Papers by Teklu Erkossa Jijo
Maize (Zea mays) is among the major cereals grown in the high rainfall areas of the sub-Saharan A... more Maize (Zea mays) is among the major cereals grown in the high rainfall areas of the sub-Saharan Africa's (SSA) such as the Ethiopian part of the Blue Nile basin. However, its productivity is severely constrained by poor soil, water and crop management practices. This study simulated water productivity of the crop under varying soil fertility scenarios (poor, near optimal and non limiting) using hybrid seeds under rainfed conditions using the FAO Aqua-Crop model. The result indicated that grain yield of maize increased from 2.5 tons·ha -1 under poor to 6.4 and 9.2 tons·ha -1 with near optimal and non-limiting soil fertility conditions. Correspondingly, soil evaporation decreased from 446 mm to 285 and 204 mm, while transpiration increased from 146 to 268 and 355 mm. Consequently, grain water productivity was increased by 48% and 54%, respectively, with the near optimal and non-limiting soil fertility conditions. The water productivity gain mainly comes from reduced evaporation and increased transpiration without significantly affecting water left for downstream ecosystem services. Therefore, this has a huge implication for a basin scale water management planning for various purposes.
The study was conducted at Caffee Doonsa (08 • 88 N, 39 • 08 E; 2400 m asl), a small watershed in... more The study was conducted at Caffee Doonsa (08 • 88 N, 39 • 08 E; 2400 m asl), a small watershed in the central highlands of Ethiopia, in order to identify farmers' goals of soil management and the indicators they use in selecting soils for a certain function, and to categorise the soils in different quality groups with respect to the major functions. Thirty-six male farmers of different age and wealth groups participated in a Participatory Rural Appraisal technique. They listed and prioritised 12 soil functions in the area and itemised the soil quality indicators (characteristics). Based on the indicators, the soils in the watershed were classified into 3 soil quality (SQ) groups (Abolse,Kooticha, and Carii). The SQ groups have been evaluated and ranked for the major soil functions. For crop production, Abolse was graded best, followed by Kooticha and Carii, respectively. The grain and straw yield data of wheat (Triticum aestivum L.) taken from the SQ groups confirmed the farmers claim, in that Abolse gave the highest grain yield (4573 kg/ha), followed by 4411 and 3657 kg/ha for Kooticha and Carii, respectively. Local insights should be included in systematic soil quality assessment, and in planning and implementation of various soil management interventions.
Soil quality indexing is a new approach in spatial and temporal evaluation of land management sys... more Soil quality indexing is a new approach in spatial and temporal evaluation of land management systems effects on soils' capacity to function. A field experiment was conducted at Caffee Doonsa (2400 m a.s.l., 08 • 57 N, 39 • 06 E) for 6 years (1998)(1999)(2000)(2001)(2002)(2003) to compare the effects of land preparation methods on soil quality (SQ) and to test the use of the Soil Management Assessment Framework (SMAF) in assessing SQ under the Ethiopian Central Highlands conditions. Four methods of land preparation [broad bed and furrows (BBF), green manure (GM), ridge and furrows (RF), and reduced tillage (RT)] were arranged in a randomised complete block design with 3 replications on permanent plots (22 m by 6 m). Physical, chemical, and biological SQ indicators were determined and scored, and a soil quality index (SQI) was developed using the SMAF procedures. Seven SQ indicators including microbial biomass carbon (MBC), bulk density, aggregate stability (AGG), soil organic carbon (C org ), pH, available water capacity (AWC), and available phosphorus were selected as a minimum dataset. The scored values of the indicators ranged from 0.21 for AGG and 0.97 for pH, both under BBF. Compared with RF (control), all the alternatives (GM, BBF, and RT) increased the scores of C org and MBC. Moreover, BBF and GM increased the score values of AWC and AGG, respectively. Consequently, there was a non-significant increase in SQI due to the use of GM, BBF, and RT compared with the control. As a result, the land preparation methods may be preferred in a decreasing order GM ≥ BBF ≥ RT ≥ RF for the management goal of crop production. The study indicated that SMAF could be a robust tool to assess the performance of land management methods on soil quality in the study area, but some modifications may be required to fit to the prevailing cropping system and soil characteristics.
