426 EXPERIMENT STATION RECORD. 



cinni sulphate to the magnesium and sodium sulphates in the total solids is approxi- 

 mately 2:1^ :1. The salts extracted from the first 2 in. of the soil by continued 

 treatment with water consisted of the same salts. They made up nearly 80 per cent of 

 the total, but the ratio was approximately 4:2:1. The aqueous extract of the second 

 2 in. of soil contained very little magnesium sulphate, no sodium sulphate, and 

 almost 51 per cent of calcium sulphate. This extract showed a large amount of 

 solul)le silicic acid, corresponding to 14.5 per cent of sodium silicate calculated on 

 the dried residue. The upper portions of the ground water are richer in total solids 

 tlian the successively deeper portions, and the salts in solution differ, especially in 

 their relative quantities. 



"Tliere seemed to be an aijundant formation of nitric acid in the upper jiortions 

 of the soil, even in portions of the plat where the alkali salts were abundant. Nitric 

 acid occurred so generally in the ground waters and its variations were so dependent 

 upon other conditions that we can not judge of the effect of the alkalis present nor 

 of that of the mechanical conditions. There W'as no relation between the amount of 

 total solids and that of the nitric acid present. There was no relation between differ- 

 ent wells in regard to the quantity of nitric acid present or its variations. Irrigating 

 the ground increased the nitric acid in the well waters; so did even light rainfalls, 

 probably due to increase of capillary exchange of the nitrates between the upper 

 portions of the soil and the ground water. The ground water from this plat is richer 

 in nitrates than that from neighboring land which is in better condition. 



"The nitrites in the ground water are relativelj'^ high and are increased by irriga- 

 tion. This is probably due to the biological conditions of the soil and the deportment 

 of solutions of nitrites toward the soil, especially in regard to the readiness with which 

 they will ])ass through it. 



"The free ammonia and ammonia salts were not especially abundant in the ground 

 water, either l)efore or after irrigation, though moreabundant after than before. The 

 ground water was slightly richer in free ammonia than the drain water from this 

 plat. The albuminoid ammonia in the ground water was not excessively high, but 

 it was materially increased l)y irrigation. The albuminoid ammonia did not appear 

 to i^ass freely into the drain water. 



"The amount of nitrates removed by off-flow water is jirobably (juite limited, as 

 their (juantity in the off-flow diminished rapidly." 



Alkali, J. D. Tinsley {New Mexico Sta. Bui. 42, jip. 5/).— A general discussion of 

 this subject, based on compiled information ajid on laboratory and field investiga- 

 tions l)y the author extending over several years. The toi)ics discussed are: Kinds 

 of alkali; composition of alkali in the Pecos Valley; reactions between some of the 

 constituents of alkali; origin of soils and alkali; soil texture, percolation, and capil- 

 larity; accuuuilation of alkali; prevention of the accumulation of alkali; relations of 

 manure to alkali; removal of alkali from the soil; amount of alkali injurious; and 

 summary of conditions in the Roswell and Carlsbad, N. Mex., and Barstow, Tex., 

 districts. 



Drainage and flooding' for the removal of alkali, J. D. Tinsley {New Mexico 

 St((. Bui. 4S, ]>p. 29, ])ls. .i-j.— About 20 acres of Hondo bottom land near Roswell, 

 N. Mex., was used in these experiments. The soil was very variable, ranging from 

 sandy loam to clay, and consisting largely of sediment deposited by the Hondo River 

 in time of flood. The soil contained so much alkali, almost entirely of the " white " 

 type, that it was suited only to alkali-resistant crops such as saltbushes. 



"Tlie drainage system consisted of a main central drain 610 ft. long running from 

 the foot of the slope to the Hondo . . . laid on a grade of 4 in. to the hundred feet. 

 The first 100 ft. from the Hondo is open, the next 270 ft. is laid with 8 in. tile, and 

 the upper 240 ft. with 6 in. tile. . . . 



"On the east side of the center there are 12 lateral drains making an angle of about 

 18 degrees with the main drain, parallel to each other and 155 ft. long. The first 8, 



