Thesis (Ph. D.) in Plant Science--University of Maine, 2000. / Includes vita. Includes bibliographical references (leaves 147-160).

Revised; Original Published: 2004 / 2 pp. / Small grains are planted for a variety of reasons, but their rotational benefit makes them a popular crop all over the world and influences the way they are planted. One of the major benefits of small grains as rotational crops is that they cover the soil and suppress weeds. Thus, small grains are most commonly solid seeded with a grain drill.

No description available.

No description available.

In the northern Great Plains of Canada, there has been limited research conducted on reduced-tillage grain production systems managed organically. The objective was to adapt an organic rotational no-till system to the growing conditions of Manitoba, and to test its agronomic performance. A set of four experiments were conducted between 2010 and 2012, in Carman, MB, Canada. Mulches with hairy vetch (Vicia villosa Roth) showed the most promising results, producing the highest mulch biomass and organic no-till spring wheat (Triticum aestivum L.) yield. Organic flax (Linum usitatissimum L.) yield was significantly higher in no-till than in the two tillage treatments. Reduced content of soil nitrate-N and perennial weeds limited crop productivity after 4 yr under organic continuous no-till. In conclusion, the successful adaptation of the organic rotational no-till system to the growing conditions of Manitoba eliminated the need for tillage for a period of 1.5 to 2 yr.

The soil structure stiffness and the index of looseness concepts were developed from the theoretical stress and strain parameters with the aim to establish the tillage mechanics evaluations of the influence of tillage geometry on soil behaviour. / In order to verify these concepts in the field, chisel tines of different blade widths and rake angles were constructed and operated at different depths of tillage in a clay loam and a sandy loam. / Field and laboratory tests were conducted to determine the shear strength parameters, the structural stiffness, the index of looseness, the dry density, the cumulative infiltration, the moisture characteristics, the mean weight diameter and the percentage aggregation developed in the tilled soil. / Polynomial regression equations that related the tillage geometry to the different measured structural behaviours were developed from the test results. / The structural stiffness and the index of looseness were significantly more sensitive than the other measured structural behaviours to the changes in the geometry of a tillage implement.

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No description available.

Thesis (M Eng) -- University of South Australia, 1993

Thesis (Ph. D.)--University of Adelaide, Dept. of Plant Pathology, 1984. / Includes bibliographical references (leaves 133-144).