; Irrigation scheduling ; Economic analysis / Kazakhstan
(Location: IWMI HQ Call no: IWMI 631.4 G772 VYS Record No: H040596)
Recent evidences from some irrigated areas worldwide, such as Central Asia, suggest that water used for irrigation contains magnesium (Mg2þ) at levels higher than calcium (Ca2þ). Excess levels of Mg2þ in irrigation water and/or in soil, in combination with sodium (Naþ) or alone, result in soil degradation because of Mg2þ effects on the soil’s physical properties. More than 30 per cent of irrigated lands in Southern Kazakhstan having excess levels of Mg2þ are characterized by low infiltration rates and hydraulic conductivities. The consequence has been a gradual decline in the yield of cotton (Gossypium hirsutum L.), which is commonly grown in the region. These soils require adequate quantities of Ca2þ to mitigate the effects of excess Mg2þ. As a source of Ca2þ, phosphogypsum—a byproduct of the phosphorous fertilizer industry—is available in some parts of Central Asia. In participation with the local farming community, we carried out a 4-year field experiment in Southern Kazakhstan to evaluate the effects of soil application of phosphogypsum—0, 4_5, and 8_0 metric ton per hectare (t ha_1)—on chemical changes in a soil containing excess levels of Mg2þ, and on cotton yield and economics. The canal water had Mg2þ to Ca2þ ratio ranging from 1_30 to 1_66 during irrigation period. The application of phosphogypsum increased Ca2þ concentration in the soil and triggered the replacement of excess Mg2þ from the cation exchange complex. After harvesting the first crop, there was 18 per cent decrease in exchangeable magnesium percentage (EMP) of the surface 0_2m soil over the pre- experiment EMP level in the plots where phosphogypsum was applied at 4_5 t ha_1, and a 31 per cent decrease in EMP in plots treated with phosphogypsum at 8 t ha_1. Additional beneficial effect of the amendment was an increase in the soil phosphorus content. The 4-year average cotton yields were 2_6 t ha_1 with 8 t ha_1 phosphogypsum, 2_4 t ha_1 with 4_5 t ha_1 phosphogypsum, and 1_4 t ha_1 with the control. Since the amendment was applied once at the beginning, exchangeable Mg2þ levels tended to increase 4 years after its application, particularly in the treatment with 4_5 tha_1 phosphogypsum. Thus, there would be a need for phosphogypsum application to such soils after every 4–5 years to optimize the ionic balance and sustain higher levels of cotton production. The economic benefits from the phosphogypsum treatments were almost twice those from the control.
2 Saifullah; Meers, E.; Qadir, Manzoor; de Caritat, P.; Tack, F. M. G.; Du Laing, G.; Zia, M. H. 2009. EDTA-assisted Pb phytoextraction. Review. Chemosphere, 74(10):1279-1291. [doi: https://doi.org/10.1016/j.chemosphere.2008.11.007]
(Location: IWMI HQ Call no: e-copy only Record No: H042522)
(0.33 MB)
Pb is one of the most widespread and metal pollutants in soil. It is generally concentrated in surface layers with only a minor portion of the total metal found in soil solution. Phytoextraction has been proposed as an inexpensive, sustainable, in situ plant-based technology that makes use of natural hyperaccumulators as well as high biomass producing crops to help rehabilitate soils contaminated with heavy metals without destructive effects on soil properties. The success of phytoextraction is determined by the amount of biomass, concentration of heavy metals in plant, and bioavailable fraction of heavy metals in the rooting medium. In general, metal hyperaccumulators are low biomass, slow growing plant species that are highly metal specific. For some metals such as Pb, there are no hyperaccumulator plant species known to date. Although high biomass-yielding non-hyperaccumulator plants lack an inherent ability to accumulate unusual concentrations of Pb, soil application of chelating agents such as EDTA has been proposed to enhance the metal concentration in above-ground harvestable plant parts through enhancing the metal solubility and translocation from roots to shoots. Leaching of metals due to enhanced mobility during EDTA-assisted phytoextraction has been demonstrated as one of the potential hazards associated with this technology. Due to environmental persistence of EDTA in combination with its strong chelating abilities, the scientific community is moving away from the use of EDTA in phytoextraction and is turning to less aggressive alternative strategies such as the use of organic acids or more degradable APCAs (aminopolycarboxylic acids). We have therefore arrived at a point in phytoremediation research history in which we need to distance ourselves from EDTA as a proposed soil amendment within the context of phytoextraction. However, valuable lessons are to be learned from over a decade of EDTA-assisted hytoremediation research when considering the implementation of more degradable alternatives in assisted phytoextraction practices.