The promotion and adoption of new tillage practices requires that their potential on-site, off-si... more The promotion and adoption of new tillage practices requires that their potential on-site, off-site, and economic effects are acceptable. Consequently, a field experiment was conducted at Caffee Doonsa (2400 m a.s.l.; 08 • 57 N, 39 • 06 E) in the Central Highlands of Ethiopia for 6 years (1998)(1999)(2000)(2001)(2002)(2003) to evaluate the effects of tillage practices on sustainable productivity and quality of the soil. Four tillage methods [broad bed and furrows (BBF), green manure (GM), ridge and furrows (RF), and reduced tillage (RT)] were arranged in a randomised complete block design with 3 replications on permanent plots (22 m by 6 m). Three crops comprising durum wheat (Triticum durum Desf.), lentil (Lens culinaries Medik), and tef (Eragrostis tef), were sown in rotation. Relative crop productivity index (RPI), financial profitability, the nutrient enrichment ratio (ER) of the eroded sediment, and soil quality index (SQI) were used as performance indicators. With its highest RPI, the use of BBF significantly increased the grain yield of lentils by 59% compared with the control, and RT resulted in the highest grain yield of wheat and tef. Economically, BBF was the most profitable option for lentils with 65% increase in gross margin, whereas RT resulted in 11% and 8% increase in that of wheat and tef, respectively. The ER indicated that the nutrient and organic matter content of the eroded sediment was always greater than that of surface soil, but there were no consistent effects associated with the treatments. The SQI showed a positive trend for GM, BBF, and RT, but differences were not statistically different at P ≤ 0.05. Overall, none of the tillage treatments was superior, but we encourage use of BBF and RT because of their positive productivity and economic trends. Further research is needed to tap the potential soil quality improvements anticipated for the GM treatment. To optimise the overall benefits, a complete system has to be developed, perhaps using BBF for lentils followed by RT for wheat and tef.
Rainfed agriculutre in Ethiopia is constrained by temporal and spatial variations in climate and ... more Rainfed agriculutre in Ethiopia is constrained by temporal and spatial variations in climate and severe land degradation caused by soil erosion that is exacerbated by lack of appropriate technologies. The continued shrinking per capita agriculutral land due to population growth and diminishing land quality challenges the livelihood of the communities. This requires multifaceted and targeted interventions. Testing and scalling up of interventions require a relatively uniform system, but the basin's potential and constraints for crop and livestock productivity is hetrogenous. Farming systems are often taken as important entry point for scaling up of agricultural technolgies. Based on secondary data on climate, soil, crop and livestock, and the master plan of the subbasins, this study clustered and mapped the major farming systems and subsystems in the Nile Basin. Two major systems, the mixed crop-livestock farming and the pastoral/agropastoral livelihoods have been identified. The former was sub-grouped into the cereal based, coffee-tree crops complex and the enset-root crops complex subsystems. The cereal based system was further classified into the single cropping, double cropping and shifting cultivation subsystems, each of which was subdivided based on the dominant crop. The current productivity of the major crops in each farming systems was analysed and found to be lower than not only their potential but also their national average. However, some selected soil, water and crop management technologies have shown substantial yield increase. Thereore, it is believed scaling up of proven tachnologies within a farming system can substantially enhance crop yield and imrpove livelhood.
In water stressed regions such as the Central Rift Valley of Ethiopia, increasing Crop Water Prod... more In water stressed regions such as the Central Rift Valley of Ethiopia, increasing Crop Water Productivity (CWP) is imperative for sustainable food and water security. This paper presents CWP of Teff (Eragrostic Tef), a staple food in Ethiopia and an important export crop. Field experiments were conducted under irrigated agriculture during the dry seasons in the periods: 1) November 2010 to March 2011; and 2) December 2011 to April, 2012 at Melkassa Agricultural Research Centre in Ethiopia. Teff crop was irrigated at sixteen different water application depths ranging from 100 to 25 % of the optimum Crop Water Evapotranspiration (ETc.) during the four growing stages, the initial, development, mid season and late season. The effect of seeding rates of 25 kg/ha and 10 kg/ha on lodging and yield of the crop was also determined. The main results were: 1) At 25 % deficit irrigation applied for the whole growth period, Teff CWP was the highest at 1.16 and 1.08 kg/m 3 respectively for the seeding rates of 25 kg/ha and 10 kg/ha; 2) the CWP slightly decreased to 1.12 and 1.07 kg/m 3 when the 25 % deficit was applied during the late season stage; 3) the crop yield response factor (K y ) of 1.09 and 1.19 was obtained for seeding rates of 25 kg/ha and 10 kg/ha respectively; the equivalent biomass response factor (K y ) was less at 0.88 and 0.96 respectively.
