232 



Journal op the Department of Agriculture. 



By way of contrast to the soil types referred to above, it was 

 Ihouglit desirable to examine a sample from alluvial lands, where 

 sweet potato culture is less successful. A small field of this type, 

 represented by sample No. 1, was found behind (i.e., to the north of) 

 the hill on which the homestead stands, in a bend or elbow of the 

 eastern tributary, or Moordkuil River, at Kleindoorn (The Causeway). 

 The crops yielded by this soil are said to be poor, not only as regards 

 sweet potatoes, but also with cereals and vegetables. For some 

 years past these lands have been manured every six months with 

 cattle manure at the rate of about one wagon-load per f morgen. 



The physical character of the soil on Mr. Robertson's farm may 

 be gathered from the results of the mechanical analyses, which are 

 given below. The soils sampled were entirely free from stones and 

 coarse gravel, their percentage composition being as follows: — 



No. 1. No. 2. No. 3. 



Fine gravel 64 Nil. Nil. 



Coarse sand 2.50 Trace. .52 



Medium sand 13.98 1.56 44.22 



Fine sand 23.92 12.54 7.11 



Very fine sand 39.20 41.35 21.49 



Silt 11.30 26.87 14.83 



Very fine silt 7.08 15.67 9.68 



Clay 1.38 2.00 . 2.14 



The above figures show the considerable differences that exist 

 between these types of soil. No. 1 is a sort of transition between a 

 fine sand and a fine sandy loam, inclining, however, more to a sandy 

 than to a loamy character. No. 2 is a silt loam and physically far 

 the best soil of the three. The above mechanical analyses would 

 also imply its chemical superiority over the other two. No. 3, a soil 

 of somewhat peculiar type, may be called a sandy loam. 



Sweet Potato Soils, 



In the North American Union the principal sweet potato growing 

 States are Alabama and Georgia, which have respectively 153,000 

 and 130,000 acres under the crop. The sandy loams of the Norfolk 

 series, which are specially adapted to sweet potato culture, cover 

 543,000 acres in those two States. The average percentage composi- 

 tion of these soils is given below, and for the sake of comparison I 

 repeat, in summarized form, the results of the Little Brak 

 analyses : — 



