362 EXPERIMENT STATION RECORD. 



land and 14.8 bu. to the soil management. It is estimated that 1.8 bu. of this increase 

 of 14.8 is due to the growing of leguminous crops, 1.1 bu. to the use of lime, and 

 11.9 bu. to the phosphorus applied. 



On the Cutler field on undrained land the same treatment increased the yield of 

 wheat from 7.9 to 17.6 bu. as an average for 3 years. On the plats receiving potassium 

 in addition, the average was further increased by 4.6 bu., which was a more marked 

 effect than that produced on the other fields. 



The data secured in 1904 on the Cutler and DuBois experiment fields, where nitro- 

 gen was applied at the rate of 100 lbs. per acre in the form of dried blood, in place of 

 growing leguminous crops, show that the land produced 6.2 bu. while the lime 

 increased the yield 3.3 bu., the nitrogen 0.5, the phosphorus 16.6, and the potassium 

 0.6 bu., giving an averageof 27.2 bu. of wheat per acre for 3 tests. It is believed that 

 the first beneficial effect of leguminous crops on this soil was not due solely, or even 

 largely, to the fixation of nitrogen, but rather to the liberation of phosphorus and to 

 the improved physical condition of the soil as brought about by the chemical action 

 of the decaying organic matter of these crops. 



The results on the Vienna soil experiment field showed that in 1904 the yield was 

 increased from 6.7 bu. on the untreated soil to 10 bu. on soil growing leguminous 

 crops and treated with lime, and to 14.8 bu. when phosphorus was also given. In 

 1905, where lime had been applied to correct soil acidity and leguminous crops had 

 added nitrogen and decaying organic matter, the yield was increased from 1.3 bu. on 

 untreated soil to 18.2 bu. per acre with leguminous crops and lime treatment; and 

 where phosphorus was added a further increase of 7.4 bu. was obtained. 



It is estimated that during the 3 years the untreated land produced 8.4 bu., the 

 growing of leguminous crops gave an increase of 10.1, the lime treatment an increase 

 of 10.4, and the phosphorus treatment an increase of 19.5 bu., or a total yield of 48.4 

 bu. The results of 4 years' experiments with pot cultures on unglaciated hill soil 

 showed that an appreciable increase in yield was made only when nitrogen was sup- 

 plied either in commercial form or by means of growing leguminous crops. 



A summarized statement is given showing the yields and value of the wheat pro- 

 duced on the different soil experiment fields. The average yield of wheat in 1903 

 was 1.9 bu. per acre on the untreated land and 11.9 on the treated land, while in 

 1904 the yields were 7.6 bu. and 10.5 bu., respectively, or a total of 18.1 bu. on the 

 treated land. In 1905 the treated land produced 28.9 bu. and the untreated land 

 only 9 bu. In 12 tests covering 3 years' work the untreated land yielded on an aver- 

 age 6.1 bu. and the treated land 19.6 bu., the use of leguminous crops and the appli- 

 cation of lime and phosphorus being responsible for this increase of 13.5 bu. The 

 cost of the soil treatment, allowing 50 cts. an acre a year for ground limestone and 

 $2.50 an acre a year for the cost of 200 lbs. of steamed bone meal, is given at $3 per 

 acre, but it is pointed out that if raw rock phosphorus at $8 a ton is substituted for 

 the steamed bone meal the total annual expense for materials may be reduced to 

 $1.70 an acre. 



Data on the effect of the soil treatment on corn, oats, and clover indicate that 

 during the first 3 years on the different fields the use of leguminous crops, lime, and 

 phosphorus increased the yield of oats 13.2 bu. per acre. As a result of this treat- 

 ment an average increase of 13.3 bu. of corn was secured in 6 tests made in 1904, and 

 an increase of 1.14 tons per acre of field-cured clover hay as due to this method of soil 

 management was obtained in 1905 in 5 different trials. The value in the increase in 

 each of the crops was more than enough to pay for the annual cost of the materials. 



An experiment showing the comparative value of steamed bone meal and finely 

 ground rock phosphate is noted in the abstract of Circular 96 (see p. 356). 



