RESEARCH OF FOUR YEARS ROTATION SYSTEMS IN CENTRAL ANATOLIA

The rotation experiments were established in two fields with shallow and deep soil profiles. The crop sequences was in four-year rotations wheat-fallow-alternative crops-wheat. Alternative crops were spring and winter lentils, sunflower, and wheat. This four types of crop rotations were compared to standard fallow-wheat-fallow-wheat system. In experiment with deep profile soils 12 cereal (durum, bread wheat and barley) varieties were grown while only one variety cv (Ġkizce) was planted in experiment with shallow soil.

In both of the experiments, soil moisture was determined in 0-120 cm soil depths. The data showed that positive effect of ½ fallow frequency was existed in only dry year such that crop yields were significantly different from other rotations having ¼ fallow frequency.

Cvs Gün-91 (bread), Yılmaz-98 (durum) and Tarm-92(barley) performed better in all rotation systems, however Aydanhanım (malting barley) and Avcı (6-row) influended adversly from dry seasons. High yield loss was obtained from fallow-wheat-wheat-wheat rotation. In both of the experiments with deep and shallow soil profiles.

The rotation system, of fallow-wheat-spring lentil-wheat was better than standard fallow-wheat-fallow-wheat rotation as grain yields of wheat, and economice point of view. Keywords : Rotation, fallow, wheat, spring lentil, winter lentil, sunflower