Abstract
Precipitation is one of the major water sources for agricultural
production in arid and semi-arid areas. Rainfalls are limited, erratic
and not always coincide with the crop growing season. Only a part of the
rain is absorbed by the soil. Soil evaporation is most severe in these
regions and the large part of the absorbed water is lost to evaporation.
The technique of collecting and conveying the runoff is known as runoff
harvesting. Microcatchments are one of the primary techniques used for
collecting, storing and conserving local surface runoff for growing
trees/shrubs. In this system, runoff water is collected close-by the
area in which it was generated, and trees/shrubs may utilize the water.
The main objective of the present research was to estimate the effect of
the design of the micro-catchment collection area (shallow basin and
deep trench) has on the efficiency of the water conservation in the soil
profile. The study was carried out during two years using regular
micro-catchments (three replicates) with a surface area of 9 m2 (3 x 3
m) and a depth of 0.1 m and trenches (three replicates) with a surface
area of 12 m2 (12 x 1 m) and 1 m depth. One and three olive trees were
planted inside the trenches and micro-catchments, respectively. Access
tubes for neutron probe were installed in micro-catchments and trenches
(four and seven, respectively) to depths of 3m. Soil water content in
the soil profile was monitored. Sap flow in trees was measured by
PS-TDP8 Granier sap flow system every 0.5 hour and fluxes computed for
the time intervals that correspond to the soil water measurements. The
first year study included flooding trenches and regular micro-catchments
once with the same amount of water (1.5 m3) and the second year study
included flooding four times with 0.25 m3 each time. Flooding was
followed by monitoring the water balance components and estimation of
evaporation losses and water use efficiency by olive trees. Evaporation
from trenches and regular micro-catchments was estimated as the
difference between evapotranspiration obtained by soil water content
monitoring and transpiration estimated by sap flow measurements. The
results clearly show that the evaporation from the regular
micro-catchments was significantly larger than that of trenches during
the entire duration of the both experiments.
Original language | English GB |
---|---|
Journal | Geophysical Research Abstracts |
State | Published - 1 Dec 2016 |
Keywords
- 1041 Stable isotope geochemistry
- GEOCHEMISTRYDE: 1615 Biogeochemical cycles
- processes
- and modeling
- GLOBAL CHANGEDE: 1813 Eco-hydrology
- HYDROLOGYDE: 1851 Plant ecology
- HYDROLOGY