Vol. X. No. 249. 



THE AGRICULTURAL NEWS. 



367 



of its mycelium undergioiind. It is not yet certain if the 

 spores can produce direct infection, or if tliey can only 

 germinate on decaying wood and thence spread to 

 healthy trees. In any case the first step when a diseased 

 tree is observed is to cut it down and burn it, before the 

 destroying fungus can produce spores upon it. When this is 

 being done, all the roots of trees in the neishbourhood should 

 be examined and any infected ones should be removed in 

 order if possible to save such trees. The soil should lie well 

 forked and dressed with lime or iron sulphate; at the end of 

 twelve months, a supply may be put in. When the disease is 

 spreading down a wind-break of pois doux, its progress may 

 be arrested by digging a trench at rightangles to the direction 

 of the wind-lireak in the manner usually recommended for 

 dealing with root diseases. 



In the ne.Kt number of the A'jrkidtural Xeivs, further 

 information will be given, derived from the same sources, 

 dealing with the subject of the other two diseases of limes 

 mentioned above. 



AGRICULTURE IN GREAT BRITAIN, 1911. 



The following statement concerning agriculture in 

 Great Britain during the present year has been issued 

 recently by the Board of Agriculture and Fisheries. 

 It is accompanied by a table giving details of the mat- 

 ters to which reference is made. 



The preliminary statement of the agricultural returns 

 collected in .June last .shows a further redaction, by 51,272 

 acres, of the cultivated area of Great Britain, arable land 

 having decreased by 20,786 acres and permanent pasture by 

 30,486. The acreage of wheat increased by 97,189 acres, 

 and reached a total nf 1,900,043 acres, being a larger area 

 than has been recorded in any year since 1899. The acreage 

 of barley, on the other hand, declined by 130,734 acres, and 

 reached a smaller total than any yet recorded. There was 

 practically no change in the acreage of oats, but the acreage 

 of beans recovered the loss shown in last year's returns. 

 The potato area increased by 6 per cent. (32,330 acres), and 

 thus nearly reached the total recorded in 1909. Mangolds 

 also have slightly extended, but other roots show a some- 

 what diminished acreage. There is some indication of 

 a revival of the cultivation of flax, which forty years ago 

 occupied about 20,000 acres but in recent years has almost 

 disappeared. The acreage of hops also fur the second succes- 

 sive year shows a slight extension, though it is still nearly 

 12,000 acres less than it was so recently as 1907. The acre- 

 age under fruit which for several years up to 1909 had 

 increased annually now remains stationary. 



The returns of horses on agricultural holdings have been 

 collected this year in fuller detail than heretofore. In addition 

 to horses used for agricultural purposes, mares kept for breed- 

 ing and unliroken horses, a return has been obtained for the 

 first time of other horses kept on farms. The number of these 

 is returned as 146,818, but it is probable that in previous 

 years some now returned under this heading may have been 

 erroneously included in the returns. The reduction shown 

 in the classes for which a comparison is possible is therefore, 

 in all probability, less than the figures indicate. The number 

 of cattle returned on June •"> was 76,937 more than in 

 1910, the total now being the largest on record. The number 

 of sheep declined by 607,953, and thus fell lower than in any 

 year since 1907. On the other hand, pigs increased by no 

 less than 20 per cent., the total number being restored to the 

 same level as in 1908. 



THE VALUE OF DIFFERENT CROPS 



AS GREEN MANURES. 



This subject, under the above heading, is discussed by 

 A. D. Hall, M.A., F.ll.S., Director of the Rothamsted 

 Experimental Station, in the Journal of the Board of A<jri- 

 ridture, Vol. XVII, p. 969. The author commences by 

 drawing attention to the fact that the practice of green 

 manuring is followed comparatively little in Great F.ritain, 

 because the custom of the country has been to feed off green 

 crops with sheep; when the material of fodder crops is buried, 

 it is generally for the reason that the farmer is afraid that he 

 may not be able to feed off the crop in time for the next in 

 the rotation. It is suggested, however, that on heavy soils 

 where sheep cannot be folded, the practice of green manur- 

 ing might well be extended, and attention is drawn to the 

 action of green manures in improving the texture of the soil. 



In pursuing the subject, mention is made of the classic 

 illustration of the value of green manuring with leguminous 

 plants in the reclamation of large sandy areas in East Prussia, 

 by Schultz, using the method of building up the soil by 

 raising successive crops of leguminous plants with the aid of 

 artificial manures, and burying them. Since the time of 

 these experiments, general acceptation has taken place of the 

 existence of the power of leguminous crops to increase the 

 soil nitrogen. In view of this, it was naturally a matter for 

 surprise that, in experiments made on the Royal Agri- 

 cultural Society's Farm at Woburn, better yields of wheat 

 were obtained after mustard (a non-leguminous crop) than 

 after a leguminous crop such as vetches, both crops having 

 been buried in the soil. Continued repetition of the trials 

 has made no room for doubt that this condition exists, and 

 the circumstance has led to the establishment of a similar 

 experiment at Rothamsted, in order to ascertain if the same 

 results would be obtained under the different conditions. 

 To state it shortly, the opposite effects were obtained, 

 leguminous plants in the latter case giving better yields of 

 wheat, when used as green manures, than when rape or 

 mustard was employed in the same way. The differences in 

 the conditions consisted mainly in the fact that the soil at 

 Woburn is light and dry, while that at Rothamsted is 

 heavier, and possesses a greater power to retain water. 



The observation was made that the grain, and particu- 

 larly the straw, of the wheat grown after the leguminous crop 

 were much richer in nitrogen than tho.se of wheat following 

 mustard or rape. Further investigation is required to find 

 if the growing of the latter crop causes the nitrogen-Hxing 

 bacteria to show an increased activity on account of the 

 supply of vegetable matter that is given to the soil. Results 

 in the laboratory have suggested that this is the ease; but, as 

 is pointed out, it does not necessarily follow that the circum- 

 stance is true in soils, on the large scale. 



In attempting an explanation of the peculiar results 

 obtained at Woburn, Dr. Voelcker has brought forward the 

 suggestion that the matter is probably connected with 

 water-supply, as the land seems to be drier and more 

 open after vetches than after mustard; this condition, 

 on the light soil, appears to affect the land more than the 

 addition of the nitrogen obtained from growing and burying 

 the leguminous crops. The experimental results are actually 

 in agreement with practical experience, and though further 

 investigation is required to determine the point, it is indicated 

 that on the heavier soils, under the conditions, leguminous 

 crops are better than non-leguminous plants for use as a green 

 manure. 



