Depending on the hard- and software used to read this text and their settings, not all elements may display as intended. Page 187, chart: the lengths of the bars are approximations of those given in the source document. Page ix-xi, List of Illustrations: Full-page illustrations were (usually) printed on unnumbered pages, and the page numbers given in the list are therefore often the page numbers opposite which the illustrations were printed. Figure numbers 44 and 45 are listed in reverse order. In the text, references to illustrations are hyperlinked to the illustrations. Descriptions such as "Actual size" in illustration captions are not necessarily applicable to this text. Page 69, In many parts of the country ... that most persistently: In the source document the first two lines of this paragraph are repeated from the previous paragraph. In the first edition (1906) of the book, this paragraph starts: “It is sometimes the case that a field of alfalfa is left infested in the fall with such a growth of grass and weeds as to make burning in the spring ....” Page 77, table: not all irrigation data add up to the totals given. Page 165 and 338, J. W. Robison/Robinson: it is not clear whether the name is Robison or Robinson. Page 166, “There is no one thing so good ...: there is no closing quote mark. Page 207, ... and printed with illustrations ...: the illustrations are not included explicitly in the source document, but figures 21-23 may act as such. Pages 271 and 338, Alfred Rasicot and Alfred Raiscot probably refer to the same person. Index: the (not consistently alphabetical) order of entries as printed in the source document has been retained. Changes: Illustrations and tables have been moved out of text paragraphs; footnotes have been moved to directly under the paragraph or table to which they belong. Fractions (forms 1/2 and 1-2 both occur in the source document) have been standardised to ¹⁄₂. Some (minor) obvious punctuation and typographical errors have been corrected silently. Texts in a dashed box have for legibility’s sake been transcribed from the accompanying illustration, and do not occur as texts in the source document. Page viii: entry Index added to Table of Contents. Page ix-xi: Illustration numbers have been added to the List of Illustrations. The smaller illustrations have been added to the list, with a descriptive caption added where that was not present in the book. Page 2: ... it was not introduced into those counties ... changed to ... it was not introduced into those countries .... Page 34: ... to snow the result ... changed to ... to show the result .... Page 62: Numerous animal and plant parasite ... changed to Numerous animal and plant parasites .... Page 98: ... four year prior to writing ... changed to ... four years prior to writing ....