Influence of organic and inorganic amendments on weeds density and chemical composition.

Incorporation of biochar to agriculture field has got a primary factor in maintaining soil fertility and productivity particularly in nitrogen and organic matter limiting environments. Clear experimental evidence to support this view, however, is still lacking. Also effective weeds control at early stage is always first priority of maize growers. Taking in account the adverse effects of synthetic fertilizers, agriculture scientists are trying for shifting inorganic farming to organic one. In the current experiment the effect of organic amendments (biochar and FYM) were evaluated along with mineral N on weeds density and their nutrients uptake from soil. The experiment was conducted at New Developmental Farm of the University of Agriculture Peshawar Pakistan. The experiment consisted of three levels of biochar (0, 25 and 50 t ha 1 ), two levels of FYM (5 and 10 t ha -1 ) and two levels of mineral N (75 and 150 kg ha -1 ) and a control treatment for comparison. The findings suggested that higher rate of BC (50 t ha -1 ), FYM (10 t ha 1 ) and N 150 kg ha -1 improved weeds density by 21%, 45% and 19%, respectively as compared to their lower application rate such as 25 t, 5 t and 75 kg N ha -1 , respectively. Application of N at 150 kg and 10 t FYM ha -1 increased weed dry weight by 45 and 29% respectively. Application of FYM @ 10 t ha -1 increased weeds N, P and K content by 37, 21 and 17% respectively over FYM @ 5 t ha -1 . Application of mineral N @ 150 kg ha -1 resulted in 29% increase in weeds N content as compared to 75 kg N ha -1 . Biochar application considerably increased weeds P and K content. Application of 50 t BC ha -1 increased weeds P and K content by 9 and 11% over 25 t BC application and by 21 and 27% over no BC treated plots. Overall, organic amendments and N fertilization increased weeds