The Food of Vegetables.

Te Aroha News, Volume II, Issue 425, 4 December 1889, Page 5

The Food of Vegetables.

The Royal Horticultural Society of England are doing good work by holding successive conferences on subjects connected with the different branches of horticulture. In September last the Society opened at Chiswick a Vegetable Conference at which Mr H. J. Veitch presided. A most interesting and instructive paper on the " Food of Vegetables '' was read by Mr J. Wright, the principal portions of which are printed below : — The mere size of vegetables doea not, in my opinion, represent superior culture, because in the first place I suspect abnornal bulk ia obtained at the expense of something of inherently greater value for instance, gold. We may see cabbages, cauliflowers, celery, turnips, and other vegetables of titanic proportions or three or four times the size of the best produce for table, but if the cost oi production exceeds the value of the articles produced where is the credit attaching to cultivation ? Observe, Ido not object to a person spei^ding money in the preparation of a horse for winning the Derby, or a bullock for securing the blue ribbon at the Smithfield Show, because there is a special object in view, the attainment of which may justify the outlay, [ and it is the same with gigantic vegetables. They may be grown for a special purpose, because invested with nn extra food value ; but if everybody were to invesb the same amount as reptesented by time and materials in attempts to produce similar examples, not only would the great majority fail in their object, but the piactice, if generally indulged in, would lead to bankruptcy. I do not believe in the utility of bloated vegetables, animals, or men, but suspect that ninety-nine out of a hundred of either of them have cost more than they are worth in the producing. The vegetables must be fed with ingredients which impart to them their distinctive qualities before they can in turn serve as food of the most enjoyable and wholesome, kind for consumers. Some so-called manure is lamentably deficient in those ingredients, and the crops that are grown by it must of necessity be deficient too. They must have all they need to render them perfect. What has Liebig said on this important subject ? Here are two of his " laws " which should be learned by heart by every gardener : — 1. "A soil can be termed fertile only when it contains all the materials requisite

for the nutrition of plantß in the required quantity and the proper form." We must note that some of the ingredients do not suffice, but " all" must be there, and in the required quantity (be it large or small), also in the proper form — a condition of vital importance. They must be soluble, ready for use when needed, or they may as well not be there so far as regards the immediate crop. 2. 4 * With every crop a portion of these ingredients are removed. A part of this portion is again added from the inexhaustible store of the atmosphere ; another part, however, is lost for ever if not replaced by man." Those are fundamental truths, and with them is incorporated the responsibility of cultivators. The atmospheric food referred to is of enormous importance. This will be apparent when the fact is grasped by all, as it is by many, that more than ninety out of every hundred parts of vegetables are derived from the . air, or in other words, 90 per cent, of the food of croos is dorived from the air under favourable conditions in the form of rain and gases that act as solvents of the matter locked up in the soil. The earth must be filled, so to say, w ith air, but it must be moist or it will be useless. And here we see the importance of tillage and drainage ; because if water cannot percolate through the soil air cannot enter to warm it and render the food therein available. Warmth represents life and growth ; cold, death and stagnation ; and it is utterly useless, indeed worse, because wasteful, placing manure in waterlogged land. Some soils are too light and porous, needing additions of heavier to increase their retentiveness otherwise the air in them would be dry and of no service ; others may be too close and need opening material for the admission of air; but no matter the texture of soil, whether sandy or clayey, if it is waterlogged it is cold, inert, even poisonous ; and the sun cannot increase its temperature till the excess of water is evaporated, any more than water with a lump of ice in it can be warmed over a fire till the ice is melted. The cultivator, therefore, for making the most of the virtues of the atmosphere and manure, must have the soil in the best condition for their absorbtion and retention, stirring, hoeing, or mulching, as it may be in turn x-equired for its permeation by health-giving, foodsupplying, moist warm air. Then and not till then, can the mineral ingredients already in the soil, or which may be added to it in the form of manure, be appropriated by crops under cultivation. Some persons condemn natural manure and extol the so-called artificial ; others condemn the artificial and extol the natural. I think it is better to do neither, but to discriminate. Ville, the great French chemist, says land to which farmyard manure only is applied is being gradually exhausted, and that its fertility can be better maintained and crops better fed with the t^ree ingredients — lime, potash, ani phosphoric acid — in combination with nitrogenous manure. Prof. Wrightson saya farmyard manure has no equal. Stephens, in his Book of the, Farm, says a ton of first-class well-made manure should contain between 121 band 141b of nitrogen, lllb to 151b of potash, 81b to 9ibof soluble salts of phosphoric acid (as in superphosphate), and 10 lb. to 13 lb. of insoluble phosphate, as in bonea. As these are all the ingredients Ville asks for, and as the manure also acts mechanically in opening the soil, supplying silica, and eventually humus — which is the nursery of bacteria or micro-organisms that render the nitrogen active by converting into nitrates — such a mixture of good things must be long in exhausting the land. It will feed the land and the crops ; but— here is the point— not one ton of manure in ten thousand equals, or even approaches, the standard named. The bulk of material that gardeners have to work with does not half equal it, and a vast quantity is but a poor "apology for the genuinearticle — thehusk withoutthe kernel, a dead body from which the spirit has gone. Then comes the Value and the need of the concentrated essences known as artificials. Every gardener should have a supply of these, and he may then not only increase the produce of the soil, but improve it — ptoring the vegetables with food, without which, though they may be passable, they cannot be perfect. Phosphoric acid with potash, the former preponderating, for the Brassica family ; potash with phosphates for the Legumes or pod - bearers, also potatoes ; and nitrogen for every crop that needs a whip on to enable it the more freely ■and fully to abstract the substantial ingiedients. With superphosphate of lime, chloride (or nitrate) of potash, the latter the more potent and costly, also nitrate of soda or sulphate of ammonia at hand, the gardener can improve his probably poor farmyard manure considerably, and, indeed, need not wait for it as so many men have to do till they lose their temper and prejudice their crops. When special manures are found to be good they contain the above-named ingredients, and possibly others, which may act beneficially in certain soils ; thus magnesia for potatoes, soda for asparagus and carrots, and chlorine for beet (both imparted by common salt), and a little iron- for' moist crops. According to the experiments of Dr. Griffiths, principal of the Lincoln School of Science, many soils do not contain suffi- , cient of this ingredient. His •' Treatise on Manures," which is an admirable work, contains striking examples of \ cwt of iron sulphate (green vitriol) per acre increasing the crop of potatoes, turnips, mangels, cereals, and beans, while it cured the stubborn root disease of cucumber (according to the evidence of Mr Crocker, of Ham Green Tomato fame), and gave him extraordinary crops. Pa a sing for a moment from vegetables, Mr Divers has recently stated in the Gardeners' Chronicle its efficacy in curing a fine peach tree of "yellows." I have seen the tree and can pronounce the cure complete. For vegetable crops about i cwb to the square yard will suffice for experimental purposes, either in solution or powder, this is to be employed only when the soil is wet to yellowish-looking plants and crops, for producing colouring matter or chlorophyll. But while the soil must be fed for feedins the crops it is possible to impair its productiveness by over-manuring, especially with matter from stables of milking cows, and decayed leaves. I once took possession of a garden that was like a mass of humus, through additions of that nature for generations, perhaps. A walking stick could be pushed down into the handle easily. One plot, I was told, would grow potato plants, but no tubers. I found that to be a fact, and recorded it in the Journal of Horticulture at the time. Peas were yellow and profitless. The soil was poisoned with acids, and lime was needed to neutralise them, also to set free the dormant nitrogen. It was given freely, as also was potash and bone meal. The effect was magical and the crops of potatoes and peas, where they would not grow before were remarkable. Why were potash and phosphates so much needed ? Because there were none in the cowyard manure. The phosphates were drawn away with the milk. Manure from milch cows, especially if largely fed on grass and roots, is greatly over-estimated. There is little good in it to feed cropß. It may make them grow, but the growth is worthless. Proof of this can he found in any cow pasture where the manure is not spread. The grass grows

