Targa, Afa and Potayta is the only and especial farming system for water and soil conservation among the D’irashe. According to the elders, in ancient times the Targa, Afa and Potayta farming system started in the lowland areas with shortage of water and no other option but rain. This indigenous farming system can be maintained in three ways. The first kind is preparing pilling the soil; the second is pilling the ban, and the third is terracing with stone. Using the three kinds of farming system, the people manage to keep the land and its resources for a long period of time through traditional soil and water conservation practice. Afa is sub-section of the farmland, and the Targa is sub-section of a single Afa. In the same way, Potayta are sub-section of a single Targa the number of Afa depends on the size of the farm land. Seven Targa lines forms an Afa. And, each Targa is again sub divided in to Pottaya ˮ
 

The Monas are lines of stalk prepared with all kinds of structures the farm, both horizontally and vertically prepared forms of Targa and Pottaya. So, Monas are found with all structures and prepared by piling the soil, maize and/or sorghum stalk. The main purpose of Mona ranges from serving as organic manure up to preventing land removal via flood. It’s organic fertilizer because Mona helps local farmers to produce two times a year on the same land, even they begin to produce three times a year in three kebeles of the D’irashe. The local people sow or plant the seed of the next type of crop and when they harvest the first type of crop, they dig up and put the residue over the bund like border of the rectangular lines then the next crop begin to appear and the residue on the line become decayed and serve as a fertilizer to the land. Therefore, creating organic fertilizer through the decaying crop residues is spread over the lines of Targa, Potayta and Afa is very amenable.

Afa refers to the stalk lines that are huge and bigger than other lines, and form vertically from one side of the farm to the other side. Often the number of Afa is determined by the size of the farmland. Afa are prepared for the purposes of demarcating the edges of targa in the field, and to determine Targa through which farmers easily identify and manage each of farming activities, especially at the time of weeding, planting seeds and digging out crop residues and piling over each pre-arranged lines.>