FERTILISER FROM FISH.

New Zealand Herald, Volume LXVIII, Issue 20982, 19 September 1931, Page 20

FERTILISER FROM FISH.

VALUABLE CONSTITUENTS. When we acknowledge fish as an important item in our diet we should not overlook that there are many by-products connected with it. These can be broadly divided under two or three main headings, namely, livestock and poultry food, fertilisers and oils. In countries where careful experiments and experience have been brought to bear on the subject the opinion is geneial that the qualities of tish make it a product so valuable as a food for human beings, as well as for stock, that they cannot afford to convert into fertiliser that quantity which its usefulness warrants. In New Zealand, however, a large excess of raw material is converted into fertiliser. Fish obtains its reputation as a fertiliser from its content of phosphatic, nitrogenous and lime compounds. It also contains a small amount of potash. Thus, from tho point of view of the supply of inorganic fertilisers generally applied to tho soil for the growth of crops, it con tains all the essential ones in varying amounts. For top-dressing, vegetable growing and orchards it is very valuable. Tt has to undergo decomposition before it is valuable as plant food, and for this reason must be applied at least a fortnight before crops can avail themselves of it. A mixture of fish fertiliser, 5 parts: sulphate of ammonia, 1 part; superphosphate, 2 parts; sulphate potash, 1 part; has been recommended as a good fertiliser suitable for most crops, and would be a quick-act-ing yet lasting manure. It must be kept dry when in store.