SOILS FOR SEED PRODUCTION. 129 



before planting. In certain French districts visited by 

 the writer, the fertilizers for mothers which are most 

 popular are used in the following quantities, calculated 

 to areas of one acre: 



("Barnyard manure 16 tons 



J J Sodic nitrate 360 lbs. 



] Siiperpliospliate of lime 3% *' 



t Colza oil ca left 132 " 



., ( Barnyard manure 20 tons. 



" 1 Ammonia sulphate 246 lbs. 



a ) Barnyard manure 20 tons. 



I Sodlc nitrate 330 lbs. 



(Barnyard manure 16 tons. 



. J Sodlc nitrate 350 n.s. 



I Superphosphate 608 " 



i^Potasslc chloride 132 " 



Whatever be the system of the fertilization of the 

 soil, it is desirable not to use the plant food in excess, 

 since this would result in a second growth of stalks and 

 a corresponding decrease in the quality of seed. 



Relations Between Soils and Fertilizers. 



The formula of a fertilizer should vary with the 

 composition of the soil upon which it is to be 

 used. Without going into extensive arguments 

 respecting soils and fertilizers in general, it will 

 be far more interesting to give an example 

 taken from practice. The beet plantation of 

 M. Legras, as previously explained, was made up of 

 small areas having very different textures and compo- 

 sitions, the variation being far greater than a general 

 survey of the land would lead one to believe. 

 The maximum and minimum of the five essential ele- 

 ments requisite for fertility, as determined by chemical 

 analysis of these soils, are here given : 



Nitrogen 



Phosphoric acid. , 



Fotassa 



liime 



Magnesia 



There were to contend with: ist, argillo-calcare- 

 ous; 2d, sandy; 3d, very calcareous soils. The fertil- 

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