RESEARCH FOR

THE INFLUENCE OF CROPPING SYSTEMS DIFFERING
IN INTENSITY ON MINERAL NITROGEN MIGRATION
al., 2001). According to the data of English researchers,
in 7 of 9 investigated organic agriculture farms
nitrogen balance was excessive (Berry et al., 2003).
Most extensive research of plants productivity under
these cropping systems have been conducted in the
United States. It is emphasized that in the first years,
during transition to biological farming, productivity of
most plants decreases (Таран и Папцов, 1992). When
crop rotations are properly applied, after 5 years of
stabilization of this agroecosystem productivity
increases (Bate et al., 1993). In literature the impact
of agriculture of various intensity on water quality is
estimated as very multiple-valued. Soil water is one of
the key elements reflecting pollution status of the whole
geosystem (Jankauskaitė, 1993). Its quality and that of
chemical elements, as well as migration of compounds
define variety of natural and anthropogenic factors.
Impact of these factors in space and time is quite
differentiated. Some of them have a greater impact on
superficial water, other - on a deeper water (Klimas et
al., 1993). Many researches unanimously claim that
leaching of chemical elements and compounds from
soil is mainly determined by the hydrothermal mode
and their content in soil (Čiuberkienė, 1999; Šileika
et al., 1998). When flushing mode is prevailing in
soils, water leakage profile is quite significant and
depends on rainfall, plants and evaporation. When
crop rotations are properly applied, after 5 years of
stabilization of this agro-ecosystem, the productivity
increases (Bate et al., 1993).
In literature the impact of agriculture of various
intensity on water quality is estimated as very
multiple-valued. Soil water is one of the key elements
reflecting pollution status of the whole geosystem
(Jankauskaitė, 1993). Its quality and that of chemical
elements, as well as migration of compounds define
variety of natural and anthropogenic factors. Impact of
these factors in space and time is quite differentiated.
Some of them have a greater impact on superficial
water, other - on a deeper water (Klimas et al., 1993).
Many researches unanimously claim that leaching
of chemical elements and compounds from soil is
mainly determined by the hydrothermal mode and
their content in soil (Čiuberkienė, 1999; Šileika et
al., 1998). When flushing mode is prevailing in soils,
water leakage profile is quite significant and depends
on rainfall, plants and evaporation (Коротков и др.,
1994). In literature, there is abundance of statements
that agricultural intensification stimulates migration
and leaching of some elements and compounds
(Tyla et al., 1997). Mineral fertilizers disrupt the
balance of solution acids and bases in soil in a way
that solution becomes acidic. When migrating of
nitrates, chlorides and sulphates occurs, along with
water of infiltration out of sorbed by soil complex
the equivalent number of cations is expelled (Ca 2+ ,
Saulius Gužys
Mg 2+ , K + , Na + ) (Богомазов и др., 1993). In this case,
plant nutrients from soil through drainage systems can
enter into the original hydrographic network and from
there into rivers, lakes and other water bodies. There
are opinions that elements and compounds migration
can be significantly stopped using various organic
fertilization systems (De Jager et al., 2001). According
to the data of German researchers, during transition
from intensive to organic agriculture, the losses from
nitrogen leaching decrease by about 50 per cent (Haas
et al., 2002). Other researchers claim that application
of manure offer more opportunities of polluting water,
because mineralization of manure in soil occurs
slowly and long time (Švedas et al., 2001). However,
it is almost unanimously recognized that leaching of
elements and compounds and unproductive losses
of fertilizers rise significantly during fertilization
in amounts that excess the needs in crop. With the
increase of area of agricultural landed property in
catchments, nitrogen concentration in river water
increases too. The increase in forest and wetland area
reduces concentration of this element (Pauliukevičius,
2000). However, unlike these researchers, Rothamsted
(Great Britain) and Russian scientists, after conducting
long-term research, claim that most nitrates polluting
water bodies fall into water during decomposition
of organic nitrogen in soil. Therefore, reduction
of fertilization cannot solve the problem of water
pollution by nitrates. This can start working only
after a long period, when amounts of organics in soil
decreases. However, the benefits of N-NO3 - leaching
decrease will be negligible, compared with the losses,
which the farmer-manufacturer will have (Addiscott,
1998). The research carried out in East Germany, has
shown that agricultural extensification in less than a
year significantly increases leaching of elements and
compounds, compared to areas farmed intensively
(Meissner et al., 1998). This can be observed in
Lithuania too: In 1992-1995, after a large decline in
agricultural production and use of fertilizers, nitrate
pollution of rivers has increased substantially (Šileika
et al., 1998). Thus, only with very large limitations
mineral fertilizers could be estimated as potential water
pollutants because of their negative impact both in
agronomic and environmental aspects this may occur
only without regard to scientific recommendations of
fertilizers application (Švedas et al., 2001;).
Research objective - estimation of nitrogen
circulation in cropping systems, applying different
systems of agricultural intensity
materials and methods
The research was carried out in 2006-2008 in
Middle Lithuania lowland, Kėdainių r., Juodkiškis
village. Soil of the subject of research - Endocalcari
Endohypogleyic Cambisol (CMg-n-w-can), sandy
160 ReseaRch foR RuRal Development 2012