12 MARKET GARDENING 



necessary for the maxinuim production from the area 

 planted. Stable manures alone niaj^ furnish sufficient plant 

 food for some classes of vegetables, but being unbalanced 

 in their content of plant food, their use cannot Ijc depended 

 upon entirely for the successful growing of all vegetables. 

 Manures have a relatively high content of nitrogen, and are 

 usually deficient in the mineral elements of phosphorous 

 and potash. To balance the ration of plant food, chemical 

 fertilizers are used. 



The plant food contained in manures becomes available 

 rather slowly, except for the nitrogen which is in the organic 

 form, ammonia. This becomes available very quickly, 

 particularly if the manure is rotted. 



Chenncal fertilizers may be obtained in forms which 

 are quickly available. This is important in intensive 

 gardening where quick results are very desirable. Slow 

 plant growth results in ^'egetables of inferior quality and 

 oftentimes the yield is small in quantity. Slow growth 

 tends to produce vegetables tough in texture and of poor 

 flavor. Rapid growth produces tender, succulent vegetables 

 of fine flavor. Then again, the more c^uickly a crop may 

 be matured, the sooner it will become ready for harvesting 

 and thus out of the way for succeeding crops. The use of 

 chemical fertilizers enat)les the grower to raise a maxinuim 

 crop of fine fiavor and quality, and to produce the crcjp in 

 the .shortest time possible. 



Chemical fertilizers should seldom be used alone; they 

 give the best results only when used as an adjunct to stable 

 manures. To get the largest results from an application 

 of chemical fertilizers, the ground must be lilierally supplied 

 with humus, and must be in a high state of cultivation. 



12. Nitrogen. The element necessary in the production 

 of tender succulent stems and leaves is nitrogen, and it is 



