The Bulletin. 57 



I have a small farm up in Maryland. When bought, in 1904, it had on it a 

 crop of corn which produced 8 bushels to the acre. In 1908 I took from it an 

 average of 60 bushels to the acre. At the start I tried to grow crimson clover, 

 but the land was too poor, so I worked a while with cowpeas, bought some 

 stable manure and put it under cantaloupes, following them with Irish pota- 

 toes, using some commercial fertilizer. I then succeeded in getting a stand of 

 crimson clover, which was plowed under for corn. The first crop of corn after 

 this crimson clover gave 60 bushels to the acre without any commercial ferti- 

 lizer. This was repeated the next year, a second crop of crimson clover having 

 been turned under. Then we had some very dry summers, and I could not get 

 a catch of crimson clover, and had to rely on commercial fertilizer, with the 

 result that crop yields ran down. Last year I got a good stand of crimson 

 clover, which was turned under this spring for corn, and my crop bids fair 

 to be as high as 80 bushels on some parts, with an average of not less than 60. 

 I believe that where crimson clover will grow, it is the best manure to put 

 under the corn crop. 



Charts 9 and 10 will give you an idea of the quantity of nitrogen-bearing 

 vegetable matter that can be produced on the land for controlling fertility by 

 growing clovers, vetches, and related crops; also the relative quantities of 

 nitrogen or ammonia (the form in which you buy nitrogen) contained in these 

 crops, together with its commercial value, also a comparison of the nitrogen 

 found in a ton of cotton-seed meal and its commercial value. The shaded lines 

 (Chart 9) represent the hay produced by certain crops, and the black lines 

 under them the quantity of stubble and roots left in the soil for fertility 

 control if the hay is taken off the land. The shaded lines in Chart 10 represent 

 the relative quantities of nitrogen or ammonia in the hay ; the black lines, the 

 relative quantities of nitrogen in the stubble and roots. This crop of red 

 clover (Chart 9) produced about 21/0 tons of hay, leaving in the soil about one- 

 half as much stubble and roots, or I14 tons, for soil improvement. This hay 

 crop had in it (Chart 10) 120 pounds of nitrogen, and the stubble and roots had 

 in them 49 pounds of nitrogen, a total of 169 pounds, equivalent to about 200 

 pounds of ammonia, which would have cost over $32 purchased in the form of 

 commercial fertilizers. This crop of bur clover produced about 3 tons of hay 

 to the acre, leaving in the soil about one-fifth as much stubble and roots, or a 

 little over one-half ton for fertility control. The nitrogen in the crop would 

 have cost over $30 if purchased in the form of commercial fertilizer. This 

 crop of crimson clover, yielding somewhat under 21/0 tons of hay, left in the soil 

 one-third as much stubble and roots. The entire crop had in it nitrogen to the 

 value of over .$31. A ton of cotton-seed meal has in it 138 pounds of nitrogen, 

 having a value of about $26. 



Charts 11 and 12 show the same data with reference to vetch, cowpeas, and 

 Canada field peas. This vetch crop of 2^4 tons left in the soil about three- 

 fourths of a ton of stubble and roots. The cowpea crop of 1% tons left more 

 than half as much, or 1 ton, of stubble and roots in the soil. The Canada 

 field-pea crop of 2 tons left about one-seventh of a ton of stubble and roots 

 in the soil. The vetch crop contained nitrogen to the value of over $30, the 

 cowpeas over $21, and the Canada field peas over $21. From these charts you 

 see the large quantities of vegetable matter we can produce to put back mto. 

 the soil and the large quantities of nitrogen they contain. Any one of 

 these crops has a value of 12 to 15 tons of good stable manure for controlling 



fertility. , ^ ^ ^. ., 



The nitrogen in the crop came partly out of the air, partly out of the soil. 

 Just how much came out of the air we do not know, but it has been estimated 

 that these crops take from one-fourth to three-fourths of their nitrogen from 

 the air Suppose we say an average of one-third. This means that these crops 

 brought to the soil from $7 to $10 worth of brand-new nitrogen per acre, cost- 

 ing but little more than the price of seed. Crimson clover seed have cost me 

 some years as high as $2.50 per acre in Maryland. We use 15 pounds or a peck 

 to the acre. The man who has charge of my farm while I am away says that 

 he would not be without crimson clover if the seed cost $20 a bushel. You see 

 what we think of crimson clover in Maryland for controlling fertility. 



It will be scarcely necessary for me to go into the details of planting of 

 these different crops. Your local people, the people here at the college and 



