is practised in Bengal for growing mankachu and in Ireland 

 for growing potatoes. The Irish system of growing potatoes 

 is called the Lazy-bed system. The land is divided into strips 

 as in the Lois-Weedon system and from the bare strips earth 

 is dug out and spread over the strips on which potatoes are 

 planted. Two such operations are equivalent to the two 

 earthings. These bare strips or trenches are used for plant- 

 ing potatoes the next year and earth is dug out of the strips 

 which had potatoes on them the previous year. Trenching 

 may be done with advantage in growing high class sugar- 

 canes. Even ordinary sugarcanes should be grown in tren- 

 ches, as from January to March when sugarcane should be 

 planted, the soil is very dry at the surface. Shallow trenches 

 may be dug with a double- mould-board plough (Fig. 2). 



FIG. 2, THE DOUBLE-MOULD-BOARD PLOUGH. 



It costs less than one-sixth making trenches with a double- 

 mould-board plough of what the cost comes to when trench- 

 ing is done with spades. There are trenching ploughs used 

 in Europe but these require very powerful horses to drive. 



127. Ridging. The object of ridging or hilling is to ex- 

 pose the largest surface to the action of air, heat, cold and 

 moisture, and also to prevent accumulation of water immediate- 

 ly at the base of plants. For clay soils ridging is of great 

 benefit especially when water logging is feared, so that most 



