PREPARE ONION BEDS.

Auckland Star, Volume LXV, Issue 129, 2 June 1934, Page 6 (Supplement)

PREPARE ONION BEDS.

SUCCESS FOLLOWS EARLY PREPARATION. Every amateur desiring- to excel in onion culture should realise the importance of early preparation of' the bod. Onions being deep rooted subjects and requiring rich fare, the ground for them should be dug at least two spits deep, working into the bottom spit a. liberal dressing of manure. Soil on the heavy side is best suited to onions. If too close textured, ashes from the garden bonfire and other gritty materials effect an improvement. After digging apply 4oz or so of basic slag per square yard', leaving the surface rough—not breaking down the lumps. Cow and pig manure will render light soil more retentive of moisture, while the addition of heavy loam aids materially. Choose an open site, where trees or other objects do not obstruct light. When arranging for onions to follow celery, dig and manure between the ridges before levelling the ground. Cabbages can follow the onions, this being a good system of rotation. CROP-SICK SOILS. When we speak of a soil being exhausted or crop-sick, it is not meant that there lias been a complete deprivation of crop-producing power, but simply a reduction of this power below a profitable point. Many persons imagine that all that is required is for a chemist to make an analysis of the soil to determine which are the plant-food elements lacking therein in order that these may be supplied, and productiveness established. Recent experience too often shows that what is called an exhausted soil may be well supplied with all needful plant food, and yet the crop fail to make satisfactory growth. At the Rothamsted experimental station an experiment was conducted for 20 years on the growth of potatoes in the same land. There were 10 plots, one received' no manure, t.'is others received either farmyard manure or various artificial manures, both nitrogenous and mineral, either alone or in combination. The manures were applied every year. At the end of the 20 years the experiment had to be abandoned, because the hind absolutely refused to' grow potatoes. It mattered not what; the description of the manure applied was, farmyard manure, or artificial fertilisers, the crop equally failed. What, we may ask, w?s the cause? It could not be lack of plant food, for in the following year (1902), cftcr the experiment with potatoes was stopped, the land was sown with bavley, without manure. The yield on some 'i the plo;s was 72 bushels of grain per aoc, and the plot which has received :io manure of ariy kind for 27 years gave 33 bushels of barley per acre. In the following year (1903) barley was sown again without manure, and the results were 9J bushels per acre, on the permanently unmanured plot, rising to 47 bushels per acre on the plot which had previously received farmyard manure. In 1904 oats were sown and in 1903 and each yca:c since barley has been grown without manure, and produced in 1909 24? bushels per acre, showing that even after eight years of corn cropping without manure this potato-exhausted land yielded a fair barley crop. Of what then does soil exhaustion and crop-sick soils consist? It usually means that plant food materials, which may still exist in the soil, no longer occur in that condition in which a particular crop can make use of them, but another crop of a different food requirement and having a different food range may be able to appropriate what was unassimilable to the former crop. Thus acid and other toxin accretions given oil' by the roots of one particular crop may become by conversion, through the aid of the various bacteria of the soil, available food for a crop of another kind, hence one great value of a rotation of crops. Hitherto cultivators of the soil have, with a few exceptions, given no thought to the invisible bacterial life that plays such an important part below the surface of the ground, and through whose agency crops and individual plants are enabled to respond to the fertilisers added to a well-tilled soil. Yet this rational conception of the fundamental i causes of productiveness will in future I have to be taken into account by horti- | culturists and gardeners in every depart-] inent of their work, if they wish to pro-| grcss with the times, and aim at deriving! The greatest benefit from capital and ] labour invested in their establishments I As it is now known that the fertility of a soil is largely determined by the activity and number of its ammonia-producing bacteria, it becomes a point of much interest to find out what is the special microbe or class of microbes .that are most beneficial to the particular crop we j wish to grow. It is recognised that afterj about 25 years of continuous growth of cucumbers or tomatoes in a glasshouse. even though the surface soil may be renewed from time to time, these crops become a failure. They either refuse t"> grow, or they get attacked by injurious insects or fungoid growths. The only known remedy appears to bo either a rotation of crops or the incorporation into the soil of some antiseptics which will help the bacteria we wish to encourage and destroy or render harmless those microbes which are detrimental tn the crop grown. It has been found that partial sterilisation of the soil by heating to 100 degrees for two hours, or treatment with antiseptics, kills off certain organisms, but leaves unhurt some spore's of the ammonia-producing bacteria which afterwards can develop to a much greater extent, because they are freed from the normal checks. PRUNING TREES. The best implement for the work is a strong and .sharp pruning knife. If a saw has to be employed, always finish off smoothly with a knife, then dressing the wound with a suitable' steriliser, such as white lead paint or tar.