HOW TO MAINTAIN FERTILITY 



for about six weeks before planting and frequently 

 harrow it to compact the soil. 



There are fourteen different chemical elements 

 that are necessary for plant growth namely, car- 

 bon, hydrogen, oxygen, nitrogen, phosphorus, 

 sulphur, chlorine, silicon, calcium, iron, potassium, 

 sodium, magnesium, and manganese. The first 

 four are derived either directly or indirectly from 

 the air, the remaining ten are derived from the 

 soil. Virgin soil contains all these soil-derived ele- 

 ments in available forms and in sufficient quanti- 

 ties for plant growth, and it has the ability to 

 absorb the air-derived elements, but our methods 

 of agriculture rob the soil of some of its elements 

 faster than it can convert them into available form 

 for the plants. Therefore we must supply these 

 elements in order to produce good crops. 



The best way of renewing these necessary ele- 

 ments is by dressings of stable manure the drop- 

 pings from horses, cows, and other domestic ani- 

 mals. Soil enriched by barn-yard manure will yield 

 better crops than soil which has been given chem- 

 ical fertilisers containing an equal amount of plant 

 food. Whether the manure shall be fresh or well 



rotted depends upon the conditions. The fertil- 



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