Effect of different tillage methods on grain yield and yield components of maize (Zea mays L.)

Tillage practices influence soil physical, chemical and biological characteristics, which in turn may alter plant's yield and growth. Field experiments were conducted to study the effects of seven tillage methods on grain yield and yield components of maize (Zea mays L.) during 2004 and 2005. The soil of the experimental site was a fine, mixed, thermic, Typic Haplacambids clay-loam soil. Tillage treatments in the study were moldboard plow + two passes of disk harrow (MDD), moldboard plow + one pass of rotary tiller (MR), two passes of disk harrow (DD), one pass of tine cultivator + one pass of disk harrow (CD), one pass of rotary tiller (R), one pass of tine cultivator (C) and no-tillage (NT) as direct drilling method. Number of plants per hectare, number of cobs per plant, number of lines per cob, number of grains per line, cob diameter and cob length (yield components) were measured and consequently grain yield was determined for all treatme nts. The study indicated that tillage method significantly (P less than or equal to 0.05) affected number of plants per hectare and number of lines per cob; the former being the major yield component explaining grain yield of maize under different tillage methods. The highest number of plants per hectare was obtained for the MDD and lowest for the NT treatment. The results suggested that tillage method significantly affected grain yield of maize in the order of MDD greater than MR greater than DD greater than CD greater than R greater than C greater than NT owing to differences in number of plants per hectare in the same order. Therefore, moldboard plow followed by two passes of disk harrow was a more appropriate and profitable tillage method in improving grain yield of maize due to reduced soil compaction, enhanced seed-soil contact, increased soil moisture storage and suppressing weed growth.