11 



does it better, for it readily works to 7 inches while the horse 

 teams usually g-o only to 5 inches. The value of this additional 

 speed has been shown in the rate at which the sow ing- of wheat over 

 the whole farm lir»s been completed. In the old days of slow horse 

 cultivalioiis, sowings could not be completed in October or 

 November, and there remained always fields to be sown in 

 January or February, according as the weather allowed. 

 Since the advent of the tractor, however, the work has been pushed 

 well forward and llie land has all been sown in November. The 

 dates of completion of sowing- are : — 



Many of our experiments show the vital necessity on this land 

 of sow ing at the proper time ; the following- is an example : — 

 Wheat sov;n in time (Nov. 24th, 1915) 26f bushels 

 . ,, sown late (Feb. 17th, 1916) ... 19^ bushels 



II. CLi-:ANIX(; SIIBHLIC.S IN AUTUMN. 



In the autumn of 1919 the arable fields were very weedy, as 

 usual over wide tracts of England where cultivation had perforce 

 been neglected for three years. Summer fallowing during 1920 

 would, of course, have been effective, but it was too costly ; instead, 

 therefore, the tractor was liberally used for cultivating the stubbles 

 during harvest, and much cleaning was done during August, 

 September and October. The effect was very striking. The weed 

 seeds germinated in the warm moist land ; the seedlings being very 

 susceptible to injury were easily killed by cultivations ; and as the 

 cultivation was carried out before instead of after sowing the crop, 

 it was entirely beneficial and did no damage. In consequence, the 

 land which had been foul in 1919 became tolerably clean in 1920 

 in spite of the fact that a second winter corn crop was sown. The 

 autumn cleaning was repeated in 1920 and a third corn crop sown ; 

 at the time of writing this remains free from troublesome weeds. 



The advantage of this method is to give us much more latitude 

 in cropping than we had before. Under the old horse cultivation it 

 was imperative to grow a root crop once in 5 or 6 years to keep 

 down weeds, and we were always rather beaten in the struggle ; 

 under the present method we can apparently grow^ any crops we 

 please, unless a prolonged w^et autumn should set in. This is 

 illustrated by the Great Harpenden Field where the crops and 

 yields per acre have been : — 



