346 EXPERIMENT STATION RECORD. 



agriculture, tiiough it may be found useful to others." It is divided into 4 sections: 

 (1) Study of the conipositioii and structure of rocks; (2) the operations of geological 

 agents, including weathering, agents of transport, etc.; (3) geologi(;al surveying; 

 and (4) study of the strata of the Britisli Isles in the order in which they wen 

 formed. 



FERTILIZERS. 



Fertilizer experiments, C. A. Mooers ( Tennessee Sla. Bal. Vol. XVI, Av. 1, pp. 

 20, figs. 5). — This bulletin gives the results of experiments on fortieth or fiftieth- 

 acre plats, to determine the fertilizer requirements of certain typical Tennessee soils 

 and to test the best methods of applying fertilizers. The crops experimented 

 with were sweet potatoes, white potatoes, grass and clover, and cowpeas. "Both 

 field experiments and laboratory work on the soils of this State are of more than 

 ordinary value, on account of the uniform composition of each type. Those of most 

 importance in East Tennessee repeat themselves in narrow strips, having a general 

 direction from northeast to southwest. The typical soils of the other sections of the 

 State are not so complicated and will require less investigation." 



Both chemical analysis and field experiments show the need of phosphoric acid 

 on all of the soils experimented with. Next to the fundamentally important phos- 

 phoric acid, nitrogen is most needed, and the least needed element is potash. In 

 the experiments with sweet potatoes, the principal object was to determine the most 

 profitable amount of fertilizer and the best proportions of the fertilizing ingredients, 

 especially the best amount of cotton-seed meal to use in connection with the standard 

 amount (300 lbs. per acre) of acid phosphate. The soil used for the experiments 

 was a sandy loam characteristic of the iron limestone formation. Greatly increased 

 yields were obtained from the use of a mixture of 350 lbs. of cotton-seed meal with 

 300 11)8. of acid phosphate. The addition of potash produced little effect. The most 

 profitable returns, however, were obtained during 2 seasons by applying 1,520 lbs. 

 per acre of a mixture consisting of 720 lbs. of cotton-seed meal, 600 lbs. of acid phos- 

 phate, and 200 lbs. of muriate of potash. "Judging from other results, however, 

 the amount of potash could have been reduced to advantage." 



The experiments with white potatoes were made on a shale soil very deficient in 

 plant food and on a very poor white gravelly hill soil. On the basis of the results 

 obtained, the following fertilizer mixture is recommended: 360 lbs. of cotton-seed 

 meal, 300 lbs. of acid phosphate, and 50 lbs. of muriate of potash, used at rates of 

 from 500 to 1,000 lbs. per acre. 



The experiments with orchard grass and clover were made on what had formerly 

 been very poor and unproductive soil, but which had been improved for the grass by 

 turning under a crop of cowpeas and rye which had been moderately fertilized and 

 manured. 



"The yields of grass and clover were greatly increased by applications of acid 

 phosjAate and nitrate of soda. Acid phosphate used alone affected the clover more 

 than the grass, while the mixture of acid phosphate and nitrate of soda resulted in 

 a predominating growth of grass. Acid phosphate, 300 lbs. to the acre, used alone, 

 greatly increa.-^ed the yield of clover, and was by far the most profitable fertilizer." 



The experiments with cowpeas were made on a soil known to be very deficient in 

 phosphoric acid, the special object being to compare the relative fertilizing value of 

 raw phosphates with acid phosphate. Acid phosphate alone gave the most profitable 

 returns. On very poor land good results followed the use of potash in addition to 

 the phosphate. In both pot and field experiments fine-ground raw rock phosphate 

 did not produce any marked increase of yield on a soil known to be poor in phos- 

 phoric acid. "In pot experiments the phosphoric acid from fine-ground raw bone 

 was found to be about one-half as efficient for both cowpeas and turnips as the 

 phosphoric acid from a.-id phosphate." 



