Interaction effect of nitrogen and rapeseed residues on sunflower (Helianthus annuus L.) seed yield and weed biomass

Crop residues are beneficial substances that influence soil properties and crop production.This Experiment was carried out to evaluate the effect of rapeseed residues and nitrogen levels on yield sunflower and weed biomass at the Experimental Farm of College of Agriculture, Shiraz University. The experimental design was split plot in four replications; in which N levels (200, 300, 400 kg ha-1 of urea) and residue rates (0% includes weed free and weedy check, 25%, 50% and 75% of rapeseed) were considered as a main and sub plot, respectively. Results showed that the lowest weed biomass and the highest sunflower yield were obtained from 200 and 400 kg N ha-1, respectively. Compared to weedy condition, the lowest weed biomass and the highest sunflower yield were obtained from 75% and 25% residues, respectively. Since, there was no significant difference between control with 300 kg N ha-1 and 25% of rapeseed residue, application of 300 kg N ha-1 and 25% of rapeseed residue, is recommended a step toward sustainable agriculture

Keywords:

Nitrogen , Residue , Weed Biomass