Tjie Bulletin.- 13 



SEED. 



The seed, being complemental of the lint, constitute from 60 to 

 72 per cent of the seed-cotton, and usually sell for»l-7 to 1-5 as much 

 per acre as the lint. 



Composition and Fertilizing Value. — The composition of cotton 

 seed will be intluenccd to a slight extent by variety, soil, season, etc. 

 The average results given in Table III, which are 2.95 per cent 

 nitrogen, 1.42 per cent phosphoric acid, and 1.19 per cent potash 

 on air-dry sample, will approximate very closely to their average 

 composition. ^Vhen using the values assigned to these constituents 

 in mixed fertilizers, the fertilizing value of cotton seed will be 

 $14.39^ per ton. This amount represents the value of reserve plant- 

 food materials of the soil that are removed from the farm in every ton 

 of seed sold. If seed are sold, then cotton-seed meal or some other 

 suitable nitrogenous fertilizing material should be returned to the 

 soil in order to maintain the supply of plant- food. A material high in 

 nitrogen is advised, because about 82 per cent of the value of cotton 

 seed is due to their content of nitrogen. However, the best way, be- 

 cause in most instances the cheapest, to return to the soil the equiva- 

 lent of nitrogen removed in the seed is by the growth of some legu- 

 minous crop, such as cowpeas, vetch, alfalfa, soy and velvet beans, 

 all the clovers, etc. When the whole plants or the vines only of these 

 legumes are returned to the soil, either directly or after their passage 

 through the bodies of animals, an average good crop will restore to 

 the soil as much or more nitrogen than was removed in the seed of 

 the previous cotton crop. The growth of vetch and bur-clover in 

 rotation wdth cotton following cotton or corn is treated at some 

 length in a Bulletin of the North Carolina Department of Agricul- 

 ture, issued during July, 1904. The mineral fertilizing constitu- 

 ents — phosphoric acid and potash- — in a ton of cotton seed are worth 

 $2.58, when valued according to the price paid for them in mixed 

 fertilizers during the past year. This amount of the mineral fertil- 

 izing constituents, of conrse, should be returned to the soil in some 

 suitable available form, if it is expected to maintain permanent 

 fertility. 



Oil. — The amount of oil present in cotton seed varies usually 

 from 16 to 23 per cent; its content being influenced by inherent 

 tendencies of the seed and environmental conditions to which the 

 plants are subjected' during growth. 



As a result of three years' field selection, we have caused the per- 

 centage of oil in seed from different stalks of the same variety gro\vn 

 in the same field to vary as much as 4 per cent. It has been pretty 

 definitely settled — certainly for the variety studied- — that increasing 

 the oil-content of the seed is accompanied by an increase in the ten- 

 sile strength of its individual fibers without decreasing the per cent 

 of lint to the seed. 



