5 Irrigation and Drainage in Polish Agriculture …
101
aimed at water conservation. Nonetheless, sprinkler irrigation is situated commonly
in the western and central part of the country, covering regions of relatively low
precipitation and fertile soils. On the other hand, referring to subirrigation systems
typically used in river valleys on permanent grasslands, occupy largely the lowland
regions (North and Central Poland).
Systems of irrigation in agriculture in Poland, serving for mitigation of water
deficits in the soil are treated as a part of land reclamation (amelioration or landwater improvement). Under prevailing climatic, soil and economic conditions in
Poland, and especially economical and structural sector in agriculture, two main
tendencies in the field of irrigation systems can be distinguished [14]:
1. Gravity systems of (driven by gravity—non pressure—schemes) irrigation on
the areas of permanent grasslands within the borders of river valleys, located
in the neighborhood of lowland watercourses on vast post-swampy ecosystems,
dependent on subsoil irrigation from the network of ditches and drains if necessary. Maintenance of appropriate groundwater table in those schemes is feasible
by: controlled drainage, sub-irrigation with a constant water level, sub-irrigation
with a regulated water table depth (groundwater hydrologic alterations).
2. Pressurized irrigation systems (equipped with puming devices). They involve
sprinkler and all types of on-site irrigation, i.e. drip, micro jets, “sweating” hoses
etc. of intensive and semi-intensive root crops, industrial crops, horticulture crops
in open air, greenhouse crops and orchards.
3. Flood and other types of irrigation (e.g. border) are used in a small extent due to
high demand for water while providing low water use efficiency.
The type of hydraulic structures for irrigation is related with irrigation method.
In sub-irrigation systems on permanent grasslands, there are various structures for
water damming and distribution (damming structures on streams, water damming
culverts, weirs, gates, dammed lakes, water intakes and discharge points), to increase
water level in streams and canals as well as to supply water to the network of ditches.
Grasslands, predominantly those located in river valleys, have been drained by open
ditches. It amounts to 25% of the drained grasslands that may be irrigated—having
been equipped with proper hydraulic structures. All in all, the subirrigation systems
are the only method used for irrigating grasslands. Nowadays, only part of these
systems is utilized by farmers. In pressure irrigation systems (sprinkling, microirrigation) there are different facilities for water intake from surface and ground
waters (wells, pumping stations), network of pipelines to supply water to fields,
facilities for water filtration and for preparing fertigation solutions. In those systems,
there is no special hydraulic infrastructure for damming water, but for drainage
systems, covered plastic or ceramic drains have been installed for desiccation of
arable soils.
The future of irrigation lies in adaptable devices, that can be adjusted properly
to field conditions and land use type (arable lands, horticulture and orchards). The
potential is visible for micro and drip irrigation, but generally variable rate irrigation
approach will gain significance due to varying environment and adaptation to climate
changes.
101
aimed at water conservation. Nonetheless, sprinkler irrigation is situated commonly
in the western and central part of the country, covering regions of relatively low
precipitation and fertile soils. On the other hand, referring to subirrigation systems
typically used in river valleys on permanent grasslands, occupy largely the lowland
regions (North and Central Poland).
Systems of irrigation in agriculture in Poland, serving for mitigation of water
deficits in the soil are treated as a part of land reclamation (amelioration or landwater improvement). Under prevailing climatic, soil and economic conditions in
Poland, and especially economical and structural sector in agriculture, two main
tendencies in the field of irrigation systems can be distinguished [14]:
1. Gravity systems of (driven by gravity—non pressure—schemes) irrigation on
the areas of permanent grasslands within the borders of river valleys, located
in the neighborhood of lowland watercourses on vast post-swampy ecosystems,
dependent on subsoil irrigation from the network of ditches and drains if necessary. Maintenance of appropriate groundwater table in those schemes is feasible
by: controlled drainage, sub-irrigation with a constant water level, sub-irrigation
with a regulated water table depth (groundwater hydrologic alterations).
2. Pressurized irrigation systems (equipped with puming devices). They involve
sprinkler and all types of on-site irrigation, i.e. drip, micro jets, “sweating” hoses
etc. of intensive and semi-intensive root crops, industrial crops, horticulture crops
in open air, greenhouse crops and orchards.
3. Flood and other types of irrigation (e.g. border) are used in a small extent due to
high demand for water while providing low water use efficiency.
The type of hydraulic structures for irrigation is related with irrigation method.
In sub-irrigation systems on permanent grasslands, there are various structures for
water damming and distribution (damming structures on streams, water damming
culverts, weirs, gates, dammed lakes, water intakes and discharge points), to increase
water level in streams and canals as well as to supply water to the network of ditches.
Grasslands, predominantly those located in river valleys, have been drained by open
ditches. It amounts to 25% of the drained grasslands that may be irrigated—having
been equipped with proper hydraulic structures. All in all, the subirrigation systems
are the only method used for irrigating grasslands. Nowadays, only part of these
systems is utilized by farmers. In pressure irrigation systems (sprinkling, microirrigation) there are different facilities for water intake from surface and ground
waters (wells, pumping stations), network of pipelines to supply water to fields,
facilities for water filtration and for preparing fertigation solutions. In those systems,
there is no special hydraulic infrastructure for damming water, but for drainage
systems, covered plastic or ceramic drains have been installed for desiccation of
arable soils.
The future of irrigation lies in adaptable devices, that can be adjusted properly
to field conditions and land use type (arable lands, horticulture and orchards). The
potential is visible for micro and drip irrigation, but generally variable rate irrigation
approach will gain significance due to varying environment and adaptation to climate
changes.