11 



From the foregoing data it is obvious that both barnyard manure 

 and green manure are beneficial to this soil when in a run-down 

 condition, but that the effects from applications of green manure 

 are decidedly more beneficial in that they are more lasting than for 

 pqual amounts of barnyard manure. The benefits from liming are 

 feo obvious that they need no comment, while potash and nitrogen 

 in combination with manure are sufficiently beneficial to justify their 

 application, at least in amounts not to exceed 250 pounds per acre, 

 put the results do not seem to indicate that when applied alone they 

 are of enough effect to warrant their use. 



That the results obtained in the above experiments are attributable 

 to the applications given to the soil there can be no doubt, but the 

 applications have been made to small samples under ideal conditions 

 lin regard to the manipulation of the soil and the growth of the plants. 

 For instance, as has been explained; the moisture content of the soil 

 in these experiments has been maintained at or near the optimum or 

 piost favorable condition at all times. Again, the' fertilizers have 

 een intimately mixed with the soil far more intimately than would 

 [be practicable in the field and therefore the same degree of success 

 may not follow under field conditions. In the case of barnyard 

 ; manure, green manure, and lime, however, there is undoubtedly a 

 physical effect in the field which does not enter into these experi- 

 hnents, and which, in the case of a soil like the Leonardtown loam- 

 poor would very likely more than overbalance the loss which would 

 fcccur in field practice from the less intimate mixture of the fertilizer 

 and the less thorough control of the conditions. The results above 

 obtained are sufficiently marked to justify the suggestion that the 

 treatments be tried on a small scale, particularly where this type of 

 Boil is in a run-down condition. 



The Bureau realizes the importance in this connection of a prac- 

 ticable field test, but this would involve much more time than has 

 been required in making the above experiments, and should prefera- 

 bly be made by the farmers themselves under the usual farm condi- 

 tions. Furthermore, it must be insisted that good results can be 

 anticipated only under the best possible conditions of tilth and 

 intelligent handling of the mechanical factors involved in cropping. 



EXPERIMENTAL RESULTS AGREE WITH PRACTICE. 



* As above stated, the results obtained with the wire-basket method 

 appear to be in harmony with the actual field: experience of successful 

 farmers in the locality. In 1900 Dr. Jay A. Bonsteel surveyed and 

 mapped all the soils of St. Mary County, Md., and in his report of 

 that year, entitled "A Soil Survey of St. Mary County, Md.," he says : 



The Leonardtown loam would benefit materially from liming, except, of course, 

 when tobacco is to be raised. The plowing under of green crops, especially the 



