NITROGEN USE OF SUNFLOWER GROWN ON A SANDY SOIL AS AFFECTED BY CROP ROTATION IN CENTRAL GREECE

摘要

Sustainable bio-diesel production from sunflower is largely dependent on farm input minimization. Inthat respect, rotation with cover crops is fundamental for yield increase, as well as for controlling soil erosion anddegradation, ground water pollution, and maintaining acceptable organic matter levels in the topsoil. A 3-year fieldexperiment with sunflower was conducted in Trikala area (Thessaly, central Greece) in the years 2007 through 2009.The study soil was a calcareous sandy loam one. A great importance of crop rotation with cover crop (Pisumsativum) was found on final seed yield in all cases particularly due to the drastic increase of the basic N uptake. Therecovery fraction was about 30% for control plots and in case of pisum was fluctuated up to 80%. The sun-seed yieldfluctuated from 2.5 to 3 t/ha in the control plots depending on the N-application and from 4.32 to 5.90 t/ha for pisumincorporation, respectively. The NUE was about 18 kg/kg (confirming relevant previous results cited in theliterature).