79-2 



The problems of reclamation presented by categories 2, 3 and 

 4 are the same in practice, so that there are really only three 

 factors which need to be considered, and since the absence of 

 nutritive materials (category 1) can be remedied by the use of 

 artificial fertilisers, the number is still further reduced to two, 

 namely, water supply and injurious conditions. 



The speaker took as a datum rainfall line the 30-in. rainfall 

 line from Northumberland to the Isle of ^Yight. He stated 

 that the waste land problem east of this line is largely due to 

 deficient water supply, and to the west frequently to the presence 

 of harmful substances, particularly acid peat. The problem in the 

 former area is solved by bndging the gap between soil conditions 

 and crop, namely, by gi'owing special crops and by altering soil 

 conditions to suit the desired crops. 



The constituents of cultivated land which fall to be con- 

 sidered in examining agricultural methods of reclamation are 

 sand, silt, clay, organic matter and calcium carbonate. Land 

 may be waste through excess of sand, clay, or organic matter, 

 or through acidity. Some constituents, as, for example, 

 organic matter, may be lacking, and the method then adopted 

 is to grow and plough in green crops such as red clover, &c. 



Examinations of waste areas are canied out by com- 

 paring the mechanical analysis of the soil of waste land with 

 that of adjoining poor land, and also of adjoining better agTi- 

 cultural land. Such an analysis reveals the factors which are 

 in excess or otherwise on the waste land as compared with the 

 asTicultural land. 



Sandy Soils. — Dr. Paissell first dealt with soils on which 

 there is a large excess of sand, e.g., on the Lower Greensand 

 and the Bagshot sands in Surrey. The higher land in such 

 cases is usually too dry and the lower too wet, with the result 

 that ripening of cereals is hastened on the high land and 

 retarded on the low, and unevenness in crop occurs. \Yhere 

 the slope is a long and gradual one, however, more uniform 

 conditions over a larger area are obtained, and the land can 

 be cultivated ; here the underground drift of water makes the 

 conditions much better. The remedy adopted abroad in the 

 case of dry sands is irrigation, but this is not possible in this 

 country, and the problem has therefore been approached by 

 attempting to diminish the loss of water due to evaporation 

 and to soaking into the sub- soil. 



The method adopted is to increase the colloidal properties- 

 of the soil by adding either clay or decomposing cellulose. 



