34 



i 



planter. These are Lime, Potash, Phosphorous and Ni- 

 trogen. 



Lime is usually present in the soil in fairly large quan- 

 tity, and it is seldom necessary to apply it as a fertilizer,, 

 because all fertilizers containing phosphate contain 

 enough lime to satisfy the needs of the average plant. 

 But lime is also used to correct acidity in sour soils aad 

 is often needed for that purpose. A soil that is sour is not, 

 suitable for citrus trees and such soils are always benefit- 

 ed by 1000 pounds or more of burnt lime or several 

 tons of finely ground limestone according to the amount 

 of acid it contains. 



Potash is the one plantfood of especial importance to 

 citrus trees, not alone to the growth of the trees, but 

 more so to the health and especially to the quality of 

 the fruit. Potash is present in the different soils in 

 varying quantities. For instance sandy soils are usually 

 poor in potash and >clayey soils contain comparatively 

 large quantities, but the actual amount present is not 

 what the planter is so much interested in because often 

 the clay soils showing large -quantities when analysed 

 are most bonefitted by an application of potash salts. This. 

 is due to the fact that the potash in the soil is usually 

 present in insoluble forms which are not available to 

 cultivated plants. The potash used for fertilizers comes- 

 from the potash mines in Germany. It is found there in 

 several forms and sold as Sulphate of Potash, Sulphate of 

 Potash Magnesia, Kainit, etc. 



Phosphorous or phosphoric acid is another plant food. 

 It is used for fertilizer in the form of phosphate of limo, 

 that is, a combination of phosphoric acid and lime. It is 

 sold as acid phosphate or superphosphate also as double 



,- ,;:..' _., ,, . 



