Response of yield and yield components of corn (Zea mays L.) to three continuous application of individual or enriched compost

In our previous studies the positive effects of organic fertilizers such as municipal solid waste compost either alone or plus with inorganic fertilizer on growth and yield of soybean (one year application) and corn (one and two year applications) were reported. According to our previous studies, a field experiment arranged in split plot based on randomized complete block design with three replications on corn cv. SC704 during 2008. Main plots were considered six fertilizer levels (consisting of control, recommended chemical fertilizer, 20 and 40 tons per hectar municipal solid waste compost alone or plus half recommended chemical fertilizers and sub plots were considered one, two and three years application of those fertilizers. According to results, type of fertilizer and application period had significant effect on grain yield and yield components. Also, interaction effect of two factors was significant for all studied traits except for row number. Increasing of application period from one to three years significantly increased total dry matter and grain yield in which the maximum grain yield recorded when 20 tons per hectare MWC CF, 40 tons per hectare MWC or 20 and 40 tons per hectare MWC plus chemical for three continuous years were applied. These results not only confirmed our pervious studies but also indicated that long-term application of MWC plus reduced amount of inorganic fertilizer could improve grain yield and yield components as well as reduction of over application of chemical inputs.