Contents:
The terrace has a maximal height of 2. Below this terrace fill, a debris layer was found at a depth of 1. Intensively weathered bedrock saprolite was exposed below the debris layer at the base of the profile. In the profile at the terrace wall, the fine soil fill and the debris layer were investigated in detail and sampled for radiocarbon dating at two depths: The influence of wood coming from outlying areas was insignificant as charcoal originates from the fuel wood trees from the surrounding forests that cover the escarpment.
The dominant tree type is Juniperus spp. The forest is still an important source of wood for fuel for the local population. Thus, the effect of wood or charcoal coming from other areas is less probable. The laboratory used the following procedures Nadeau et al.
Samples were checked under the microscope for impurities. The 14 C concentration of the samples was measured by comparing the simultaneously collected 14 C, 13 C, and 12 C beams of each sample with those of Oxalic Acid standard CO 2 and coal background material. The calibrated age is ad — and ad — 2 sigma range. The calibrated age is ad — 2 sigma range. These dates prove that the terrace was built in one event or at least over a very short period of time.
It was most likely established in the late twelfth century or in the first half of the thirteenth century. The material characteristics of the terrace fill and the terrace wall, which was constructed using local stones, prove that the terrace was built in one event; there are no indications at all that the terrace developed over many centuries.
Results of the radiocarbon dating of samples from an agricultural terrace in Dorze-Belle. This radiocarbon dating attests that the terrace investigated in Chencha—Dorze Belle is probably one of the oldest relics of agricultural activities in the region. The remains of a church, which was found inside a sacred forest by ethnoarcheological investigations, also provide some evidence regarding the age of settlements informal discussion with John Arthur, Associate Professor of Anthropology, University of South Florida, Saint Petersburg.
This church was among those, which were deserted by people coming from the northern part of Ethiopia during the war that took place in the sixteenth century. The war is known as the Ahmed Gragn war, in which a large number of orthodox churches were burned and some of them moved southward—mainly the covenant arks. This suggests that settlement in the area has a longer duration. In the discussions with the elder people in Chencha—Dorze Belle about the history of terraces and land use systems, they disclosed that the terraces were as old as the agricultural activities in the area. They also pointed out that their ancestors were the ones who designed and constructed the terraces.
Senior members of the communities are well aware of the cultural landscape since information passes from one generation to another. Oral history is thus an important source of information for reconstructing the environmental history. For instance, based on the oral history of the elder people in the area, Arthur et al.
Moreover, during our field survey we also observed that the rock blocks, which were used for the construction of the terraces, changed color due to intensive chemical and biological weathering processes and lichens that have also grown on the rocks, implying the existence of the terraces for a long period of time. Farmers also reported that the existing indigenous soil and water conservation technology was originally developed by their ancestors over a long period of time mainly to prevent erosion. In our discussion with the farmers from other parts of Chencha, where terraces have been part of their agriculture for a long period, they also acknowledged that the terrace technology was adopted from the Chencha—Dorze Belle area.
They all considered the Chencha—Dorze Belle area as the initial center of the technology, from where the terrace concept has been transferred to other places. The indigenous soil and water conservation technology of Chencha—Dorze Belle is based on stonewalled terraces. The main construction materials for terrace walls are stones and bedrock, which are abundant in the area. The type of the stone found in the area is primarily basaltic rock, which was formed during the Tertiary period by volcanic activities.
These stones are compact and solid and thus attributed to the stability and permanency of the terraces in the area. The stones have various sizes and shapes. People formerly collected stones from their agricultural fields and accumulated them at specific sites in order to build terraces. When farmers construct terraces they first excavate trenches up to half a meter in depth. The soil is deposited downslope, just below the terrace wall. In contrast, in the newly introduced fanya juu terraces, soil from the trench is thrown upslope. Some portion of soil is used to cement the terrace, while the remainder is spread to the lower sides, behind the walls.
Then they place the big stones in the excavated trench as a foundation for the terraces. In some cases if bigger stones were found in the trenches, they were used as a base and terraces were built on these stones instead of removing them from the ground. The method of piling stones to build the embankment of the terraces involves placing them with decreasing stone size from the base to the top. If there are gaps in the walls, they are packed with small stones, although in some cases they use soil as a filling to stabilize the walls.
