Nitrogen, Manure and Municipal Waste Compost Effects on Yield and Photosynthetic Characteristics of Corn (Zea mays L.) Under Weedy Conditions

A two-year field experiment was carried out to investigate the effects of nitrogen, composted manure, municipal waste compost, and weeds on yield and photosynthetic characteristics of corn. Experimental design was split split plot factorial with 3 replications. Main plots were weedy and weed-free, sub plots were nitrogen fertilizer levels [0 (N0) and 200 (N200) kg N ha -1 as urea], and sub sub plots were factorial application of municipal waste compost [0 (C0), 25 (C1) and 50 (C2) t ha ] and manure [0 (M0), 25 (M1) and 50 (M2) t ha] with all possible combinations. Manure and municipal compost increased photosynthetic rate (A) (27 and 7 %, respectively), stomatal conductance (gs) (12 and 25 %, respectively) and chlorophyll content of corn leaves same as nitrogen fertilizer. There was no significant difference between C2+M2 and C2+M2+N200 for corn yield. Weed presence significantly decreased A, gs, chlorophyll content, and yield of corn. Increase in organic or inorganic fertilizers did not decrease the detrimental effect of weeds on corn. Our results showed these organic amendments are valuable potential as nutrient sources for corn production and allow our farmers to recycle livestock and municipal waste products; however, they could also increase weed competition. These findings can use to improve organic fertilization as an essential part of integrated weed management.