224 Methods of Field Manurial Trials. 



In harvesting grain crops the scythe should be used, and the 

 corn bound into sheaves at once and weighed upon the ground. 

 Dr. Wagner's method is to take during reaping some half-dozen 

 samples (ears and straw, as cut), weighing twelve or fifteen 

 pounds altogether, from various parts of the plot, and tie them 

 up in a sack, which is numbered according to the plot from 

 which it comes. The sheaves are then left to the owner of the 

 field, and the only point to be carefully observed is that they are 

 immediately removed (if the experiment is to be continued on 

 the field). The yield of corn per acre and the proportion of 

 grain to straw can be calculated from the samples. Dr. Wagner 

 finds this method preferable to leaving the corn for some days 

 upon the field before being weighed, as serious errors may result 

 from the grain falling out or weather conditions, sources of error 

 which are all the greater as the different manuring will have 

 induced different degrees of ripeness. It is preferable also to 

 carting off and threshing the whole crop from a plot, since much 

 grain is lost in the loading, transport, unloading, &c. 



The sacks containing the samples are hung up (so that mice 

 may not get at them) in a light, airy room, and after eight days 

 or so are brought out on to trestles in the open air and the 

 contents threshed by a hand machine. The straw is then 

 chopped up, the grain cleaned, and the husks mixed with the 

 chopped straw. Of this a sample of about thirty to forty 

 grammes is taken in order to determine the moisture content ; 

 another sample of about two pounds is also taken for further 

 examination and chemical analysis. Two hundred grammes of 

 the grain are taken for the same purpose. 



In the case of roots, as soon as they are pulled up from the 

 ground the leaves are cut off, and both they and the roots are at 

 once weighed. A sample of thirty to forty pounds of roots and 

 about sixteen to eighteen pounds of leaves are taken from each 

 plot. Only normal roots are taken for this purpose, very large 

 or very small ones being excluded. The samples are put up in 

 sacks, and immediately carried to the experimental station ; if 

 this cannot be done the same day they are laid down separately 

 (so as not to heat each other), and removed the next morning. 

 The sample leaves are dealt with as soon as possible : each is 

 weighed, chopped, and an average sample of exactly one kilo- 



