A greenhouse study of the effects of fine limestone applied in the row with legume seed on acid soils
1937
Greiner, L.M. | Walker, R.H. | Brown, P.E.
Greenhouse experiments were carried out on two acid Iowa soils, Marshall and Grundy silt loams, to determine the value of fine limestone applied in the row with certain legume seed. Small amounts of fine limestone applied in the row with sweet clover seed on Marshall silt loam caused a depression in the early growth of the plants when grown in deep greenhouse pots. There was no depression in the case of alfalfa nor with sweet clover on Grundy silt loam. Limestone applied in the row appeared not to be depressive to the formation of nodules. The death rate of seedlings caused by pythiaceous fungi was decreased 3.4% for the alfalfa, 3.7% for the sweet clover, and 8.2% for the red clover by applying fine limestone with the seed at the time of planting. As determined by the direct microscopic ratio method fine limestone, when applied in the row with legume seed on Marshall silt loam, stimulated the growth of micro-organisms. The average number of micro-organisms counted for samples taken 0 to 4 cm deep in the row was 93.7 million per gram of soil. This was 46.8 million more than was found in the check soils. As indicated by pH determinations, penetration of limestone when applied in the row was evident in soils receiving water from below only.
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