1226 



FERTILIZERS 



FERTILIZERS 



gen, a fair amount of available phosphate, and high 

 percentages of potash. In the case of sugar-beets, if 

 grown for their sugar-content, the proper relationship 

 of these fertilizer ingredients to one another is of great 

 importance. 



Cabbage, kale, cauliflower, brussels sprouts, turnips and 

 kohlrabi. 



These crops are all remarkably helped by hming on 

 soils which are fairly acid. Liming, especially with 

 caustic or slaked lime, has a tendency to lessen the 

 development on these plants and on turnips, of the 

 disease known as "club-foot" and "finger-and-toe." 



What has been said of the action of the soda of the 

 nitrate of soda, in connection with beets, is true also 

 to a considerable degree of these crops; nevertheless, 

 when the period of growth is long and the soil is either 

 a heavy silt or clay, or exceptionally open and sub- 

 ject to leaching, a combination of several sources of 

 nitrogen in the fertilizer, is usually preferable. The 

 reference to heavy silt and clay soils is made in con- 

 sideration of the fact that sodium carbonate is left as a 

 residual product after the plant has taken up the nitric 

 acid of the nitrate of soda; and this sodium carbonate 

 tends to defiocculate such soils and make them stiffer 

 and more difficult to work than before. 



Heavy applications of nitrogen are required for all 

 these crops and some of them, as shown at Rothamsted 

 and elsewhere, are more dependent than beets upon 

 generous supplies of soluble and available phosphoric 

 acid. These plants require also large quantities of 

 potash. 



The Swedish turnip, or rutabaga, usually responds to 

 liming rather more than the flat turnip, although lime 

 is often very helpful to the latter. 



Several of these plants are especially dependent for 

 their quality on rapid growth; hence, the nitrogen 

 and phosphoric acid must be derived, to a large extent, 

 from readily available materials. 



One or two experimenters in this country who have 

 grown turnips in pots and boxes claim to have found 

 that the turnip can utilize rather unavailable forms 

 of phosphoric acid, yet these results need further sub- 

 stantiation in the field before their final acceptance, 

 and in the light of the past field evidence, generous 

 fertilizing with soluble phosphates appears to be desir- 

 able. These plants, like the group described previously, 

 respond to liberal amounts of potash salts, yet these 

 salts seldom give very satisfactory results unless they 

 are used in conjunction with liberal amounts of super- 

 phosphate and nitrogenous fertilizers. 



Carrots and chicory. 



The carrot is less likely to show benefit from liming 

 than most root crops, and chicory is even subject to 

 injury by hme when carrots are slightly benefited. 

 Owing to their long period of growth the nitrogen 

 supply for these plants should not only include small 

 amounts of nitrates and ammonium salts, but also 

 soluble and insoluble organic nitrogen, in order that 

 some of the nitrogen may be continually at the dis- 

 posal of the plant throughout the growing season. 

 These plants are dependent upon reasonable supplies 

 of phosphatic maniu'cs, and generous amounts of potash 

 are likewise highly essential. The carrot responds in 

 a less degree than mangels, to applications of soda. 



Spinach, lettuce, endive and cress. 



These plants are all likely to be greatly benefited by 

 liming, even on soils of moderate acidity. Because of 

 the fact that the quality and market value of these 

 plants depends upon their making a rapid growth, 

 large amounts of immediately available plant-food 

 are essential. Some of the nitrogen should be present 

 in the fertilizer in nitrates, some in ammonium salts 

 and some in quickly available organic forms. No 



attempt should be made to economize unduly in the 

 use of readily available phosphates and potash salts, 

 for the reason that these crops must have ample sup- 

 plies of both. The growth of early lettuce, and of 

 spring spinach in particular, may often be pushed 

 forward with remarkable rapidity in the early spring 

 by the use of fertilizers containing generous amounts 

 of nitrates. In fact, these crops may be brought to 

 maturity by such means much faster than b}' the sole 

 employment of farmyard manure, especially if the 

 manure is poor in nitrogen and not thoroughly rotted. 



Onions. 



The onion wi\l not thrive and mature properly on 

 highly acid soils which are extremely deficient in car- 

 bonate of lime. It is often possible, where fairly good 

 crops can still be grown without the use of lime, 

 nevertheless to hasten the maturity of the onion crop 

 from ten days to three weeks, by its employment. A 

 lack of lime is often one of the causes of thick necka 

 and of failure to ripen properly. 



Since the onion crop is planted very early in the 

 season, and because of the consequent opportunities 

 for the loss of nitrogen if too large a part of it is 

 applied in nitrates, appropriate proportions of nitrogen 

 in ammonium salts and in suitable organic forms 

 should also be emjiloyed in order to insure an adequate 

 supply as needed. 



Generous amounts of potash are required by these 

 crops and it is of vital importance to use for the onion 

 a large amount of superphosphate, because of the fact 

 that it, like lime, hastens the maturity and the proper 

 ripening of the crop. It is also equally important not to 

 use such a large amount of nitrogen as to make it 

 out of balance with the potash, and in particular with 

 the phosphoric acid, for if this is done growth will be 

 unduly prolonged, the onions will have thick necks, 

 and they will not ripen satisfactorily nor quickly. 



Potatoes. 



Fertilizers for potatoes must be very different 

 according to the section of the country in which they 

 are grown. For example, in the North, where the sea- 

 son is short, the nights cold, and where the crop must 

 be hurried along to the utmost, unusually large pro- 

 portions of nitrates and of ammonium salts are indis- 

 pensable, whereas in warmer regions, organic sources of 

 nitrogen may be employed more largely, or perhaps in 

 some favorable cases, they may be used exclusively. 

 The potato crop is in need of quite large quantities 

 of nitrogen, ranging usually from forty to ninety pounds 

 an acre. 



The percentages of potash required in potato fer- 

 tilizers should be adjusted more particularly with 

 reference to the locality, and whereas in many of the 

 potato regions of New England 200 pounds of potash 

 (equivalent to 400 pounds of muriate of potash) are 

 considered necessary for each acre, the quantity could 

 be reduced to one-half or even less in certain portions 

 of the Middle West, or it might perhaps in some excep- 

 tional cases be omitted altogether. 



For several reasons it is important to insure high 

 percentages of soluble and available phosphoric acid 

 in potato fertilizers, since it often becomes the Umiting 

 factor in potato-production over large areas of the 

 United States. 



The effect of the fertilizers may be somewhat nulli- 

 fied or intensified, according to the choice of seed. In 

 all cases, seed which has heated or which has been 

 exposed to frost, should be avoided. It has also been 

 shown at the Agricultural Experiment Station in Rhode 

 Island that, if other things are equal, seed tubers which 

 are rich in nitrogen will usually give larger crops than 

 those in which the nitrogen-content is low. The advan- 

 tage of the high nitrogen-content of the tuber becomes 

 magnified in case they are sprouted once or twice 



