Abstract:
The influence of long-term
fertilization on wheat and maize yield and
soil fertility has been investigated at the
Agricultural Research and Development
Station of Podu-Iloaiei since 1968. The
experiments have studied the influence of
mineral fertilization, manure and crop
residues on production, in peas-wheat-maize
crop rotation and on soil fertility, on 16%
slope field. Investigations were carried out
on a typical Cambic Chernozem, which
prevails in the Moldavian Plain and have
established the fertilizer rates ensuring
efficient yield increases and increasing the
content of organic carbon from soil. The soil
on which the experiments were set up have
a clay-loam texture (420 g clay, 315 g loam
and 265 g sand), a neuter to weakly acid
response and a mean nutrient supply. On
weakly eroded soils, the annual application
of crop residues, which resulted from peas,
wheat and maize crops, together with the
rate of N80P60, have resulted in maintaining
the content of organic content from soil at
values of 18.8 g/kg soil. On highly eroded
soils, the increase in the organic carbon
content of soil from 18.8 to 21.6 g/kg soil
was recorded by the long-term application
of the rate of N80P60+60 t/ha manure. On
16% slope lands, the use of a crop structure
made of 25% maize, 25% perennial grasses
and legumes, 25% peas and 25 % wheat has
determined the diminution by 62% of soil
losses by erosion and the reduction by 61%
of water runoff and mineral elements,
compared to maize continuous cropping.
