MANURES AND MANURING. the soui'fe ;iiid availability of the essential con- stituents of fertilizers, especially of the organic nitrogen, it is often desirable to purchase the unmixed materials, either for use separately or to be mixed on the farm as required. To use fertilizers to the best advantage it is necessary to take into consideration a variety of conditions, among the more important of which are the character of the fertilizer itself, the cliar- aeter of the soil and its previous manuring and cropping, the climate, and the crop to lie grown. In general, concentrated fertilizers prove most prohtable on: (1) soils in good physical condi- tion, i.e. well tilled and abundantly suiiplied with humus; and (2) high value crops, such as are grown in market-gardening. Different classes of farm crops vary in their fertilizer requirements. 24 MANURES AND MANURING. growing beets and mangels; soluble phospliates in abundance for the turnip; and potasli for po- tatoes, white and sweet. That is, while the fertiliz- ers should contain all three elements, individual crops, because of their peculiarities of growth, re- quire certain fertilizing constituents in greater relative amounts and in immediately available forms. Fruit trees are slow-growing plants and therefore do not need quick-acting fertilizers as a rule. Highly soluble manures, such as nitrate of soda, are likely to be washed out of the soil without being utilized. For this reason the use of nitrate of soda is not advised except where the growth of nursery stock is to be forced or where bearing trees exhibit a lack of luxuriance in foliage. The old and still common practice of fertilizing fruit trees everv few years with slow- COMPOSITION OF THE PrINCIP.AL COMMEnCI.^L FERTILIZING MATERIALS Xitropen Available phosphoric acid Insoluble phosphoric acid Total phosphoric acid Potash Chlorin 1. SupplviiiK iiitTOfji'ii; Per rent. 15.5 to 16 13 to 20.5 12 to U 10 to 11 11 to 12.5 5 to 6 7 to 9 6.5 to 7.5 6 to 6 Per cent. Per cent. Per cent. 3 to 5 1 to 2 11 to 14 6 to 8 1.5 to 2 1 to 1.6 26 to 28 13 to 16 33 to 35 26 to 32 16 to 20 32 to 36 17 to 18 20 to 25 22 to 29 15 to 17
- n.4 to23
Per cen t. 2 to 3 1 to 1.5 50 48 to 62 26 to 30 12 to 12.5 16 to 20 20 to 30 2 to 8 1 to 2 6 to 8 Per cent. 2. SujiplyiiiK' plioHplioric acid : South Cnniliiui rock phosphate. South Carolina rock super- phoHphat*' ((iisHolved South Carolina roek phosphate) Florida lanil rock phosjihate Flnrida. ttflihlt' nhcisnhate 26 to 28 Ito 3 33 to 35 26 to 32 Ito 4 32 to 30 Ito 2 15 to 17 16 to 20 2 to 3 12 to 15 Florida suprrphoHphate (dis- Bolvod Fhjrida phosphate) 14 to 16 Bonfblai'k superphosphate (dis- 15 to 17 5 to 8 6 to 9 13 to 15 2.5 to 4.5 1.5 to 2.5 2 to 3 Dissolved bone 3. Supplying potash : 45 to 48 Sulphate of potash (hiph grade) Sulphate t>r potash and mag- .Sto 1.5 1.5 to 2.5 .10 to .32 Svlvlnit 42 to 40 7 to 9 1 to 2 1 to 1.5 3 to 5 2 to 3 • In pood Tliomas slag at least 80 per cent, of the phosphoric acid should be soluble in amtnonium citrate, I.e. OTallable. j , ,. j + f'(>tton-bnll ashes contain about 10 per cent, of lime, unleashed wood ashes 30 to 35 per cent., and leached wood ftehes 35 to 40 per cent. ly decomposing manures, such as barnyard ma- nure, leather waste, horn refuse, wool waste, leaf mold, tobacco stems, etc.. is thus seen to have more or less of a scientific basis. Frequently, however, it is desirable to stinnilate the growth and fruitfulness of the trees, and for lliis pur- pose more active fertilizing materials tlian the above are neeiled. In selecting and mixing the latter the fact that fruits are potasli feeders should be taken into consideration. The fertilizer re(|Uiiements of small fruits are similar to those of orchard fruits, but, hcing as a rule more rapid growers, they can utilize to advantage heavier The cereals, maize excepted, and grasses are simi- lar in their hal)its of growth, and arc able to utilize comparatively insoluble forms of mineral plant food, Imt are muih benefited by nitrogen, especially nitrates, applied in time to carry them through the jieriod preceding maturity. It is for the latter reason that nitrogen has been termed the ruling or dominant element for this class of plants. Leguminous plants — clover, peas, beans, etc. — which are capable of acquiring nitrogen partly from the air, make liberal use of the min- eral constituents, especially ]w>tash and lime. Fertilizers for such plants should therefore con- tain an abundance of the mineral constituents applications of soluble fertilizing materials and only, potash being the dominant element. Root do not derive the same benefit as orchard fruits and tuber crops require an abundance of nil the from slowly decomposing manures, fertilizing const iluents in rc.Tilily available forms. It may be said that in general crops grown on Of the three classes of fertilizing constituents, soils poor in decaying vegetable matter (humus) the nitrogen is especially useful for the slow- are as a rule benefited by applications of nitrog-
