46 V.-On t h e AppZicatiorL of &-on SiilplintP i n Agricultiwe, and its V ~ Z L L ! as a PLtrLt-Jlbod. By DR. A. B. GRIFFITHS, Lecturer on Chemistry and Physics, Technical College, Manchester, &c. IN tliis paper, details are given of some of my most recent work on the use of ferrous sulphate as a manure. This year, I have grown legumii~ous, root, and cereal crops with and without an iron manure. The experimental plots of land were (as in the experiments last year) in the vicinity of Bromsgrove, Worcestershire. The soil consists chiefly of clay and loam derived from the Lias, or the upper members of the New Red Sandstone formations, and in a former paper, “Expei.imenta1 Investigations on the Value of Iron Sulphate as a Manure f o r Certain Crops,” (this Journal, Trans., 1884, p.71), analyses of this soil are given. This year, six plots of well-drained land were chosen all about the same area. On plots Nos. I and 11, the experiments performed last year on a leguminous crop (beans) were repeated. Plot No. I was manured with crystallised ferrous sulphate of commerce (the quantity applied being 4 cwt. to the acre). Plot No. I1 was left in its normal condition. As in former experiments, the same number of bean seeds were planted on the same day, on each plot of land. At the end of the season the yield of each plot of land was as follows :- TABLE I. ~~ Plot of land (manured with FeSO,). Plot, of land (normal). Total weight of crop (grain + straw) .. .. .. .. .. .. 1 6215 lbs. 1 5325 lbs. I 4793 Ibs. (2.) Weight whcm dry. 4105 lbs. The crop of beans (Vicia faha) grown by the aid of the iron manure ~iclded 44 bushels of grain, whilst the crop grown without the iron manure yielded only 28 bushels, so again there is a marked difference iu the weight of the produce of the two plots of land.Last year (loc. cit.), the iron manure gave an increase of 21 bushels of beans, and now there is an increase of 16 bushels.GRIFFITHS ON THE APPLICATION OF IRQN SULPHATE. ETC . 47 TABLE II.-Awlyses of Ashes of E n t i r e Plants . 4 -910 17 -965 18 -021 5 *999 8 -002 1 -734 40 *831 1 *162 1.376 100 000 ..... Iron oxide. Fe.03.. .............. Potash. K20 .................... Soda. Na. 0 .................... Lime. CaO .................... Magnesia. MgO ................ Silica. SiO. ....................Phosphoric oxide. P,O. .......... Sulphuric oxide. SO, ............ Sodium chloride ................ 1 *002 20 -984 18 ‘213 7 e125 8 -839 2 *836 37 *814 1 -396 1.790 99 -999 .-. Plants grown with iron manure . W i t h iron manure . Plants grown without iron manure . Without iron manure . ...-...... .... I... ~~~~ TABLE 111.-Analyses ?[ Ashes of Pods ~ niitus the Seeds . Iron ocide.Fe20. ................ Potash. K,O .................... Soda. Na. 0 .................... Lime. CaO .................... Magnesia. MgO ................ Silica. SiO. .................... Phosphoric oxide. P.O. .......... Sulphuric oxide. SO. ............ Chlorine ...................... 1 Grown with iron 1 manure . 2 -094 40 999 2 -986 7 ‘001 7 *142 0 *552 36.235 2 *582 0 -407 Grown without iron manure . 0 *924 42 *332 3 -715 6 -548 7 ‘231 0 -525 34 *400 3 -442 0 -883 I loo *Ooo 1 99.998 TABLE TV.-Analyses of Aslies of the Seeds ........ Iron oxide, Fe203 .............. Potash, K20 .................... Soda, Na, 0 .................... Lime, CaO .................... Magnesia, MgO ................ Silica, SiOz .................... Phosphoric oxide, P.O. .......... Sulphuric oxide, SO3 ............ Chlorine ........ , ..... , ....... 0 -575 42 *502 1 -362 4 *783 7 -111 0 ‘800 38 -799 2 a546 1 *511 0 ‘574 42 *498 1 -365 4 -779 7 *124 0 *810 38 ‘800 2 *531 1 *519 99.989 1 100-00048 GRIFFITHS ON THE APPLICATION OF 1883. 4 -221 1 .063 3.158 41 -902 37 *941 3-961 With iron Without manure. iron manure. The analyses were performed in duplicate.From the tables (pp. 46, 47)’ it will be seen that the crop of beans was greatly increased by manuring the land with iron sulphate ; in fact as much as 1422 lbs. when gathered, and 1220 lbs. when dry, also with an increase of 16 bushels of grain. Comparing them with the results obtained last year, the analyses of the ashes of the various parts of the plant agree very remarkably. Last year an increase of 1573 !bs. was obtained with the iron manure when the crop was gathered, and 13951bs. when dry, and an increase of 21 bushels of grain over the crops grown without the iron manure. From last year’s analyses and in those given in the present