EXPERIMENTS WITH FERTILIZERS. 73 



both potash and superphosphate. There was much lodged 

 straw where the nitrogeneous fertilizers were used, the 

 amount of lodged straw increasing with the amount of nitro- 

 gen used. 



It was also interesting to notice the special action of these 

 dilTerent fertilizing materials on the plants. It is generally 

 recognized that fertilizers act in various ways on soil and 

 crop. One of these special actions is of a physiological 

 nature, modifying the development of the plant. This ac- 

 tion was very noticeable in these experiments. Superphos- 

 phate always stimulated an early development of the plant, 

 with very dark-green foliage, and on potatoes a thick, curly 

 appearance in the leaves. It also hastens the ripening of the 

 crop and increases the proportion of seed to the stalk. 

 Nitrogeneous materials also hasten the development of the 

 plant, but increase the amount of foliage more than the 

 seed. Potash induces a slow and sickly growth at first, 

 with very light-colored foliage, but it lengthens the life or 

 growing season of the plant, and if the other constituents of 

 plant-food are present, it greatly increases the crop ; but 

 where the soil is deficient in other needed constituents of 

 plant-food, it only induces the plant to make a useless eflbrt 

 to do what it cannot ; and under such circumstances we only 

 get a lot of flashy foliage. On good land superphosphate 

 will produce very early potatoes with many in the hill, but 

 potash on suoh land will give a larger, later and better crop, 

 with nearly all lars^e ones. 



By some it is claimed that such experiments are on so 

 small a scale as to be valueless ; that the difiereuce of fertility 

 in different parts of the same field would often equal the dif- 

 ference in yields of diflerent plots, and thus vitiate the 

 result. These objections are, to a certain extent, true. 

 Farming, from the fact of the varying composition of the 

 soil, the changeableness of the weather, and the variation 

 in the composition of the same crop grown on different 

 soils, can never become an exact science. All we can ex- 

 pect is to reduce it to an approximation to exactness. These 

 experiments, while they are not exact, can, by repetition on 

 the same plots and on other parts of the farm, be rendered 

 near enough to exactness to answer for practical purposes ; 



