xiii] THE SOWING OF FERTILISERS 371 



the hay as carted, and preserve it for a dry-matter 

 determination in the laboratory. 



In dealing with root crops it is found convenient to 

 cut the tops off and weigh them in large baskets in the 

 field ; the roots themselves are carted off to the weigh- 

 bridge. Whatever the crop, the whole produce of the 

 plot should be weighed ; to cut out and weigh a small 

 area introduces a fatal source of error — the selection 

 of the area. There are a number of other precautions 

 to take which cannot be here enumerated, but speaking 

 generally, the original records should be as full of detail 

 as possible ; forms for the entries should be drawn up 

 beforehand in such a fashion that there is a place for 

 every figure obtained in the work without any additions 

 or subtractions, and all this original material should be 

 preserved untouched. 



In the use of fertilisers, whether for experimental 

 purposes or in practical farming, it is very important to 

 get them distributed evenly on the land ; nothing is 

 more common in a hay or cereal crop where nitrate of 

 soda has been used as a top dressing than to see regular 

 waves of a darker green and stronger growth than the 

 bulk of the crop, representing the places where the 

 fertiliser fell from the sweep of the sower's arm. With 

 other manures the irregularity is not so evident, partly 

 because they are often sown before the final working of 

 the ground, and partly because they have not the 

 striking effect upon the colour and vegetative develop- 

 ment of the crop that nitrate of soda has. But if 

 artificial manures are to be sown evenly by hand, it is 

 necessary to mix them with a much greater bulk of 

 burnt earth or ashes and to go over the land more than 

 once ; better and quicker work will always be done by 

 a machine if there is enough work of the kind on the 

 farm to justify its purchase. Some fertilisers, basic slag 



