the soil decomposing bodies which encourage and assist these changes. Hence it is that the presence of organic matter in the soil is always necessary, for if it has not one duty devolving upon it, we may be sure that it has others, which always make it valuable to the land.

Some have argued against the necessity for the use of this organic matter, because it has chiefly been obtained from the atmosphere, and therefore other plants, it was said, could get their supply from the same source. This will not bear the test of practice, if for no other reason than the fact that plants possess this power of drawing upon the atmosphere in very different degrees. Even if the needed supply could be obtained, it is evident that other duties which are performed by the organic matter in the soil would be neglected. We must also remember that all this organic matter in its growth has drawn upon the soil for mineral matter in an active condition. The consequence of this is that as the decay of the organic matter proceeds in the soil, so we have a gradual restoration of this mineral matter, and in a form highly favourable for use by the growing crop. So fully does this restoration take place, that it has become an accepted practice on many soils, which have little power for holding manure, to make use of this means for keeping a supply of plant-food ready for the requirements of the crop. By the application of farm-yard manure to the clover crop, we are enabled by encouraging the growth of clover to preserve much of the manure, which under ordi

nary circumstances would have been washed away from these soils. In such a case the manure takes a new form, and is built up in the clover plant. This produces an abundance of clover root which, as it decays in the soil during the growth of the following crop, yields up a large store of fertilising matter. It has the further advantage of giving this supply of food gradually, whereas the farm-yard manure would have given a larger supply at first, but much of it would have been entirely lost to the crop before the plants were approaching maturity, and were more than ever requiring assistance for perfecting the crop.

CHAPTER X.

THERE are various terms in common use respecting soils, to which we may now refer, and this is the more desirable because these terms indicate certain practical opinions as to character, which are derived from experience in their cultivation. Some soils are described as being hungry. This character has been gained by the fact that they are constantly in want of food. Sands and gravels, which have little or no power of holding manures which may be added to the soil, are of this class. They were generally distinguished by an absence of the double silicates and ferric oxide, as well as a short supply of organic matter. Just as a heap of cannon balls, with the openings filled with small shot, will give a free pass

E

age for water, so these soils offer little or no impediment to the passage of the rain, and have little or no power to soak up and retain any fertilising matter which may be in a soluble form. Hence the common mode of improving these soils is to add clay in some form or other, and encourage the accumulation of vegetable matter, thereby increasing the organic constituents of the soil. In this way such soils are rendered more capable of preserving any fertilising matter added to the land, and of securing it for its proper duty of giving food to the growing crop. Just in proportion as this is done, so the land ceases to have that hungry character attached to it.

Another class of soil are known as tough and obstinate. These are generally found to contain a large quantity of clay, but in the majority of cases they only reveal these points of character when under bad management. For instance, a piece of clay land ploughed up in the spring of the year in preparation for root crops, or for fallow, is likely to become hard, tough, and obstinate as it dries in the sun, and to demand an immense amount of horse labour to reduce it to the condition of a good seed bed. If, on the other hand, such a soil had been well drained and ploughed up in the autumn, or early winter, and left well exposed to the action of the atmospheric agents we have so frequently referred to, it would have become reduced to a finely pulverised condition in the spring. This change of condition is infinitely more perfect than any state to which we can reduce it by long-continued horse

labour. If, however, after this has been done, the farmer is too anxious to push forward his work, and by cross-ploughing the land he buries the fine soil, and brings up earth which has lain too deep for the winter frost to act upon it, then we find he has exchanged a soft, powdery soil for one that is stiff and obstinate. Thus, whilst he should take advantage of the powers for breaking up the soil by atmospheric agents, he must not undo the work again, by allowing the soil to be brought up in the objectionable condition we have named. Yet some of these soils, when they have become hard and baked, attain a condition which the farmer recognises as tender. If, under these circumstances, a gentle shower of rain falls, and the drags and harrows are sent over it at the right moment, they crumble to pieces at once. If, however, a little too much rain falls, then they show how tender they are, by becoming muddy and pasty. Such soils as these try the patience of the farmer very severely; but just in proportion as he has more organic matter spread through the soil, so they lose these undesirable points of character, and show less temper in their management.

We also have other soils which are kindly and grateful, yielding good and abundant returns for any manure which is judiciously applied. As a rule these soils are generally loamy soils, having sufficient sand and organic matter in them to enable them to be worked without any great difficulty, and sufficient clay to preserve and rightly use the manure they

receive. These are the most pleasant soils to manage, and they relieve a farmer from many of the anxieties which appertain to other soils. They represent those intermediate forms of soil, to which all good management endeavours to reduce those which have too much sand or too much clay. The strong clay soil, by the introduction of organic matter, becomes mellowed, so that it can be more easily cultivated; whilst the sands, by good management, acquire greater firmness of character. Both, as they are thus improved, assume more of the character of kindly and grateful soils.

Then we have our soils which are on the invalid list, and known as sick." It is with soils as with individuals; there are a great many causes for their not being in a healthy condition. Hence, although we may see signs of sickness, there is a very great variety of cause, and we must not decide upon that cause without due and proper consideration. Soils generally become sick from either of two causes. It may be the presence of some objectionable body or bodies in the soil, or because something which the plant requires is absent from the land. In some few cases both of these causes act at one and the same time. Drainage, deep autumn cultivation, and a thorough exposure of the soil to the atmosphere during the winter months, these will, with very few exceptions, meet the difficulties of the first class. The washing of rain water through the soil is very effective in removing injurious matter, and this is secured by good