340 AFTER-EFFECTS OF THE NITRATES. 



both of which results favour the supposition that one effect of the ni- 

 trates upon the quality of the grain is to increase the proportion of gluten, 

 and thus to render them, as is generally believed, n-iore nutritive. This 

 is a result which theoretically we might be led to anticipate, were there 

 no large increase in the quantity of the produce — for then we might 

 naturally expect the nitrogen of the nitric acid to be expended solely in 

 enriching the grain with gluten. But the increase of crop contains in 

 many cases more nitrogen than we add to the soil when we dress it with 

 one cwt. of nitrate of soda per acre ; there is, therefore, no excess of ni- 

 trogen which we can suppose to go to such an enriching of the more 

 abundant crop of grain. For this reason, among others, I am inchned 

 to doubt whether further careful examination will prove the flour from 

 nitrated grain to be always richer in gluten, and, therefore, more nutri- 

 tious. At all events increased experiments are to be wished for. 

 . d. After-effects of these nitrates. — It is comparatively seldom that 

 any good effects have been observed upon the crop which succeeds that 

 to which the nitrate of soda has been applied. Where they have been 

 noticed it has been chiefly in cases where from some cause (drought or 

 dryness of soil chiefly) the salt has been prevented from exerting its full 

 and legitimate action upon its first application. Thus, 



1°. Failing to improve turnips on a rubbly chalk soil, it greatly be- 

 nefitted the succeeding crop of barley (Mr. Drewitt, Guildford, Surrey). 



Producing little effect on tares (upon a clay soil ?) it improved very 

 much the turnip crop which followed (Mr.Barclay,L8atherhead,Surrey.) 



2°. In the following instances the benefit was seen on successive 

 crops :— 



After producing an increase of one-sixth in the wheat crop, both 

 grain and straw, on a light sandy soil (subsoil?), the turnips of the fol- 

 lowing year were decidedly better where the nitrate had been sown (Hon. 

 H. Wilson, Brandon, Suffolk.) 



After improving the crop of wheat, the after-crop of hay was also 

 better (Mr. Grey, of Dilston.) 



At Upleatham, the second cut of clover was nearly as much im- 

 proved as the first (Mr. Vansittart), and at Dilston the aftermath hay 

 was greater in quantity, and better relished by the cattle (Mr. Grey). 



3°. A curious effect is noted by Mr. Rod well, of Alderton, Wood- - 

 bridge — the white clover failed after barley on which nitrate had been 

 used ! 



The solubility of these nitrates is so great, that in our climate, in sea- 

 sons of ordinary rain, and on lands having a moderate degree ofincli-^ 

 nation, we should expect that they would be in a great measure washed 

 out of the land in a single year. Hence one reason — even supposing 

 little of the salt to have entered into the roots of the growing crop — why 

 we are not entitled generally to expect any marked effect from it upon 

 a second crop. But let the season be so dry, or the soil so retentive, 

 §rid the land so level, as to prevent its being all taken up by the roots, 

 or washed away by the rains during one year, and we may then look 

 for after-effects, such as those above described, 



e. Circumstances necessary to ensure the success of iKesc saline ma- 

 nures, — This explanation will appear more satisfactory if we glance for 



