SECTION III. MANURES FOR SPECIAL SOILS 

 AND CLIMATES 



Light Soils. Ivight soils are, as a rule, deficient in potash, 

 nitrogen and humus. Their water-retaining powers are very 

 poor, they readily permit the fertilizers used to drain away, 

 and sometimes they are deficient in lime and phosphates 

 as well. The manures most likely to be successful are super- 

 phosphate, sulphate of ammonia and either chloride or 

 sulphate of potash. Farmyard manure is almost invariably 

 essential. Such soils are easy to plough and dig, but are 

 difficult to maintain in high fertility, due to their low 

 retentive power ; it is sometimes not profitable to use large 

 dressings of fertilizers since the losses by drainage are heavy. 

 Very much waste land is uncultivated because it is too dry. 

 A soil which is very light and sandy may be a fine fertile 

 soil on the west coast, and uncultivated on the east coast, 

 because of the difference in rainfall. Where there is an ample 

 supply of underground water many of these light soils are 

 very prolific. At the base of the South Downs there are 

 many fields which consist largely of flints and coarse particles 

 brought down by washing from the Downs, but water is 

 obtainable within a foot or so of the surface. This under- 

 ground water originates from the higher land in the South 

 Downs and, in the process of making its way to the sea, 

 it supplies water for the growth of all plants, even though 

 the physical properties of the soil may not be very good. 

 As there is no heavy leaching of fertilizing ingredients, 

 chemical fertilizers may be safely used in large amounts. 



Where there are no natural advantages of high rainfall, 

 irrigation is necessary for supplying the required water. 

 Before the dawn of history, elaborate networks of irrigation 

 canals in Mesopotamia and Persia were fully established. 

 When climate permits, as it does in many parts of the 



