STREET O N INFERIOR AMMONIATES I N COMMERCIAL FERTILIZERS. Availability by: Alkaline permanganate method.
. ------
--
Pot experiment.
Sample NO.
......... ......... .......
Barley. 52 10
23 27 42.. 19 49......... 34
Millet. 70 49 0 39
Oats. 62 38 38 21
Organic. 43 37 32 15
Total. 46 37' 37 35
Pepsin method. 49 45 6 12
Without discussing the results and variations therein, it is sufficient t o observe t h a t both the permanganate and pepsin methods clearly agree as t o the superiority of sample 23, and are in accord with the results b y pot experiment. The writer has found it useful in interpreting availability figures secured b y laboratory methods t o determine the ratio between organic nitrogen and the organic matter present, in both crude stock and fertilizers. The testing of crude nitrogenous stock by field or pot experiments will, of course, show their availability when used alone or in dry mixed goods. Another factor is introduced when these materials are used in so termed wet mixed goods. The organic nitrogen is here subjected t o a sulphuric acid treatment and considerable heat is produced which, judging from analo,T with the results b y the Kjeldahl nitrogen process, cannot decrease the availability. It is impossible to duplicate the manufacturing process on a small scale in the laboratory, although the use of a fireless cooker after the addition of sulphuric acid has been suggested. To settle this interesting point i t will be necessary for the manufacturer t o work with parties who are so situated t h a t they can conduct availability experiments, a t least t o the extent of furnishing suitable quantities of authentic samples of the various questionable nitrogen-containing materials, before and after the sulphuric acid treatment. The writer clearly realizes t h a t both the methods outlined are empirical and far from perfect, but believes it nevertheless true t h a t by their use the majority of goods of unquestionable excellence as to nitrogen availability may be quickly and positively eliminated, leaving a relatively small number for more elaborate examination. VERMONTEXPERIMENT STATION. BURLINOTON, VERMOXT.
THE DETECTION OF INFERIOR AMMONIATES IN COMMERCIAL FERTILIZERS. By J O H N PHILLIPSSTREET. Received February 17, 1910.
It is a recognized fact t h a t the use of a filler in commercial fertilizers is often necessary and at times even desirable if a d r y and friable fertilizer is t o be obtained t h a t will not clog on drilling. When a filler is used for this purpose alone there is no legitimate objection to its use, provided t h a t the claimed com-
311
position of the fertilizer is maintained and provided t h a t the use of fillers does not encourage t o too great a degree the manufacture of low-grade mixed fertilizers, which are always a relatively expensive form of plant food for the farmer. In recent years, however, the subject of fillers has taken a different aspect. It has been found t h a t dried peat is a n admirable absorbent and that its use in a fertilizer generally assures excellent mechanical condition. Fortunately, or unfortunately, dried peat contains a considerable percentage of nitrogen, often Over 3 per cent., which repeated experiments have shown t o be exceedingly inert. The use of such a nitrogen-bearing filler in compounding mixed fertilizers has given the agricultural chemist much difficulty in interpreting his results, especially when b y the policy of the fertilizer control of his state he is expected to affix a commercial valuation to the mixture. N o one will argue t h a t dried peat should receive the same valuation as blood, high-grade tankage, fish, bone or cottonseed-meal. Accordingly, i t is incumbent upon the chemist to devise some method whereby ' this inferior form may be differentiated from those whose value is unquestioned. The manufacturers claim t h a t the amount of peat used seldom exceeds 200 or 300 Ibs. per ton. I n a high-grade fertilizer, guaranteeing 4 or 5 per cent. of ammonia, it is admitted t h a t the introduction of this relatively small amount of peat is without great practical significance. But in the case of the numerous class of fertilizers, carrying a guaranty of r per cent. ammonia, the problem is quite different, for here the peat nitrogen may easily make up one-half of the total nitrogen, a condition which I found in a t least one brand during m y last inspection. Various methods ha\-e been suggested for the detection of peat in mixtures, the microscope, the various permanganate of potash methods and the pentosan method of the writer. I n a dry-mixed fertilizer the microscope is of undoubted x-alue in the detection of peat, but where the ?vet-mixing process has been employed i t is far more reliable. The alkaline permanganate method of Jones has given excellent results in the hands of some chemists, but personally I have never been able to control conditions so as t o warrant uniform determinations made a t different times with this method. The neutral permanganate method suggested by the writer some years ago has given excellent results with raw materials, clearly distinguishing between high-grade and inferior ammoniates. When applied t o mixed fertilizers, however, th- details of manipulation hitherto given with the method fail to furnish a n y sharp line of demarcation between the good and the bad. The pentosan method, likewise suggested by myself, is too local in its application t o be of much practical value. I n states like my own, Connecticut, where immense
312
T H E JOGRN.4L OF IiVDUSTRIAL AND EiYGINEERING C H E M I S T R Y .
