500 



THE GARDEN AND FIELD, 



April, 1914 



& Cultivation of the Vine ^ 



Continued from last issue. 



By H. R. Laffer. 



— The Addition of Nitrogen. — 

 It may be contendetl that the 

 practice of green manuring neces- 

 sitates delay in the ])loughing un- 

 der most conditions, but, even so, 

 there will 1)e little ■difficulty ex- 

 perienced in getting the crop to 

 decay, which after all is the con- 

 trolling factor. Th<;n, again, it is 

 aUvavs jiossible to crop only alter- 

 nate rows each vear where large 

 areas are l)eing dealt wdth, thus 

 rendering it possible to plough 

 half /of the vineyard early each 

 vear ; in fact, this was the prac- 

 tice adopted in the vineyard s± 

 .\lburv, alreadv referred to. So 

 far, the srreen crop has only be<n 

 referred to in connection with the 

 increase of orijanic matter as ' a 

 jjhvsical imjirovement to the soil, 

 but it has a further action as the 

 source of or cyanic nitrogen. In this 

 respect it has a twofold action, 

 namely, the accumulation of at- 

 mosnheric nitrogen on the one 

 hand, and the decay nnd subsequent 

 nitrification of the orcranic matt<:r 

 on the other. This nitrogen must 

 undero^o transformation into one 

 one or other of the mineral forms 

 before it can be assimilated by 

 plants. In dealing with the addi- 

 tion of nitrofren to a vineyard, it 

 must be borne in mind that in 

 addition to the organic form re- 

 ferred to, there are also purely 

 ininc-ral forms of nitrogen, such as 

 sulphate of ammonia and nitrate 

 of soda, which are readily soluble 

 in water and are in a form that 

 can be absorbed by the plants. 

 The effect of these two forms of 

 nitrofren are characteristic and op- 

 nosite. Organic matter on the one 

 hand tends to the development of 

 an excess in tannic acid in the 

 wine, thercbv inaterially increas- 

 ing the keepine cjuality and prolong- 

 inrr the period of maturing. Min- 

 eral nitrojren in excess tends to- 

 wards the opposite extreme, pro- 

 moting 'an excess of albuminoids, 

 which are a frequent source of dan- 

 ger to the resulting wine if not 

 properly dealt with. In the well- 

 balanced soil tannin counteracts 

 the albumen, causing its coagula- 

 tion and precipitation. Manv vine, 

 yards benefit by dressings of pure- 

 ly inineral nitrogen, and for this 

 purnosp recourse must be had to 

 cither ammonium sulphate or sodi- 

 um nitrate. In price they are Iboth 

 hif'h and about the .same, but the 

 former will Hve the better equiva- 

 lent of nitroj^. Owing to their 



expensive nature, it is i)ossible to 

 innlv them in such costly dress- 

 ings as to render their use unre- 

 munerative, owing to the value of 

 the manure applied being in excess 

 of requirements and beyond the 

 value of any ordinary increase in 

 crop. It is here that the need for 

 experimental work is empha.sised, 

 because no hard and fast rule can 

 be laid down for any one soil. As 

 a eeneral guide, it may be said 

 that from i cwt. to 2 cwt. of 

 either of these substances may be 

 :iP"1ied Der acre. Its method of 

 apnlication is in the early spring, 

 either bv means of a drill or else 

 placed in shallow furrows alon;: 

 the rows of vines. In addition to 

 these forms of mineral nitrogen 

 there are various other forms of 

 nitro<renous fertilisers to be ob- 

 tained, sueh as dried blood and 

 slaup^hter-house refuse ; also bone- 

 dust and bone super., which con- 

 tain a fair percentage of nitrogen 

 as well as their phosphatic nroi->»'- 

 ties. All these substances are valu- 

 able as fertilisers if they can be 

 obtained in sufhciently large <iua"- 

 tities and there is enough moisture 

 to dissolve the vital elements from 

 their com-position. 



— Phosphoric Acid. — 

 South Australian vineyards, in 

 common with the bulk of our agri- 

 cultural lands, show a deficiency in 

 this element of plant food. Its ap- 

 plication may be said, then, to 

 rank next in importance to nitro- 

 jren. So far as manuring is car- 

 ried out at the present time in 

 South Atistralian vineyards, super- 

 ])hoisphate is, in many cases, the 

 only form of fertiliser u.sed. There 

 can be no doubt, however, that 

 where super, is givinor n-ood results 

 at the present time the need 

 ortranic or mineral nitrogen will 

 1 ecomc apparent in the nofi- ''■ 

 ture if consistent yields are to be 

 obtained. The vine uses less phos- 

 phoric acid in proportion to its 

 •rrowth and fruit production than 

 do most plants, but neverthckss it 

 IS of vital mportance to the gene- 

 ral health and fruit development of 

 the vine. Particularly does this 

 apply at the latter end of the 

 summer, when the plants are 

 rippninp- off their wood and storing 

 up in the pith a reserve supply of 

 nourishment to feed the young 

 (Tovvth in the early spring. The 

 use of super, in connection with 

 trrecn manuring has been dealt 

 with, but whatever may be the 



claims of this practice, it must be 

 remembered that in many cases 

 phosjihatic manures directly ap- 

 plied are giving excellent results. 

 There exists a considerable differ- 

 ence of opinion as to the best time 

 to apph- ])hosphates, but if we 

 look into the matter carefully we 

 find that it depends upon the type 

 of soil and the amount of moisture 

 a^■ailable during the growing sea- 

 son. Being a slf^wlv soluble man- 

 ure, it is generally recognised +h^ + 

 it should be a])plied in the winter 

 months alontr with the first plough- 

 in?, and this would appear to be 

 the most common practice. There 

 are some erowers, however, who 

 prefer to drill in their super, dur- 

 inf the summer months, while 

 others, asfain, claim the best re- 

 sults from spring application. The 

 first case suits the bulk of our vine- 

 yard areas. In the second, the 

 result of the manure is not looked 

 for until the following; A^ear, and 

 the third is adapted to certain 

 ';necial cases, mainly lisrht sandy 

 lands in districts of eood rainfall. 

 The latter is the case of those 

 HrrTit-colored sandy soils, such as 

 is found in portions of the Barossa 

 district. L'pon these soils winter 

 application of superphosphate gave 

 no increase, as the manure was 

 leached from the o'^m loose soil bv 

 the winter rains ; in fact, it is said 

 that one grower applied a heavy 



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