Row-crop planter attachments in a conservation tillage system: A comparative study

Poor com (Zea mays) stand establishment in the presence of surface plant residue in conservation tillage may reduce yield potential and thus limits the adoption of the method by farmers. A study was conducted to compare the effects of three tillage systems and three types of planter attachment on the amount of surface and subsurface residues after planting, emergence rate index, seed spacing indices and seeding depth of com in a soil covered with previous wheat (Triticum aestivum) residues. Tillage treatments were single pass of disc harrow, three passes of disc harrow, and single pass of disc harrow followed by chisel plowing. Corn was planted with a planter equipped with either a plain rolling coulter, a row cleaner or a combination of row cleaner followed by plain rolling coulter. Tillage treatments did not show any significant effect on measured variables except seeding depth. Seeding depth was highest and the most uniform for the planter prepared with three passes of disc harrow. No interaction on measured variables was observed among treatments incorporating tillage modes and planter attachments. Row cleaner and row cleaner followed by rolling coulter retained less surface residue as compared to coulter attachment. Row cleaner retained less subsurface residue as compared to row cleaner followed by rolling coulter. Lower surface and subsurface residues in the case of row cleaner attachment treatment led to the highest emergence rate index. Coulter attachment increased quality of feed index as compared to planter with no attachment. Row cleaner increased the quality of feed index and decreased miss and precision indices. Row cleaner followed by rolling coulter had highest quality of feed index and lowest values of miss and precision indices; this treatment exhibited deepest and the most uniform seeding depth mainly because of better residue cleaning and efficient cutting of the soil and trash. (c) 2007 Elsevier B.V. All rights reserved.