Vlll 



Contents 



peat King crab, mussels and lobster shells Seaweed 

 Wood-ashes and Tanbark-ashes Coal-ashes Cot- 

 ton-hull-ashes Corn-cob-ashes Cocoa shells Green 

 sand marl Agricultural salt Powder waste 

 Gas lime Gypsum or calcium sulfate Phosphorus 

 powder Calcium carbide waste Oxy-acetylene 

 residue Purchase and use of miscellaneous materials . 



118 



CHAPTER VII 



FARMYARD AND GREEN-MANURES 119-134 



Farmyard Manures Variations in manures Ma- 

 nure produced by different animals Composition of 

 stable manure Solid and liquid portions Sources of 

 loss in manures Care of manures Manure preserva- 

 tives The improvement of manures Application of 

 yard manure Poultry and pigeon manure Composts 119-128 



Green-manures "Nitrogen gatherers" and "nitro- 

 gen consumers" The most useful crops Green- 

 manure crops that consume the nitrogen in the soil 

 Mixtures are advisable Precautions in the use of 

 green-manures . . 128-134 



CHAPTER VIII 



LIMB AND CALCIUM COMPOUNDS . . . . . . 136-152 



Occurrence of Lime ....... 136 



Forms on the Market Caustic lime Ground lime- 

 stone Calcium-magnesium lime Ground burned 

 lime Hydrated lime Air-slaked lime Oyster shell 



lime Shell marl 136-140 



Action of Lime on Soils Mechanical effects of lime 



Chemical effects of lime Lime supplies a necessary 

 base Lime assists the decomposition of organic matter 



Lime makes soil potash available Lime makes soil 

 phosphates available Less plant-food required Inju- 

 rious chemical effects Effects of gypsum . . . 140-145 



Biological Effects of Lime Biological effects may 

 be harmful 145-146 