paper, it will be seen that the percentage of ferric oxide in the ashes of the various parts of the plant is much larger when the plants have been grown with ferrous sulphate than without it ; and also that the phosphoric oxide in the ash increases as the ferric oxide increases.I n Table IV, which is theresult of the analyses of the ashes of the seeds, it is plain that there is no difference whether the crop is grown with or with- out an iron manure. Thus confirming for a second time on a large scale that the ash of the seed or embryo of a plant is very constant in its composition whatever manure is appiied to the land. The next two tables illustrate the percentage of Ir’e,O, and P,O, in the ashes of the two seasons’ crops. 1884. ?Fithout Difference. manure. iron manure. ___-------___,--_______ 4.910 1 ‘008 3 ‘908 40.831 37.814 3 -017 I With iron Fe,O,. P,O, . 1883. With iron 1 Without manure.iron manure. Difference* 0.911 1.110 1.821 Fe,O3. 2.021 1884. With iron Without manure. iron manure. -- ---- 2.094 0.924 1-170 36.235 34.400 1-835 TABLE VI.-Fods minus Seeds.IRON SULPHATE IN BGRICULTL’RE. 49 From the above, i t is evident that there is an increase of about 3 per cent. of ferric oxide and phosphoric oxide in the ashes of the entire plant, when grown iu a soil containing an iron manure ; and an increase of about 1 per cent. of ferric oxide, and nearly 2 per cent. of phosphoric oxide in the ashes of the pods. I am fully convinced that the proposition I advocated nearly two years ago (Chem. News, 47, 27), that a “fairly large proportion of soluble irorL in a soil i s favourable to the growth of plants deaeloping n large amoicnt of clilorophyll,” is a proved fact; and this has been con- firmed by all my subsequent researches, and by the recent determina- tiom of chlorophyll which Dr.W. J. Russell has performed on plants grown with and without an iron manure. I shall refer again t o Dr. Russell’s experiments in the latter part of this paper. Cereal Crops. The next crop to be considered is the cereal. As in the experi- ments with beans, these wheat crops were grown on well-drained land and under like conditions as to sunshine and rainfall. Of two plots each of the same area, one was manured with iron sulphate (+ cwt. to the acre) and the other was left in a normal condition. At the end of the season, the yield of each plot was as follows :- TABLE VII. Plot of land manured with FeS04. Plot of land (normal).Total weight of crop (grain + straw) ,. ,. .. .. .. .. 5021 lbs. 1 4301 lbs. I 5030 lbs. 1 4360 Ibs. The crop of wheat grown by the aid of the iron manure yielded 28 bushels of grain, whilst the crop grown without the aid of the iron manure yielded 27 bushels of grain. From these investigations, an iron manure does not appear t o be of so great a value as a plant-food in the case of the cereal as in the leguminous crop; for the yield is much the same whether an iron manure is used or not. But there is one well ascertained fact in favour of the use of ferrous sulphate for wheat crops, and that is, t h e plants VOL. XLVII. E50 GRIFFITHS ON THE APPLICATION OF Grown with iron manure. were healthier and completely resisted the attack of the wheat mildew (“rust ”) : whilst the other crop not manured with iron was attacked to a certain extent; and this may account for the increase of 1 bushel of grain over the crop grown on the normal plot of land.As in the experiments with the leguminous crop, analyses (in duplicate) of the ashes of the various parts of the plants of each plot of land were made with the following results :- Grown without iron manure. TABLE VIIL-Analyses of Ashes of E’ntire Plant. - 2 *ooo 12 ‘561 2 ’4q10 3 -710 5 -334 64 -724 4.524 4 ‘222 0 ”514 99.999 ------ Iron oxide, Fe,O, ............... Potash, K20,. .................. Hoda, Na,O .................... Lime, Ca.0 .................... Magnesia, MgO ................ Silica., SiO, .................... Pho.sphoric oxide, P,O, .......... Sulpliuric oxide, SO, ............Chlorine ...................... I-----I---- ------ 2’521 12 ‘024 2.135 3 *634 5 -412 64 -846 4 *424 4 *511 0 -493 100 ‘ GOO TABLE 1X.-Analyses of Ashes of Seeds. ~~ ~ I Grown with iron manure . I Grown without iron manure. Iron oxide, Fe,O, ............... Sods, Na,O .................... Lime, CaO ..................... Magnesia, MgO ................ Silica, SiO, .................... Phosphoric oxide, P,05 .......... Sulphuric oxide, SO, ............ Chlorine ..................... Potash, K,O ................... 