quantities of cottonseed meal are used either alone or in mixtures, the pentosan method is practically valueless. Convinced t h a t the neutral permanganate method was based on proper principles, I have been working recently t o determine whether certain modifications might not be introduced which would render i t a reliable, workable method. During our last inspection of fertilizers in ConnecIieut, i t was observed that the filtrate in the citrateinsoluble phosphoric acid determination was often very dark colored, sometimes almost opaque, ranging Xrom a reddish brown t o nearly black. This appearance suggested the presence of a humus-bearing material, and the number of all samples yielding these dark-colored filtrates were noted and later tested by the neutral permanganate method. T h e method used was as follows: Weigh on to a moistened 9 cm. S. & S. KO. 595 filter a quantity of , the fertilizer equivalent to approximately 45 mgs. of organic nitrogen and wash with water at room temperature t o about 2 0 0 cc. Transfer filter and contents to a 300 cc. low-form Griffin beaker, and digest with 1 2j cc. of I . 6 per cent., neutral potassium permanganate solution in a hot water bath for thirty minutes. Set the beaker down in the bath so t h a t the surrounding water shall be higher than the solution in the beaker, cover with a watch-glass, and stir twice a t intervals of ten minutes with a glass rod. A t the end of the digestion remove from bath, add IOO CC. of cold water, and filter through a heavy folded filter. Wash with cold water, small quantities a t a time, until the total filtrate amounts to 400 cc. When sufficiently dry t o handle, transfer filter and contents to a nitrogen flask and determine nitrogen by the Kjeldahl method. The nitrogen obtained, less the blanks from the two filters used, is the nitrogen not oxidized by the permanganate. , The only essential difference between this and the method earlier suggested by me, is the amount of material taken, a change of great importance, as will be shown later. As a preliminary test of the method, eight mixtures were prepared. These were all made in 50-gram portions, each containing I O grams of muriate of potash and varying amounts of organic nitrogenous material, each yielding, with the exception of No. 8, I . j o per cent. of nitrogen in the total mixture; acid phosphate was then added to each mixture t o make up a total of j o grams. The exact proportions of the ingredients follow, omitting the muriate of potash, which was I O grams in each : h-0. 1 KO. 2
5 5 in 5 SO. 3 30 o S o . 4 11 0 No. 5 8 5 X o . 6 20 0 No. 7 25 0 5 0 No. 8
grams dried blood, grams tankage, grams garbage tankage, grams cottonseed-meal, grams fish, grams ground bone. grams peat, grkm's peat, 8 g. blood,
3 4 . 5 grams acid phosphate, 2 9 . 5 grams acid phosphate.
10.0 grams acid phosphate. 29 .O grams acid phosphate.
31.5 grams 20 . O grams 15 . O grams 2 7 . 0 grams
acid phosphate. acid phosphate. acid phosphate. acid phosphate.
July, 1910
The following tabulation shows the availability figures obtained in the original raw materials and in the same materials after they were mixed with acid phosphate and muriate of potash : Availability. ---A____
I n original material.
. . . . . . . . . . . . . . . . . . . 95.6 ..................... 95.1 .............. 58 . 9 . . . . . . . . . . . . . . . 95 . 1 .................... 96.4 .................. 9 3 . 6 ......................... 42.8 .......... 89.1
Dried blood. Tankage.. Garbage tankage.. Cottonseed-meal. Dried fish.. Ground bone. Peat.. Dried blood and peat..
