THE EFFECT OF CROP ROTATION ON NITROGEN USE OF MAIZE ON A CLAY SOIL IN CENTRAL GREECE

摘要

The viability of energy crops for biofuel production is largely dependent on input minimization. Rotationwith winter legume crops seems to be very strong management practice. Research indicated that the maize response topea residues was of grate importance. Nitrogen is a key input for sustaining high yields in cereal crops, but the fertilizerN uptake efficiency in these crops is relatively low (< 50%). A 2-year field experiment with maize was conducted incentral Greece (Larissa area, Thessaly plain) in the years 2007 through 2009. The study soil is characterized by high claycontent and vertic properties. The experiment was a factorial split plot design in three blocks. The first factor concernsthe cultivation of Pisum sativum in the winter periods in 3 treatments: control, harvested or incorporated in the soil. Thesecond factor was N-dressings at 4 levels (0, 80, 160, 240 kg/ha). The results point to a great positive effect of croprotation with pisum especially if the cover crop is incorporated into the top soil. The seed yield of maize ranging from 5.6t/ha to 7.5 t/ha depending on N-dressing increased substantially in the crop rotation plots and fluctuated from 9.7 (zero Napplication)to 13.2 t/ha (dressing 240 N/ha). The NUE at a value of 58 kg/kg was found generally, confirming relevantprevious results cited in the literature. The base (control) uptake increased from 80 kg/ha to 160 kg/ha, and the recoveryfraction increased from 13% in the control plots to 31% for the plots that pisum was incorporated.