MOVKMKXTS OF SALTS i.\ SOILS. 



107 



but otherwise there was a large percentage of gain, the phos- 

 phates increasing 60 to 70 per cent. In the Norfolk Sand and 

 in the Norfolk Fine Sandy Loam there were considerable losses 

 in many cases. It is true of these soils that they are the ones 

 v/hich had been most heavily fertilized the season the trials 

 were made, and an absorption was, perhaps, to; be expected. 

 There is no case where. the HC0 3 has not increased and only 

 three cases of a reduction of the phosphates. 



The mean changes for the six soil types are given in the next 

 table : 



Mean change in water-soluble salts in six soil types after 70 days of 

 naked fallow and capillary movement. 



These general averages point with some assurance to a ten- 

 dency of naked fallows to increase the water-soluble salt con- 

 tent of the soil, especially if it was low to begin with, and the 

 observed relations are in accord with, the usual immediate in- 

 creased productive power of naked-fallow fields, if it is true that 

 an increase in the amounts of readily water-soluble salts in soils 

 favor an increase of yield. 



INFLUENCE OF 3-INCH EARTH MULCHES ON THE DISTRIBUTION 

 OF NITRATES, SULPHATES AND CHLORIDES, IN SOILS. 



If the mean amounts of nitrates, sulphates and chlorides, 

 which were recovered from the respective levels in the six soil 

 types under the loose and firm surfaces are brought together, 

 they stand as given in the next table: 



