Your search found 10 records
1 van Rensburg, L. D.; Groenewald, D. C.; Botha, J. J.; Anderson, J. J.; van Staden, P. P.; Kundhlande, G. 2003. The development and evaluation of a physical model for the communication of new crop production techniques to communal farmers. In Beukes, D.; de Villiers, M.; Mkhize, S.; Sally, H.; van Rensburg, L. (Eds.). Proceedings of the Symposium and Workshop on Water Conservation Technologies for Sustainable Dryland Agriculture in Sub-Saharan Africa (WCT), held at Bloem Spa Lodge and Conference Centre, Bloemfontein, South Africa, 8-11 April 2003. Pretoria, South Africa: ARC-Institute for Soil, Climate and Water. pp.239-244.
(Location: IWMI-HQ Call no: IWMI 631.7.1 G100 BEU Record No: H034408)
2 Botha, J. J.; Anderson, J. J.; Van Staden, P. P. 2015. Rainwater harvesting and conservation tillage increase maize yields in South Africa. Water Resources and Rural Development, 6:66-77. (Special issue: Managing Rainwater and Small Reservoirs in Sub-Saharan Africa). [doi: https://doi.org/10.1016/j.wrr.2015.04.001]
Rainwater ; Water harvesting ; Water productivity ; Water conservation ; Techniques ; Conventional tillage ; Minimum tillage ; Zero tillage ; Mechanical harvesting ; Soils ; Crop production ; Crop yield ; Maize ; On farm research ; Farmers ; Rural areas / South Africa / Eastern Cape / Limpopo / Free State
(Location: IWMI HQ Call no: e-copy only Record No: H047514)
(0.23 MB)
Poverty and food insecurity are common amongst rural communities in the sub-Saharan African region. The rural population of South Africa is not excluded from poverty. With normal conventional tillage practices, crop failures are common on marginal soils in semi-arid areas with low and erratic rainfall. Therefore, selected rural communities in the Eastern Cape, Limpopo and Free State Provinces of South Africa were introduced to appropriate rainwater harvesting and conservation agricultural techniques to contribute towards the reduction of food insecurity through improved maize yields. Conventional tillage, no-till, minimum tillage, mechanized basins, in-field rainwater harvesting and the Daling plough were tested in on-station and on-farm field experiments over three to five maize growing seasons (2008/09–2011/13). The rainwater harvesting (in-field rainwater harvesting and Daling plough) and conservation (mechanized basins, no-till and minimum tillage) techniques resulted in slightly higher yields than conventional tillage due to their potential to conserve rainwater better and to harvest additional rainwater. Conventional tillage, no-till and minimum tillage had lower grain yields because they lost on average 18% of the total rainfall to ex-field runoff. The rainwater productivity of the Daling plough treatment was very similar to that of in-field rainwater harvesting, followed by mechanized basins, conventional tillage and no-till or minimum tillage.
3 Hussein, M. A.; Muche, H.; Schmitter, Petra; Nakawuka, P.; Tilahun, S. A.; Langan, Simon; Barron, Jennie; Steenhuis, T. S. 2019. Deep tillage improves degraded soils in the (sub) humid Ethiopian highlands. Land, 8(11):1-15. [doi: https://doi.org/10.3390/land8110159]
Agricultural production ; Deep tillage ; Soil degradation ; Humid zones ; Highlands ; Watersheds ; Conventional tillage ; Hardpans ; Sediment ; Rain ; Runoff ; Soil loss ; Soil moisture ; Infiltration ; Maize ; Crop yield / Ethiopia / Robit-Bata Watershed
(Location: IWMI HQ Call no: e-copy only Record No: H049375)
(2.40 MB) (2.40 MB)
Intensification of rainfed agriculture in the Ethiopian highlands has resulted in soil degradation and hardpan formation, which has reduced rooting depth, decreased deep percolation, and increased direct runoff and sediment transport. The main objective of this study was to assess the potential impact of subsoiling on surface runoff, sediment loss, soil water content, infiltration rate, and maize yield. Three tillage treatments were replicated at five locations: (i) no tillage (zero tillage), (ii) conventional tillage (ox-driven Maresha plow, up to a depth of 15 cm), and (iii) manual deep ripping of the soil’s restrictive layers down to a depth of 60 cm (deep till). Results show that the posttreatment bulk density and penetration resistance of deep tillage was significantly less than in the traditional tillage and zero-tillage systems. In addition, the posttreatment infiltration rate for deep tillage was significantly greater, which resulted in significantly smaller runoff and sedimentation rates compared to conventional tillage and zero tillage. Maize yields were improved by 6% under deep tillage compared to conventional tillage and by 29% compared to no tillage. Overall, our findings show that deep tillage can be effective in overcoming some of the detrimental effects of hardpans in degraded soils.