3 Simmons, R.; Qadir, Manzoor; Drechsel, Pay. 2010. Farm-based measures for reducing human and environmental health risks from chemical constituents in wastewater. In Drechsel, Pay; Scott, C. A.; Raschid-Sally, Liqa; Redwood, M.; Bahri, Akissa (Eds.). Wastewater irrigation and health: assessing and mitigating risk in low-income countries. London, UK: Earthscan; Ottawa, Canada: International Development Research Centre (IDRC); Colombo, Sri Lanka: International Water Management Institute (IWMI). pp.209-238. (Also in French).
Wastewater irrigation ; Pollutants ; Metals ; Semimetals ; Soil amendments ; Bioremediation ; Nutrients ; Arsenic ; Salinity ; Irrigation methods
(Location: IWMI HQ Call no: IWMI 631.7.5 G000 DRE Record No: H042611)
(0.26 MB)
There is a significant imbalance between the number of publications describing potential and actual environmental and health impacts from chemically contaminated wastewater, and reports outlining concrete options to minimize the related risks where conventional wastewater treatment is not available. This gap applies more to inorganic and organic contaminants than excess salts or nutrients. This chapter outlines some of the options available that could be considered in and around the farm, looking at heavy metals, salts, excess nutrients and organic contaminants. The emphasis is placed on low-cost options applicable in developing countries. While such measures can reduce negative impacts to a certain extent, it remains crucial to ensure that hazardous chemicals are replaced in production processes; industrial wastewater is treated at source and/or separated from other wastewater streams used for irrigation purposes; and fertilizer application rates and related possible subsidies adjusted to avoid over- fertilization.
4 Simmons, R.; Qadir, Manzoor; Drechsel, Pay. 2011. Mesures mises en oeuvre aux champs pour reduire les risques pour la santé humaine et l’environnement lies aux constituants chimiques des eaux usees. In French. [Farm-based measures for reducing human and environmental health risks from chemical constituents in wastewater]. In Drechsel, Pay; Scott, C. A.; Raschid-Sally, Liqa; Redwood, M.; Bahri, Akissa. L’irrigation avec des eaux usees et la sante: evaluer et attenuer les risques dans les pays a faible revenu. Colombo, Sri Lanka: International Water Management Institute (IWMI); Ottawa, Canada: International Development Research Centre (IDRC); Quebec, Canada: University of Quebec. pp.227-257. (Also in English).
Wastewater irrigation ; Pollutants ; Metals ; Semimetals ; Soil amendments ; Bioremediation ; Nutrients ; Arsenic ; Salinity ; Irrigation methods
(Location: IWMI HQ Call no: IWMI Record No: H044468)
http://www.iwmi.cgiar.org/Research_Impacts/Research_Themes/Theme_3/PDF/French%20book.pdf
https://vlibrary.iwmi.org/pdf/H044468.pdf
https://vlibrary.iwmi.org/pdf/H044468.pdf
(0.80 MB) (5.96MB)
There is a significant imbalance between the number of publications describing potential and actual environmental and health impacts from chemically contaminated wastewater, and reports outlining concrete options to minimize the related risks where conventional wastewater treatment is not available. This gap applies more to inorganic and organic contaminants than excess salts or nutrients. This chapter outlines some of the options available that could be considered in and around the farm, looking at heavy metals, salts, excess nutrients and organic contaminants. The emphasis is placed on low-cost options applicable in developing countries. While such measures can reduce negative impacts to a certain extent, it remains crucial to ensure that hazardous chemicals are replaced in production processes; industrial wastewater is treated at source and/or separated from other wastewater streams used for irrigation purposes; and fertilizer application rates and related possible subsidies adjusted to avoid over- fertilization.
