TRANSLATORS' PREFACE. 11 



land the deeper it should be ploughed, and the more compact 

 the land the deeper it should be ploughed." 



According to F. T. Bioletti, of the Viticultural Depart- 

 ment, University of California,* " In some of the loose, 

 deep, rich soils of California, such deep subsoiling as recom- 

 mended by Viala is unnecessary. In other soils, however 

 it has been found very advantageous to subsoil deeply, 

 especially in somewhat exhausted land, or that in which a 

 " plough-sole " has been formed by years of shallow 

 ploughing. There are very few cases in California where 

 deep subsoiling is a disadvantage, as our top soils are, as a 

 rule, fairly deep. In some soils, however, which are very 

 stony, deep subsoiling is impracticable, and in other soils 

 where a stiff, raw clay is but a short distance from the sur- 

 face it may sometimes be harmful." 



There is another important feature in deep cultivation of 

 vineyards, namely, the removal of stagnant or excessive 

 water, as well as the roots of Eucalypts, &c., which are 

 generally left to decay in situ. When an excess of water is 

 present in a soil, the internal channels being choked, prevent 

 the access of the necessary amount of oxygen, on which the 

 activity of the soil, considered as a laboratory for the elabora- 

 tion of plant food largely depends. Again, when trees have 

 been badly grubbed, and roots left in the soil, f the mycelium 

 of different fungi [Dermatopkora necatrix (R. Hartig.), 

 Agaricus melleus (L.) or Armillaria Mellea (Vahl.), Rcesleria 

 hypogcea (Thum. and Pass.)] develop rapidly, especially in 



* Communicated to us. September, 1900 [R. Dubois]. 



t Palladius (370, 395 A. D.), a Latin author, describes trenching in his 

 work on Agriculture, Book II., section X, and refers to the removal of 

 roots. " The time has now arrived for working the land intended for vines 

 with the pastinum. This may be done in different ways, by disturbing the 

 whole surface, by making trenches, or by forming pits. The soil should be 

 wholly turned over, so as to remove stumps, roots of ferns, and other detrimental 

 plants." Palladius was a noted plagiarist ; it is supposed that his agricul- 

 tural methods were largely borrowed from Magon, of Carthage, who wrote 

 an Encyclopaedia of Agriculture in 22 volumes, 540 B.C. When Carthage 

 was conquered by the Romans, the Roman senate ordered this great rural 

 encyclopaedia to be translated for the benefit of Roman agriculturists. 