4 Belay, S. A.; Schmitter, Petra; Worqlul, A. W.; Steenhuis, T. S.; Reyes, M. R.; Tilahun, S. A. 2019. Conservation agriculture saves irrigation water in the dry monsoon phase in the Ethiopian highlands. Water, 11(10):1-16. [doi: https://doi.org/10.3390/w11102103]
Conservation agriculture ; Irrigation water ; Arid climate ; Monsoon climate ; Highlands ; Conventional tillage ; Irrigation scheduling ; Farmers ; Irrigation practices ; Water use efficiency ; Irrigated farming ; Crop yield ; Onions ; Garlic ; Farmer-led irrigation ; Soil moisture / Ethiopia / Dengeshita
(Location: IWMI HQ Call no: e-copy only Record No: H049377)
(1.45 MB) (1.45 MB)
Water resources in sub-Saharan Africa are more overstressed than in many other regions of the world. Experiments on commercial farms have shown that conservation agriculture (CA) can save water and improve the soil. Nevertheless, its benefits on smallholder irrigated farms have not been adequately investigated, particularly in dry monsoon phase in the Ethiopian highlands. We investigated the effect of conservation agriculture (grass mulch cover and no-tillage) on water-saving on smallholder farms in the Ethiopian highlands. Irrigated onion and garlic were grown on local farms. Two main factors were considered: the first factor was conservation agriculture versus conventional tillage, and the second factor was irrigation scheduling using reference evapotranspiration (ETo) versus irrigation scheduling managed by farmers. Results showed that for both onion and garlic, the yield and irrigation water use efficiency (IWUE) was over 40% greater for CA than conventional tillage (CT). The soil moisture after irrigation was higher in CA compared with CT treatment while CA used 49 mm less irrigation water. In addition, we found that ETo-based irrigation was superior to the farmers’ irrigation practices for both crops. IWUE was lower in farmers irrigation practices due to lower onion and garlic yield responses to overirrigation and greater water application variability.
5 Assefa, T.; Jha, M.; Reyes, M.; Worqlul, A. W.; Doro, L.; Tilahun, S. 2020. Conservation agriculture with drip irrigation: effects on soil quality and crop yield in Sub-Saharan Africa. Journal of Soil and Water Conservation, 75(2):209-217. [doi: https://doi.org/10.2489/jswc.75.2.209]
Conservation agriculture ; Drip irrigation ; Soil quality ; Crop yield ; Forecasting ; Agricultural policy ; Conventional tillage ; Crop production ; Environmental modelling / Africa South of Sahara / United Republic of Tanzania / Ghana / Ethiopia / Dangishita / Robit / Yemu / Mkindo
(Location: IWMI HQ Call no: e-copy only Record No: H049628)
(0.66 MB)
The traditional agriculture production system in sub-Saharan Africa (SSA) caused significant soil erosion and degradation of soil quality. In addition, dependability of rainfall for irrigation needs limits the crop production. Advanced agricultural practices are thus needed at the local level to sustain the livelihood of smallholder farmers in the region. In this study, conservation agriculture (CA) practice with drip irrigation technology was compared (using field experiments and watershed modeling) with the traditional conventional tillage (CT) practice for its potential in improving soil quality and crop productivity in the region. Biophysical data were collected (2015 to 2017) from a total of 43 paired plots (CA and CT) at four study sites in SSA: Dangishita and Robit in Ethiopia, Yemu in Ghana, and Mkindo in Tanzania. The Agricultural Policy/Environmental eXtender (APEX) model was calibrated and validated with reasonable efficiency in simulating crop yields for both CA and CT practices; average PBIAS =±12% and =±11%, for CA and CT. The impact of the CA system on soil quality (soil carbon [C] and nitrogen [N]) was analyzed based on the well-tested model prediction results. The total C and N were increased under CA across the study sites on average by 6% and 4.1%, when compared to CT over the study period. Both the experiment and model prediction showed that crop yield was significantly improved by CA—on average 37.4% increases across the sites when compared to CT. Conservation agriculture with drip irrigation was an efficient local strategy to improve crop production in the region while enhancing the ecosystem.
