Page 362 - FRUTAS DEL TRÓPICO

362 Frutas del trópico

Knowledge of soil suction and volumetric water content for a particular soil provides a
translation between the suction required to remove water from the soil and the volumetric

water present. One device

that is often used to measure soil suction is tensiometers. Tensiometers are a physical

device that can be implemented to monitor and/or trigger irrigation based on a specified soil

moisture tension.

Other soil moisture sensors, such as capacitance or time-domain based equipment mea-

sure soil moisture as an electronic response. The electronic response (generally voltage) is

defined in terms of volumetric water content which is then translated into soil suction using a

soil moisture curve (as depicted in Fig. 2). Determination of soil moisture curves require spe-
cialized equipment, such as tempe cells and Richard’s pressure plates.

Irrigation systems and efficiencies

In addition to the techniques used to determine when to irrigate, irrigation equipment and sys-

tem design is equally important for an efficient irrigation system. No irrigation system will apply
water without some waste or losses because the prohibitive cost related to preventing all

losses. Thus, some water losses are expected and accepted in proper irrigation system design,

installation, and management. However, excessive water waste may result from poor irriga-

tion system design, improper installation, poor management, and equipment failures. Water

waste may occur due to non-uniform water applications, excessive applications, evaporation

or wind drift during application, surface runoff from the irrigated area, conveyance seepage,

percolation below the root zone, evaporation from the irrigation distribution system, leakage
from defective pipe connections, or other losses (Haman et al., 1996).

Universidad Autónoma de Chiapas