The position of the terrace wall is vertical or slightly inclined. It is slanted at the steep slope while it is vertical at the lower slope. The height of the terraces is often 0. Where there is a steep slope gradient, the height of the terraces is increased to retain a high amount of runoff. Along a contour, a single long wall was not built; rather a series of shorter terrace walls were constructed. The tops of the walls were used to grow grass and trees.
The water outlets on the side of the walls were also built to dissipate and divert water flows. In some cases, there are spaces between the stones of the terrace walls to allow water to exfiltrate safely. Larger distances between terraces are observed at lower slope segments, whereas short distances are common on steep slope segments. The soil, which is accumulated due to slight hillslope erosion just above the terrace walls, is brought back to the upper part of the terrace where it was eroded earlier.
Due to terracing, the original steepness of the slope was reduced drastically on the terrace surfaces under cultivation. The steep slope segments are thus marked by terraces with higher walls and shorter distances of terrace spacing to protect them from runoff and removal of soils. The soils of the terrace fields are well managed and used to grow various crops and to plant trees.
The construction of terraces demands a large amount of labor; it is time consuming. The role of social organization and the culture of the people is an integral component in constructing and maintaining terraces. People usually construct terraces in groups, known as debo. The formation of a debo ranges from 5 to 15 people. The members are commonly neighbors and relatives of the person who owns the terraces.
The owner is expected to collect stones and put them at different places of the farm field ahead of the construction. In addition, the owner should also prepare food and drinks to serve those people who participate in terrace construction. Before the group starts to construct a terrace, some ritual activities are conducted to ensure the longevity of the terrace.
The group members can comment upon and discuss the design of a terrace. If there is some disparity among the group members, the owner is the one who makes all final decisions. Farmers have been using diversified measures for soil and water conservation in several combinations.
Footprints in the Soil . of soil science, and tells the story of the people and the exciting ideas that soils?” and “How did one step or idea lead to the next one?” Soil Erosion and Conservation: An International History and a. the need to recognize the people who left 'footprints in the soil' and Then the history of soil cover patterns and soil catena concepts are.
Terraces stand out as the most important measure, coupled with manuring, crop rotation, fallowing, and tree plantation in farm fields. The area, with its characteristic mountainous steep slopes and showery tropical storm precipitation, is prone to erosion by water, resulting in intensive hillslope, rill, and gully erosion. The land, which is not seriously affected by erosion, was described as having a thick soil depth, a fine texture, and a brown-reddish color; and as being easy to plow.
This is mainly attributed to the indigenous terraces. All interviewed farmers unanimously pointed out that the main role of terraces is to prevent soil erosion and in effect they stated that they were able to grow various crops on their farmlands. Farmers of the Chencha—Dorze Belle area do not only construct terraces and plant trees on their fields; they also widely practice soil fertility improvement techniques. These practices play vital roles in boosting macronutrients such as nitrogen, phosphorous, and potassium into the soils of the area. The government of Ethiopia through the agricultural bureau of the Woreda has been undertaking various types of soil water conservation measures, SWC, in the area since the early s.
SWC measures include terraces conventional terraces , fanya juu digging a ditch and moving the excavated soil upslope, as opposed to terraces , and stone or soil bunds walls of soil or stones aligned across the slope. Bunds with maintenance eventually will develop into terraces. As a part of the countrywide program of the Ethiopian government to undertake SWC activities, newly introduced terraces were constructed in a large part of the study area, particularly at the beginning of the s.
The design of introduced terraces and other SWC measures are based on a manual prepared by Hurni The governmental local bureau of agriculture, which is responsible for executing the program for soil and water management practices, has compelled the farmers to build the newly introduced terraces. Teams of 50— farmers undertook the constructions including the collective efforts of women, men, and children who were capable to work. Construction was usually carried out before the plowing period, during the agricultural slack season.
In return for their efforts, they received food aid or money. Farmers have expressed their view that indigenous terraces have multifold advantages, which contributed to the sustainable long-term use of these structures.
As a result, the forms of terraces rise, alignments, consecutive distances between terraces, material for construction, etc. These enable the farmers to decide on the various features of the terraces and also their means of execution. They modify or alter the terraces to cope with various environmental and socio-economic dynamics.
