226 CHEMICAL DEl'AiriMENT. 



regai'ils the other two })luts, the results on the two lialves are 

 very near to each other. There is iKjt a (hfference of as much 

 as two bushels per acre b(^tween the half that was manured ^vith 

 superphosphate in l(StS() and that manured in LScSS, showing that 

 a considerable residue of the phosphate applied two years before 

 was still in the ground, and available even for the short-lived 

 wants of a cereal cr(jp. 



Plots 31 to 34 were once more utilised t(-) show the effects of 

 ilouble doses of nitrogen and potash. The plot to which a 

 d(Aible dose of nitrate of soda was applied gave the largest croj) 

 on the station. Sulphate of anmionia, when applied in d(^uble 

 cpiantity (plot 32), has not done (juite so well. It is a slower 

 manure than nitrate of soda, and not so well adapted for appli- 

 cation during a season of drought. Had tlie season been a wet 

 one, the probability is that the crop on both these plots would 

 have been too heavy to stand. The double dose of sulphate of 

 potash (33) has had no marked effect upon the croj), but the 

 double dose of muriate (34) has diminished the cro]> very con- 

 siderably. 



Plots 7, 8, !j, and 10 are one-year-old duplicates of the tive- 

 year-old plots 27, 11, 21, and 17 respectively. Plot 7 was left 

 unmanured for the barley crop, and has produced a very small 

 crop, but still it is fully hve bushels per acre better than the 

 half from which manures have been withheld for two years, and 

 nearly ten bushels per acre better than plot 27, that had not 

 been manured for more than five years. Plot <S had no phos- 

 phate put on it for the barley crop, but only nitrate of soda and 

 potash salts. The result is the production of a full crop, show- 

 ing that the barley did not feel the want of phosphates. Plot 

 ^) had nitrate of soda and phosphates, but no potash salts, ap- 

 plied t(j the barley. The result is a full crop, showing that the 

 barley did not feel the want of potash. Phjt 10 had phosphates 

 and potash salts applied to it, but no nitrate of soda, and the 

 result is the same as if no manure had been applied at all. It 

 is the nitrate of soda that has exerted the greatest influence 

 over the whole station, and practically it has rescued the crop 

 from failure. 'Hie value of nitrate of soda, applied with the 

 seed during a seas(jn of drought, is the most ]>romiiu'nt fact 

 exhibited by the barley crop at Harelaw. 



We may therefore sum up the results obtained mi tlic Hare- 

 law station as follows: — 



IJ} 11 u (inured Sectiui i . 



1. On one half of the station no manures had been applied for 

 tAvo years, and in the meantime a crop of oats and a crop of 

 potatoes had been removed f)om the land : nevertheless, the 



