76 



CALCAREOUS MANURES— PRACTICE. 



was accompanied by stable manure, there appeared no sign of injury. 

 The products of the three successive crops were as follows: 



An accidental omission prevented the measurement of s t 5, in 1832. 



This experiment has been made with much trouble, and every care be- 

 stowed to ensure accuracy. Still several causes have operated to affect 

 the correctness of the results, and to prevent the comparative products 

 showing the true rate of improvement, either from the marl or the putres- 

 cent manure. These causes will be briefly stated. 



1st. The quantity of marl (800 bushels) on q r and r p is nearly double 

 the amount that ought to have been used ; and this error has not only in- 

 creased the expense uselessly, but has served to prevent the increase of 

 product that would otherwise have taken place. This loss is proved by 

 the gradual increase, and at last the greater product of w p, marled at only 

 450 bushels. 



2d, The comparative superiority of all the marled ground to s q, not 

 marled, is lessened by this circumstance: most of the large logs, as well 

 as all the small branches, were burnt upon the land, when it was cleared 

 in 1 824, before the experiment was commenced ; and the ashes have dura- 

 bly improved a spot where each of these large fires was made on s q, but 

 have done no good, and perhaps have been injurious, to the marled pieces 

 that were made sufficiently calcareous without the addition of ashes. At 

 least, the good effect of ashes, on spots, is very evident in s q, and has 

 helped somewhat to increase all its measured products, and no such benefit 

 has been visible on the marled parts. 



3rd. The quantity of putrescent manure applied to st (900 to 1100 

 bushels) was much too great both for fair experiment and profit ; and the ex- 

 cess of quantity, together with the imperfectly rotted state of the stable 

 manure, has given more durability to the effect, than is to be expected from 

 a more judicious and economical rate of manuring on such land when not 

 marled. For these several reasons, it is evident that far more satisfactory 

 results than even these would have been obtained, if only half as much of 

 either marl or manure had been applied. 



There are other circumstances to be considered, which, if not attended 

 to, will cause the comparative increase or decrease of product in this ex- 

 periment to be misunderstood. It is well known that poor land put under 

 tillage immediately after being cleared, as this was in 1824, will not yield 

 near as much as on the next succeeding course of crops. This increase, 



