182 



poor sandy soil, thinly, but uniformly, covered with heather. In No- 

 vember, kainite and basic slag were sown all over the field, and in May 

 1891, a strip about eleven yards wide and forty-eight yards long was 

 inoculated with surface soil, from old cultivated lupin land (8 cwt. 

 •per acre). The whole was harrowed and sown with lupins. The 

 wet weather at the commencement of the experiment was unfa- 

 vourable, but soon after the first leaves were formed the inocula- 

 tion was shown to have been effective by the presence of nodules on 

 the roots of the young plants. The plants growing on that part of th** 

 field which had not been inoculated had, as was expected, no nodules, 

 with the exception of a few isolated plants. The difference in the ap- 

 pearance of the above-ground growth was soon very marked, the ino- 

 culated plants being quite normal in growth, the others light-red and 

 yellowish. The amount of produce without, and with, inoculation, was 

 100 : 552. 



Similar results were obtained with while clover, the heather being 

 completely suppressed by the clover under the influence of inoculation. 



In experiments with lupins growing in a heavy loam Schmitter ob- 

 tained an increase of only 11 per cent, of corn and straw by inocula- 

 tion. But, as Salfeld points out, such a soil is most unsuitable for lu- 

 pins ; moreover, the quantity of inoculating soil employed by Schmit- 

 ter was very small. With regard to the eJSect of the physical nature 

 of soil on the growth of lupins, it may be mentioned that in the 

 pot experiments at Rothamsted(i there was far more growth in loose, 

 white sand, than in the lupin sandy soil itself from which the sand 

 was inoculated. Billwiller {^^^) in discussing green manuring, gives two 

 groups of plants suitable for different soils : — 



1. For light to medium soils, white, yeUow, and blue lupins, and 

 serradella ; and for calcareous soils, kidney- vetch, and lotus. 



2. For medium to heavy soils, peas, scarlet, clover, sand vetch, Bok- 

 hara clover, red clover, alsike, and yellow clover ; and for mixtures, 

 horse-beans. 



Light, sandy soils which are unsuitable for clover are chiefly to be 

 utilised for green manuring — in Germany with lupins or serradeUa. 

 It was, however, hoped that it might be possible to grow peas, and 

 similar plants, successfully on such land, and some experiments were 

 instituted in which garden and field peas were inoculated from pea 

 soil. Lentils were also included, but there was no suitable soil availa- 

 ble for their inoculation. The land was well manured with kainite 

 and basic slag, and the two halves received respectively quicklime and 

 marl (carbonate of lime). On the limed portion or the plants nearly 

 all failed, and it was found that the roots were quite free from no- 

 dules, the microbes having apparently been destroyed by the lime. 

 On the marled half of the field vegetation was luxuriant. The ques- 

 tion of the effect of lime is one of considerable importance for some 

 soils, and Dr. Tacke, of Bremen, accordingly made a number of pot 

 experiments with the view of solving it It is not necessary to give 



11. Lawes and Gilbert, Journal R.A.S.E., 1891. 3 Vol. 11., p. 683. 



12. Inaug. Diss. Bern, 1895. 



