10 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



Perhaps fortunately, he never carried out this intention. Or, again, 

 we quote Jethro Tull, who in 1730 instances a farm formerly let at 

 £10 per annum rent (i.e. about 2s. an acre), " which, whilst in arable 

 was like to have undone the tenant, but being all planted with St. 

 Foin by the owner, was let at one hundred and ten pounds per annum 

 and proved a good bargain." We might quote the Rothamsted experi- 

 ments, showing that wheat grown after clover gives as good a crop as if 

 it had received a heavv dressing of artificial fertilizers : or we could 

 give numerous instances new and old from the United States. 



Perhaps the most convincing evidence of all is the fact that fanners 

 have universally adopted the practice, and regularly grow clover alone, 

 or clover mixed with grass every fourth or fifth year, sometimes leaving 

 the mixture down for a period of years so as to intensify the effects. 



The third factor in soil making can also be controlled — the securing 

 of conditions necessary for decomposition of the organic matter. The 

 soil organisms will do their work if they are given a chance : it is 

 necessary to ensure that they get their chance. 



Liming and drainage are the usual improvements wanted on the 

 large scale : they must be followed by good cultivation and soil manage- 

 ment. No short cuts are possible. : deep digging in autumn, good tilths 

 in spring, and ample surface cultivations in summer are all necessary. 

 It is not my purpose now to go into the question of soil management : 

 horticulturists recognize its need even though they sometimes fail 

 to ensure it. Unless cultivation is good the soil organisms have no 

 proper chance of working well. 



Numerous attempts have been made to improve the soil population 

 by adding certain strains of bacteria. Hitherto these attempts have 

 succeeded only in a few rather special cases. In some of the Belgian 

 and Dutch reclamations of heath land it has been found beneficial to 

 apply a compost made by mixing ordinary soil and farm-yard manure. 

 No great quantities are needed : only a few hundredweights an acre : 

 but the effect is said to be very marked. A great part of the benefit 

 is attributed to the bacteria thus introduced : the explanation seems 

 reasonable. The micro-organic population of peat land, especially wet 

 peat land, differs considerably from that of a normal arable soil. No 

 doubt the change from wild conditions to the cultivated state would 

 ultimately bring about a corresponding change in the micro -organic 

 flora, just as a change in soil conditions brings about considerable 

 change in the vegetation. But matters are hastened by judicious 

 seeding, and it seems to be admitted that the clover crop benefits con- 

 siderably. Attempts have also been made to introduce the organisms 

 appropriate to the clover plant. If this could be done it would repre- 

 sent a grtat improvement — anything benefiting the clover crop 

 naturally benefits the succeeding crop — and bacteriologists are still 

 hoping to achieve the result. These efforts have met with some 

 measure of success in the United States. They have also been 

 somewhat successful in Germany. Hiltner, in a recent publication 

 addressed to Bavarian farmers, strongly urges inoculation of legu- 



