t 542 ] 



with sewage at Rs. 144 (2 men employed for pumping 

 out the sewage with a don and distributing the same and 

 also tending the cattle), the total expense may be put 

 down at Rs. 214. The value of 75 maunds of milk at 12 srs. 

 to the Rupee comes to Rs. 250. This calculation gives some 

 practical idea of the small value per ton of sewage and the 

 difficulty of utilising it in places where a large capital would 

 be required to make use of sewage, or where milk does not 

 command a ready sale, or where land is dear. But it also 

 shows that in favourable localities grass farms can be made to 

 yield large profits by the use of sewage, and the Government 

 Grass Farm at Allahabad is a case in point. 



870. Cabbages, mangolds and straw-berries have been 

 also grown successfully with sewage. Light soil resting on 

 sandy or gravelly subsoil is the best for sewage irrigation. 

 Sewage water should never be sprayed or sprinkled over 

 a crop, but always applied to the land put up in ridges, along 

 furrows. It should not be used at the last stage of the 

 growth of a crop. 



871. Animal manures, such as flesh, blood &c., are better 

 than vegetable manures, as they contain more N, and decom- 

 pose more readily in the soil giving up greater quantities of 

 plant-food to crops in a shorter time, 



CHAPTER LXXXIX. 



PHOSPHATIC MANURES. 



\fiINERAL phosphates. Phosphates occur in soil and 



rocks chiefly in the form of Apatite. As a rule, crystals 



of apatite occur in microscopic dimensions, but occasionally 



rich deposits of apatite crystals, several inches in length and 



