66 Journal op the Department of Agriculture. 



price up rapidly, and to-day it sells at about £15 per ton. This makes 

 it rather an expensive source of nitrogen, viz., 25s. for 1 per cent, of 

 nitrogen per ton, or 25s. per "unit" of nitrogen. In guano the 

 nitrogen costs to-day not more than 12s. per unit. (1 unit = 1 per 

 cent, per ton = 20 lb.) 



Meat-meal, Whale Meat, WJiale " Guano, '^ Fiah " Guano, ^^ 

 Crayfish " Gua?io," are all products appearing on the market from 

 time to time in limited quantities, and contain varying percentages 

 of nitrogen and phosphoric oxide. Their nitrogen is usually some- 

 what slower acting than guano or blood nitrogen, but if their cost 

 is reasonable they might well be used in making uji fertilizer mix- 

 tures. The intending purchaser should always obtain a guaranteed 

 analysis, give the phosphoric oxide a value of about 7s. per unit (at 

 to-day's market rates), and calculate the price per unit of nitrogen. 

 In this way he can judge if he is getting good value for his money. 



Nitrate of Soda is a " mineral " fertilizer found in enormous 

 deposits in Chili (South America). It contains about 15 per cent, 

 nitrogen, and has the advantage of being soluble in water and imme- 

 diately available to the vine roots. On the other hand, it is easily 

 washed out of the soil by rains, and is, therefore, usually applied 

 somewhat later than other forms of nitrogen. Prior to the war it 

 was sold at about £14. 10s. per ton, but in recent years has been 

 practically unobtainable. Limited quantities are now obtainable at 

 about £25 per ton, i.e. over 30s. per unit of nitrogen. 



Sulphate of Annmonia is another mineral fertilizer obtained as a 

 by-product in the coal-gas, coke, and coal-tar industries. It contains 

 20-21 per cent, of nitrogen, and is also soluble in water, but some- 

 what slower than nitrate of soda. Prior to the war it cost about £18 

 per ton (imported), but in recent years has also been practically 

 unobtainable. At present we understand this material is being manu- 

 factured locally. If the price is reasonable it may well have a place 

 in the fertilizing of our vineyards. Sulphate of ammonia shows its 

 best effect on soils which contain a good supply of lime, or which 

 have previously received an adequate dressing of lime. At present 

 tlie quoted price is £35-£36 per ton, i.e. about 35s. per unit of 

 nitrogeji. 



Nitrate of Livie and Calcium, Cyanam^ide {Lime Nitrogen) are 

 manufactured fertilizers whose nitrogen is obtained from the 

 atmosphere. The former contains about 13 per cent, nitrogen, readily 

 available, and the latter about 18 per cent, nitrogen, rather slower 

 in its action. These have been used very little as yet in this country. 

 Nitrate of lime was recently quoted at £22. 6s. 5d. per ton at Cape- 

 town, i.e. about 34s. per unit of nitrogen. 



(6) Phosphatic Fertilizers.. 

 SuperpJiospJtate or Acid Phosphate is manufactured from finely 

 ground rock phosphate of lime, or bone-ash by the action of sulphuric 

 acid. The good grade article should conUiin from 17 per cent, to 

 22 per cent, of phosphoric oxide, of which practically all is water- 

 soluble, and, therefore, quickly available. This, however, is not 

 such an important consideration for vineyards as in the case of 

 grain crops, and slower-acting phosphates may give quite as good 

 results as superphosphate. Prior to the war large quantities were 

 imported from overseas and the price was as low as £5 per ton. 



