Comparative studies on the effects of conventional and conservation Agriculture practices on Tef yield insouthwestern Shewa Zone of Oromia Region- Ethiopia

Abstract

Historically, crop production systems have relied on the cultivation and inversion of the top soil layer to prepare a seed-bed and to control weeds. This concept of bare soil technology by manual and mechanical means has resulted in a gradual deterioration of soil structure resulting in a pulverized soil which is prone to erosion and with low levels of nutrient. Continuous use of ploughs at the same depth and during periods of moisture content creates compact subsurface layers known as plough pan. Such a phenomenon will have damaging effects on the development of plant root system, oxygen availability and soil water movement. In our farming community, there is often a pronounced shortage of animal traction and many hours of hand labour are spent in clearing, land preparing for planting crops, which are grown primarily for subsistence. Traditionally, tillage forms an important part of crop production. The principal motive to prepare the soil is to facilitate planting and accelerate seedling growth. Besides that, land preparation is considered necessary to obtain uniform crop without the interference of weeds The concept of conservation agriculture (CA) is based on building up the organic matter layer on the soil surface with crop and other organic residues to form mulch as well as to keep the crop root and stalks intact in the soil. There is absolutely no soil inversion, which can destroy the soil structure.

The present experiment was carried out to seek for sustainable and harmless alternatives to our resource poor farmers. The study was carried out at kuraluku village 80 km distance from Addis Ababa .The result showed that yield per hectare varies from farm to farm in both CA and Non-CA ranging from 9_ quintals/ha to 21_ quintals/ha. The difference could be site factors, such as differences in moisture regime. However, the difference in yield between CA and Non-CA had not been that significant for all farmers. Thus, CA’s advantage was not shown to be on increment of yield of Tef, but mainly in reduction of cost of production, and may also be on improvement of soil structure due to less tillage, better weed control and conservation of soil moisture.