Abstract:
The paper presented the
results of investigations concerning the
influence of long-term fertilization (43
years) on some chemical characteristics of
soil from the Moldavian Plateau, of wheatmaize
rotation. The studies were performed
on a typical cambic chernozem soil,
prevailing in the Moldavian Plateau, and
followed the dosing of fertilizers which
ensures an efficient production increases
and determines maintain or increase soil
organic carbon content. Soil that has been
placed experiences-clay loam, neutral to
slightly acid reaction and a medium nutrient
supply. On lands from the Moldavian
Plateau, maintaining a good supply in
mobile phosphorus for field crops (37-72
mg/kg) was done in case of the annual
application of a rate of N100P100, and a very
good supply in mobile phosphorus (69-78)
and mobile potassium (over 200 mg/kg) was
found at a rate of N100P100+60 t/ha manure.
In wheat-maize rotation, applying a rate of
N100P100 , for 43 years, has determined the
pH decrease until the limit of moderately
acid interval (5.1-5.8) and was maintained
within the weakly acid interval (5.9-6.8) in
case of the annual application of a rate of
N50P50 + 60 t/ha manure. Soil organic
carbon content, in wheat - maize rotation,
decreased after 43 years of experiences from
19.8 to 16.3 g/kg in unfertilized variant and
until 18.1 g/kg in case of the annual
application of a rate of N100P100. In wheat -
maize rotation, the significant increase in
organic carbon content from soil has been
registered at higher than N50P50 + 40 t/ha
manure and at N100P100 + 60 t/ha manure.
The determinations of mean annual amounts
of nitrogen exported from soil by wheat
(grains + straw) have shown that in wheat
crop, its values varied according to
fertilizers system, between 71.5 and 128.4
kg/ha. In maize crop, of the mean annual
amounts of nitrogen exported from soil
varied according to applied fertilizers,
between 64.6 and 178.9 kg/ha.
