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

Abstract

10Farmer 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$ 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. 11 12 13 14 15 16 17 18 19 20 21 22 (A. Astatke).while the last pass can reach approximately 20 cm in 35 depth (Astatke and Kelemu, 1993). Cropland is usually 36 tilled in preparation for the main rainy season, extend-37 ing from June to September. For tef (Eragrostis tef), 38 the principal cereal crop of Ethiopia, seeds are sown 39 during the middle of the main rains. For other crops, 40 e.g. local wheat (Triticum spp.) and pulses, seeds are 41 sown at the beginning of the main rains on light soils 42 and close to the end of the rainy season on heavy clay 43 soils such as Vertisols. 44 About 12.6 million ha of Vertisols, comprising 45 roughly 30% of the Vertisol area in Africa, are lo-46 cated in Ethiopia. Vertisols cover 10.3% of the total 47 surface area of Ethiopia, and two-thirds of the Ver-48 1 tisol area is located in highlands >1500 m a.s.l. (El 49 Wakeel and Astatke, 1996). Despite their high agri-50 cultural potential, Vertisols are generally regarded as 51 problematic soils in Ethiopia due to their character-52 istic hydro-physical properties, which lead to a high 53 incidence of prolonged water-logging during the main 54 rainy season. For this reason, most crops are sown 55 on Vertisols towards the end of the main rainy sea-56 son. Thus, the tilled soil is exposed to intense rainfall 57 during the major portion of the rainy season; due to 58 the lack of adequate vegetative cover, this results in 59 a high rate of soil erosion. Furthermore, crops sown 60 late on Vertisols in order to escape water-logging uti-61 lize residual soil moisture to mature, and inevitably 62 experience water stress during the seed filling stage, 63 lowering grain yield levels....

N fertilisation, soil type and cultivars effects on N use efficiency in tef [Eragrostis tef (Zucc.) Trotte]

“…The % FNUE values reported for the Nitosol are adequate (above 50%). Vertisols are generally regarded as problematic soils in Ethiopia due to their distinctive hydro-physical properties, which lead to a high incidence of prolonged water-logging and limitation of nutrient availability and plant growth (Asgelil et al 2001;Syers et al 2001;Astatke et al 2003).…”

The State of Soil Degradation in Sub-Saharan Africa: Baselines, Trajectories, and Solutions

“…Extensive research has been conducted into the broader frameworks of integrated soil fertility management [130][131][132][133][134][135][136][137], conservation agriculture [138][139][140][141][142][143], erosion control [144][145][146][147][148], and improved grazing management [149][150][151]. There is also a wealth of information on the benefits of specific practices such as short legume rotations (improved fallows) [152][153][154][155][156][157][158], agroforestry systems [159][160][161][162][163][164][165], and no-till systems [166][167][168][169][170].…”

Effect of Reduced Tillage and Mineral Fertilizer Application on Maize and Soybean Productivity

“…Reduced cost of production, such as reduced labour, fuel and machinery, is a key advantage of reduced tillage practices (Fowler and Rockstrom, 2001) and is reported to result in more net benefits in reduced than in conventional tillage (Knowler and Bradshaw, 2006). For example, Astatke et al (2003) found a higher gross margin of US$132 per hectare for wheat production in reduced than in conventional tillage in Ethiopia. In another study carried out over a 16-year period in Spain, no significant differences in gross margins between reduced and conventional tillage were found, although the margins tended to be higher for the former than for the latter tillage practice (Sánchez-Girón et al, 2004).…”