I n mixed fertilizer . 92.9 Y1.8 L -
15.1
92.9 90.0 92 . o 3 i ,1 86 . O
It will be observed that the method shows blood, tankage, cottonseed-meal, fish and bone to possess a higher degree of availability either a s determined in the original material or when mixed with acid phosphate and muriate of potash. On the other hand, garbage tankage shows a much lower availability, while peat shows about one-third the availability of any of the high-grade ammoniates. The differentiation is most marked, and I would have no hesitation in classing as doubtful a fertilizer showing less than 90 per cent. availability by this method, a n inferior one showing less than So per cent.; one showing less than 50 per cent. must be classed as made from very inferior ammoniates. The mixture of peat and blood was interesting. By error I introduced more blood in the mixture t h a n I intended, and the peat nitrogen only made up oneseventh of the total nitrogen ; but even this small amount of peat was sufficient to reduce the availability from 9 2 . 9 to 86 per cent., thus placing i t in what I should call the doubtful class. Let us now consider the practical application of this method. Seventeen samples of mixed fertilizers aroused our suspicion by the dark-colored citrate filtrates already referred to. These were all tested by the neutral permanganate method, using z grams material and 7 j and 4 j mg. of organic nitrogen respectively. The results are tabulated below : Availability of organic nitrogen. Total S
No,
.......
9 10 . . . . . . . 11.. . . . . . 12.. , , . , . 13... . . . . 14 15 . . . . . . .
.......
4.72 5.16 3.59 4.28 2.34 2.72 3.06
........ .... 2.72 ....... 2 . 1 4
15a..
l5b.. . . . . 16 . . . . . . . 17 18 19 20 21.. . . . . . 22 23 24 . . . . . . . 25 . . . . . . . 25a.. 256..
....... .......
.......
....... .......
2.20 2.95, 1.63 2.25 2.58 1 .14 1 .10 0.95
........
........
--
2 grams Organic N. materials 3.51 2.62 2.48 2 .os 2.04 1.84 1.62 1.10 2
.zn
1.62 1.60 1.56 1.48
1.47 1.41 1.26 1.02 0.86 0.50 0.54 0.43
i~ mg. org. nit.
81.6 81.2 80 .5 84.7 69.5 74.2 67 . 3 57 .o
80.2 84.7 84.1 90.0 80.0
83.2 54.T
....
.... 78.7 81.9 79.8 83.1 79.9 78.0 77.8 76.0 67.4 75 .O
....
....
75.6
I
69.5 71.7 70.1 69.1 70.5 64.0 i.5 .2 61,s 58.7 54.3 46.4 63.7
45 mg.
org. nit. 93.3 88.9 85 3 89.3 is 5 85.4 83.2 70.9 89 7 75 3 76 4 74.6 57.1 76 9 75.1 74 0 67.8 62.4 62.8 54.7 70.9
LI-0-Y -4-l-D BIZZELL O N
V-AILABILITY OF SOIL XITR0GE.V.
