100
L. Łab˛ edzki et al.
The possibility of irrigation and drainage is provided by various types of channels
that have a direct connection with watercourses. Their length is 6.8 thousand km
(Table 5.1), while they are maintained at 65% of their length, and at 23% of the
length they are eligible for reconstruction.
The combined systems—drainage-irrigation ones (i.e. double-acting) that are
usually put into force on permanent grasslands, clearly belong to a minority. The
statistical data show that in Poland about 4 million hectares are covered with permanent grasslands (meadows, pastures). Only 9% of this area can be irrigated, and
as much as 36% of this area is equipped with only drainage systems, without the
possibility of water retention, e.g. rain or thawing water on-site.
5.3.3 Irrigation and Drainage Techniques
The core of irrigation techniques in Poland from sixties of the XX century onwards
involved permanent valley grasslands. Large drainage-subirrigation networks were
put into operation there, covering the approximate surface of 0.5 mln ha. Not before
than in the middle of the sixties, the first attempts to implement the pressure irrigating
devices in the field crop cultivation were completed. Initially, in the sixties, the
portable sprinkler systems, semi-portable and stationary systems were launched.
With the passage of time, the equipment became more automatic; mainly side-roll
wheel systems and reel hose travelling rain guns were introduced. On the state-owned,
large-area farms, the center pivot pipelines of a continuous rotation around the central
axis were employed, on condition the source of water was finally found: usually wells
or hydrants of underground feeding pipeline. On account of transformation in the
national economy after 1989, big state-owned farms were held back followed by
sprinkling irrigation systems abandonment, and finally their exploitation came to a
standstill.
At the end of the seventies and in the eighties several forms of micro-irrigation
were introduced. The first system of that type of irrigation was a set of equipment for
irrigations under the crown of trees in orchards, with the application of micro-jets. It
was found to be widely applied in orchards, greenhouses and plastic tunnels as well as
tree and shrub nurseries. By the end of the 1980s, it used to be the main system, applied
to irrigate orchards in Poland. At the same time, the development of sub-crown microjets was followed by drip irrigation rapidly taking place in orchards and “under the
roof”. Simultaneously with the introduction of sub-crown micro-jet irrigation, the
attempts were undertaken in Poland to make drip irrigation systems more popular
which would take advantage of inspirations and solutions, being practised in other
countries.
At present, the irrigation takes place in considerably smaller areas, that is in
orchards and within vegetable fields in particular. Drip irrigation systems are taking
steps ahead much faster than any other type of irrigation in Poland. At the same time
action is being taken to restore part of the drained river valleys and introduce solutions
dedicated to increase retention capacity. There is a number of introduced solutions,
L. Łab˛ edzki et al.
The possibility of irrigation and drainage is provided by various types of channels
that have a direct connection with watercourses. Their length is 6.8 thousand km
(Table 5.1), while they are maintained at 65% of their length, and at 23% of the
length they are eligible for reconstruction.
The combined systems—drainage-irrigation ones (i.e. double-acting) that are
usually put into force on permanent grasslands, clearly belong to a minority. The
statistical data show that in Poland about 4 million hectares are covered with permanent grasslands (meadows, pastures). Only 9% of this area can be irrigated, and
as much as 36% of this area is equipped with only drainage systems, without the
possibility of water retention, e.g. rain or thawing water on-site.
5.3.3 Irrigation and Drainage Techniques
The core of irrigation techniques in Poland from sixties of the XX century onwards
involved permanent valley grasslands. Large drainage-subirrigation networks were
put into operation there, covering the approximate surface of 0.5 mln ha. Not before
than in the middle of the sixties, the first attempts to implement the pressure irrigating
devices in the field crop cultivation were completed. Initially, in the sixties, the
portable sprinkler systems, semi-portable and stationary systems were launched.
With the passage of time, the equipment became more automatic; mainly side-roll
wheel systems and reel hose travelling rain guns were introduced. On the state-owned,
large-area farms, the center pivot pipelines of a continuous rotation around the central
axis were employed, on condition the source of water was finally found: usually wells
or hydrants of underground feeding pipeline. On account of transformation in the
national economy after 1989, big state-owned farms were held back followed by
sprinkling irrigation systems abandonment, and finally their exploitation came to a
standstill.
At the end of the seventies and in the eighties several forms of micro-irrigation
were introduced. The first system of that type of irrigation was a set of equipment for
irrigations under the crown of trees in orchards, with the application of micro-jets. It
was found to be widely applied in orchards, greenhouses and plastic tunnels as well as
tree and shrub nurseries. By the end of the 1980s, it used to be the main system, applied
to irrigate orchards in Poland. At the same time, the development of sub-crown microjets was followed by drip irrigation rapidly taking place in orchards and “under the
roof”. Simultaneously with the introduction of sub-crown micro-jet irrigation, the
attempts were undertaken in Poland to make drip irrigation systems more popular
which would take advantage of inspirations and solutions, being practised in other
countries.
At present, the irrigation takes place in considerably smaller areas, that is in
orchards and within vegetable fields in particular. Drip irrigation systems are taking
steps ahead much faster than any other type of irrigation in Poland. At the same time
action is being taken to restore part of the drained river valleys and introduce solutions
dedicated to increase retention capacity. There is a number of introduced solutions,