40 The Bulletin 



suitable leguminous crops, properly inoculated, on the land and turning 

 all or part of these into the soil. By the use of such a plan not only 

 will the supply of nitrogen and organic matter be increased, but the 

 physical properties of the soils will be greatly improved by the addi- 

 tion of the organic matter to such an extent that "baking" would be 

 greatly reduced after rains and plowing be made easier and much more 

 satisfactory. 



Other materials that may be depended upon to supply the needs of the 

 soils of the county are farm manures and commercial fertilizers. The 

 commercial materials that carry moderate or high percentages of nitro- 

 gen are usually expensive. It is frequently difficult to have low-priced 

 products like corn pay well for other than moderate applications of 

 farm manures. Of course, when corn is selling at as high prices as it 

 is at the present time much larger amounts, when properly used, may 

 be added to advantage. Where a crop like cotton is growai and the prices 

 secured for the seed and lint are fair to high, farmers will find, usually, 

 that the use of commercial forms of nitrogen in proper amounts may be 

 used profitably, provided they are combined with other materials that 

 will supply the other needs of the crop when it is grown on any particu- 

 lar soil type. 



Where grains or grasses are grown mainly, other sources of nitrogen 

 than commercial ones will generally have to be depended upon to a large 

 extent. Barnyard manure furnishes one of the most desirable sources 

 of this constituent, as combined with it are large amounts of organic 

 matter and moderate amounts of phosphoric acid and potash. This ma- 

 terial, however, is not very well balanced in plant-food constituents to 

 meet the requirements of the soils of the county. It will, therefore, 

 have to be supplemented by materials carrying the required constituents 

 needed by the soils, the chief of which will be phosphoric acid, when a 

 sufficient amount of manure is added to provide for the nitrogen needs. 

 As valuable as barnyard manure may be, it cannot be solely depended 

 upon by farmers generally to keep up the organic matter and nitrogen 

 supply of their soils, as the amount produced on the average farm is 

 relatively small as compared with the acreage devoted to the growing 

 of crops. 



PiiosPHouio Acid — This constituent is contained in very small 

 quantities in the Durham Sandy Loam and Cecil Sandy Loam types. 

 It is not high in any of the types of soil except those mentioned above. 



With the farmer it will generally be necessary, in order that his profits 

 may be greater, for him to use phosphoric acid applications on crops 

 grown on most of the types of soil of the county. Particularly will this 

 be so with those soils low in phosphoric acid. Taking everything into 

 consideration, the two common forms that will have to be depended upon 

 largely at the present time to supply available phosphoric acid will be 

 acid phosphate and basic slag. Of course, there will be added to the 



