BEETROOT AND CARROT CROPS

Timaru Herald, Volume CXLV, Issue 21180, 29 October 1938, Page 15

BEETROOT AND CARROT CROPS

TO PRODUCE SUCCULENT ROOTS While it is true that root crops in general should not be planted in freshly-manured land, it is sheer folly to Imagine that, as a natural consequence, they will yield a good return in poor soil which has had only the scantiest of preparation. The main essentials are a deeply-dug site and good drainage, but, unless the soil has sufficient “body" to promote strong, healthy growth, under-sized, tough, and flavourless roots will inevitably be the result.

Fresh manure is only to be eschewed because of its tendency to encourage forking or coarse growth, and split, forked, or hollow roots are naturally equally unacceptable. The aim should, therefore, be to choose a plot which has been well manured in previous years and is capable of supporting a healthy crop without further addition to its humus content. This should not be difficult to manage in a wellplanned vegetable garden or allotment, where a rotation scheme is faithfully followed out.

Many growers have, of course, to contend with poor, hungry land, which is not capable of supporting a second crop without some help. In this event, the only course is to rely on artificial fertilisers for this season, and, as it is now rather late to think of working them through the soil, they will be best applied in the nature of topdressings at a later stage of growth. Light soils will benefit from a good dressing of wood ashes or salt forked into the surface just before sowing, but wood ash in particular must on no account be given to heavy land, for it will simply tend to aggravate its wet and sticky nature. Long Varieties for Storing

'lt is universally recognised that for the main crop the long-rooted varieties of both carrots and beets are unsurpassed. For early work, the shorthorn and globe varieties are equally unrivalled. There are circumstances, however, when the long-rooted kinds are not a wise choice. For instance, it is useless to expect them to return a considerable crop on shallow land, where they do not have the chance to delve deeply into the soil. By far the better course, when the depth of cultivated land is shallow and cannot be increased, is to choose one of the intermediate types, which are really midway between the globe and the long in the case of beet, and the long and the stump-rooted in that of the carrot. Obelisk beet and St. Valery carrot are both splendid varieties, and will keep in storage every bit as well as the longest-rooted kinds. In most gardens sowings of Shorthorn and stumprooted carrots have already been made, leaving only the main crop to be dealt with. It is particularly important to complete sowings for the year as early as possible, for a late start invariably entails increased risk of damage from the carrot fly, a pest which, as many growers know to their cost, can ruin the finest crop. Both the intermediate and long-rooted varieties should be allowed plenty of room, and the drills should be drawn at least 121 n apart . Another point carrot seed can hardly be too lightly covered. The best plan is to draw fairly wide and very shallow drills, and then sift some fine soil over the seeds by hand. Germination will be fairly rapid, and the first thinning of the plants must not be delayed once they are large enough to handle without damage. This is an operation which must not be accomplished at one fell swoop. Instead, it should be a gradual process, and a start can be made by thinning out the seedlings to about two inches apart each way. Then, when the foliage meets in the rows, every alternate root can again be drawn out. Though tiny, these thinnings make a useful and tasty dish quite early in the year. The roots must eventually stand not less than six or seven inches apart, and one further thinning will still be necessary. After each one, the soil must be firmly pressed around the roots left standing, either with the back of an iron rake, or with the fingers, as this will prevent the fly from laying its eggs in the loosened surface soil. A further preventive which has proved remarkably successful is that of placing saucers, containing a piece of flannel, soaked in paraffin, between the rows. If fresh paraffin is added at intervals of about a fortnight, it Is most unlikely that the fly will make an appearance, and, if it is kept at bay, there will, of course, be no maggots to destroy the crop at a later stage. New-mown grass scattered between the rows will also serve, if it is renewed at fairly frequent intervals.

THE MANAGEMENT OF SOIL SOME CHEMICAL REACTIONS The soil is an ideal scene for chemical reactions, usually of the slow type. The simplest, barrenest soil, devoid of organic ingredients, consisting of particles varying in size from pebbles to fragments of clay 1002 millimetres in diameter, and the still smaller colloidal particles, and composed of mineral matter such as sand (silicon dioxide), chalk (silicate of alumina), chalk (calcium carbonate), is affected chemically when exposed to air and to rain. The action of water alone is fundamental, first acting physically as a solvent, and by this means removing soluble salts such as chlorides, nitrates; but it fortunately does not readily carry away dissolved potassium and ammonium salts. These, and also phosphoric acid, are readily “absorbed” by certain constituents of the soil. Secondly, mineral matter in solution in water undergoes electrolytic dissociation; a certain proportion of the dissolved compound substances divides into two ions, one basic or positively charged, the other acidic or negatively charged, and it is in this form that they are reactive chemically. This solution is assimilable by the plant; in fact, gives the plant the substance for its structure, without which the organic matter introduced through the green part of the plant would be of little service.

Except for the bleakest, wind-swept rock, surface soils contain an appreciable amount of organic matter, and the chemical changes in connection with this are totally different from those already referred to; here the process Is one of decay of the organic matter, be it animal or vegetable. This refuse ultimately breaks up, helped by the action of soil animals, worms, bacteria, moles, into the following gases:— Simple carbon compounds, carbon dioxide, CO2, methane or marsh gas CH4; more of the latter and less of the former if the supply of air is scanty. Simple sulphur compounds, sulphur dioxide, SO2, sulphuretted hydrogen, H2S, again the proportions being regulated by the supply of oxygen, hydrogen compounds, mainly water vapour; free hydrogen if oxygen is absent; and nitrogen compounds, chiefly ammonia, which is readily oxidised to nitrous and nitric acids, leaving a final solid residue of inorganic salts, e.g., phosphates, sulphates of the metallic elements, potassium, calcium, magnesium, iron; and it is this solid residue which is a treasure house for the growing plant; the very compounds in the acceptable form required by the growing plant, a heritage from the previous generation of plants. In the intermediate stages of this disintegration the soil is generously supplied with the necessary carbonaceous matter, humus, an important factor in rendering the soil fertile, partly because of its texture and its moisture-holding nature, and partly because of the organic acids it evolves in the process of further decay. The rate of this disintegration is increased by the presence of alkali in the soil. The bacteria responsible for causing the decomposition thrive only in an alkaline environment. Moreover, the products of decomposition are acidic, the alkali neutralises this acid, and so encourages the formation of more acid. Acidity or sourness in soils (not accurately measured by means of such indicators as litmus) is due, in part anyway, to the active hydrogen ions; here, again, electrolytic dissociation, this time of acids, into positive and negative radicles takes place. Lime or chalk will serve to neutralise this acid, be it organic or inorganic; the corresponding calcium salt will be formed; the introduction of more calcium into the soil changes the relative proportion of the necessary bases (magnesium, sodium, potassium, calcium), which fundamentally affects the character of the soil; moreover, the soil colloids have their affinity for bases satisfied, and flocculation can take place. Thus we see that this addition of lime can lead to three different types of chemical reaction.

Now we have built up a picture of this soil universe, complete with atmosphere, moisture, elaborate and varied mineral content, varied both as regards physical structure and chemical composition, microscopic flora and fauna, all contributing to the production of a complex environment for the roots of the plants, which in their turn affect this environment. SHADINGS FOR GREENHOUSES Make lib of wheat flour into a thin paste with boiling water, to which add Hb tallow, dissolve lib of powdered whiting in cold water, and mix thoroughly the two solutions together, add Brunswick green to give the desired shade of colour. Apply warm when the sun is shining. Whitewash to which buttermilk, salt or size is added to make it adhere may be used for temporary washes. Apply with a brush or spraying syringe.