The results where 2 grams of material were used show insufficient differences in availability to make results conclusive. The range was from 6 j . 4 t o 9 0 . 0 , with a n a\-erage of So. 3. IVhere ij mg. of organic nitrogen were used striking differences were obtained, but, owing to the large amounts of material used, the permanganate was in excess (as shown by the colored filtrate) in only 4 out of 2 1 cases, thereby introducing a possible inaccuracy in the results. The range was from 5 4 , 3 to 84.j , with a n average of So. j . Where .+j mg. of organic nitrogen were used the results are \-cry satisfactory, only 2 of the 2 1 samples not showing the permanganate color in the filtrate. The range was from 6 2 . 4 to 93.3, with a n arerage of 7 8 ,I . Fortunately we know something of the history of certain of the samples which aids us materially in judging the value of the method. I n e\-er?- case where the presence of peat was suspected from the color of the citrate filtrate, the manufacturer was ad\-ised of our finding. In some cases the use of peat was frankly admitted, together with the amount used per box, in others the use of' peat denied and a satisfactory esplanation made. For instance, in S o s . 9 and I O the manufacturer denied the use of peat but admitted the use of 150 lbs. of dirt per box; our a\-ailabilit?- figures of 9 3 . 3 and 8 8 . 9 , respectively, confirm the correctness of his statement and show t h a t the color of the citrate filtrate, unsupported by other evidence. is not conclusiA-e as to the presence of peat. In S o . I j the manufacturer admits using 246-2.6 j per cent. nitrogen; the al-ailability figure is j 6 . 4 . I n S o . 1 5 the manufacturer admitted that he had used 312 lbs. of peat ( 2 . j per cent. nitrogen) per ton in one of the samples making up our composite, while in the other no peat, but high-grade blood, was used. The separate samples. S o s . I j t z and I j b , in the table, n-ere tested, and in one a n a\-ailability of 7 0 . 9 n-as obtained and in the other S g . 7 , thus confirming the manufacturer's statement and proving the value of the method. In S o . 2 5 , from the same manufacturer. a similar statement n-as made, 2 j ( z containing 2 0 0 lbs. peat ( 2 . 5 per cent. nitrogen) and 2511 no peat (the form of nitrogenous material used was not stated). in the In the peat portion the availability was j 4 other 70 9 : apparently in the latter some other relatil-ely inert form of nitrogen was used, assuming the manufacturer's statement t o be correct. By this method, setting the minimum availability a t So. 13 of these samples would be condemned and 6 passed, the last without exception being fertilizers in which the total nitrogen is high, and the watersoluble nitrogen also relatively hiuh. Three of these 9 we know to contain no peat. Twenty samples of tankage and three oi garbage
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tankage were also tested by this method. The availability of 18 samples of tankage ranged from 8 7 . 9 t o 9 4 . 0 , with a n average of 9 2 . 5 ; the other 2 tankages showed availabilities of S I 6 and 8 3 . 7 , which, together with their low percentage of phosphoric acid, suggested the presence of peat. The three garbage tankages showed availabilities of 47 5 , 48 o and51 I. -
AVAILABILITY O F SOIL NITROGEN I N RELATION TO THE BASICITY O F THE SOIL AND TO THE GROWTH O F LEGUMES. B y T LYTTLETON LYON AND
J\\lES
A
BIZZELL.
Received April 2 1 1910
I t is well known that the lack of lime compounds in the soil is a serious hindrance to the growth of alfalfa. The application of lime to the soil not only produces a larger growth but also a better color of the alfalfa plants. These differences may frequently be noticed to extend to the grass or to the weeds growing with the alfalfa. The beneficial effects of the lime are apparently shared by the yegetation associated with the legume. The yucstion as to the nature of the processes by which this improvement takes place naturally presents itself. The phenomena observed on our experiment plats were these: (I) The alfalfa grew better and had a better color on the limed soil. (2) The grass and weeds growing with the alfalfa were likewise better on the limed soil. (3) On two plats of land both of which were limed, but one of which was planted to timothy and the other to a mixture of alfalfa and timothy, the timothy made a better growth on the plat having the mixture. Analyses were made' of alfalfa from ten plats of land. One-half of each plat had been limed four years before a t the rate of 3,000 pounds of quicklime per acre. The indicated lime requirement of the top foot of soil as determined by Yeitch's method was 4,000 pounds per acre. I n every case the alfalfa from the limed portion of the plats contained a higher per cent of nitrogen. -411 samples of alfalfa were taken a t the same time, and represented as closely as possible the same stage of growth. Examination of the alfalfa roots showed the presence of tubercles in practically all cases. The difference in composi-' tion was, therefore, not due to the presence or abience of tubercles, which has been shown by Smith and Robinson1 to influence the nitrogen content of alfalfa. On these plats Erzgeron awLy1Us was a common weed, and this apparently shared the good or poor condition of the alfalfa. Samples of the weed were taken from the limed and unlimed portions of each plat. Sine of the ten plats produced plants with a higher nitrogen content on the limed soil. \Iichigdn Stdtiriii Bicll 224, pp 125-132.