6 Belay, S. A.; Assefa, T. T.; Prasad, P. V. V.; Schmitter, Petra; Worqlul, A. W.; Steenhuis, T. S.; Reyes, M. R.; Tilahun, S. A. 2020. The response of water and nutrient dynamics and of crop yield to conservation agriculture in the Ethiopian highlands. Sustainability, 12(15):5989. [doi: https://doi.org/10.3390/su12155989]
Conservation agriculture ; Water use ; Nutrient availability ; Crop yield ; Highlands ; Supplemental irrigation ; Conventional tillage ; Irrigation water ; Water management ; Crop management ; Pepper ; Growth period ; Fertilizers ; Phosphorus ; Nitrogen ; Leachates ; Rain ; Runoff ; Evapotranspiration / Ethiopia / Dengeshita
(Location: IWMI HQ Call no: e-copy only Record No: H049873)
(2.48 MB) (2.48 MB)
Smallholder agriculture constitutes the main source of livelihood for the Ethiopian rural community. However, soil degradation and uneven distribution of rainfall have threatened agriculture at present. This study is aimed at investigating the impacts of conservation agriculture on irrigation water use, nutrient availability in the root zone, and crop yield under supplementary irrigation. In this study, conservation agriculture (CA), which includes minimum soil disturbance, grass mulch cover, and crop rotation, was practiced and compared with conventional tillage (CT). We used two years’ (2018 and 2019) experimental data under paired-t design in the production of a local variety green pepper (Capsicum annuum L.). The results showed that CA practices significantly (a = 0.05) reduced irrigation water use (13% to 29%) and runoff (29% to 51%) while it increased percolated water in the root zone (27% to 50%) when compared with CT practices under the supplementary irrigation phase. In addition, CA significantly decreased NO3-N in the leachate (14% to 44%) and in the runoff (about 100%), while PO4-P significantly decreased in the leachate (33% to 50%) and in the runoff (16%) when compared with CT. Similarly, CA decreased the NO3-N load in the leachate and in the runoff, while the PO4-P load increased in the leachate but decreased in the runoff. The yield return that was achieved under CA treatment was 30% higher in 2018 and 10% higher in 2019 when compared with the CT. This research improves our understanding of water and nutrient dynamics in green pepper grown under CA and CT. Use of CA provides opportunities to optimize water use by decreasing irrigation water requirements and optimize nutrient use by decreasing nutrient losses through the runoff and leaching.
