lo Xov.. 1910. J Potato Experimental Fields, igog-10. 



the latter, and these, coupled with the ])roper aeration of the soil, are the 

 controlling factors in its fertility. 



The percentages of loss on ignition and moibtiu-e represent the amount 

 contained in 100 lbs. of the soil in an air dry condition, and shows its 

 power to retain the moisture it has receiyed. The difference in moisture 

 ■content between 4.16 in plot Xo. 2 and 2.30 in plot No. 3 does not appear 

 very great, but it represents nearly double the amoimt and is still more 

 striking when shown in lbs. per surface foot per acre. The same applies 

 to the organic matter. This difference is still more striking when plots 

 2 and 3 are compared with No. i. 



The relatiye position of these fields as regards moisture, organic matter, 

 and yield is shown in Table E : — 



Table E. — Moisture Coxtents. 



There is no doubt that, if plot 3 had received the same treatment as No. 

 I and No. 2, it would have shown a higher percentage of organic matter, 

 with a correspondingly higher percentage of moisture and a hea\-ier 



Yield. 



Experiments with Aktii-icial Manures. 



Table F.— Manures and Y'ields. 



Turning to the eftect of the different manure dressings on the three plots 

 it will be evident that the one containing the highest percentage of 

 phosphoric matter responded most evenly to the manures. Section i of 

 plot No. I shows an increase of i ton 1 1 cwt. per acre for a dressing of 

 2 cwt. superphosphate, and section 2 only of 10 cwt. per 1 cwt. sulphate of 

 ammonia. Tt was noted during the growing period that this section had 

 a more luxuriant growth of foliage, and these tender plants evidently gave 

 way under the influence of a prolonged dry spell. In connexion with 

 section 3, i cw^t. sulphate of potash gave the most satisfactory returns 

 obtained during five years. This may be attributable to the character of 

 the .soil, its high percentage of moisture and the presence of a larger 

 amount of lime than is generally met with in these soils. Section 5 has 