5 Mekuria, Wolde; Getnet, Kindie; Noble, Andrew; Hoanh, Chu Thai; McCartney, Matthew; Langan, Simon. 2013. Economic valuation of organic and clay-based soil amendments in small-scale agriculture in Lao PDR. Field Crops Research, 149(1):379-389. [doi: https://doi.org/10.1016/j.fcr.2013.05.026]
Soil amendments ; Economic value ; Smallholders ; Farmers ; Farming systems ; Crop yield ; Seasonality ; Maize ; Rain ; Sensitivity analysis ; Cost benefit analysis / Laos / Xaythany District / Veunkham / Naphok
(Location: IWMI HQ Call no: e-copy only Record No: H045994)
(1.68 MB)
At a farm level, economic returns are the single most important attributes that drive farmers to adopt agricultural technologies. This study was carried out at the Naphok and Veunkham villages, Lao PDR,to evaluate the yield response of a maize mono-cropping system to soil amendments and analyze the economic return of such interventions. The amendments were rice husk biochar, bentonite clay, compost, clay-manure compost, and rice husk biochar compost, in isolation and in various combinations. Over a period of two cropping seasons (2011–2012),the enhancement of maize yield due to soil amendments ranged from0.77 to 3.79tha-1 at Naphok and from 1.21 to 5.14tha-1 at Veunkham, resulting in net revenues ranging from -794 to 841 and -331 to 1391 US$ha-1 , respectively. Soils amended with low-cost amendments such as compost, rice husk biochar, rice husk biochar compost, and clay-manure compost were economically viable within the first cropping season. In contrast, soils amended with higher-cost amendments such as bentonite clay requires up to five years to be economically viable. Such variations indicate that taking into account maize yield revenues only does not provide sufficient incentives to farmers to adopt higher-cost soil amendments conclude that there is a possibility to sustainably increase agricultural productivity and improve the income of smallholders using locally available low-cost soil amendments. Our findings provide important information for decision makers to promote the adoption of low-cost soil amendments, and,thereby,to contribute to productivity growth and food security through sustainable intensification.
6 Mekuria, Wolde; Noble, Andrew; Hoanh, Chu Thai; McCartney, Matthew; Sengtaheuanghoung, O.; Sipaseuth, N.; Douangsavanh, Somphasith; Langan, Simon; Getnet, Kindie. 2014. The potential role of soil amendments in increasing agricultural productivity and improving the livelihood of smallholders in Lao PDR. Paper presented at the 15th National Agriculture and Forestry Research Institute Anniversary Symposium on Agriculture and Forestry Research for Development, Vientiane, Lao PDR, 8-10 April 2014. 15p.
