Combined Effect of Three Pesticides (Zoom, Topik and Ortiva) and Phosphorus Fertilization on Some Physicochemical Parameters of Soil

The purpose of this study was to verify the effect of three pesticides (Zoom, Topik and Ortiva) on some physicochemical parameters of soil. To do this, phosphate fertilizer was applied before planting and pesticides were sprayed pre- and post- emergence of Durum wheat. Particle size analysis showed that the soil was characterized by a clay texture and the value of residual humidity does not exceed 8%. The study of pH showed a remarkable seasonal variability; it was in the vicinity of neutrality at the beginning of culture (7.22) to the vicinity of acidity after crop harvest (5.78), thus the change in pH water was due to the phenomenon of dilution. The electrical conductivity proved that the soil was not saline. The content of soil organic matter was experiencing significant seasonal variation. After applying different doses of phosphate fertilizers, soil phosphorus varied remarkably with the seasons, which can be affected by adsorption, precipitation, heading stage, and the presence of clay cation Fe, Al and Ca. It was also noticed an increase in the content of soil available phosphorus during the tillering stage, which is due to the phenomenon of desorption and dissolution. The existence of traces of pesticides indicates that the Topik molecules are more resistant to degradation.