1.142 31.024 2 ’504 10.503 3 *676 1 *937 46 .d%d 1,300 0 *cis2 100~000 ---- 1 *124 32.392 2 *497 10 *668 1 964 45.269 1 *294 1.007 3.784 99.999 The Zeaves of the wheat gave 3.814 per cent. of ferric oxide when the crop had been grown with iron, and only 1.642 per cent.when not so treated. The ash analyses in the case of the entire wheat plant show that there is an increase of about per cent. of ferric oxide in the plants manured with iron; but this is all that can be said, and the phos- phoric oxide is increased by nearly 1 per cent.IRON SULPIIATE IN AGRICULTURE. Plot of land manured with FeSO,. -__---__ 51 ------- Ivon ox7..de, Fe20, .............. Potash, K20.. .................. Soda, Na,O .................... Lime, CaO .................... Silica, SiO, .................... Phosphoric oside, P20, .......... Sulphuric oxide, SO2 ............ Magnesia, M go ................ Chlorine.. ..................... Root Crops. A8 before, two plots of land were chosen; one was manured with iron sulphabe (4 cwt.to the acre) and the other was left normal. On these two plots of land, turnips were grown ; the yield of each plot was as follows :- TABLE X. -. Total weight of crop (root + leaves) ............ 50,104 lbs. Plot of land normal. ----__.- Weight; when gathered. 44,216 lbs. The plot of land manured with ferrous sulphate gave 164 tons, whilst the plot of land in its normal state gave only 13 tons of turnip roots. It is evident that there is a great increase in the produce by manuring the land with iron sulphate. The next two tables give the analyses of the ashes of this root- crop. TABLE XI.-Analyses of Ashes of Turnip Roots. Grown with iron manure. --- 1 '210 43 *a43 3 *862 12 968 1 .goo 0 *816 1'7 -910 5.010 3 '487 Grown without iron manure.---- 0.321 50 *124 3 -621 13 '024 2 .ooo 1.215 16 412 G .954 6 328 The analyses in XI and XI1 (which were done in duplicate) show that there is an increase of nearly four times the amouut of frrric oxide in the turnip roots grown with the iron manure over those grown without it ; and in the turnip leaves there is more than three times the per- E 2GR'IFFITHS ON THE APPLICATION OF Grown with iron manure. -_- ----- ------ Grain ........................ 4 -920 Straw ........................ 2 *188 centage of ferric oxide in the ashes of the crop grown with iron as compared with that grown without iron. Grown without iron manure. -- 4,869 1.198 TABLE XI.-Analyses of Ash of Turnip Leaves. Grain ........................ Chaff'. ......................... Straw.......................... ----- ----- ------- ] ~ o n ozide, Fe20, .............. Potash, K20 ................... Sods, Na,O .................... Limz, CaO ................... Silica, SiO, .................... Phosphoric oxide, P20, .......... Chlorine.. ..................... Magnesia, MgO ................ Sulphuric oxide, SO3 ............ 1 899 0 *820 0 -674 3.393 --- Grown with iron manure. 3 -202 26.124 6.210 34.452 2 *541 1 -462 6 *943 13 *910 5 -154 99 -998 Grown without iron manure. -_I_-- 0 *986 27 -921 7.024 35 *G20 4.199 2 .I34 4.218 11 *999 5.898 99 *999 Nitrogen in the Crops. The next set of three tables gives my determinations of the per- centage of n i t r o g e n i n each crop. TABLE XIII.--ni'itrogen in Beans (Vicia faba). TABLE XIV.-Nitrogen ii~ Wheat (Trit'icum vulgare). Grown with iron manure.Grown without iron manure. 1.802 0.821 0.363 2.9S6IRON SULPHATE IX AGRICULTURE. 33 Grown with iron manure. TABLE XV.--Nitrogert i n Turnips (Brassica rapa). Grown zoithout iron manure. Root .......................... Leaf .......................... ---______---- I---I---- - 2.189 2 *181 4 280 8.265 6 . 4 9 6.416 ---- __--______--...--I Soluble carbohydrates.. \h'oodyfibre ........ ,. Fat.. ................ I have also estimated the percentage of soluble carbohydrates (soluble in dilute acids), woody fibre (insoluble in dilute acids), and fat. Table XVI details the results. Plants grown withozct iron manure. Beans. 1 2:;. Wheat. Ez:: Turnip. ______ ~ .......... 49 -32 38 *24 66.21 31 *95 6.29 '7.93 33.67 1 2-98 43.69 1 45 1.32 ~ 1.48 0.32 1.65 1 TABLE XVI.Plants grown with iron manure. I-- /--I-- I--I--- ------ Soluble carbohydrates.. 55 -81 I Woody fibre.. ........ 10.21 Fat.. .............. 