7 Kumara, T. M. K.; Kandpal, A.; Pal, S. 2020. A meta-analysis of economic and environmental benefits of conservation agriculture in South Asia. Journal of Environmental Management, 269:110773. [doi: https://doi.org/10.1016/j.jenvman.2020.110773]
Conservation agriculture ; Economic value ; Environmental factors ; Climate change ; Cropping systems ; Water use ; Conventional tillage ; Soil texture ; Carbon sequestration ; Greenhouse gas emissions ; Emission reduction / South Asia
(Location: IWMI HQ Call no: e-copy only Record No: H049916)
(0.68 MB)
Agriculture plays a key role in ensuring food and livelihood security in South Asia. However, this region is vulnerable to climate change which is likely to impact the livelihoods of millions of marginal and small holders. Agriculture is not only impacted by climate change but also one of the major contributor to global warming in South Asia. As compared to the traditional practices, Conservation Agriculture (CA) practices help mitigate the impact of climate change through a reduction in carbon emission and conservation of natural resources. In this article, a meta-analysis of the important studies was done for the impact of CA on carbon sequestration, water use, greenhouse gas emissions and cost and net returns. Carbon sequestration potential was found significantly higher in the CA practices (+16.30%) as compared to the conventional tillage. Inclusion of legumes, clay-rich soils, irrigation and presence of soil cover are the major drivers for higher carbon sequestration potential in the region. Additionally, a significant amount of water was also saved as CA practices led to relatively less consumption of water over the conventional tillage. Further, the adoption of CA based management practices resulted in a substantial reduction of CO2 (-4.28%) and CH4 (-25.67%) emissions both in aerobic and anaerobic soil conditions. However, the emission of NO2 and N2O–N gases were higher under the CA, +14.45 and + 5.20% respectively. Nevertheless, the emission of N2O–N was lesser in CA (-1.78%) under aerobic conditions whereas it is increased under anaerobic soil conditions (+12.15%). The adoption of CA practices resulted in higher returns and lower costs as compared to the conventional system. Although CA has significant environmental benefits, the study suggests judicious use of inorganic inputs under CA for managing the impact of climate change in South Asia. Therefore, CA is a sustainable agricultural practice that deserves outscaling in South Asia for mitigation and adaptation of climate change.
8 Belay, S. A.; Assefa, T. T.; Worqlul, A. W.; Steenhuis, T. S.; Schmitter, Petra; Reyes, M. R.; Prasad, P. V. V.; Tilahun, S. A. 2022. Conservation and conventional vegetable cultivation increase soil organic matter and nutrients in the Ethiopian highlands. Water, 14(3):476. (Special issue: Hydrology and Sedimentology of Hilly and Mountainous Landscapes) [doi: https://doi.org/10.3390/w14030476]
Conservation agriculture ; Conventional tillage ; Soil organic matter ; Soil fertility ; Nutrients ; Highlands ; Vegetable crops ; Irrigation water / Africa South of Sahara / Ethiopia / Dengeshita
(Location: IWMI HQ Call no: e-copy only Record No: H051088)
https://www.mdpi.com/2073-4441/14/3/476/pdf?version=1644302965
https://vlibrary.iwmi.org/pdf/H051088.pdf
https://vlibrary.iwmi.org/pdf/H051088.pdf
(1.69 MB) (1.69 MB)
Agriculture in Africa is adversely affected by the loss of soil fertility. Conservation agriculture (CA) was introduced to curb the loss of soil fertility and water shortages and improve crop productivity. However, information on how CA practices enhance soil quality and nutrients is scarce in the sub-Saharan Africa context. The objective of this study was to investigate the effects of CA and conventional tillage (CT) on soil organic matter and nutrients under irrigated and rainfed vegetable on-farm production systems. During the dry and wet monsoon phases in the northern Ethiopian Highlands, a four-year experiment with CA and CT was carried out on ten vegetable farms under rainfed and irrigated conditions. Although the increase in concentration of organic matter in CA was generally slightly greater than in CT, the difference was not significant. The average organic matter content in the top 30 cm for both treatments increased significantly by 0.5% a-1 from 3% to almost 5%. The increase was not significant for the 30–60 cm depth. The total nitrogen and available phosphorus concentrations increased proportionally to the organic matter content. Consequently, the extended growing season, applying fertilizers and livestock manure, and not removing the crop residue increased the nutrient content in both CA and CT. The increase in CA was slightly greater because the soil was not tilled, and hay was applied as a surface cover. Although CA increased soil fertility, widespread adoption will depend on socioeconomic factors that determine hay availability as a soil cover relative to other competitive uses.