Agricultural production ; Water productivity ; Soil amendments ; Smallholders ; Living standards ; Maize ; Nutrient uptake ; Biomass ; Economic aspects ; Case studies / Lao People's Democratic Republic
(Location: IWMI HQ Call no: e-copy only Record No: H046433)
The present study was undertaken in Lao PDR to investigate the impacts of organic and clay-based soil amendments on maize yield, total nutrient uptake and crop water productivity (CWP), and analyze the economic return of such interventions. 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. CWP and the soil water balance of the various treatments were determined using the AquaCrop model. To determine the costs and benefits of soil amendments over the two cropping seasons a cost-based valuation method was applied. Significant (p < 0.05) treatment effects in maize grain yields, total nutrient uptake and CWP were observed. At Veunkham, differences in yield between the control and amended soils 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. Differences in CWP between the amended and control plots at Veunkham varied between 0.3 and 1.0 kg m-3 in 2011 and from 0.05 to 0.29 kg m-3 in 2012, whereas differences at Naphok varied between 0.1 and 0.6 kg m-3 in 2011 and from 0.1 to 0.4 kg m-3 in 2012. Differences between the control and amended soils in yield and the associated CWP can be attributed to the improvements in total N and P uptake, soil pH, exchangeable Ca++ and Mg++, and CEC following the application of soil amendments. At both sites, in most of the treatments, yields and CWP in 2012 were significantly (p < 0.05) lower than 2011. This difference can be attributed to late season drought. Over the two cropping seasons , the enhancement of maize yield due to soil amendments resulted in net revenues ranging from -794 to 841 and -331 to 1391 US$ ha-1 at Naphok and Veunkham, respectively. The study found that soils amended with low-cost amendments such as compost, rice husk biochar, rice husk biochar compost, and clay-manure compost were economically viable within the first cropping season. In contrast, soils amended with higher-cost amendments such as bentonite clay required up to 5 years to be economically viable. Such variations indicate that maize yield revenues alone are an insufficient incentive for farmers to adopt higher-cost soil amendments. The results of this study confirm that soil amendments can be effective in improving crop yield and the associated CWP. In addition, the income of smallholders can be improved using locally available low-cost soil amendments. These findings provide important information for decision makers wishing to improve agricultural productivity and food security through sustainable intensification.
7 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.
8 Mekuria, Wolde; Noble, Andrew; McCartney, Matthew; Hoanh, Chu Thai; Douangsavanh, Somphasith; Langan, Simon. 2015. Soil management for raising crop water productivity in rainfed production systems in Lao PDR. Archives of Agronomy and Soil Science, 62(1):53-68. [doi: https://doi.org/10.1080/03650340.2015.1037297]
Soil management ; Soil amendments ; Soil organic matter ; Clay soils ; Crop production ; Water productivity ; Rainfed farming ; Climate change ; Evapotranspiration ; Land degradation ; Maize ; Biofuels ; Acidity / Lao People's Democratic Republic
(Location: IWMI HQ Call no: e-copy only Record No: H046994)
(0.26 MB)
This study investigated the impacts of organic- and clay-based soil amendments, and their combinations on crop water productivity (CWP) using maize as a test crop. On-station field trials were established over two consecutive years at the Naphok and Veunkham sites in Laos. At each site, 10 treatments were applied in a randomized complete block design with three replications. The treatments were control, rice husk biochar (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), bentonite clay + biochar, bentoniteclay + compost, biochar + compost, and bentonite clay + biochar + compost. All treatments were applied in 2011. Significant (p < 0.05) treatment effects in CWP and growing period evapotranspiration were determined. At Naphok, differences between the amended and control plots in CWP varied between 0.1 and 0.6 kg m-3 in 2011 and from 0.1 to 0.4 kg m-3 in 2012, whereas differences at Veunkham varied between 0.3 and 1.0 kg m-3 in 2011 and from 0.05 to 0.29 kg m-3 in 2012. At both sites, CWP in 2012 was significantly lower than 2011. Our results illustrate that organic- and claybased soil amendments improve CWP, indicating that soil-based interventions could be suitable options for improving agricultural productivity.
