INTRODUCTION. 13 



again, perpetually building up new forms. In regard to the nature of commercial 

 fertilizers, there is a general notion among farmers that they are mere stimulants, 

 and that while they can be used to increase crops, their final effect is to exhaust 

 the soil. The injudicious way in which commercial fertilizers have been used in 

 the Eastern Middle States, and in the Southern States, has led to this opinion. 

 Used as they have been in the past by the cotton and tobacco growers of the South, 

 they have been a curse to the country, and have led to poverty of soil and poverty 

 to the farmer. 



But this is not the fault of the commercial fertilizer, for well prepared fer- 

 tilizers are simply plant food, such as we find in any manure; and if properly used 

 for the improvement of the soil, they can be made the means of restoring and 

 maintaining the fertility of our lands more efficiently and cheaply than in any 

 other manner. The only classes of substances used as applications to the soil 

 to which the term stimulant can be properly applied are lime and plaster. These 

 are used not so much for their value as plant food, but for their effects in ren- 

 dering other matters, notably potash, available in the soil. They thus stimulate 

 the soil to give up to plants matters it already has, and thus gradually tend 

 to the exhaustion of these things if carelessly used, with the notion that lime and 

 plaster will make land rich because we see a good effect from their application. 

 There are extensive districts in the North, where once the farmers got large crops 

 from the use of plaster alone, and imagining that plaster was all they needed, 

 they kept on in its application, and now find that there is nothing more for the 

 plaster to give them and are compelled to use commercial fertilizers liberally. 

 Had they known more of the real work the plaster was doing for them they could 

 have avoided the gradual exhaustion of the mineral elements in their soil. But 

 there are some writers who would persuade the farmer that in the use of com- 

 mercial fertilizers alone they have all that is needed, and that land can be kept 

 perennially fertile simply by giving every crop a liberal application of a complete 

 fertilizer. They beg us, when we urge the farmer to adopt a good rotation of 

 crops in which the legumes are brought frequently to accumulate humus in the 

 soil, to "give humus a rest," insisting that humus is not plant food, and that crops 

 can be grown as well without it as with it. It may be that in a season of very 

 favorable weather and abundance of moisture in the soil, the commercial fertilizers 

 will have their best effects, even if there is no humus or vegetable decay present. 

 But in a season like the one we have just passed through, we have found in late 

 October, in a soil deficient in humus, all the fertilizer applied in the furrow, as dry 

 as it was when applied. Not two hundred feet away was land in which the humus 

 content was much greater, and here the plants had gotten the dissolved plant food, 

 because of the superior mosture-retaining nature of the decayed vegetable matter. 

 Therefore, even if this decay furnished us no nitrogen, it would still be valuable 

 for its mechanical effects in making the soil mellow, and in its power of retaining 

 moisture for the plants. What we try to impress upon our readers in this book, 

 above all else, is the fact that the true use of the commercial fertilizer is the main- 

 tenance and increase of the fertility and productiveness of the soil, and not so 

 much for the immediate returns in sale crops. True farming does not consist 

 in the dosing of the soil for every crop with a prescription some land doctor 

 advises as a specific for that crop, but in so using these valuable plant foods in the 



