Impact of different tillage systems and organo-mineral fertilization on soil physical and chemical characteristics in the Moldavian Plain

Abstract

The investigations conducted during 1998 – 2008 followed the influence of different soil tillage systems on crop yield and soil chemical and physical characteristics. Trials were set up in split–split plots on a typical Cambic Chernozem of clayey-loam texture, mean humus content (3.2 %), weakly acid reaction and mean supply in mineral elements. After 11 years of experiences, ploughing to a depth of 20 cm has resulted in settling the soil layer at depth of 19-25 cm, causing the increase in apparent density to 1.52 g/cm3, the decrease in total porosity to 43.3 % and the increase in compaction degree until 16.2 % of the volume. In case of the tillage system with chisel and paraplow, the mean yields obtained in the last 10 years were lower by 2-5% (53-145 kg/ha) in wheat, by 4-5% (202-282 kg/ha) in maize and by 4-8% (106-206 kg/ha) in soybean, in comparison with ploughing to a depth of 20 cm. At soil tillage with chisel + disk in maize crop, the percent of hydrostable aggregates from soil, at depth of 0- 30 cm was by 15% higher, in comparison with ploughing to a depth of 20 cm. Soil tillage with chisel and paraplow determined the increase by 5.5 mg/kg (12%) and 16.0 mg/kg (7.0%), respectively, in mobile phosphorus and potassium content from soil, in comparison with ploughing to a depth of 20 cm, due to improved soil physical characteristics. At soil tillage with chisel and paraplow, the content of organic carbon from soil was higher by 0.33-0.38 g/kg, in comparison with ploughing to a depth of 20 cm.