Ethiopian Journal of …, Jan 1, 1999
Ethiopian Journal of Natural Resources., Jan 1, 2007
Abstract (English) Soil microbial biomass is part of the active pool of soil organic matter playi... more Abstract (English) Soil microbial biomass is part of the active pool of soil organic matter playing a vital role in the decomposition of organic matter, nutrient cycling and biophysical manipulation of soil structure. It is both source and sink of plant nutrients in the soil. It is a ...
Soil use and management, Jan 1, 2005
Vertisols are among the most common, high-potential soils in the central highlands of Ethiopia, w... more Vertisols are among the most common, high-potential soils in the central highlands of Ethiopia, where over 88% of human and 77% of the livestock population are located. Productivity from these soils is constrained by severe waterlogging due to their physical properties and intensive rainfall in summer. Traditionally, farmers plant late in the season to avoid the waterlogging, which results in harvest yields that are far below optimal. To bridge this yield gap, the broad-bed and furrow system for surface drainage has been introduced. Despite reported yields of various crops, little is known of the on-site and off-site impacts of this system. Consequently, four land preparation methods viz. (i) broad-bed and furrow (BBF), (ii) green manure (GM), (iii) the traditional system of ridge and furrow (RF) and (iv) reduced tillage (RT) were compared on standard runoff plots for 5 years (1998 -2002) at Caffee Doonsaa in the central Highlands of Ethiopia. Runoff, sediment, organic carbon and nutrient (organic nitrogen and available phosphorus) losses were determined during the last two years (2001 and 2002). Over 50% of the seasonal rainfall was lost as runoff, regardless of the treatment, with significantly more of the excess water running off BBF and RT treatments in both years. The BBF system drained 67% and 54% of rainfall as runoff in 2001 and 2002, respectively, compared with 61% and 53% from the RT system during the measurement period. Although not statistically significant, the largest sediment and total nutrient losses tended to be from the BBF. The effect of the treatments on total nutrient loss and enrichment ratio was inconsistent. The nutrient concentration in the eroded sediment was greater than that of the originating surface soil but was strongly correlated. The effect of the land preparation methods was significant and varied with crops. Recommended options for best crop productivity are BBF for lentil and RT for wheat and tef.
Irrigation and Drainage, Jan 1, 2011
Waterlogging is a challenge to wheat (Triticum durum Desf.) productivity under the rainfed system... more Waterlogging is a challenge to wheat (Triticum durum Desf.) productivity under the rainfed system on Vertisols in the Ethiopian Highlands. However, using suitable seedbed types and manipulating planting dates can minimize the effects. A four-year (2000-2003) field experiment was conducted to evaluate three seedbed types, broad bed and furrows (BBF) with early planting, the traditional ridge and furrows (RF) and its modified version (wide ridge and furrows (WRF)), both under early and late planting, in terms of water productivity of wheat. The FAO AquaCrop model was used to estimate crop water requirements. The result indicated that late planting on WRF or RF significantly ( p < 0.05) increased grain yield and water productivity. Late planting on WRF (LWRF) increased rainfall water productivity by 66, 44 and 51%, respectively, as compared to BBF, earlyplanted WRF (EWRF) and late-planted RF (LRF). This was because of its increased effective area for crop growth over the RF and its relative suitability of planting time over the BBF. Therefore, late-planted WRF can be used for enhanced water productivity of wheat, while introducing fast-grow crops that are tolerant to waterlogging and growing early in the season may further enhance the land and water productivity in the area.
Agricultural Sciences, Jan 1, 2011
Maize (Zea mays) is among the major cereals grown in the high rainfall areas of the sub-Saharan A... more Maize (Zea mays) is among the major cereals grown in the high rainfall areas of the sub-Saharan Africa's (SSA) such as the Ethiopian part of the Blue Nile basin. However, its productivity is severely constrained by poor soil, water and crop management practices. This study simulated water productivity of the crop under varying soil fertility scenarios (poor, near optimal and non limiting) using hybrid seeds under rainfed conditions using the FAO Aqua-Crop model. The result indicated that grain yield of maize increased from 2.5 tons·ha -1 under poor to 6.4 and 9.2 tons·ha -1 with near optimal and non-limiting soil fertility conditions. Correspondingly, soil evaporation decreased from 446 mm to 285 and 204 mm, while transpiration increased from 146 to 268 and 355 mm. Consequently, grain water productivity was increased by 48% and 54%, respectively, with the near optimal and non-limiting soil fertility conditions. The water productivity gain mainly comes from reduced evaporation and increased transpiration without significantly affecting water left for downstream ecosystem services. Therefore, this has a huge implication for a basin scale water management planning for various purposes.
