66 The Bulletin. 



erallj grown have been tested. Those giving the best results are 

 the ones belonging to the prolific or two or more ears to-the-stalk 

 kind. Among these, Weekley's Improved, Cocke's Prolific and 

 Biggs' Seven-Ear have done specially well. The results of variety 

 tests have been published each year in detail and the results are 

 summarized in the February (1900) Bulletiiy. These results can 

 be had for study by any one specially interested in them. 



Fertilization. — Analysis of these soils show that they are very 

 low in phosphoric acid, high in potash, and have a fair supply of 

 lime, the quantity of nitrogen depending on the amount of vegetable 

 or organic matter in the soil. Experiments show that phosphoric 

 acid is the most needed single constituent for the production of corn 

 on these lands; nitrogen coming next and being very essential, while 

 potash is of but little importance. It is likely not possible with 

 present results to say just what is the best proportion of these con- 

 stituents for most profitable returns, but it is certain that the fer- 

 tilizer should carry a high percentage of phosphoric acid and nitro- 

 gen, and a low percentage of potash. Indications are that a mixture 

 containing 10 per cent available phosphoric acid, 5 per cent nitrogen 

 and 1| per cent potash will give close to if not the best returns. Six 

 per cent of nitrogen is not too much on lands which have been 

 grown continuously, or practically so, in cotton, corn and small 

 grain. Five per cent nitrogen is equal to 6.08 per cent ammonia. 

 This mixture can be used at the rate of 300 to 500 pounds per acre 

 with good returns and profits. Larger quantities can be used with 

 good results, but the profits, on basis of fertilizer used, will not be 

 proportionately so large. 



The nitrogen may be all derived from blood, tankage, cotton-seed 

 meal or similar products, or in part from one or all of these and in 

 part from nitrate of soda or sulphate or ammonia. Nitrate of soda 

 may be used as the entire source of nitrogen when divided into two 

 parts. 



Kainit, manure salt, sulphate or muriate of potash may furnish 

 the potash, and acid phosphate the phosphoric acid. 



Three hundred pounds of the above mixture would contain thirty 

 pounds of available phosphoric acid, 4^ pounds potash, and 15 pounds 

 nitrogen ; and 500 pounds would contain 50 pounds available phos- 

 phoric acid, 1\ pounds potash and 25 pounds nitrogen. The required 

 amounts of phosphoric acid in 300 and 500 pounds respectively of 

 this mixture would be supplied by 214.3 pounds and 357.1 pounds 

 of 14 per cent acid phosphate; the nitrogen by 115.4 pounds and 

 192.3 pounds of 13 per cent dried blood, and the potash by 22.5 

 pounds and 37.5 pounds of manure salt. Other materials or other 

 grades of these materials may be used, and it will not be difficult, 

 knowing just what they contain, to use such quantities of them 



