Field experiment was conducted to investigate the influence of ground corn cobs, gypsum, and chemical fertilizers on the growth and yield of corn.
The treatments included the addition of the followings: , .
Four rates of ground corn cobs (i.e. 0,20, 40, 80 ton/ha), four rates of gypsum (i.e. 0, 2,4, 8 ton / ha), triple super phosphate (46% P205) and potassium sulfate (45% K20) at a rate of 1.2 ton/ha each , and urea, the rate of which depended on the rates of ground corn cobs and its C/N ratio. The influence of different treatments on seedling emergence, root system length, leaf area and yield of corn were determined. Results exhibited the followings: Seedling emergence increased from 96, to 100% when 20 ton/ha ot corn cobs was added to the silt loam and clay loam soils 150 days after incorporation. As for the silty clay loam soil the emergence rate increased from 15.9% for the original soils to 39.8, 60.8, and 73.8 /« when 5,10, and 80 ton/ha were added, respectively 150 days after incorporation. Addition of corn cobs increased corn roots length and leaf area. Means of roots length per plant increased from 0.60, 0.62, and 0.26m/plant to 1.11, 1.21, and 0.77m/plant for the silt loam, clay loam, and silty clay loam soils, respectively. Means of leaf area were 0.78, 0.81, and 0.55 m2 per plant for the three soils, respectively when 80 ton/ha of cobs were added. Yield of corn increased with the increase in the rate of corn cobs and gypsum addition. Mean values of corn yield were increased from 11.75,11.92, and 1.41, to 19.0,20.0, and 5.74 ton.ha for the silt loam, clay loam, and silty clay loam soils, respectively, after 150 days ot incorporating 80,ton of cobs and 8 ton of gypsum/ha. |