8 FARM CROPS 



deepening of the seed and root bed until ten or a 

 dozen inches are turned to the air for purification 

 and rejuvenation. I say gradual, because some 

 soils would be physically hurt by sudden deep 

 plowing. The innovation must, in many cases, 

 come slowly or the soil may be injured for years. 

 When there is a probability of injury by deep plow- 

 ing, let the plow down gradually. Go one, two or 

 even three inches deeper at every plowing, until a 

 deep and comfortable seed bed is obtained. 



Chemical fertilizers will aid in soil improvement. 

 So will some medicines aid people when they are 

 sick. But let us not depend on either too much. 

 They are costly in the first place, and then, again, 

 they may do harm. Alcohol may be used as a 

 medicine, yet may lead to disease. Commercial 

 fertilizers add plant food to the soil and produce 

 better crops for a time, but if depended on too 

 much, they may do serious harm ; for under the 

 commercial fertilizer system of farming the humus 

 in the soil is soon exhausted, and these sorts of 

 fertilizers do nothing to restore this invaluable in- 

 gredient. 



THE FUNCTION OF FERTILIZERS AND 

 LEGUMES 



Commercial fertilizers are to be used as acces- 

 sories to tillage and rotation. Tillage improves the 

 physical condition of the soil. The rational way to 

 use commercial fertilizers is to ascertain the ele- 

 ments needed in the soil and then apply such fer- 

 tilizers as are needed. Investigations may show 

 that of the elements needed for plant growth, nitro- 

 gen, potassium and phosphorus, one or all may be 



