1921.] 



Notes on Manures for June. 



265 



Basic Slag is very little affected by storage, and can be kept 

 almost indefinitely in a reasonably dry shed or store. 



Sulphate of Ammonia is somewhat more easily affected by 

 atmospheric moisture, especially if it comes from small gas works 

 where it has not been well finished. The well-made neutral 

 sulphate, however, is less affected. In any case the material is 

 best stored in bags placed on planks or on a layer of peat 

 rather than on the bare earth or brick floor. It may cake some- 

 what on storage, and should then be broken up with a wooden 

 crusher. 



Nitrate of Soda, Kaiuit and Sulphate of Potash. — These 

 substances will keep indefinitely under dry conditions, such as 

 the merchant's store ; they may also be preserved for a long 

 time in a well built shed on a farm. They undergo no inherent 

 deterioration, but they may become lumpy through the action of 

 moisture, and must then be crushed. There is no practical 

 Hmit to the length of time the above fertilisers may be kept so 

 long as the conditions are suitable. 



Snperplwsphate is in a rather different category, and under- 

 goes slow change on storage, which up to a certain point is advan- 

 tageous. Well made sam.ples in good condition have been stored 

 for the necessarv time by the makers; but prolonged storage 

 may cause deterioration to set in. On the whole it is advisable 

 to avoid the necessity of storing by careful calculation of the 

 requirements and by using early in the following season any 

 material that happens to be left over. 



N'trate of Lime cannot easily be stored once the package has 

 been opened, as it is liable to absorb moisture in damp situations. 



Ground Limestone can be stored indefinitely, either in bags or 

 in bulk : but lime cannot be stored in bags, again because of its 

 great power of absorbing moisture. 



Nauru Phosphate. — Much interest is being taken in Nauru 

 phosphate, and enquiries are being made by farmers and 

 others as to its probable value. Samples are not yet to hand, 

 but arrangements haVe been made at Bothamsted for a field 

 test as soon as the material arrives.* Even if it proved 

 unsuitable for direct application to the land, it might still be 

 found valuable in the manufacture of superphosphate. It ia 

 stated to be very rich in phosphate, containing phosphoric 

 acid equivalent to 85-86 per cent, of tricalcic phosphate, with 

 occasional patches running as high as 87-88 per cent.: there 

 is said to be no low grade, and that it would be impossible to 

 ship a cargo running below 80 per C(^nt, without deliberate 



* Experiments are already being undertaken elsewhere. 