9 Woldetsadik, D.; Drechsel, Pay; Marschner, B.; Itanna, F.; Gebrekidan, H. 2017. Effect of biochar derived from faecal matter on yield and nutrient content of lettuce (Lactuca sativa) in two contrasting soils. Environmental Systems Research, 6(1):1-12. [doi: https://doi.org/10.1186/s40068-017-0082-9]
Waste management ; Faecal sludge ; Nutrients ; Septic tanks ; Nitrogen fertilizers ; Lettuces ; Soil amendments ; Soil fertility ; Biochar ; Composting ; Residues ; Yields
(Location: IWMI HQ Call no: e-copy only Record No: H047945)
http://environmentalsystemsresearch.springeropen.com/track/pdf/10.1186/s40068-017-0082-9?site=environmentalsystemsresearch.springeropen.com
https://vlibrary.iwmi.org/pdf/H047945.pdf
https://vlibrary.iwmi.org/pdf/H047945.pdf
(1.05 MB)
Background: Faecal matter biochar offers an interesting value proposition where the pyrolysis process guaranties a 100% pathogen elimination, as well as significant reduction in transport and storage weight and volume. Therefore, to evaluate the effect of (1) biochar produced from dried faecal matter from household based septic tanks, and (2) N fertilizer, as well as their interaction on yield and nutrient status of lettuce (Lactuca sativa), lettuce was grown over two growing cycles under glasshouse on two contrasting soils amended once at the start with factorial combination of faecal matter biochar at four rates (0, 10, 20 and 30 t ha-1) with 0, 25 and 50 kg N ha-1 in randomized complete block design. Results: For both soils, maximum fresh yields were recorded with biochar and combined application of biochar with N treatments. However, the greatest biochar addition effects (with or without N) with regard to relative yield were seen in less fertile sandy loam soil. We have also observed that faecal matter biochar application resulted in noticeable positive residual effects on lettuce yield and tissue nutrient concentrations in the 2nd growing cycle. For both soils, most nutrients analyzed (N, P, K, Mg, Cu and Zn) were within or marginally above optimum ranges for lettuce under biochar amendment. Conclusions: The application of faecal matter biochar enhances yield and tissue nutrient concentrations of lettuce in two contrasting soils, suggesting that faecal matter biochar could be used as an effective fertilizer for lettuce production at least for two growing cycles. Moreover, the conversion of the faecal matter feedstock into charred product may offer additional waste management benefit as it offers an additional (microbiologically safe) product compared to the more common co-composting.
10 Nartey, Eric Gbenatey; Amoah, Philip; Ofosu-Budu, G. K.; Muspratt, A.; Pradhan, Surendra Kumar. 2017. Effects of co-composting of faecal sludge and agricultural wastes on tomato transplant and growth. International Journal of Recycling of Organic Waste in Agriculture, 6(1):23-36. [doi: https://doi.org/10.1007/s40093-016-0149-z]
Faecal sludge ; Agricultural wastes ; Vegetables ; Tomatoes ; Transplanting ; Seedling production ; Composting ; Cocoa husks ; Solid wastes ; Organic wastes ; Greenhouse crops ; Inorganic fertilizers ; Temperature ; Nutrients ; Biochar ; Nitrogen ; Soil amendments ; Waste management
(Location: IWMI HQ Call no: e-copy only Record No: H047992)
http://link.springer.com/content/pdf/10.1007%2Fs40093-016-0149-z.pdf
https://vlibrary.iwmi.org/pdf/H047992.pdf
https://vlibrary.iwmi.org/pdf/H047992.pdf
(585 KB)
Purpose: Faecal sludge (FS) has been co-composted with many organic solid wastes globally. Agricultural wastes, such as oil palm empty fruit bunches (EFB) and cocoa pod husks (CPH), have received very little research attention as far as combining with FS is concerned. This study aimed at co-composting these wastes at different ratios to produce safe compost for use as soilless medium for raising tomato transplants. Methods: Dewatered FS (DFS) was mixed with shredded EFB and CPH at five different ratios: 1DFS:1EFB, 1DFS:1CPH, and DFS:EFB:CPH in ratios of 1:1:1, 2:1:1, and 2:2:1 and composted for 3 months. Select physicochemical parameters and pathogens were monitored every fortnightly and 3 weeks, respectively. Results: Maximum temperatures obtained ranged 46.8–54.5 °C. Though these temperatures were lower than sanitizing temperatures prescribed by USEPA, no E. coli was found in any of the piles at the end of composting. The ratio 2DFS:2EFB:1CPH was found to be the safest formulation and hence was used to grow tomato under greenhouse conditions. Tomato seeds were sown in three different growing media: 100% FS-based compost, 100% rice husk biochar, and 50% FS-based compost–50% rice husk biochar mix. Conclusion: Results showed that FS-based compost was a suitable growing medium for tomato. Further studies into the optimal rate and frequency of application of compost teas on tomato are recommended.
