 An excavation was made in the field to the depth of six feet, and a stream of water was directed against the vertical wall of soil until it was washed away, so that the roots of the plants growing in it were laid bare. The roots thus exposed in a field...  Practical Farm Drainage: Why, when and how to Tile Drain - 第 15 頁Charles Gleason Elliott 著 - 1882 - 92 頁完整檢視 - 關於此書
 | Maine. Board of Agriculture, Maine. Department of Agriculture - 1873 - 516 頁
...against the vertical wall until it was washed away, so that the roots of the plants growing in it were laid bare. The roots thus exposed in a field of rye,...presented the appearance of a mat or felt of white fibers to a depth of about four feet from the surface of the ground. Roots of winter wheat were observed as... | |
 | Ohio State Board of Agriculture - 1873 - 750 頁
...against the vertical wall until it was washed away, so that the roots of the plants growing in It were laid bare. The roots thus exposed in a field of rye,...presented the appearance of a mat or, felt of white fibers to a depth of about four feet from the surface of the ground. Hoots of winter wheat were observed as... | |
 | United States. Department of Agriculture - 1869 - 724 頁
...vertical wall of soil until it was washed away, so that the roots of the plants growing in it were laid bare. The roots thus exposed in a field of rye,...presented the appearance of a mat or felt of white fibers to a depth of about four feet from the surface. The roots of winter wheat he observed as deep as seven... | |
 | Samuel William Johnson - 1868 - 408 頁
...vertical wall of soil until it was washed away, so that the roots of the plants growing in it were laid bare. The roots thus exposed in a field of rye,...presented the appearance of a mat or felt of white fibers, to a depth of about 4 feet from the surface of the ground. The roots of winter wheat he observed as... | |
 | Samuel William Johnson - 1868 - 408 頁
...vertical wall of soil until it was washed away, so that the roots of the plants growing in it were laid bare. The roots thus exposed in a field of rye, in one. of beans, and in a bed of garden peas, ] (resented the appearance of a mat or felt of white fibers, to a depth of about 4 feet from the surface... | |
 | Commissioner of Agriculture - 1869 - 728 頁
...vertical wall of soil until it was washed away, so that the roots of the plauts growing in it were laid bare. The roots thus exposed in a field of rye,...presented the appearance of a mat or felt of white fibers to a depth of about four feet from the surface. The roots of winter wheat he observed as deep as seven... | |
 | United States. Department of Agriculture - 1869 - 724 頁
...vertical wall of soil until it was washed away, so that the roots of the plants growing in it were laid bare. The roots thus exposed in a field of rye,...presented the appearance of a mat or felt of white fibers to a depth of about four feet from the surface. The roots of winter wheat he observed as deep as seven... | |
 | Washington Government Pritning Office - 1869 - 722 頁
...vertical wall of soil until it was washed away, so that the roots of the plants growing in it were laid bare. The roots thus exposed in a field of rye,...presented the appearance of a mat or felt of white fibers to a depth of abont four feet from the surface. The roots of winter wheat ho observed as deep as seven... | |
 | Vermont - 1872 - 746 頁
...against the vertical wall until it was washed away, so that the roots of the plants growing in it were laid bare. The roots thus exposed in a field of rye,...presented the appearance of a mat or felt of white fibers to a depth of about four feet • from the surface of the ground. Roots of winter wheat were observed... | |
 | Michigan. State Board of Agriculture - 1872 - 366 頁
...against the vertical wall until it was washed away, so that the roots of the plants growing in it were laid bare. The roots thus exposed in a field of rye,...presented the appearance of a mat or felt of white fibres to a depth of about four feet from the surface of the ground. Roots of winter wheat were observed... | |
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