Soil Aggregation—Organic Matter Relationships in Redtop-Potato Rotations1
- M. Salomon2
Beneficial effects of redtop residues on yields of potatoes grown on a Bridgehampton silt loam were correlated with increased soil aggregation; particularly with larger aggregates. There was an accumulation of carbon in all aggregates studied. However, the quantity does not appear to be related consistently to degree of aggregation. Analyses of total soil and aggregates (> 1 mm., 1 to 0.25 mm., 0.25 to 1 mm.) for microbial gums, polyuronides and acid hydrolyzable polyhexose carbohydrates indicate a similarity in quantities of these constituents as functions of organic carbon. Generally, somewhat wider C/N ratios (13:1) were found in larger aggregates where redtop was included, compared with smaller sizes (11:1). Extraction of organic matter with 0.5N NaOH and neutral 0.1M pyrophosphate indicates similar humic materials loosely held by this silt soil regardless of source. About 6 to 9% of the total carbon found in aggregates could be consistently accounted for as acid-hydrolyzable carbohydrate. There was little difference in this fraction due to rotation or size of aggregate.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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