Influence of alfalfa on the change of virgin soils in the cotton districts of Armenia
1930
Mirimanoff, K.P.
The prolonged cultivation of alfalfa had a favorable influence on the change of virgin, uncultivated soils in the Echmiadzin region which is typical for the cotton districts of Armenia. This favorable influence is believed to be due to changes which may be summarized as follows: In the virgin soils after prolonged cultivation to alfalfa the silt and clay fractions increased, especially in the upper layers. The physical properties of soils after alfalfa cultivation were considerably improved, due to increasing non-capillary porosity and the raising of the water-capacity of the soil. The amount of organic matter in the surface layers greatly increased. The amount of hygroscopic moisture also increased. The nitrogen content increased in the first layer, but decreased in lower layers. A marked depression in CO2 content was observed. In water extracts from soils cropped to alfalfa the amounts of dissoluble salts decreased, due mainly to the decline of alkalinity. The amount of exchangeable cations greatly increased in the upper layers, due to the increasing amounts of calcium and potassium. On the contrary, the amount of exchangeable sodium decreased remarkably.
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