Abiye Astatke

Soil water dynamics under cereal and forage legume mixtures on drained Vertisols in the Ethiopian highlands

Abstract At the Debre Zeit Station cereals (wheat and maize) and forage legumes (lablab, cowpea, vetch and clover) were grown as sole crops and as cereal/forage combinations on the broadbeds separated by drainage furrows (BBF). This is an improved land management system, developed by ILCA in collaboration with other national and international partners, to raise productivity of Vertisols. Soil water content monitored at soil depths of 0–50 cm and 50–100 cm indicated that lablab and cowpea deplete significantly greater amounts of available soil water during the growing season than vetch and clover. Deep rooted forage legumes lablab, cowpea and vetch are more suitable for combination with cereals such as maize than with wheat due to the phenological differences between the two crop types. Grain yields of wheat and maize were higher when intercropped with legumes than as sole crops in the absence of external N input. Moisture use by the various crop-forage land use types are discussed.

Participatory conservation tillage research: an experience with minimum tillage on an Ethiopian highland Vertisol

Farmer participatory tillage trials were conducted in a highland Vertisol area of Ethiopia during the 1999 and 2000 cropping seasons. This participatory initiative clearly demonstrated that incorporating farmers’ knowledge, ideas and preferences could improve the wheat production package. A traditional practice of Chefe Donsa farmers—applying ash from their homesteads to their fields to enable early-sown crops to withstand frost—led to the verification of the yield-enhancing effect of inorganic potassium fertilizer on wheat. Farmer adoption of a minimum tillage production system increased the gross margin of wheat production by US

TECHNICAL AND ECONOMIC PERFORMANCE OF ANIMAL-DRAWN IMPLEMENTS FOR MINIMUM TILLAGE: EXPERIENCE ON VERTISOLS IN ETHIOPIA

132 per hectare—based on 1999 prices—relative to the traditional flat seedbed system. The minimum tillage system was characterized by a much lower level of soil manipulation relative to the traditional flat seedbed system, and, as a consequence, markedly reduced the total human labor and draft oxen requirements for wheat production. Thus, the minimum tillage system could be an effective intervention for soil conservation due to early-season vegetative cover of the soil surface. Also, the early crop harvest associated with the minimum tillage system was highly beneficial for small-holder farmers—since the early harvest coincided with the cyclical period of severe household food deficits and high grain prices in local markets.

Options to intensify cropland use for alleviating smallholder energy and protein deficiencies in the East African Highlands.

SUMMARY Land degradation is one of the major problems related to low productivity in Ethiopia. Vertisols are potential agricultural lands but are underutilized due to water-logging during the rainy season and are prone to soil erosion due to the traditional practices of planting crops at the end of the rainy season exposing bare land to heavy rains. An animal-drawn implement, the broad-bed maker (BBM), was tested to facilitate drainage of the vertisols. Improved drainage enables earlier planting of crops to use the resultant prolonged growing period for attaining higher yields. In order to further improve the BBM package, the frame of the BBM was used for attachment of other implements to minimize tillage practices and reduce seed and fertilizer rates, labour and animal power requirements and soil erosion. The attachments were tested both on-station and on-farm with positive results. INTRODUCTION In most crop-livestock mixed farming systems in developing countries, different kinds of animal-drawn simple and mould-board ploughs are used for tillage. The number of cultivations or passes needed to achieve a good tilth depends on soil type, moisture level, crop to be grown and adequacy of draught animals. On some kinds of soils extensive tillage damages soil structure and contributes to soil erosion. Zero-and minimum-tillage practices are often recommended to avoid such problems. In Ethiopia, 90% of land preparation for crop production by smallholder farmers is done with the traditional ‘maresha’ plough pulled by a pair of local zebu oxen. Three to five cultivation passes, each pass perpendicular to the previous one, with the maresha are required for all types of soils before a field is ready for planting. The first pass reaches a soil depth of 8 cm while with the last pass up to 20 cm depth can be attained (Astatke and Ferew, 1993). Land is usually prepared before the main rainy season and some crops, for example the principal cereal tef (

Effect of different cropping options on plant-available water of surface-drained vertisols in the Ethiopian highlands

Abstract Land-use intensification in the east-African highland zone is required for meeting food and feed demands from the rising human and animal populations. A single crop of wheat has been a traditional practice for the 8 Mha of vertisols in the Ethiopian highlands with both grain and residues finding use. With proper drainage, early sowing of crops becomes feasible, and this study compared the local wheat system with eight other land-use types (LUTs). Replacing local wheat with genetically superior wheat, cv. ET 13, significantly increased grain and fodder and also the metabolizable energy from a land unit. When ET 13 was followed by grasspea, and intercropped with clover and/or sown between sesbania alleys, the feed, protein and energy outputs from the same land unit were further enhanced many fold compared to the traditional landuse. By combining crops and forages with different maturity and harvest times, it was also possible to change feed availability patterns during the year. How these different options could be targeted to serve multiple crop/livestock objectives of the smallholder is discussed briefly.

Investment options for integrating water-livestock-crop production in sub-Saharan Africa

The productivity of the Vertisols in the Ethiopian highlands could be raised by facilitating the removal of excess water from the fields in the main rainy season. This could be accomplished by the introduction of an animal powered broadbed maker (BBM) which shapes the soil into broadbeds and furrows. Thus with proper drainage, early sowing of crops becomes feasible. This study compared the plant-available water in the soil layer and the water use efficiency of local wheat and eight other cropping options and also assessed the grain and fodder productivities. Replacing late-sown local wheat with an early-sown improved wheat variety (ET-13) improved the utilization of the plant-available water during the rainy season and significantly increased grain and straw yields with a high rate of water use efficiency. The variations of the available moisture in the soil layer between the different cropping options tested were small during the rainy months of July and August due to the continuing replenishment of the used water. Differences of plant-available water in both upper and lower soil layers for the various cropping options became distinct at the onset of the dry season. Even though results showed that growing of a sequential crop, such as grass pea, following wheat is possible with a starter irrigation in the dry season, yields were generally depressed.