THE UNIVERSITY OF ILLINOIS LIBRARY (o30.7 cop. CIRCULAT ICIRCUL Substitution of Commercial Fertilizers For Manure in Vegetable Production By J. W. LLOYD and E. P. LEWIS UNIVERSITY OF ILLINOIS AGRICULTURAL EXPERIMENT STATION BULLETIN 421 CONTENTS FACE PLAN OF EXPERIMENTS 579 RESULT OF EIGHT YEARS' EXPERIMENTS WITH VEGETABLES 583 High Spinach Yields Obtained With Manure Substitutes and Supplements 583 Lettuce Highly Responsive to Balanced Fertilizers 585 Nitrogen Increased Yield of Beets 588 Manure Alone Gave Uneconomical Increases With Peas... 590 Beans Varied Widely in Response to Different Fertilizer Treatments 593 Superphosphate Gave Most Economical Yield of Tomatoes 5% Phosphorus Important Fertilizer for Peppers 600 Superphosphate With Manure Gave Highest Yields of Carrots 603 All Treatments Gave Economical Increases With Cauliflower 604 Manure and Superphosphate Produced Highest Yields of Potatoes 606 Manure Supplements Proved of Value With All Ten Crops 608 SUMMARY.. . 610 Urban*, Illinois December, 1935 Publications in the Bulletin series report the results of investigations made by or sponsored by the Experiment Station Substitution of Commercial Fertilizers for Manure in Vegetable Production By J. W. LLOYD, Chief in Olericulture, and E. P. LEWIS, formerly Associate in Olericulture IN COOK COUNTY, Illinois, there is concentrated the most inten- sive vegetable production of the state. Approximately 1,800 of the 3,200 farms in this area produce vegetables for market. Such inten- sive culture requires soil of high fertility, which means constant and heavy applications of plant food. The material reported in this bulletin is the result of eight years of experimental work (1925-1932) with fertilizers for market-garden crops at the Cook County Experiment Station near Des Plaines, Illi- nois. The object of the experiments was to determine the response of various vegetables to different fertilizer treatments used as substi- tutes for and as supplements to animal manure. The results of the first five years' work were published in Bulletin 377 of this Station. The present publication brings together the results for the eight-year period, thus affording a more comprehensive basis for conclusions regarding the use of fertilizers for market-garden crops in northern Illinois. PLAN OF EXPERIMENTS Arrangement of Plantings The tests reported herein involved the use of seven acres of land divided into 96 plots. Two series of market-garden crops were planted. In Series I there were five early-maturing crops spinach, leaf lettuce, beets, peas, and beans. In Series II there were five late-maturing crops tomatoes, peppers, carrots, potatoes, and cauliflower. Each year, after the five early crops of Series I were removed, a cover crop of rye and vetch was seeded on the land. This was plowed under about May 1 of the next year, two weeks before the late crops of Series II were planted. The land occupied by the late crops was plowed in the fall without cover crops and was used early in the spring for planting the early crops. In this way, the two series were rotated and organic matter was supplied in alternate years. Excellent growth of cover crop was obtained every year. 579 580 BULLETIN No. 421 [December, Arrangement of Plots The 96 plots used for these experiments were laid out in 1925 in eight tiers, twelve plots in each tier (Fig. 1). A space 11 feet wide was left between the plots in a tier, and an alley 8 feet wide separated the different tiers. Each plot was 50 feet wide and 43.5 feet long, or essentially % acre. Five crops were planted across each plot, giving each crop on each plot an area 10 feet wide and 43.5 feet long, or % o acre. Plots 25 to 48 in each series of plantings were duplicates of Plots 1 to 24 in fertilizer treatment as well as in crops. Both series of plantings received exactly the same fertilizer treat- ments, the only difference between them being that on Series I the five early crops were planted, and on Series II the five late crops. The location of each series in 1925, 1927, 1929, and 1931 is shown in Fig. 1. In alternate years, the locations of the two series were inter- changed. The detailed planting of one plot in each series is shown in Fig. 2. In 1930, one-half of each series was discontinued and Plots 1 to 24 only were used until 1932. Thus the data in this report include duplicate plots for the first five years and single plots for the last three years. Treatment of Plots Sixteen different soil treatments and eight check plots receiving no treatment were included in each series of plantings. These treatments are indicated in the following outline. The quantities stated represent the rate of application per acre. Plot 1. Manure 20 tons (M) 2. Check 3. Manure 10 tons, 4-8-6 fertilizer* 500 Ibs. (M 4-8-6) 4. 