Effects of Tillage, Fertilization and Weed Control Methods on Corn Yield in the Northern Part of Khuzestan

In order to evaluate the effects of seed bed preparation, fertilization and weed control (after planting) methods on growth and corn yield in northern part of Khuzestan a field experiment was conducted as split blocks in a randomized complete block design with four replications during 2009 and 2010. Three seed bed preparations consisting of Makhar condition (wet seeding) + conventional tillage (plough + disk + leveler), makhar condition + reduced tillage (disk) and without makhar + reduced tillage were performed in horizontal plots. Two methods of fertilizing (Broadcast and Drill) as main factors and weed controlling methods (once using of field cultivator in four-leaf stage (20 cm height of plants), two times using rolling cultivator in four and seven-leaf stage (20, 40 cm height of plant), using two liters Nicosolforon herbicides when the plant produced 3 - 4 leaves, and checking treatments (weed free and weed infect) as the sub-factors were conducted in vertical plots. The results indicated that population and biomass dry weight of weeds were significantly (p< %5) affected by Makhar. Planting in without makhar soil, caused reduction in the population and weed weight (30% and 40%) in the 5th week. In all tillage methods, the effect of two times using rolling cultivator and chemical control on grain yield and biological yield was statistically similar. In fertilizer drill method, grain yield and biological yields, kernel in rows and rows in ear were significantly (P<%1) higher than broadcast method. The most grain and biological yield were obtained in combination of makhar condition and fertilizer drill (in treatment of makhar condition + reduced tillage, grain yield was 9003.25 kg/ha.). Two times using rolling cultivator reduced the population and weight of weeds significantly more than chemical control in farm with plenty of Bind weed. In all of the Broadcast fertilizer methods, chemical control treatment had more yield (16%), but in fertilizer drill method there was no significant difference between chemical and two times using of rolling cultivator treatments. It seems that in corn farms when broadcasting fertilizer method is used, the chemical control of weed due to higher yield (15%) is more effective; two cultivator weed control method is recommended if the distribution of fertilizer is used with drilling method. The highest grain yield (9183 kg/ha) was obtained from the combination of makhar, reduced tillage, fertilizer drilling method and two times using rolling cultivator.