The impact of the cropping systems on yield, erosion and soil fertility in the Moldavian Plain

The influence of long-term fertilization on wheat and maize yield and soil fertility has investigated at the Agricultural Research and Development Station of Podu – Iloaiei, since 1967. These experiments were carried out on a 14 % slope field, with clayey loam texture (418 g clay, 324 g loam and 258 g sand), a neuter to weakly acid reaction and a mean nutrient supply. Within the experiment, the following rotation schemes have been followed: wheat and maize continuous cropping, two-year rotation (wheat-maize), three-year rotation (peas-wheat-maize) and four-year rotation + reserve field cultivated with legumes and perennial grasses (alfalfa + Lolium or Sainfoin + Bromus). The use of 3 and 4 year- rotations with annual and perennial meliorate plants has resulted in yield increases of 28.8 – 31.5 % (742 – 811 kg/ha) in wheat and 29.0-32.5% (1270-1420 kg/ha) in maize, as compared to continuous cropping. The investigations conducted on 16% slope fields, by means of erosion control plots, have shown that mean annual of soil losses by erosion were between 3.095 and 6.717 t/ha in row crops and between 0.548 and 1.779 t/ha in wheat and peas crops