312 SANDS AND THEIR MANAGEMENT 



I 

 legumes and manure in supplying the much-needed organic 



matter (see index). 



Liming Sands. — For most sands Ume may be regarded as the 

 second important need in thflfs improvement. This is necessary, 

 not only to supply available calcium for crop needs, but to render 

 the fertilizing elements in the soil more available as well (Figs. 

 206 and 207). 



Without sufficient lime alfaKa cannot be grown on acid sands. 

 Mammoth, mediimi red, crimson and Japan clovers are much 

 benefited when sands of slight to medium acidity are limed. 



/ Fig. 208. — A good crop of soybeans on sandy soil. 



Soybeans (Fig. 208), cowpeas, and velvet beans grow v6ry well on 

 sands having slight to medium acidity, but when the soils are 

 strongly acid liming is necessary for best results (p. 229). 



Phosphorus and Potassium Needs. — Some sands, especially 

 those of slight to medium acidity, require phosphorus as second 

 in importance to nitrogen and organic matter. On most sands, 

 however, phosphate and potash fertilizers are indispensable; 

 the potash being of most value during the first few years 

 of improvement. 



Of the phosphate fertilizers, acid phosphate and steamed bone 

 meal are most commonly used. Best results in the use of these 

 fertilizers are secured after the nitrogen and organic matter have 

 increased, and acidity has been reduced by liming. Acid phos- 

 phate may be apphed at the rate of 300 to 500* pounds to the acre, 

 applied as a top-dressing and disked in. This application should 

 be made to benefit the legume crop, and may be repeated at least 

 once in a three-year rotation. 