9 Fuentes-Ponce, M. H.; Gutierrez-Diaz, J.; Flores-Macias, A.; Gonzalez-Ortega, E.; Mendoza, A. P.; Sanchez, L. M. R.; Novotny, I.; Espindola, I. P. M. 2022. Direct and indirect greenhouse gas emissions under conventional, organic, and conservation agriculture. Agriculture, Ecosystems and Environment, 340:108148. (Online first) [doi: https://doi.org/10.1016/j.agee.2022.108148]
Greenhouse gas emissions ; Conventional tillage ; Organic matter ; Conservation agriculture ; Reduced tillage ; Intercropping ; Carbon dioxide ; Methane ; Nitrous oxide ; Agroecosystems ; Biomass ; Fertilizers / Mexico / Cocotitlan
(Location: IWMI HQ Call no: e-copy only Record No: H051403)
(3.08 MB)
Farm activities contribute to approximately one-third of Greenhouse Gas (GHG) emissions. Most of the GHG in the atmosphere comes from carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O). The main objective of this research is to investigate direct and indirect GHG emission in five different agroecosystems, contrasted by tillage agricultural, farm practices (oat and maize-fava and vetch).CO2, N2O y CH4 concentrations were measured using two closed static chambers. Total biomass and production costs were determined. Indirect emissions were calculated from fuel used in producing and packing of synthetic fertilizers and herbicide, and sheep manure mineralization. The results showed that CO2 was the gas that most contributes to GHG emissions followed by the CH4 and NO2. The agrosystem with reduce tillage and synthetic inputs had the highest emissions (979 CO2 eq kg ha-1). Agrosystems using synthetic inputs (conventional and reduce tillage) showed higher indirect emissions (958 and 856 CO2 eq kg ha-1 respectively). Maize in monoculture produced more than the systems with rotation or intercropping. Reduced tillage with intercropping and organic inputs was the most expensive to produce but had the least gas emission per dollar invested and per kilogram of biomass produced while conventional tillage agrosystems with organic or synthetic inputs stored little carbon in the soil, produced less biomass per unit area and presented higher CO2 eq emissions per unit of biomass.
10 Mulimbi, W.; Nalley, L. L.; Strauss, J.; Ala-Kokko, K. 2023. Economic and environmental comparison of conventional and conservation agriculture in South African wheat production. 20p. (Online first) [doi: https://doi.org/10.1080/03031853.2023.2169481]
Conservation agriculture ; Wheat ; Conventional tillage ; Policy making ; Environmental impact / South Africa / Western Cape
(Location: IWMI HQ Call no: e-copy only Record No: H051711)
https://www.tandfonline.com/doi/epdf/10.1080/03031853.2023.2169481?needAccess=true&role=button
https://vlibrary.iwmi.org/pdf/H051711.pdf
https://vlibrary.iwmi.org/pdf/H051711.pdf
(1.74 MB) (1.74 MB)
Global wheat yields must increase to meet current and rising global demand despite the increasing threats to production resulting from climate change. One climate change adaptation strategy in wheat production in the Western Cape of South Africa is conservation agriculture (CA). Using a data set of 1,043 plot-level wheat observations collected at Langgewens and Tygerhoek research farms from 2002 to 2020, this study conducts a stepwise Life Cycle Assessment (LCA) to estimate the environmental and economic impacts of switching from conventional wheat production to CA’s zero tillage (zero-till) and no-tillage (no-till) systems. The results indicate that CA is more profitable and has a higher environmental efficiency, than conventional tillage wheat production. In Langgewens, zero-till and no-till are respectively 113% and 55% more efficient than conventional tillage when comparing the environmental impact of producing one kg of wheat. Findings also suggest that, compared to 100% conventional tillage wheat production, the adoption of CA systems has led to reductions in environmental damage valued between R269.2 and R402.5 million in the Western Cape.
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