World Applied Sciences …, Jan 1, 2011
With its an estimated human population of 85 million which increases annually at about 2.7 per ce... more With its an estimated human population of 85 million which increases annually at about 2.7 per cent, Ethiopia is the second most populous country in sub-Saharan Africa (SSA) only after Nigeria. Agriculture contributes about 45% and 85% to the GDP and the export earnings, respectively. However, agriculture largely depends on the highly variable rainfall. Accentuated with the rampant land degradation, the seasonal and annual variation in rainfall severely impedes agricultural productivity. In the face of soaring global food prices, importing agricultural products is becoming more challenging. This entails a substantial increase in water and land productivity through investment in both rainfed and irrigated agriculture. Irrigation projects often require huge financial and capital investment. As a result, rain fed agriculture may continue to play a major role in the near future, especially in areas with sufficient rainfall. Therefore, prioritization and resources allocation to the rainfed and irrigated agriculture should ensure the efficient use of the limited resources. This study compared the efficiency of the small-scale irrigation (SSI) and the large-scale irrigated agricultural schemes in different river basins against the rain fed system. The study indicated that irrigated agriculture is more efficient both in terms of water use and economics regardless of the typology or the basins considered. The large-scale schemes are more efficient than the small-scale ones. This may be attributed to the use of other complementary crop management technologies such as fertilizers and the use of improved crop varieties. Although rainfed agriculture remains important for a long period to come, gradual transformation to irrigation particularly to largescale schemes may lead to efficient use of resources for economic development.
African Journal of Environmental Science and …, Jan 1, 2012
In the highlands of Ethiopia, tillage methods and frequency affect drainage, soil erosion, moistu... more In the highlands of Ethiopia, tillage methods and frequency affect drainage, soil erosion, moisture conservation, weeding and harvesting of crops. This is through their effects on soil physical, chemical and biological qualities. In this study, four tillage methods for land preparation, "broad bed and furrows"," green manure", "reduced tillage "and the traditional tillage "ridge and furrows" were evaluated for their effects on soil physical quality indicators. The study was superimposed on the field experiment conducted on a vertisol area at Caffee doonsa for five years (1998 to 2002) in the central highland of Ethiopia. Penetration resistance (PR), aggregate stability, water-holding capacity, crust strength and thickness, texture, porosity, saturated hydraulic conductivity, bulk density and water holding capacity were the soil physical quality indicators considered. The result indicated that only PR was significantly (p<0.05) affected, where as the other parameter have shown a slight changes that are consistent with the effects on the bio-chemical parameters as previously reported. Broad bed furrows, and reduced tillage resulted in the highest and the lowest PR, respectively under both the moist and dry soil conditions. Green manure increased aggregate stability and reduced surface crust strength, which was linked to its increased organic matter content and consequent improved microbial activities.
Water …, Jan 1, 2012
Volume 5 | Issue 2 Bossio, D.; Dile, Y.; McCartney, M.; Killiches, F. and Hoff, H. 2012. Water im... more Volume 5 | Issue 2 Bossio, D.; Dile, Y.; McCartney, M.; Killiches, F. and Hoff, H. 2012. Water implications of foreign direct investment in Ethiopia's agricultural sector. Water Alternatives 5(2): 223-242 Bossio et al.: Water implications of foreign direct investment in Ethiopia ABSTRACT: Ethiopia is often highlighted as a country in which a lot of foreign land acquisition is occurring. The extent to which these investments also constitute significant acquisitions of water is the subject of this paper. It is apparent that water availability is a strong driver of the recent surge of investments in agricultural land globally, and in general the investments occur in countries with significant 'untapped' water resources. Ethiopia is no exception. We propose that the perception of unused and abundant water resources, as captured in dominant narratives, that drives and justifies both foreign and domestic investments, fails to reflect the more complex reality on the ground. Based on new collections of lease information and crop modelling, we estimate the potential additional water use associated with foreign investments at various scales. As a consequence of data limitations our analyses provide only crude estimates of consumptive water use and indicate a wide range of possible water consumption depending on exactly how foreign direct investment (FDI) development scenarios unfold. However, they do suggest that if all planned FDI schemes are implemented and expanded in the near future, additional water consumption is likely to be comparable with existing water use in non-FDI irrigation schemes, and a non-trivial proportion of the country's water resources will be effectively utilised by foreign entities. Hence, additional water use as well as local water scarcity ought to be strong considerations in regulating or pricing land leases. If new investments are to increase local food and water security without compromising local and downstream water availability they should be designed to improve often very low agricultural water productivity, and to safeguard access of local populations to water.
IWMI Conference …, Jan 1, 2008
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Papers by Teklu Erkossa Jijo