THE MONTHLY BULLETIN. 125 



learus to recognize the signs of need or distress. For instance, the 

 foliage on a potato plant which is getting dry becomes a dark, almost 

 black green, which can be distinguished almost as far as the plant can 

 be seen. It is very different from the normal, healthy green of a 

 plant well supplied with moisture, and also different from the sickly 

 light yellow that is produced by excessive irrigation. 



In order to be of the greatest possible benefit to the tree or plant 

 irrigated, moisture must penetrate as deeply into the soil as the roots 

 can feed to advantage. Water penetrates open, sandy soil readily, 

 and tlie biggest problem in this kind of land is to get it over the surface 

 without wasting too much through the subsoil. Checks or furrows 

 must be short and a big head of water used. 



"Where the land is heavy, with a large per cent of clay and silt, as it 

 is in a great part of the Sacramento Valley, the difficulty is to get 

 enough penetration. When the soil is thoroughly dried out to a con- 

 siderable depth as it was last year, a small stream of water must be run 

 for a long time before it penetrates three to five feet. Two years ago. 

 at the Monroeville orchard of the Sacramento Valley Irrigation Com- 

 pany on the Sacramento River near St. John in Glenn County, the soil 

 was thoroughly dried out to a depth of 15 feet and the rains of the 

 winter of 1912-1913 penetrated only 2 or 3 feet, and did not connect 

 the lower with the upper moisture. During the season of 1913 we were 

 compelled to run small streams along the tree rows for 10 days in order 

 to get a 3 to 5 foot penetration as indicated by the steel rod when 

 slioved into the furrow, but irrigators were required to get this penetra- 

 tion, and so controlled the streams that very little was wa.sted at the 

 end of the 660 foot rows. 



In our orange grove at Orland, which is on ver>^ heav}' clay land — 

 in fact I do not know of any heavier soil in the Valley — it had been 

 the practice for years, Avhenever it was irrigated at all, to flood the 

 land. After government water was available three or four years ago, 

 it was flooded everj^ ten days or two weeks and cultivated between irri- 

 gations. This practice was rapidly breaking down the granular struc- 

 ture of the soil and burning out the humus and vegetable matter; and 

 after the first irrigation, after we purchased the place in June, 1912, 

 I could find no place in the orchard where it was possible to stick a 

 spade, or even to dig without a pick, over 9 inches into the soil. For 

 the next irrigation we plowed four furrows between the rows, made 

 head ditches and controlled the water into the furrows through lath 

 lioxes. The soil was so hard that it was almost impossible to plow the 

 furrows, it being necessary to go through two and three times with 

 the plow before they could be opened up enough to run water in. Too 

 large a stream was turned in for the first irrigation, and the bottoms 

 of the furrows silted over so that the water ran through the 400-foot 

 rows almost as well as though the furrows had been cemented. They 

 were furrowed out again — a little deeper this time — and a small stream 

 turned in that required twenty-four to forty-eight hours to get through 

 the rows, soaking in pretty well as it passed along. Such an extreme 

 measure as this is seldom necessary but it certainly was in this case, and 

 we kept a small stream running for four or five-day periods, cultivating 

 and furrowing out between times, nearly all of the summer season of 

 1912, and irrigated a great deal in the same way during the dry winter 

 2—1.5979 



