LIME 67 



remove the lime. Professor A. D. Hall states that lime 

 is disappearing from the unmanured plots at Rothamsted 

 under arable cultivation at an approximate rate of 1000 Ibs. 

 per acre per annum a rate which is increased by the 

 use of manures like sulphate of ammonia, but diminished 

 by the use of nitrate of soda and of dung. He says that 

 " failing the renewal of the custom of chalking or liming, 

 the continuous removal of calcium carbonate thus indicated 

 must eventually result in the deterioration of the land to 

 the level of that which has never been chalked at all, and 

 even a state of sterility will ensue if much use is made of 

 acid artificial manures." Dr. Phipson has shown that, on 

 a sugar estate in British Guiana, in fields which have been 

 under cultivation from ten to fifteen years, the percentage 

 of lime in the soil was -44 to -64, but the percentage in 

 fields cultivated for sixty years had fallen considerably, 

 amounting only to 0-11 to 0-40. 



The action of lime on clay is to cause the minute particles 

 to become grouped together to form larger grains with 

 wider interstices, so that both air and water can percolate 

 more freely. Lime binds sands together somewhat, so 

 that in both cases it improves the tilth and the capillarity 

 of the soil. However, there is a danger of rendering sandy 

 soils too light and open. 



Lime is also of much value when applied after ploughing 

 into the soil the cut stems and leaves of the banana, or 

 the green manuring, as it helps to decompose the organic 

 matter, or humus, and thus encourages nitrification and 

 makes the nitrogen and other constituents of the humus 

 available to the crop. If, therefore, there is only a small 

 quantity of humus in the soil, and it is not renewed, lime 

 does more harm than good, as the humus is speedily used 

 up, and the soil becomes sterile. 



It improves sour land by neutralizing the acid materials. 

 By combining with certain constituents of the soil, it sets 

 free potash and other useful food material, and so, although 

 not exactly a manure in itself, the effect on the land is 

 that of a manure. 



