NITROGEN DEPLETION BY WEEDS FROM ORGANIC AND INORGANIC NITROGEN SOURCES IN WHEAT CROP

A field experiment was carried out to examine nitrogen removal by weeds from nitrogen sources in wheat crop at the research farm of the University of Agriculture, Peshawar, Pakistan during year 2014-15. A randomized complete block design (RCBD) with three replications was used for the experiment. There were seven treatments consisting of control (no fertilizer), basal dose of P and K fertilizer, basal dose of N from Urea, basal dose of N from FYM, basal dose of N from PM, basal dose of N from compost of FYM and basal dose of N from compost of PM. Results exhibited that N application significantly increased weeds fresh and dry biomass, N concentration and uptake over control, while N application had no significant effect on plant moisture content. Nitrogen applied at the rate of 120 kg ha^-1 from urea significantly increased weed fresh and dry biomass by a maximum of 40.3 and 30.9%, respectively. Nitrogen applied at the rate of 120 kg ha^-1 from compost of PM increased N concentration and uptake by a maximum of 43.1 and 78.8%, respectively. Weeds removed a maximum of 23.4 kg N ha^-1 from wheat crop where basal dose of N was applied from compost of PM. Thus, it is suggested that proper weed control is very much crucial for maintaining soil fertility and improving crop yield.