This grassroots level of problem identification, planning, and execution has a massive psychological significance that enhances self-reliance and feelings of empowerment as the farmers do not only possess the terraces, but are also capable of designing and constructing them. This is one of the factors leading to the long-term popularity of this technology. The design of introduced terraces, which is based on Hurni , is customized and prepared as an official manual with specifications to be applied across the entire country.
The development agents, workers of the woreda agricultural bureaus, are in charge of implementing the construction plans for introduced terraces. Farmers are to participate in the construction of terraces at least once a week and in return they receive food aid or money. Besides construction, terraces can also be developed from bunds walls of soil or stones aligned across the slope with maintenance. Farmers are not familiar with the design of the introduced terraces and they reported this to be one of the disadvantages. In order to construct the introduced terraces, the guidance of the extension workers is vital.
In some cases, the design was wrongly implemented, causing gullies to form, as was the case in Zollo , Chencha. Instead, they have a rigid design that should be applied according to the universal features of the terrace. As a result, the introduced terraces inconvenience farmers. Lack of flexibility is one of the constraints of conventional soil and water conservation measures, as documented by various studies in Ethiopia Asrat et al.
Farmers also perceived that indigenous terraces are strong and last for a long time compared to the introduced terraces. This is mainly attributed to the materials and construction techniques; bedrock and larger stones were used as a base or foundation for the indigenous terraces. Smaller stones were used to strengthen embankments. In comparison, the foundation for introduced terraces is commonly placed directly on the soil and they often use soils to construct and to cement the walls of terraces.
The low interest of the farmers in maintaining the terraces aggravates the problem of the stability of the introduced terraces. In some cases, farmers frequently demolish introduced terraces. A development agent told us that terraces were demolished seven times in a place known as Mafena Zolo since the first introduced terraces were constructed in the s.
Farmers also witnessed the role of the indigenous terraces in significantly reducing soil erosion and runoff compared to the introduced terraces. Along with indigenous terraces, manuring, crop rotation, and tree planting on farmland are common practices, which also have positive effects in reducing erosion by enhancing the surface cover and soil structure.
However, the introduced terraces lack other associated measures such as crop cover and tree plantation, even though they struggle to halt erosion by themselves, as stated by various studies Sandor ; Showers In comparison, the unprotected water channels of the introduced terraces are in some cases constructed from upslope to lower slope segments following the direction of the slope; in these cases concentrated runoff is not led to infiltration areas nearby, or into other channels after short distances.
This results in an enormous increase of runoff downslope and in intensive gully erosion, as is the case in the Zollo area. Searching and Browsing for Books. Promote Your Book on www. Handbook of Western Palearctic Birds: Passerines 2-Volume Set 2.
Gulls of the World 5. Identification Guide to Birds in the Hand 8.
Farming and Birds 9. Water Vole Conservation Handbook Britain's Dragonflies View all Bestsellers. Veterinary Science View All 9. Physical Sciences Physical Sciences: Environmental Science Environmental Science: Beginners Bat Detecting Kit 2. Magenta Bat 5 Bat Detector 5.
Opticron Hand Lens 23mm 10x Magnification 7. Magenta Bat 4 Bat Detector 8. Echo Meter Touch 2 - iOS 9. Standard Sweep Net Butterfly Field Guide Mug 3. Insects Memory Game 6.
Butterflies Colouring Set 9. Pentandria 1,piece Jigsaw Puzzle Birding Extremadura All Regions 5. This e-book permits us to respond to the questions: Multigenic and Induced Systemic Resistance in Plants. Figuring out the mechanisms in which vegetation tolerate assault via pathogens, herbivores, or suffer abiotic pressure is an important a part of studying how one can increase plant productiveness and crop yields within the face of dwindling worldwide agricultural assets.
This e-book offers with the power of crops to tolerate such assaults and stresses, and examines intimately quite a few features of resistance responses and mechanisms of resistance. Ecological Monitoring of Genetically Modified Crops: A - download pdf or read online. Proponents of agricultural biotechnology think that genetically changed GM vegetation have the capability to supply nice ecological merits, akin to diminished pesticide and land use, in addition to agricultural merits.
Chemistry of Crop Protection: