26 Liquid Manure. 



5. Sandy soils remove from liquid manure but little ammonia 

 and likewise not much potash. 



6. With the exception of purely sandy soils, liquid manure, 

 as used in practice, leaves the greater portion of all the most 

 valuable fertilizing matters in the generality of soils. 



7. The comparative power of different soils to remove am- 

 monia, potash, and phosphoric acid from liquid manure differs 

 greatly. 



8. Liquid manure passed through sandy soils rich in soluble 

 silica takes up soluble silica. 



9. Soils that absorbed much ammonia also absorbed much 

 potash, and the soils which absorbed little ammonia also absorbed 

 little potash. 



10. Soda-salts (common salt) are either not at all removed 

 from liquid manure or only to a small extent. 



11. Chlorine, and generally sulphuric acid, remain unaltered 

 in quantity in liquid manure passed through different soils. 



12. In most cases, liquid manure left in contact with different 

 soils becomes richer in lime. 



13. The proportion of lime which liquid manure takes up 

 from the soils with which it is brought in contact does not alto- 

 gether correspond with the relative proportions of lime in the 

 different soils. 



14. Liquid manure, passed through a sandy soil greatly 

 deficient in lime, became poorer in lime : thus showing that the 

 property of soils of storing up food for plants is not confined to 

 ammonia, potash, or phosphoric acid ; but that it is a property 

 which manifests itself in a variety of ways. Thus, soils rich in 

 lime yield this substance to liquid manure ; soils in which lime 

 is deficient may abstract it from liquid manure. Again, potash 

 usually is removed from liquid manure left in contact with soil ; 

 but, in particular cases, liquid manure may even become richer 

 in potash after filtration through soil. 



15. Very soluble saline fertilizing compounds are probably 

 injurious to vegetation when supplied too abundantly to the land. 



16. All moderately fertile soils have the power of rendering 

 the more important soluble fertilizing matters much less soluble ; 

 but in none of the experiments were ammonia, potash, phos- 

 phoric acid, and other compounds that enter into the com- 

 position of the ashes of our cultivated crops, rendered perfectly 

 insoluble. 



17. It does not appear probable that plants take up mineral 

 food from the soil in the shape of totally insoluble combinations. 



Eoyal Agricultural College, Cirencester. 



