Evaluation of Yield, Yield Components and Nitrate Leaching in Soybean Affected By Different Types of Fertilizers and Weed Interference
In recent decades, chemical fertilizers have had an adverse effect on the life cycles and sustainability of farming ecosystems. Weed interference is one of factors that reduce crop yield. To investigate effect of fertilizer types and weeds management on yield, yield components and nitrate leaching in soybean an experiment was carried out as split plot based on complete randomized block design with three replications in two years. Fertilizers types including chemical fertilizer, manure and nano-chelates spraying as the main plot and also, weed control in three levels including weeding after emergence to beginning flowering, weeding during the critical period of weed interference and no weeding were considered as sub-plots. The results showed that among the weeds control treatments, grain yield with control at critical time as well as control until flowering was achieved in a statistical group and were significantly more than non-control treatment. The highest weeds dry weight was obtained in non-weeding treatment and increase weed control time caused their weight loss. Among the fertilizer treatments, the highest dry weight of weeds was observed by chemical fertilizer use. Maximum nitrate concentration of soil at a depth of 80-100 cm were obtained by using chemical fertilizer. Weeds dry weight increased and the nitrate concentration of soil decreased when the weed control duration was reduced.