246 EXPERIMENTS ON THE CULTUKE OF TURNIPS. 



soil of the five, combining depth with firmness and fertility, but 

 is a little handicapped by its elevation above sea-level. 



All the stations have a southern exposure, with the exception 

 of Craichie, which slopes gently to the north. 



The oat stubbles on all the stations were ploughed during the 

 months of November and December of 1879, and w^ere prepared 

 last spring in the usual way for the turnip crop. The weather 

 during the latter operation was exceptionally dry, so dry, in- 

 deed, that it necessitated a considerable amount of care in the 

 manipulation of the soil during its preparation in order to retain 

 sufficient moisture to secure a braird. The labourino: of the 

 plots was in every case done along with the rest of the field, 

 and were only measured off after the drills were ridged up ; the 

 tops of these were harrowed down with a hand-rake to make 

 them ready for the manure. 



The experimental plots being sown along with the general 

 crop of the farm, necessitated the sowing of the various stations 

 at difterent times to suit the circumstances of the farm on which 

 each was situated. The lighter sharper soils being, as a matter 

 of prudence, sown later in the season, thus providing against the 

 too early maturing of the crop, and increasing the chance of its 

 being a heavier one ; the deeper and heavier soils being, of 

 course, better able to withstand the variations of the weather, 

 were sown earlier. J3esides this, considerable differences of 

 opinion exist as to the proper time for sowing this crop. All 

 these circumstances were considered, and the stations were 

 selected so as to have variety of soils, as well as differences in 

 dates of sowing, in order to see if these varied conditions 

 influenced the results to any extent. 



To make the test between the soluble and insoluble phos- 

 phates as equal as possible, I arranged to have the superphos- 

 phate manufactured from the same material as the ground 

 phosphates ; the kind of phosphate selected was " Curacoa." A 

 sufficient quantity of this article was got to supply all the 

 stations ; it was ground to an impalpable powder ; after being 

 mixed, it was sampled and sent to two different analysts, with 

 the following results, 87'48 per cent., and 91 '14 per cent., 

 respectively, of tribasic phosphate. A sufficient quantity of 

 curacoa superphosphate was also got, which was carefully 

 broken down and thoroughly mixed, also analysed in dupli- 

 cate, with the following results, — one sample containing 

 41*12 of soluble, and I'oO of insoluble; the other, 42*87 

 soluble, and 1-65 insoluble. The superphosphate was in fine 

 dry condition. 



The potash salts used were home manufactured sulphate, 

 analysing 77 per cent, of sulphate. The nitrogen used was in 



