Laboratory tests on some hoof and horn materials used in horticulture. II.—Materials heat-treated during processing

✍ Scribed by O. Owen; G. W. Winsor; M. I. E. Long

• Publisher: John Wiley and Sons
• Year: 1953
• Tongue: English
• Weight: 696 KB
• Volume: 4
• Category: Article
• ISSN: 0022-5142
• DOI: 10.1002/jsfa.2740040905

✦ Synopsis

Abstract

Nineteen samples of ‘calcined’ hoof and horn materials have been examined in the laboratory with particular reference to their nitrogenous constituents. All the samples, which included hoof, horn and mixtures of the two materials, were milled in the laboratory before testing. The nitrogen content of the samples ranged from 12.98 to 15.10%. Considerable differences were found in the initial rates of mineralization of the nitrogen of the samples in soil. Highly significant correlations were found between the initial rates of mineralization of nitrogen and the contents both of water‐soluble nitrogen and of ammonia as determined by distillation with magnesia.

A rapid test, in which aqueous extracts of the hoof and horn samples were titrated with a standard solution of sodium hydroxide in the presence of formaldehyde, was found to give results approximating to the ammonia values as determined by distillation and highly correlated with the soil‐incubation tests. A positive correlation was also found between the initial rates of mineralization of nitrogen and the bulk density of the samples. After incubation for 10 weeks in the soil the percentage mineralization of nitrogen in the samples ranged from 62 to 76%; no correlation could be found between these values and the other properties of the samples tested.

It is concluded that calcined hoof and horn materials constitute a reasonably homogeneous class of nitrogenous fertilizer, except where the preliminary heat treatment was insufficient to destroy the fibrous nature of the horn samples.