freely enough, .bub the animals refuse to eat it, and eventually tussocks form and j pastures are spoiled. Manure from fullgrown, well-fed bullocks is very different, for it is rich in phosphates and other nutritive or manurial properties. It is well then, as I Baid before, to discriminate. If weak manure is supplied to the garden, and I have often had it so weak that it would not ferment when moist, mix half a peck or more of good guano in a load. The mass will soon heat then, and eventually its value for the land will be a good deal more than doubled. Instead of conflict between natural and artificial manures wa then have combination, and the union is a happy one for whatever crops are fed with the preparation. But how should we feed? By placing what is good for plants within immediate reach of the roots at the moment of their formation. Digging manure deep down and leaving the surface poor is poor practice. Ido not say have the soil poor bejpw ; on the contrary, have it.as rich as the crops need ; butdo not, as many do, forgot the surface ; also remember that young plants like quick acting nitrogenous i-ather than slower mineral food. The advantage of a good free start in growth cannot be ovei'-valued, and the start is often slow and weak in strong land, and always so in poor soils. Collect decayed leaves or other vegetable matter, wood ashes, light soil of any kind with a dash of soot, and mix well When moist, and only then, pour on liquid'manure, such as drainings from heaps, or what is very good, half an ounce of sulphate ammonia to a gallon of water. A few weeks later, when the time of sowing comes, draw deep drills, fill with this mixture, and in it sow the seed. That is food for infant plants, and they thrive on it. This little attention at the outlet may make all the difference between success and tailnre with certain crops in naturally poor or ungenial soils. Just another sentence or two. Quickacting nitrogenous manures, such as nitrate of soda and sulphate of ammonia (the former for light and dry, the latter lor heavy and cold soils), should be applflP early in the season to growing crops, never late in the autumn ; phosphatic and potassic manures earlier still, before growth commences and before dry summer weather sets in or they cannot be appropriated, because not dissolved by tho crops they are intended to support. Chemical manuies have often been condemned as worthless, when the fault rested with the users in simply applying what was really good at the wrong time for attaining the object in view. Thosa remarks are founded on practice. I think they cannot do harm to any and may possibly be suggestive to some who may engage in the cultivation of food-producing crops.