Influence of excessive Manuring of Crops.
The influence of large quantities of manures is seen in the case of certain root crops. It is found, in such a case, that while the roots are larger, they are more watery in composition and of less nutritive value. Again, it seems to be a fact pretty generally known to practical men, that nitrate of soda seems to have a bad effect on the quality of hay. It would seem, further, that the influence of nitrogenous fertilisers on cereals is to increase the percentage of nitrogen in the grain, but that they have no such influence in the case of leguminous crops. Phosphatic manures, on the other hand, in the case of leguminous crops, seem to have the effect of diminishing the amount of nitrogen in the seed.
FOOTNOTES:
[241] Though not necessarily at the same time or to each succeeding crop. There may be comparatively long intervals between the applications of farmyard manure in many cases.
[242] Of course what is meant here is the direct influence of such manures. Their indirect value may be shown in the soil by the increased crop residues they give rise to.
[243] This is very concisely and clearly put in Mr Warington's admirable 'Chemistry of the Farm.'