A study of soil structure in Red River soil associates and of modification under culture

Abstract

In the naturally fertile soils of the semi-arid regions of North America, especially those of clay and sandy texture, the physical properties are highly significant and have a profound effect upon the productive capacity of the soil. Favorable soil structure is essential in the maintenance of soil productivity. Under a system of intensive cultivation deterioration of soil structure occurs. In the Red River Valley the maintenance of desirable structural characteristics is essential if maximum crop yields are to be obtained. A natural degradation process similar to the classical "solonchak-solonetz-solod" series occurs in the Red River Valley. Structure in the "solonetz" of Europe and North America has been correlated with the existing physical and chemical conditions. The morphological conditions characteristic of "solonetz" as typified by European investigators are known to exist in the "valley". Under arable culture, deterioration of soil tilth has become a problem throughout much of the Red River Valley. In the alkalinized and degraded alkalinized phases of the Morris Soil associate, dispersion of the colloidal material of the soil apparently occurs. A massive structural condition has been developed, under which plough draft is doubled and soil made impervious to water. Both natural degration processes and cultural practices have been involved in the formation of undesirable physical properties in the heavy textured valley soils...