South Dakota Fertilizer Experiments 1957

The soil fertility experiments reported in this summary were conducted on representative soil types in the major crop areas of the state. The growing season in 1956 was characterized by an abundance of spring and early summer moisture. The June temperatures were below normal. The July temperatures, especially for the eastern part of the state, were above normal. The high temperatures in July hastened the maturity of small grains which reduced yields, especially in the case of late planted grain and late varieties. The cool temperatures in August and September retarded the growth and maturity of the corn crop. Maintenance of the productive capacity of the soil requires the restoration of plant food through soil improvement practices which include the application of fertilizers, returning manure, crop residues, and use of good rotations including a legume. The experiments reported in this summary are concerned with these practices and serve as a guide for the development of sound soil management systems for the various crop and soil areas of the state. The crop yields reported for the various experiments are for the year 1957 only and may not reflect the average response, which will be obtained over a period of years