Agriculture Reference
In-Depth Information
fertilizers such as compost that is mixed with the top soil prior to plan-
tation, the conventional agriculture usually relies on fertigation methods
where liquid fertilizer is implemented through the irrigation system during
the growing season. As such, establishment irrigation in intensive organic
farms, which is implemented in the early stages of the growing season, re-
sulted in high down-leaching of nitrate that is produced in the wet top soil.
This down-leaching is unavoidable since the soil is wet while plants roots
are undeveloped and incapable of signifi cant water and nutrient uptake.
On the other hand, in typical conventional agriculture fertilizers are imple-
mented along the growing season with the irrigation system according to
the plant demand. As such nutrient uptake by the plant is more effi cient,
and down-leaching of nitrate is minimal. This concept has been approved
on one of the organic farms that practice fertigation methods rather than
application of solid compost in the soil. In this farm liquid fertilizers that
were produced from guano extracts were implemented through the irriga-
tion system. As a result, the vadose zone nitrate profi le characteristics on
this organic farm were similar to those observed in conventional farms
and signifi cantly lower than those observed in organic farms that rely on
compost as the main fertilizer.
Long-term decision making on groundwater resource management re-
quires substantial data on the fate of pollutant transport from their sources
near land surface across the vadose zone to the groundwater. Data on the
link between land use and groundwater quality may be obtained through
monitoring technologies that are designed to provide real-time informa-
tion on the quality of the percolating water across the vadose zone. In this
study we have demonstrated how implementation of vadose zone monitor-
ing systems provided valuable information on potential pollution threat to
groundwater long before groundwater pollution became evident.
REFERENCES
1.
Amiaz, Y., Sorek, S., Enzel, Y., and Dahan, O.: Solute transport in the vadose
zone and groundwater during flash floods, Water Resour. Res., 47, W10513,
doi:10.1029/2011WR010747, 2011.
2.
APHA: Standard Methods for the Examination of Water and Wastewater, 17th Edn.,
American Public Health Association, Washington, D.C., 1989.
