10 Oct.. 191-'] Rcldtioii of T.iiiic l<> Soil Fertility. 62 j 



Sufficient Phosphates I-.ssential. 



Lime will not g'.ve a good result on land which is too ])(K)r in avail- 

 uihle ])ho.sphoiic acid. This may occur very frequently. Where 'iine 

 is used, phosphates should be used just as usual. On pasture land ih*" 

 need for lime cannot be determined until it has tjeen tried with, as well 

 as without, phosphates. In Victoria lime will seldom fail to act L-e- 

 KL-ause of a deficiency of potash. 



Wet Land must first be Drained 



It is no use applying lime to land that is swampy and requires drain- 

 ing. On wet land, owing to the exclusion of air, the production of 

 soil acids is too great for the land to be sweetened by ordinary aj)];l 

 cations of lime. Drainage b\ admitting air removes the cau.se of extreme 

 acidity, and lime cm only remove the effect. To continue liming vvet 

 soil in order to keep it sweet is like trying to keep a leaking bucket full 

 -of water. 



Lime Diminishes Soil Humus. 



An important constituent in a soil is the organic matter or humus 

 which it contains. Soil humus is important in that it increases ihe 

 water-holding capacity of a soil, opens up stiff clavs, and provided lime 

 is present has a binding action on sands. In its decay it also furni.shes 

 nitrates directly from itself, and mineral con.stituents of plant food, both 

 •directly and also indirectly from the fine rock mas.ses of the soil. Good 

 soils are always well supplied with organic matters, and market gardeners 

 rightly place great confidence in farm yard manure because it forms humus. 



Lime hastens the decay of the .soil organic matter. While fresh 

 vegetable residues as in stubbles, green manures and, where practicable, 

 farm-yard manure should be returned to cultivated land in any case, 

 lime increases the necessity of doing so. The farmer who neglects this 

 matter is living upon his capital in so far as his land will steadilv 

 deteriorate under continued cropping. If he still neglects it after using 

 Imie he will be living upon his capital more quickly than ever. 



Lime may help to add Humus 

 But while I'me increases the need for returning fresh vegetable matters 

 to the soil, it also makes the operation more easy. It may do so m 

 ^veral ways During the year of pasture, which is commonlv allowed 

 in the wheat areas between successive crops, the growth of clover and 

 trefoil, where these are indigenous to the soil, will be stimulated. Lime 

 will also assist in giving a good stand of rape and rye, but particularly 

 of vetches where these can be sown in autumn for feeding or ploughing-in 

 in spring before the land dries out. Phosphate .should be used with 

 those catch crops. Then, again, if the use of lime brings the deter- 

 mination to plough in stubbles, instead of burning while preparing lanrl 

 for fallow, the lime will be a profitable investment. Such ploughing 

 should be overtaken early, so that in the damp soil the lime will help 

 the stubble to rot. Lime increa.ses alike the practical feasibility, and 

 the need, of returning fresh organic matter to the land. 



When is Lime Required. 



It is by the combint^d use of lime and organic or green manures that 



the regeneration of worn-out land will most frequentlv be accomplished. 



As to the question of whether anv particular piece of land requires lime 



iLSf mav be made of the chemical analvsis of the soil, or of the litmus 