11 Getnet, K.; Mekuria, Wolde; Langan, S.; Rivington, M.; Novo, P.; Black, H. 2017. Ecosystem-based interventions and farm household welfare in degraded areas: comparative evidence from Ethiopia. Agricultural Systems, 154:53-62. [doi: https://doi.org/10.1016/j.agsy.2017.03.001]
Ecosystems ; Households ; Welfare ; Farm income ; Nutrition ; Soil organic matter ; Soil amendments ; Agricultural production ; Land degradation ; Organic fertilizers ; Composts / Ethiopia
(Location: IWMI HQ Call no: e-copy only Record No: H048464)
Agricultural productivity and farm household welfare in areas of severe land degradation can be improved through ecosystem-based interventions. Decisions on the possible types of practices and investments can be informed using evidence of potential benefits. Using farm household data together with a farm level stochastic simulation model provides an initial quantification of farm income and nutrition outcomes that can be generated over a five year period from manure and compost based organic amendment of crop lands. Simulated results show positive income and nutrition impacts. Mean farm income increases by 13% over the planning period, from US$32,833 under the business as usual situation (application of 50 kg DAP and 25 kg urea ha- 1 yr- 1) to US$37,172 under application of 10 t ha- 1 yr- 1 farm yard manure during the first three years and 5 t ha- 1 yr- 1 during the last two years. As a result of organic soil amendment, there is an associated increase in the available calorie, protein, fat, calcium, and iron per adult equivalent, giving the improvement in farm household nutrition. The evidence is substantive enough to suggest the promotion and adoption at scale, in degraded ecosystems, of low cost organic soil amendment practices to improve agricultural productivity and subsequent changes in farm household welfare.
12 Minhas, P. S.; Qadir, M.; Yadav, R. K. 2019. Groundwater irrigation induced soil sodification and response options. Agricultural Water Management, 215:74-85. [doi: https://doi.org/10.1016/j.agwat.2018.12.030]
Groundwater irrigation ; Soil amendments ; Sodic soils ; Water use ; Conjunctive use ; Infiltration water ; Alkalinity ; Irrigation water ; Irrigation scheduling ; Tillage ; Crop production ; Varieties ; Fertilizer application ; Organic fertilizers
(Location: IWMI HQ Call no: e-copy only Record No: H049167)
(0.84 MB)
The continuous surge in irrigation, particularly using groundwater for sustaining food security in many developing countries, has necessitated the utilization of low-quality waters especially in water-scarce arid and semi-arid regions. Inappropriate irrigation with these waters results in land and environment degradation produced by associated salts, sodium and other toxic elements. Generally the soil’s sodification process is insidious and build-up of exchangeable-Na is initially gradual. It stabilises at levels governed by sodicity indices of irrigation water, soil type, cropping sequences and agro-climatic conditions. As the soils become sodic, crop productivity declines and ultimately soils can become unsuitable for cropping. As a result, cultivators are forced to opt for tolerant crops, which are typically of less economic value. To minimize harmful effects of sodicity, remedial measures have been developed at the crop, root zone, farm and district/basin levels. These include water quality driven conjunctive uses, chemical amelioration of soils and irrigation waters, mobilising native calcite through phyto-remediation, growing tolerant crops, and other specialised tillage, fertiliser use and irrigation practices. This review seeks to critically analyse the role of these measures and the crop, water and soil factors defining the sodification vis-à-vis infiltration problems. The conclusions provided here are expected to be helpful for a range of stakeholders to promote irrigation with sodic/alkali waters, thereby partly alleviating the forecasted scarcities in water for agriculture.
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