326 EXPERIMENTAX STATIONS — KEPORT FOR 1881. 



none of which are ground to the fineness required for the success 

 of insoluble manures, especially when applied to a cereal crop 

 whose period of growth is short. Accordingly we find that the 

 dried blood on plot 16 has not come into operation, and the 

 amount of crop is quite comparable with those which received 

 no nitrogenous manure at alL Dried blood is supplied in a form 

 consisting in great measure of very hard, corny particles, which 

 are capable of being ground to a very fine powder, and until this 

 is done dried blood cannot be considered a profitable manure to 

 apply directly to the soil, especially for a cereal crop. Cake dust, 

 like dried blood, contains a considerable amount of oil, which 

 retards its decomposition, and the resinous matter contained in 

 these substances has a similar preservative effect. 



As regards potash manures only two were employed — the 

 sulphate and the muriate — and while the former maintains the 

 superiority it has shown in former years in the yield of grain, 

 the differences otherwise are not so well marked as to call for 

 special notice here. 



The guano plots show an interesting difference from former 

 years. The chief peculiarity is the great improvement shown 

 by the plot manured with fish guano, and it is accounted for in 

 two ways. In the first place, and chiefly, because the kiod of 

 fish guano employed was that improved form now being im- 

 ported which has been in great measure deprived of its fatty 

 matter and is thus rendered much more active. The inferiority 

 of the crop produced on this plot (No. 24) four years ago was 

 attriljuted to the fatty nature of the manure, and the correctness 

 of that explanation seems borne out by the result obtained this 

 year. In the next place, we may assume that the favourable 

 action of the manure this year may also in some measure be due 

 to the long-delayed action of the less soluble form of fish guano 

 employed in former years. The improvement in the manufac- 

 ture of fish guano is undoubtedly a very important matter for 

 agriculture, especially for the future of agriculture in this 

 country ; for while we are in sight of the time when the supplies 

 of Peruvian o-uano will be exhausted, and while we know that 

 the supply of Ichaboe guano must necessarily be always very 

 limited, we have in fish guano a source of manure which is inex- 

 haustible, and is capable of restoring to the land in an indirect 

 manner that large amount of mauurial wealth which our ex- 

 travagant system of sewer drainage is continually carrying down 

 from our large cities into the sea. It is therefore much to be 

 desired that the quality of this manure should continue to be 

 improved until it rival the real ammoniacal guanos in the 

 rapidity of its action, and provide us with a manure which in 

 constancy of composition and certainty of action may even be 

 superior to these. 



