Evaluation of different tillage systems and plant densities effects on silage corn yield after wheat harvesting

In order to investigation the effects of tillage systems and plant densities on silage yield and its component on corn (Zea mays L.cv.sc704) after wheat harvesting an experimental randomized complete block design , in a strip plot was used. Treatments arrangement  with four replications in agricultural reseach station of Dashte-Naz in Sari for three years( 2011-2012-2013). Orizontal plot was subjected to tillage systems in three levels: 1. Plow and Disck system (PDS). 2. Disk system (DS) - 3. No tilage (NT). Other factor(vertical plot) was plant density in four levels (70000, 80000 , 90000 and 100000  plant/ha) .Plant distances in row ,were  19,16.7,14.8 and 13.3 cm with 306,304,296 and 306 cm row length respectively.Row distance was 75cm.Each treatment was planted in six rows.Treatments were measured on four middel rows. Plant height, ear height , row number, kernel number in row, ear length,  ear diameter, wet and dry silage yield, wet and dry ear weight, wet and dry stem weight, wet and dry leaf weight and amount of protein were measured. The results (in three years)indicated that the most silage yeild (55.23 t/ha)was obtained from Disck system(DS) in density of 90000 plants/ha ,that had not significant difference effects with No tilage system (NT) in density of 90000 plants/ha with silage yeild of 54.5t/ha. The results also indicated that the most dry forage yeild (18.23 t/ha)was obtained from No tilage system (NT) in density of 90000 plants/ha ,that had not significant difference effects with Disck system(DS) in density of 90000 plants/ha with silage yeild of 18.16t/ha.