2.94 I 1.82 0.81 The above table shows that the carbohydrates, woody fibre, and t'at are all more or less increased when the plants have been grown by the aid of ferrous sulphate. The next table gives the determinations by Dr. W. J. Russell of the d u t i v e amounts of c h l o r o p h y l l in samples of t,he leaves from each of my crops. He has kindly determined the relative amounts in equal weights and in eqrial areas of each sample, with the following re- sults :-54 GRIFFITHS ON THE APPLICATION OF TABLE XVIL-Dr. Russell’s Estimation of the Relative Amount Of Chlorophyll in the Leaves.No. of Sample. 1 ........ 2 ........ 1 ........ 2 ........ 1 ........ 2 ........ Leaves. Beans (grown with FeSO,) ........ Beans ( .. withoict FeSO,) ..... Turnip ( .. without FeSO,).. ... Wheat ( .. with .. ).. . . . Turnip (grown with FeSO,) ....... Wheat ( .. without .. ). .... I n equal areas. -- 100 79 59 4Q 115 100 I n equal weights. 100 76 61 39 ’72 81 - The leaves were collected on the same day, and were of the same age in each case. From the above determinations, it is evident that iron nourishes the chlorophyll granules, a proposition I advanced some few years ago. From Dr. Russell’s analyses, it will be seen that in each plant-with the exception of wheat-when the plants have been grown with an iron manure, the chlorophyll in “ equal areas ” and in “ equal weights ” has been greatly increased.And now comes the question, what has increased the chlorophyll ? The iron, because it nourishes the granules, and always is to be found near to the granules themselves in the crystallised condit>ion when sections of the leaves are examined microscopically. (See my paper, Cjienz. SOC. J., Trans., 1883, p. 195.) General Conclusions. My enquiries on this subject have led me to the following con- clusions as to the effect of ferrous sulphate as a plant-food :- I. I n the case of those plants which develop a large amount of chlorophyll, for examples, beans, cabbages, and turnips, an iron manure is most beneficial, considerably increasing the harvest. (See the present paper and Trans., 1884, pp. 71-75 ; Chenz.News, 47, 27 11. An iron manure greatly increases the percentage of soluble carbohydrates, woody fibre, and fat in certain plants, this, of course, being an outcome of the increase in the amount of chlorophyll in the leaf; for the chlorophyll forms starch, which is converted into “ carbohydrates,” cellulose, &c. 111. I have found monoclinic crystals of ferrous sulphate near t o the chlorophyll granules when sections of the leaves are examined under the highest powers of the ~nicroscope, the crystals being tested chemically and proved to be ferrous sulphate. (See Trans., 1883, pp. 125-197 ; also Journal Royal Microscopical Society, 1883, p. 536.) -78.) (See the present paper.)IRON SULPHATE IN AGRICULTURE. 55 IV. That in certain cases the phosphoric oxide in the ashes of plants grown with this new manure increases as the ferric oxide increases.(See present paper ; also Trans., 1884, pp. 71-75 ; Chem. News, 47, 27-28.) V. That ferrous sulphate is a good plant-food, proved by the increase in the harvest as shown above; yet in excess it acts as a poison to plant-life, a solution containing 3 per cent. of FeSOI being fatal to most plants; and when the amount of ferric oaide in the ash of all the plants examined was 10yer cent. the plant previously died. (See Chem. News, 50, 167; Chemiker-Zeitung, 1884, p. 757; and Chem. News, 50, 193,) VI. The sulphur of the ferrous sulphate acts as a, food for the protoplasm of the cell, and the iron for the chlorophyll itself. (See (:hem. News, 49, 237, 265; 50, 32 ; also Chefiaiker-Zeitung, 1884, 1). 863 ; this Journal, Abstr., 1884, p. 848.) VII. The nitrogen in the plants grown with ferrous sulphate is to some extent increased. VIII. Iron sulphate increases the amount of chlorophyll in the leaf. (See Dr. Russell’s estimations in present paper.) IX Iron sulphate acts i n the soil as an antiseptic agent, destroy- ing t o some extent certbin parasitic diseases which attack our crops. (See Ohern. News, 49, 279 ; Abstr., 1884, p. 1070.) X. My experiments have also led me to conclude that the most active rays of white light for root-absorption are between Fraunhofer’s lines D and E. (See present paper.) (See Trans., 1884, pp. 74-75.) In conclusion, I wish to tender my best thanks to Dr. W. J. Russell, F.R.S., for his determinations of the relative amounts of chlorophyll in the plants. I also wish to thank Dr. T. L. Phipson, F.C.S., and my friends Mr. T. P. Wright, Dr. J. Johnstone, M. E. C. (jonrad, F.C.S., of Bordeaux, and Mr. E. L. Rhead (Demonstrator in Chemistry, Technical College, Manchester), for many kind sugges- tions.