The Bulletin". 49 



Yet we go over this State and find farmers who are producing 40, 60, SO, 100, 

 or more bushels of corn to the acre, and others producing a full bale, a bale 

 and a half, or In some places two bales of cotton to the acre. Why this dif- 

 ference between the average yield per acre for the State and these magnificent 

 yields producetl on some of our farms? Is it not that the average farmer is 

 not skillful in controlling fertility in the soil? I am led to think that this is 

 the case; and why? It seems to me, and I think you will bear me out, that 

 the average farmer in the State of North Carolina — and we can extend this 

 observation throughout the entire South— has not the right idea of fertility in 

 the soil. He seems to think that fertility in the soil means the presence of 

 plant food in the soil, or that it means the commercial fertilizer that he pours 

 into the soil often in quantities much larger than are necessary to produce the 

 crops that his soil can grow. Now, that is a very narrow idea of fertility. 

 Fertility means much more than that. 



WHAT IS FERTILITY ! 



Fertility means the presence in the soil of those conditions which are neces- 

 sary to the growth and development of plant roots. Your crop above the 

 soil is dependent upon the growth and development of the roots down in the 

 soil, out of sight. We usually give these roots too little thought. These roots, 

 as I said, need certain conditions for their growth and development — moisture, 

 plant food, air, heat, and the absence of acid or disease or anything that would 

 tend to injure their growth. Then in every soil that grows the best crops we 

 find large numbers of germs or bacteria which are at work helping to bring 

 about the conditions necessary for root growth. If we would get the best crops 

 we must control every one of these conditions needed by the root. The pres- 

 ence of these conditions in the soil constitutes fertility. 



A fertile soil, then, is one well supplied with moisture, with plant food; a 

 soil which is well ventilated, which is sanitary, and well supplied with germ 

 life. We must control every condition if we would get best results. There 

 are many ways of doing this. Every operation performed on the land, whether 

 it be plowing, harrowing, fertilizing, cultivating, practicing a given cropping 

 system, or whatever it may be, influences in some way these conditions or 

 factors of fertility; and whenever we go to perform such an operation on the 

 land we should take thought as to its influence on fertility, and act accordingly. 

 To-day I want to call your attention to just one way to control fertility, to an 

 agent which is the most powerful agent at the command of the farmer for the 

 control of fertility in the soil. That agent is decaying vegetable matter or 

 humus. 



We know that our soils are made up of sand, clay, and decaying vegetable 

 matter. What is the attitude of these soil ingredients toward the factors 

 of fertility? You know that sand does not hold water well. Rain falling on 

 sand leaches through it, taking plant food with it, and crops on sandy soil 

 suffer from lack of moisture during dry weather. When rain falls on clay it 

 does not sink in readilv. If there is any slope to the land the water runs off, 

 carrying soil and plant food with it. Decaying vegetable matter is porous and 

 spongelike and capable of absorbing and holding large quantities of water. 

 I'ut into a sandy soil, it closes up the large pores and helps the sand to hold 

 more water. Put into clay land, it makes it more open and porous and helps 

 it to take in and hold water. In closing up the sand it also checks excessive 

 ventilation ; but it opens up the clay and admits more air, improving the ven- 

 tilation of the clay. So we see that decaying vegetable matter is very useful 

 in controlling the moisture and ventilation factors of fertility in the soil. 

 Soil well supplied with vegetable matter will grow crops through dry seasons 

 much better than soils deficient in this ingredient. 



Sand and clay contain plant food that is not readily available. Humus or 

 decaying vegetable matter, which is plant tissue itself, is comparatively rich 

 in plant food. The nitrogen or ammonia in your soils is contained very largely 

 in the decaying vegetable matter or humus. A soil well supplied with humus 

 is well supplied with nitrogen. This humus as it decays produces certain 

 acids which act on the potash and other compounds of plant food locked up 

 in the clay and sand, setting free the plant foods so the crops can use them. 

 It is in the humus of the soil that the bacteria which make up the important 



4 — December 



