Dense soil tillage pans can develop from the improper use of tillage tools. The influence of compacted layers or pans on plant growth and development, although much studied, is not clearly understood. This greenhouse experiment evaluated the influence of uniformly compacted soil and thin layers of compacted soil placed at various depths on early growth of winter wheat (Triticum aestivum L.). Artificially compacted soil [Alliance silt loam, Aridic Argiustoll (Eluviated Brown Chernozem); A horizon] profiles were constructed in polyvinyl chloride tubes of 150-mm diameter by 350 mm long. Treatments were: (1) uniformly noncompacted (bulk density 1.30 Mg m−3) soil; (2) uniformly compacted (bulk density 1.80 Mg m−3) soil; (3) a compacted (bulk density 1.80 Mg m−3) soil layer at 100- to 120-mm depth with the remaining soil noncompacted (bulk density 1.30 Mg m−3); or (4) a compacted (bulk density 1.80 Mg m−3) soil layer at 180- to 200-mm depth with the remaining soil noncompacted (bulk density 1.30 Mg m−3). Generally, winter wheat grown in cores that were uniformly compacted or compacted in the upper layer responded similarly. Plant height, at the end of the experiment (32 d after planting), for the uniformly compacted and upper compacted layer treatments was 280 mm, compared to 323 mm for the control (uniformly noncompacted). Leaf area development was similar to the response indicated for plant height throughout the growth period. Root mass and length tended to be less in layered or compacted soil than in noncompacted soil. Roots accumulated within or immediately above compacted soil layers. Higher bulk density or a shallow compacted layer produced winter wheat with reduced height, leaf area, and dry matter compared with soil of normal density or with a deeper compacted layer. Key words: Bulk density, Triticum aestivum L., tillage pan, wheat (winter)
Whole Genome Association Mapping of Plant Height in Winter Wheat (Triticum aestivum L.)
