138 EFFECTS WITH PUTEESCENT MANURE. 



The two last experiments, as well as the 4th, were especially de- 

 signed to test the amount of increased product to be obtained from 

 marling, and to show the regular addition to the first increase, 

 which the theory promised at each renewal of tillage. As to the 

 main objects, all the three experiments have proved failures and. 

 from the same error, that of marling too heavily. Although, for 

 this reason, the results have shown so much of the injurious 

 effects, still, taken altogether, the experiments prove, clearly, not 

 only the great immediate benefit of applying marl, but also its con- 

 tinued and increasing good effects when applied in proper quantities. 

 1835.] 



Experiment 12. 



On 9 acres of sandy loam, marled in 1819 at 400 bushels (25 

 per cent.), nearly an acre was manured during the same summer, 

 by penning cattle. With the expectation of preserving the ma- 

 nure, double the quantity of marl, or 800 bushels in all, was laid 

 on that part. The field in corn in 1820 ; in wheat, 1821 ; and at 

 rest 1822 and 1823. 



Results, 1824. In corn, the second rotation after marling. The 

 effects of the dung have not much diminished, and that part shows 

 no damage from the quantity of marl, though the surrounding 

 corn, marled only half as thickly, gave signs of general, though 

 very slight injury from that cause. 



Experiment 13. 



Nearly two acres of loamy sand were covered with barn-yard 

 manure, and marl (45 per cent.), at the same time, in the spring 

 of 1822, and the field put in corn the same year, followed by wheat. 

 The quantity of marl not remembered but it must have been 

 heavy (say not less than six hundred bushels to the acre), as it was 

 put on to fix and retain the manure, and I had then no fear of 

 damage from heavy dressings. 



Result, 1825. Again in corn ; and except on a small spot of 

 sand almost pure (nearly a " blowing sand," or liable to be drifted 

 by high winds in dry weather), no signs of disease from over- 

 niarliug were seen, then or afterwards. 



