20 COTTON CULTURE 



MANURING OR FERTILIZING 



The proper selection and application of plant food, 

 called manures and fertilizers, is really the most im- 

 portant feature in making cotton at a profit. The 

 planter must always bear in mind that manures or fertil- 

 izers are useful in agriculture as plant food only to the 

 extent that they contain potash, phosphoric acid, and 

 nitrogen. Other substances are necessary, such as iron, 

 silica, lime, etc., but most soils contain such in ample 

 quantities, with perhaps the exception, occasionally, of 

 lime. The mechanical improvement of soils is quite a 

 distinct feature from the manuring or fertilizing of them. 

 Both lime and organic matter improve the mechanical 

 condition of soils, and potash salts (used in the form of 

 fertilizers) increase the power of soils to withstand drouth. 



It is important at the outset for the planter to under- 

 stand fully just what work the three plant-food ingre- 

 dients are expected to do; for their work is precisely the 

 same, whether derived from farmyard manure or mineral 

 fertilizers. All three ingredients, potash, phosphoric 

 acid, and nitrogen, are absolutely necessary. If any one 

 of them is missing, plants will not thrive and grow. In 

 fact, each of these three fertilizing elements has its own 

 separate and individual function, and one cannot be sub- 

 stituted for the other. 



All manures are valuable, almost solely for the potash, 



