EXPERIMENTS UPON SWEDES, 



AGRICULTURAL experiments are of little or no practical utility 

 unless they are continued from year to year for a long period, 

 and tried on a variety of soils in good and in bad seasons in a 

 manner which allows us, if not to eliminate, yet clearly to recog- 

 nise the disturbing influences of climate, season, condition of 

 soils, and other circumstances which often affect the produce in 

 a higher degree than the manures on which we experiment. A 

 single field-experiment is as likely to lead us in a wrong as in a 

 right direction. Few persons have the inclination or are in a 

 position to persevere in such a laborious, expensive, and in many 

 respects unthankful course of investigation. But little trust- 

 worthy experience and no knowledge is gained from the great 

 majority of published experiments with artificial manures which 

 meet our eye from time to time in the agricultural newspapers, 

 from the want of this continuity of action. For this reason I 

 have continued field-experiments upon swedes, similar to those 

 published in this Journal in 1855 and 1858, and have now 

 the pleasure of presenting to the Royal Agricultural Society a 

 third report on field-experiments upon swedes. I regret to say 

 that in 1858, and again in 1860, my experiments were failures ; 

 and only in 1859 did I succeed in getting an even plant and 

 results on which reliance can be placed, and from which I trust 

 some useful information may be gathered. 



Although I completely failed in securing an even crop in 

 1858, it still appears to me advisable that 1 should describe 

 briefly the kind of experiments which I then made, and give the 

 weight of the produce ; for sometimes useful lessons may be 

 learned from failure as well as from success. 



In previous trials, extending over five seasons, I found that, 

 on the soils on our farm : 



1. Ammoniacal salts, such as sulphate of ammonia, used 

 alone, had a decidedly injurious effect upon the turnip-crops, 

 even when used in small quantities. 



2. Ammoniacal manures applied to swedes at first checked 

 the growth of the plant, and had ultimately no beneficial effect 

 on the crop, either alone or in conjunction with phosphates. 



3. Guano proved a less economical manure than superphos- 

 phate of lime. 



4. The addition of salt to superphosphate seemed to benefit 

 the crop. 



5. In dry seasons the best artificial manures are often of little 



B 



