74 CALCAREOUS MANURES-PKACTICE. 



1824. In corn. Two quarter acres, chosen as nearly as possible on the 

 same spaces that were measured in 1821, produced as follows: 



No. 1 made 8 bushels, 2 pecks, or to the acre, 34 bushels. 

 The same in 1821, before marling, 7.3^ 



Increase, 



No. 2 made 7 bushels, 2^ pecks, or to the acre, 30.2 

 The same in 1821, after marling, 16.2^ 



Increase average, 13.3^ 



The second dressing of marl, or the larger quantity, had but little effect 

 in making the increase of crops greater than in 1821. The difference was 

 caused mainly by the greater length of time since the clearing of the land. 

 1825. The whole twenty-six acres, including the subjects of all these ex- 

 periments and observations, were in wheat. The first marled piece, in 

 Exp. 1, was decidedly the best— and a gradual decline was to be seen to 

 the latest. I have never measured the product of wheat from any experi- 

 ment, on account of the great trouble and difficulty that would be encoun- 

 tered. Even if the wheat from small measured spaces could be reaped 

 and secured separately, during the urgent labors of harvest, it would be 

 scarcely possible afterwards to carry the different parcels through all the 

 operations necessary to show exactly the clean grain derived from each. 

 But without any separate measurement, all my observations convince me 

 that the increase of wheat, from marling, was at least equal to that of corn, 

 during the first few years, and certainly greater afterwards, in compari- 

 son to the product before using marl. 



It was from the heaviest marled part of Exp. 1, that soil was analyzed 

 to find how much calcareous earth remained in 1826, (page 50.) Before 

 that time the marl and soil had been well mixed by ploughing to the depth 

 of five inches. One of the specimens of this soil then examined consisted 

 of the following parts— half an inch of the surface, and consequently the 

 undecomposed weeds upon it, being excluded. 

 1000 grains of soil yielded 



769 grains of silicious sand moderately fine, 

 15 finer sand. 



784 



8 calcareous earth, from the manure applied, 

 180 finely divided gray clay, vegetable matter, &c. 

 28 lost in the process. 



1000 



This part, it has been already stated, was originally somewhat lighter 

 than the general texture of the remainder of the land. 



' Experiment 4, 



The four acres marked A D n o were cleared in the winter of 1823-4. 

 The lines p q and r s divide the piece nearly into quarters. The end nearest 

 Kpo is lighter, and best for corn, and was still better for the first crop, 

 owing to nearly all that half having been accidentally burnt over. After twice 

 coultering, marl and putrescent manures were applied as follows ; and the 

 products measured, October 1 1th, the same year. 



