Conditions of peasant irrigation in the locality of Inquisivi, La Paz-Bolivia

Freddy Rojas; Vladimir Orsag Céspedes

Abstract

The agriculture in the valleys of Inquisivi develops on slopes of pronounced, under sub humid dry climatic conditions, the average annual precipitation is 900 mm year^-1 with water deficit from the month of April to November that demands the need for irrigation. The objective has been to evaluate the current irrigation and its relationship with the water needs of the crops, operating conditions and the improvement alternatives through technified irrigation on the hillside. The study was developed in the town of Inquisivi, the methodology for assessing the local climate were climatic indices and to study the functioning of the irrigation system a socio-technical approach was applied, which consists of "water monitoring" and interviews with key informants. The distribution of water is at free demand in most irrigation systems, operating pressures were variable, depending on the height of load and the type of pipe, which sometimes causes social problems when several users irrigate in the same period. Many systems operate with low pressures of 1 to 2 bar, resulting in the sprinklers reach minor radii of wet from 3 to 7 m, so the irrigators change position every three to five hours to reach greater areas of irrigation but with smaller sheets of water, the loamy sandy-gravel texture of the soils determines 20% water losses, which means that frequencies of two to three irrigations per week are carried out in the dry season and one in the season of moderate rainfall. In systems operating at pressures greater than 4 bar, a low uniformity of water distribution is generated. The water need of the crops is subject to the possibilities of operation and water management by the farmer, time of year, capacity of operation, which demand more labor and better social organization around the irrigation system for the adequate distribution of water.