ON THE LAND

New Zealand Tablet, 13 March 1919, Page 37

ON THE LAND

The three elements of plant nutrition are nitrogen, potash, and phosphoric acid, but - which is the greatest of these no man knows, said Professor - Bowker in a lecture on plank foods. He added that it is believed that phosphoric acid is the most important, not be-" cause it is the most required, for in the composition of the plant it is the least required, but because it is a “catalyser” as well as a fertiliser; that is, besides furnishing the needed phosphoric acid, it assists in the diffusion and assimilation of. other plant food ingredients—as condiments assist digestion and assimilation of food.”

THE STORAGE OF POTATOES. Darkness and low temperature are primary requisites in storing potatoes (explains the Fields Division of the N.Z. Department of Agriculture). An important point is to reduce the temperature as low as possible directly after the product is stored. The ideal temperature is 35 deg. F. If the ground is well drained, so that there is no danger from water in the winter, inexpensive potato storage may be made by merely digging a trench about 5 feet wide and 4 feet deep and as long as is needed to secure the required capacity. The roof should be given a pitch merely sufficient to shoot water, and a gutter dug to keep the rain-water from running into the pit. A rough cave hollowed out in a hillside is also a good plan. Potatoes have been known to keep fresh for over a year in an old mine tunnel with a current of air passing through. The temperature in this case remained at about 40 F.

INJURIOUS INSECTS IN NEW ZEALAND. , Our injurious insect fauna is comprised not only of exotic forms but also of some indigenous species which have forsaken their natural food-supply far the more succulent products of the settler (says Mr. David Miller, Entomologist, in the N.Z. Journal of Agriculture). Of these insects 82 per cent, are exotic and only 18 per cent, indigenous. Most of the former originated from Europe, and a few from Australia, North America, Pacific Islands, and South Africa. The greatest number are orchard pests, but are held in check by rigorous spraying methods; about 22 per cent, affect live-stock and man, but cause no appreciable loss in New Zealand ; stored products and household goods are attacked by about 21 percent. Field and vegetable crops are damaged by about 19 per cent., and, although this is the smallest group, the greatest loss probably occurs amongst these crops, due, perhaps, not only to there being no legislation necessitating the control of these insects as in the case of some of the other groups, but also to the comparative absence of information regarding them. WOOL-PURCHASE BY IMPERIAL GOVERNMENT. The War Office is now engaged in completing its wool accounts for the year ending March 31, 1918 (says the N.Z. Journal of Agriculture), and it will be understood that it is a complicated, lengthy, and laborious task. Such figures will include the greater quantity of the New Zealand 1916-17 clip, but not the whole. In fact, a portion of the 1916-17 clip has not even yet left New Zealand. In the making of tops, Australian and New Zealand wools are blended according to their suit-

ability, and not according to their origin, and wool of different season's clip is similarly dealt with. The wool control and operations in .the United Kingdom have been rendered much more difficult than in pre-war times by diminished transport and storage facilities and by depleted staffs. <. ; : - It is thus impossible in the circumstances of to-day to ascertain the profit realised on the New Zealand clip for each separate year. Although no such provision was made in the original bargain, the Imperial Government has decided that the profit-sharing arrangements should be extended so as to include the results of the processes of top-making and carbonising,, it being the desire of the Imperial Government to deal with such questions in a broad and equitable manner. It will be understood, however, from the processes of blending above referred to that the division of the results of the operations between New Zealand and Australia will be to some extent a question of estimate, in proportion to the total values of Australian and New Zealand wool used in the two operations. There is no doubt, however, that the calculation will be made in a manner' satisfactory to all parties. The position regarding surplus profits may be summarised as follows: About 20 per cent, of the New Zealand clip is issued, for civilian purposes, and half the profits made on such sales will be returned to New Zealand growers. The accounts now being completed include the greater portion of the 1916-17 clip, and the amount for distribution should be available early in 1919 for a pro rata distribution on a basis to be arranged. Further distributions will be made available on subsequent clips during the following years. Woolgrowers will, of course, understand that the amount for distribution is unlikely to be individually large, but no indication of the amount is yet possible.

.. . j THE VALUE OF THE HOE. Experiments well-nigh innumerable, and extending over long periods, have been conducted with a view to the solution of such questions as to the depth at which to cultivate or hoe the conservation of moisture in the soil, and the influences of a fine tilth produced by hoeing on plant growth. The results obtained by these experiments have brought into prominence the enormous advantage of a soil in . such condition that the roots can extend freely on all sides, #nd that air and water can pass readily through it, and in the course of their passage assist in setting free some portion of the food constitutents locked up within the particles. If the soil is regarded as a storehouse of plant food rather than as an inert mass, the value of efficient tillage will be the more readily appreciated. Further aid in the appreciation of thorough cultivation will be obtained by remembering that the soil contains immense numbers of micro-organisms actively engaged in breaking down certain of the soil constituents, and converting them into a form in which they can be utilised "by the plant in building up its structure. For those not less than for the roots, air, moisture, and" warmth are necessary and these can only be obtained in proportions favorable to the maintenance of bacteria in an active state, when the soil has been prepared in accordance with advance practice. Depth is essential to a full development of the root system other than those which do not extend far below the surface, and it is not less necessary that the soil . should be converted into a comparatively fine tilth throughout its whole depth.-