type of grain — -just as has been done in connection with the citrus fruit 

 industry of California, which is the most conspicuous example in modern 

 horticulture of co-operation in the production of one particular product, 

 namely, the Navel orange. 



During my stay at Washington, I had also the pleasure of renewing 

 my acquaintance with Dr. L. J. Briggs, the Physicist in Charge of Dry- 

 land Investigations. Briggs, although still a young man, has already won 

 distinction by reason of his researches in soil physics and more especially 

 for the ingenious instruments which he has devised for automatically 

 recording precipitation and evaporation. Special attention is being given 

 to the study of the moisture relations under different methods of cultiva- 

 tion, different crops, and different climatic conditions. • The moisture con- 

 tent of each foot of soil is determined by sampling with a soil-tube, drying- 

 each sample, and then weighing it and noting the difference in weight. These 

 soil tubes are made of cold rolled seamless steel tubing and are so con- 

 structed that samples can be taken to a depth of fifteen feet if necessary. 

 A comparative study of soil temperatures in lands giving different 

 methods of treatment is also in progress. That is to say, the temperature 

 of the seed-bed under summer fallow, fall (autumn) and spring ploughing 

 is being carefully studied. The worth of these matters is too plain to 

 need any emphasis ; but they all go to show how profound and varied 

 are the problems which come under the head of dry-farming. Summing 

 up it may be said that the main efforts of the Department of Agriculture 

 in dry-land agriculture are to be found along the following lines : — Soil 

 management, cereal investigations, plant breeding, soil moisture determina- 

 tions, meteorological research, and lastly, but by no means least, 

 bacteriological studies. And when it is remembered much of the work is 

 done in the Bureau of Plant Industry — a division that now numbers 

 1,058 persons— the number of experts at the service of the dry-farmer will 

 be more readily realised. 



.Mr. Gifford Pinchot, Chief of the Bureau of Forestry, kindly gave 

 me the following information in regard to forest planting in the semi-arid 

 regions and the influence of windbreaks upon the surrounding crops. 



The semi-arid plains of the United States are almost wholly lacking 

 in native timber. With the gradual settlement of this region, however, 

 considerable planting has been done for protection against wind, for the 

 production of farm material, and for decorative purposes. Hardy 

 drought-resistant trees, such as honey locust, Russian mulberry, black 

 locust, green ash, hackberry, box elder, yellow pine, Scotch pine, and 

 jack pine have been most frequently used. Cottonwood, silver maple, and 

 lombardy poplar have been planted to some extent in moister localities. 

 Thorough and frequent cultivation to check evaporation of moisture 

 from the soil is necessary for successful tree growth on the semi-arid 

 plains. 



The deodar cedar and coulter pine have been planted experimentally 

 by the Forest Service in the semi-arid mountain regions of southern 

 California. Although the experiments have been conducted but for a 

 short time, the results indicate that both of these trees can be successfully 

 grown under rather trying conditions in that region. Other species which 

 are being planted on the National Forests in regions of deficient rainfall 

 are yellow pine, jack pine, Douglas hr, and Engelmann sprnce. 



