Scientific Agriculture. 



458 



[May 1908. 



Lime promotes nitrifying ferment and 

 makes possible their existence in many- 

 cases that would be impossible with- 

 out, its presence. Lime is especially 

 valuable it applied after a crop has 

 been turned under from green manuring 

 as it acts chemically ou the organic 

 matter and causes it 'to decompose 

 rapidly. All these facts teach us that 

 lime is not a substitute for manure, 

 bub a reinforcement for it. 



The continual application of lime to 

 any soil without the addition of ferti- 

 lisers tends in a short time to make the 

 soil sterile, and it is that gave rise to 

 the old saying: "Lime enriches the 

 father, but beggars the son." The 

 excessive use of lime on a farm may be 

 of benefit to the tenant for a few years 

 but is bad for the owner, and in some 

 parts of the world land-lords have for- 

 bidden their tenants by contracts from 

 using lime on their estates. Soils that 

 are rich in organic compounds, such, 

 as swampy and peaty are greatly 

 benefited by the application of lime. 

 Stiff clay lands, even if not con- 

 taining much organic matter are 

 also greatly benefited by lime, the ac- 

 tion is principally upou the mineral 

 matters which it splits up and renders 

 the food contained in them available to 

 the plants, and the soil becomes easier 

 to work. On a light sandy soil the ac- 

 tion of lime is also beneficial in help- 

 ing to bind the particles together, and 

 increasing the cohesive and capillary 

 power to the soil. 



Lime is of great value in places where 

 the land has an acid reaction. This 

 acidity or sourness of the soil is gener- 

 ally due to the decomposition of the 

 remains of plants in the soil forming 

 organic acids and this condition is more 

 noticeable ou wet than on dry soils. 

 The acidity or sourness is readily correc- 

 ted by lime, and the good effect of lime 

 on sour grass land is very noticeable. 



HOW TO KNOW IF LIME IS REQUIRED. 

 — The easiest way in which this cau be 

 determined is to' obtain a few pieces of 

 blue litmus papers (this can be obtain- 

 ed from almost any chemist for a 

 few pence) ; place a piece of this 

 paper in contact with the moist 

 soil ; if the soil is sour it will turn red, 

 and the degree of acidity can be deter- 

 mined by the quickness with which it 

 changes colour and the density of the 

 redness produced. Another method, if 

 the soil is dry, is to place two pable- 

 spooufuls of soil in a cup, moisten, it 

 with enough water to make the mas 

 like a thick paste, make a cut with a 

 knife and insert a piece of blue litmus 

 paper, and allow it to remain in contact 

 with the soil for about fifteen minutes ; 



if the blue colour has turned to red the 

 soil will be benefited by liming. 



Method of applying. — Clayey soil can 

 stand more frt quent and heavier appli- 

 cations of lime than light s^ndy soil-, as 

 the action tMids to improve the mech- 

 anical condition of such soils. The 

 quantities applied vary according to the 

 soils and the customs prevalent in various 

 parts of the world fiom about two tons 

 per acre for lij^ht soils to as high as 12 

 tons per acre on cold heavy clays, and 

 such applications are made at intervals 

 of from five to six years. 



Our soils in this State are mostly of a 

 light nature, and a smaller dressing of 

 lime at more frequent intervals would be 

 likely to prove of benefit, except in some 

 of our swampy lands in the South-West 

 District, where a heavier application 

 would most likely prove beneficial. 



The autumn is the be"t time of the year 

 to apply lime to the ground, but if not 

 convenient to apply at this time, a 

 moderate application may be made at 

 almost any time. The best method to 

 apply lime is to make small piles of lime 

 ou the surface at regular intervals, and 

 cover theee with earth ; the moisture in 

 the soil will soon cause the lime to slack, 

 and as soon as it has come to the 

 powdery condition it should be spread 

 evenly over the soil and harrowed in. If 

 the soil is very dry, the application of a 

 quantity of water to cause it to slack 

 may be desirable. It should be re- 

 membered that lime in its caustic or 

 quick state has the most power of 

 producing the necessary chemical and 

 physical changes in the soil ; and, there- 

 fore the object should be to get the lime 

 into the soil in its natural state, and well 

 mixed with the soil before it has time 

 to lose any of its active principles. Lime 

 should not be allowed to "air slake' 

 before beiug applied to the soil, as by 

 doing so it absorbs the carbonic acid 

 from the air and is changed back to the 

 carbonate, the form in which it existed 

 before burning, and consequently the 

 lahour expended in burning the lime- 

 stone has been lost. The action of slaked 

 lime is exactly the same as of stone or 

 quicklime, but is not so pi onounced, and 

 it is generally of more benefit to use the 

 lime unslacked or only partly slacked as 

 mentioned above. In America powdered 

 caustic lime has been placed on the 

 market, which can be sown with the 

 ordinary seed drills direct into the land, 

 and this is, theoretically, the best way, 

 as it applies the lime evenly, and in its 

 best possible conditions ; but, unfor- 

 tunately, we in this State have not yet 

 created a demand sufficient to induce 

 anyone to erect machinery for this 

 purpose. 



