178 



THE TROPICAL AGRICULTURIST. 



[August i, i88z. 



growth, and the long period during which the land 

 is bare, "r there is little growth, aud so subject to 

 loss of nitric acid by drainage. 



9. When salts of ammonium, or nitrates, are 

 applied as manure, the chief, if nut the ouly unex- 

 hausted residue of nitrogen left within the soil avail- 

 able for future crops, is that in the increased roots 

 and other residues of the crops ; and this is only 

 slowly available. 



10 "When oilcakes or other foods are consumed by 

 •took, the formation of nitric acid from the manure 

 produced is slower, but continues longer than when 

 salts of ammonium are used. When there is a liberal 

 use of animal-manures, an accumulation of nitro- 

 genous and mineral matter takes place in the soil, 

 and such accumulation is known under the term 

 " condition." Under such circumstances the fertility 

 of the soil is maintained, or it may even be con- 

 siderably increased. — Journal of the Royal Agricultural 

 Society of England, 



NURSERY TREATMENT OF PLANTS. 



AB young trees before being removed to plantations 

 should be transplanted from the seed-beds into positions 

 in the mu'seiy approaching, where practicable, those into 

 which they are ultimately to be transferred, and the 

 state of the plants ought to be regulated to suit the 

 soil and site. Thus for bare and exposed tracts small 

 robust plants well furnished mth fibres are necossaiy, 

 larger ones with similar roots for those less exposed, 

 and for sheltered positions, with a good open loam, those 

 with moderately furnished roots will answer, provided 

 they are able to sustain theu' vigour ; but for open, 

 sandy, and stiiF, tenacious soils the plants cannot be 

 too well rooted. I will not enter here into the question 

 of the most sititable sizes of plants for planting, and 

 need only state that this must be regulated by attend- 

 ant cu-eiimstances, just as exposm-e, the natiu'e of the 

 ground, and the natural covering that may be gi-owing 

 upon it. 



In my opinion the non-stabiUty of the trees, where 

 that exists, is not traceable to any elaborate treatment 

 they receive in their younger stages, but in some case 

 it may be owing, especially with conifers, to the man- 

 ner of perfonning the necessary operations in the nm'se- 

 ry. As ah'cady stated, the roots ought to spread out 

 equally all round the plant, and not, as frequently is 

 the case, all on one side, for when such are plante d, 

 by some of the methods at present in vogue, they are 

 placed pei-manently in the ground mth theu' roots dkectt'd 

 in one direction, so that fresh roots requu'e to strike 

 out from the base of the plant in an opposite one, and 

 they never attain the same vigom' and strength as the 

 others ; it is therefore not smiu'ising that numerous 

 trees are heeled over when a strong wind strikes them 

 from a point opposite to that of their roots. 



The methods adopted when transplanting in the nurse- 

 ry are "dibbling" and "laying," but to have properly 

 formed roots these operations must be efficiently earned 

 out. In the case of small coniferous plants, \rith a 

 nui'seiy soil of a loose aud open character, dibbling is 

 to be preferred before laying, as better developed roots 

 are formed if they are di'opped du'ect down in the open- 

 ing formed by the dibble ; but if the opening so made 

 is not of sufficient capacity, either as to depth or width, 

 the roots inevitably get . doubled up with then- points 

 near the surface, which causes them to be of an un- 

 natural form, and thereby hiu-tful for a time to the 

 growth of the plants and to the fui'ther developmeant of 

 their undergi'ouud ramifications. Laying is performed 

 by cutting a trench in the form of a light or acute 

 angle, deep enough for the roots of the plants to be 

 inserted, and to in-oject duect do;\-n to theu- fuU ex- 

 tent, and when that is done they will be formed in a 

 satural manner; but wl.en the trench is opened, as is 



too often done, to a depth quite insufficient for the 

 requh-ements of the roots, the consequence is that they 

 are jdaced at something like a right angle to the stem, 

 and when not covered in that position they are gener- 

 ally doubled up and pressed against the face of the trench 

 by the operator when pressing in the loose soil to cover 

 them, so that they become shaped according to the way 

 in which they are placed ; and, if they be again trans- 

 planted, the contortions of the roots are further aggi'av- 

 ated. I do not mean to aver that when such are planted 

 and gi-owing in plantations they will not be capable of 

 withstanding storms of wind, but they wiU be more 

 ready to succumb than those whose roots have been 

 gi-oi.vn in a foi-m more nearly approaching those in a 

 natural state. 



There are particular soils on which plantations are 

 more Uable to suffer than on others, such as those of 

 a loose, open, and thin character, and on thin soils 

 with a coid, tenacious, or impervious stratum under- 

 neath ; on these, whether the trees have grown there 

 dh-ect from seed, from seedlings planted there, or from 

 plants prepared in the nm-sery, they would be equally 

 liable to suffer. 



In conclusion I may state that what ought to be more 

 looked to in treating plants in the nursery is greater 

 attention and care in transplanting, so that roots may 

 be produced of a more natui-al foi-mation, aud when they 

 are transferred from there to the forests they should be 

 placed in the gi-ound in as natural a position as possible. 



With a view to nullify the effects of winds upon plant- 

 ations, belts of trees, which are most capable of weather- 

 ing the storms, sboidd be planted on all then' most 

 exposed boundaries, and particular attention must be 

 paid to these, if they are to he of any benefit, both in 

 then' arrangement when planthig, and in after yeai's. 

 Trees of a low-gi'owing habit ought to be kept on the 

 outer margin, and taller ones behind, and they should 

 never be allowed to become crowded together, but have 

 plenty of room for encom-aging the development of side 

 branches, and extentling thek roots underground. Hill- 

 ocks and ridges might also be taken advantage of, 

 where these would be likely to afford shelter to other 

 portions of the plantation, arranging and treating the 

 trees upon them for that pui-pose. — ^Andrew Slater 

 Jun., Wyreside Cottage, Lancaster. — Journal of Forestry. 



BIOLOGY AND AGRICULTURE. 



Recent advances in our knowledge of the lowest 

 forms of life have tended to bring into prommence 

 not only their relation to disease but to the ever- 

 increasing importance of the part which they play 

 in our arts and idustries. Probably in none of the 

 industrial arts, save those concerned with ferment- 

 ation, commonly so called, has the progi'ess of this 

 branch of biology shown such remarkable develop- 

 ment as in its bearing on the art of agriculture. 



It was even been suggested that a bacterium is at 

 the bottom of the present state of agricultural de- 

 pression, and there is a considerable amount of force 

 in this suggestion. The loss of nitrogen from the 

 in the form of nitrate is one of the most serious 

 difficulties with which the farmer has to contend ; 

 and, as this loss takes place by the washing out of 

 nitrates m the drainage and its diffusion into the 

 subsoil below the reach of the roots of plants, it is 

 necessarily greater in wet seasons such as have been 

 the rule for the last few years. 



We believe that Pasteur was the first to suggest, 

 twenty years ago that the process of nitrification 

 going on in soils and waters might be due to the 

 agency of an organism ; but it was not until the last 

 five years that the researches of Sclilusing and Miintz 

 and of Waringtou conclusively showed that this is 

 the case and that the organism is a bacterium. This 

 bacterium is present in all fertile service soils and 



