The continued demand for information concerning the distribution of alkali soils and proper methods of handling them have led this department to make these preliminary investigations. In coming in contact with farmers in the eastern portion of South Dakota, where there is an abundant supply of rain-fall, the question was asked many times, "What shall we do with small areas where alkali is making its presence known by killing crops?" It seems that the system of cultivation of the soil has induced such excessive evaporation that the salts have been left on the surface. It has also been observed that in places where these spots are small in size that they are growing larger. The popular term designates alkali soils, with reference to poorly drained areas where there is usually an accumulation of white or brownish white salt on the surface. These salts usually make their appearance during the latter part of the growing season, being, of course, influenced by the distribution of rain-fall. For convenience we may classify alkali salts under two groups, (1), soluble, (2), less soluble salts. The more common soluble salts consist of three chief ingredients, sodium chloride, (common salt); sulphate of soda, (Glauber'ssalt), and Sodium carbonate. They are all detrimental to plant growth, the latter being known as "black alkali". The name, black alkali is very appropriate in that it produces black spots or puddles. This is because of the soluble effect of the sodium carbonate on humus. It hardly ever happens that only one of these salts is present but the three always seem to be associated. Commonly magnesium sulphate, potassium sulphate, sodium phosphate, and sodium nitrate are also present.
alkali soils, soluble salts
South Dakota Experiment Station, South Dakota State College of Agriculture and Mechanic Arts
Willis, C. and Bopp, J.V., "Alkali Soils" (1911). Agricultural Experiment Station Bulletins. 126.