WHEN AND HOW TO APPLY LIME AND MANURE.

Manawatu Times, Volume XLIX, Issue 2672, 5 May 1925, Page 7

WHEN AND HOW TO APPLY LIME AND MANURE.

A PTAV PRACTICAL HINTS EXPLAINED IN A PRACTICAL AVAY. As the autumn is the best time of the year to apply lime,, a few hints as to its application and a few words of advice may not come amiss'to our readers. . . - i There still exists a great axnoum jef doubt and misunderstanding concerning the value of lime and its | methods of application, but the idea of applying dressings of 5 to 10 tons to the aero is now regarded, not only as wasteful but as more or less defeating- its own object. Taking New Zealand soils all round,, there are very few that are not deficient in lime. * The best authorities are agreed that a good -fertile soil should contain from one-half to one per cent, of lime and It is only by A proper soil analysis that -the exact deficiency is ascertainable. The usual appplicatloris made to-day range- from . four and five to ten „e arpur)d lime'ear acre, anuallv

distributed over the land by means of a manure drill or lime distributor. - A Simple Explanation.

In order to appreciate the benefits of lime, it is necessary to have an elementary understanding of the chemical and mechanical effects it has on the soil.

Through the perpetual decomposition of organic matter which is going on in the soil, humic acid is formed the accumulation of which eventually renders the soil sour or acid. Very few of our cultivated grains and crops will grow well in such soil, while others will be attacked by such plant diseases as finger-toe, club-root, etc. The chemical action of lime on such soil is to neutralise the acid in the soil, the lime uniting with-the humic acid and forming what is chemically called humate of lime. The action of lime on (Slay land is to break up the fine particles of clay and so render the soil easier to work and admit the air and sun’s rays, thereby rendering the land warmer and improving the tilth. The effect on light and sandy soil is exactly the opposite making the soil more retentive and less loose in the texture.

Lime arid Bacterial Activity

Apart from these direct effects on the soil itself, lime has, however, many other valuable activities. Bacterial action in sour or acid soils is very slow, if not entirely absent, and the application of certain manures may almost be entirely wasted on these soils on account of such bacterial inaction. This is particularly the case when fertilisers, such as dried blood and bone, grains, etc., are used, which must be first decomposed by bacteria before they become available as plantfood. It will be seen, therefore, that in the absence of bacterial action such fertilisers fall to accomplish their purpose, and it is only by an application of lime, that this bacterial action Is assured.

Another effect of lime on heavy clay land, is to make available the large amount of potash that is practically locked up in such soil and which is liberated by the chemical action of the lime. Superphosphate No Substitute for Lime. An idea still prevalent among many farmers is that superphosphates, on account of containing such a large amount of lime, will take the place of burnt lime. This is entirely wrong. There is certainly a large amount of lime used in the manufacture of superphosphate, but this lime has already performed the very purpose it is asked Ip perform in tilled soil. In other words, the lime in superphosphate is already saturated with sulphuric acid which is used during the process of manufacture and so has become sulphate of lime. This sulphate of lime is quite incapable of neutralising any more acid in the soil and for this reason cannot perform the function of ordinary burnt lime.

Another important factor is, never to apply lime with manures or at the same time as manures. The phosphoric acid in superphosphate for instance is rendered soluble by the>, chemical action of sulphuric acid during its process of manufacture and is thereby made available as plant-food. To apply It with burnt lime or at the same time as burnt lime, is undoing this work and rendering the phosphoric acid insoluble. If lime is applied with nitrogenous manures such as dried blod or sulphate of ammonia, the result will be equally disastrous, as much of the ammonia in these fertilisers will be liberated and escape In the air. s How To Proceed.

The ideal method of procedure in liming and manuring is for every farmer to first of all learn to know his own soil. This can only be done by sending a representative sample of soil either to the Government chemical laboratory at Wallacoville or to a private, analytical chemist. Apply the necessary quantity of lime and follow up by an application of superphosphate or any other manure that may be recommended." Hundreds of experiments made throughout the world have proved beyond tihe shadow of a doubt, that a„ sound and scientific method of liming arid manuring is the best and safest, investment any farmer can make.