Physical Properties Of Sassafras Silt Loam As Affected By Long-time Organic Matter Additions.

WITH the introduction of the tractor and the development of a highly mechanized method of farming in the potato growing section of Long Island a considerable change was made in soil management practices. Previous to the general use of the tractor, the horse was the source of power and also the source of a considerable amount of'manure. Now that machines are being used little or no manure is available and the potato crop is fertilized primarily by means of commercial fertilizers.-Considerably more heavy wheel traffic is involved in the tillage of the soil than formerly. The addition of organic matter to the soil as a means of modifying the physical properties of the soil is widely practiced. The effect of organic matter on the water relationships, aggregation, bulk density, resistance to compaction, and numerous other physical properties of the soil has been widely studied. At the Long Island Vegetable Research Farm, Riverhead, Long Island there were available plots that had received differential organic treatments for a 2 5-year p'eriod. These plots were located on a Sassafras silt loam. In the summer of 1948 a study of these plots was started to evaluate 'the effect of the organic matter levels that had been built up over the 2 5-year period on various physical properties of the soil. This paper is a preliminary report of the results of this study.