365 



application of organic manures, we seldom have recourse to 

 such as furnish carbonic acid alone ; yard manure and other 

 organic matters always yield ammonia, and the general in- 

 organic constituents of plants ; nor do we, except at fallow 

 time, mix them sufficiently with the soil to cause them to 

 have much effect on the silicates contained therein. The 

 roots and vegetable fibres, however, which are constantly 

 increasing in all ordinary cultivated soils, yield by their 

 decomposition quantities of carbonic acid, which, acting 

 powerfully on the silicates, has an important influence on 

 the growth of clover and other plants. Under these cir- 

 cumstances, it is advisable to encourage the increase of 

 vegetable matter in your soil, by preserving every particle 

 of waste on your farms, and not allowing so great a loss 

 to take place in farm-yard manure by fermentation before 

 applying it to the soil. 



With regard to the use of lime as a means of liberating 

 the potash for the clover, I have no doubt that a portion 

 worked into the land at the time of sowing the barley would 

 produce a beneficial effect. The lime, however, would act 

 with the greatest energy when first applied, consequently a 

 larger quantity of potash would be liberated at that time 

 than at any other ; and as this is not the time when the 

 clover plant requires it to any extent, a great quantity 

 would be washed away by the winter rains, and a small 

 quantity only remain for its summer growth ; hence this 

 method of liberating potash would not prove so serviceable 

 as we might otherwise expect. This lime might be applied 

 as a top-dressing to the clover in the early part of spring, 

 but its eff*ects would be considerably modified by its not 

 being mixed with the soil, and, I fear, to such an extent 

 as to prevent its being employed in all cases with success. 

 I would certainly recommend, in preference to these methods, 

 that the potash be put on in some artificial compounds, giving 



