90 



IKISH GARDKMNG 



JUNE 



lacking-- food suhsl.incc. Siippo.se the soil to l->c 

 poor in phosphates, to add an all-round manuie 

 in sufficient quantity to supply enoui^h o( this 

 ingredient would mean i;i\ int;" to the soil 

 a i^^reat deal more ol the other two than is 

 necessary. Therefore, to avoid such ob\ ious 

 waste the required excess ci phosphate can be 

 sup|->lied 1\\ the application o( a purely phos- 

 phatic fertiliser in addition to an ordinary 

 application o( tarmvard manure. This is the 

 fundamental principle of rational manurinj,^. l.el 

 us take a concrete example. We are i^^rowinj^. 

 say, tomatoes in a ratlicr claye\ soil. We mix 

 with the soil about one pari to eii^hl of' tlecayed 

 farmyard manure. Hut the clay is lackinj^ in 

 phosphoric acit.1 and perhaps in lime ; we there- 

 fore mix in with the manure a certain quantity 

 of basic slag-. This will provide the two sub- 

 stances that are lacking", and hence make a more 

 balanced food supply in the soil. When the 

 plants enter upon the exhausting process of fruit 

 production it will aid the plant in its work to 

 supply it, say, fortnightly with an easily 

 absorbed all-roimd ration made up of two parts 

 of sulphate of ammonia, four parts double super- 

 phosphate, and one part sulphate of potash, 

 well mixed together, and which may be applied 

 as a top-dressing in solid form at the rate of 

 2 ozs. per square yard. But it should be under- 

 stood that no hard and fast rules as to actual 

 quantities can possibly be given, as so many 

 factors influence the growth, such as variation 

 in soil, composition of farmyard manure, variety 

 of plant, and so forth. Observation and ex- 

 periment must g-o hand in hand with gardening. 

 I'or instance, if it is found that the tomato 

 plants in the above example are getting too 

 luxuriant in stem and foliag^e, then less 

 ammonia must be supplied, and a good dress- 

 ing of bone meal applied to steady the growth. 

 Gardeners with little experience in the use 

 of artificial fertilisers should try experiments 

 on a small scale, and carefully note the results. 

 It is rather futile to attempt such a compli- 

 cated matter as the feeding of a crop by merely 

 following instructions in books and gardening- 

 papers. One may acquire a fair working 

 knowledge of the principles underlying- the 

 practice of manuring by intelligent reading 

 and study, but the successful application of 

 such principles can only be attained by actual 

 trial and from observation and reasoning based 

 upon comparative results. 



.Shoukl a crop appear to lack vigour, the 

 growth too stunted, antl the foliage a sickly 

 green, try the eflect o\ a little nitrate of soda. 

 .Such an appearance is olten i.\u\: to nitrogen 

 starxation, and the nitrate will supply the 

 missing eUiiunt. 0\} the other hand, a too 

 luxuriant gro\\th oi sIukU is frequently due to 

 excess o\' nitrogen compounds and a poverty 

 with lespect to either phosphates or potash. 

 Should you niMice such excessive growth, try 

 the etfcct ol an aj-iplication of superphosphate ; 

 it has a great steadying iniluence, checking 

 shoot lormatioii and encouraging the produc- 

 tion ol llowci' and fruit. 



Potash appears io have a great influence 

 upon the rate of starch- and sugar-making in 

 the green leaves of the crop, and as the bulk 

 and weig-ht oi' the crop depends upon the 

 amount of starch made during the hours oi' 

 sunlight, the presence of potash in sufficient 

 quantity in the soil is very essential to success. 

 Clays are usually well supplied, but sandy, 

 chalky, and peaty soils are, as a rule, insuf- 

 ficiently supplied for the needs of ordinary 

 garden crops. Wood ashes contain potash in 

 an easily absorbed state. Sulphate of potash 

 is a very convenient salt to use. It is niuch 

 purer than kainit (the most commonly used 

 potash manure), and, although dearer in 

 price, it is the best to use in a small garden, 

 especially during the summer months. 



In applying manures, the nature of the crop, 

 as well as the composition of the soil, must be 

 understood. Peas and beans, for example, will 

 benefit little, if at all, from being fed with a 

 nitrate, as owing to the work of the bacteria 

 in their root nodules they can get their supply 

 of nitrogen from the air. All Leguminous 

 plants are similarly independent of nitrogenous 

 manures. On the other hand, green crops will 

 thrive best with an abundance of nitrogenous 

 food, while fruit trees will produce too much 

 shoots and too little fruit if over-fed with rich 

 nitrogenous substances. Again, root crops, like 

 turnips, have a difficulty in obtaining minerals, 

 especially phosphates, while potatoes demand 

 relatively large quantities of potash. 



The above remarks were sug^g-ested by the perusal 

 of a little manual on '* The Science and Practice of 

 Manuring," by W. Dyke, sent to us for review. It 

 deals with the whole subject in an accurate yet popular 

 style, and any one desirous of knowing- more about the 

 subject can get the booklet from the Lockwood Press, 

 I Mitre Court, Fleet Street, London, for is. 2d. postfree. 