4-8-6 fertilizer' 1,000 Ibs. (4-8-6) 5. Check 6. Manure 10 tons, 6-8-6 fertilizer' 500 Ibs. (M 6-8-6) 7. Limestone 3 tons (L) 8. Check 9. Nitrate of soda 200 Ibs., dried blood 300 Ibs. (N) 10. Nitrate of soda 200 Ibs., dried blood 300 Ibs., limestone 3 tons (N L) 11. Check 12. Dried blood 500 Ibs., bone meal 500 Ibs. (Bl Bo) 13. Manure 10 tons, bone meal 500 Ibs. (M Bo) 14. Check 'These fertilizers were home-mixed. In each case half the nitrogen was de- rived from nitrate of soda and half from dried blood. The phosphorus was supplied from superphosphate and the potassium from muriate of potash. 29J5] SUBSTITUTION OF COMMERCIAL FERTILIZERS FOR MANURE 581 (T Ul g to .01 .01- .01 .01-^ UJ h- I UJ (ft W1 z u. H UJ (O z 0. u UJ Ul UJ * CO Q. CO .01 -.01- -.01 .01 -.01 -.05- -X)S- I S3W3S d to a,. : 3 S 5t I S3IU3S 582 BULLETIN No. 421 [December, 15. Dried blood 500 Ibs., bone meal 500 Ibs., muriate of potash 200 Ibs. (Bl Bo K) 16. Manure 10 tons, bone meal 500 Ibs., muriate of potash 200 Ibs. (M Bo K) 17. Check 18. Superphosphate 800 lbs., m limestone 3 tons (sP L) 19. Superphosphate 800 Ibs.' (sP) 20. Check 21. Rock phosphate 2,000 Ibs. (rP) 22. Manure 10 tons, superphosphate 800 Ibs.* (M sP) 23. Check 24. Manure 10 tons, rock phosphate 2,000 Ibs. (M rP) Each of the materials mentioned above, except limestone, was applied annually. Limestone was applied in 1925, 1927, and 1930. Plot 1 received 20 tons of manure an acre, which is considered a normal application and is taken as the basic treatment. When manure was supplemented with some form of commercial fertilizer (Plots 3, 6, 13, 16, 22, and 24), 10 tons of manure an acre was applied. The pH, or relative acid content, of all plots and the relative available phosphorus content at the close of the 1932 season are shown in Table 1. Method of Interpreting Results For all crops except tomatoes and peppers, the yields were calcu- lated on the basis of actual yield of marketable produce. For tomatoes and for peppers the yields were corrected for a perfect stand if a plant or plants failed to grow following transplanting. The yields are expressed in all tables as pounds to the plot, which is an area of % 00 acre for each crop. The plot yields given are the averages of the plot yields for each treatment and the average yields of the untreated check plots for the eight-year period. In the accompany- ing tables are shown the average increase in yield of each treated plot over its adjoining untreated check, the "odds" calculated by Student's method* 5 to show the significance of the increase in yields, and the 'Plots 18, 19, and 22 each received 800 pounds of 16-percent superphosphate annually from 1925 to 1929 inclusive. The treatment was changed to 600 pounds of 20-percent superphosphate in 1930, 1931, and 1932. b For reference see: Student. The probable error of a mean. Biometrika 6, 1-25. 1908. Love, H. H. A modification of Student's table for use in interpreting ex- perimental results. Jour. Amer. Soc. Agron. 16, 68-73. 1924. Love, H. H., and Brunson, A. M. Student's method for interpreting paired experiments. Jour. Amer. Soc. Agron. 16, 60-68. 1924. 'Odds of more than 30 to 1 indicate that there is a real or significant difference. 1935] SUBSTITUTION OF COMMERCIAL FERTILIZERS FOR MANURE 583 TABLE 1. AVAILABLE PHOSPHORUS AND pH OF ALL PLOTS IN 1932" Series I Series II Plot pH Available phosphorus Plot pH Available phosphorus 1... 6.16 5.89 5.94 6.35 6.33 7.14 7.45 6.93 6.35 7.02 6.45 6.44 6.52 6.39 6.15 6.40 6.52 7.54 7.26 7.12 6.38 6.42 6.35 6.33 Ibs. per acre 75 75 100 100 100 150 100 100 75 75 75 100 75 75 150 200 75 75 200 100 300 200 100 200 1. . 6.63 6.76 6.80 6.43 7.18 7.54 7.75 7.26 6.49 6.58 6.42 6.08 6.45 6.82 6.95 7.26 7.37 7.33 7.25 7.40 6.73 6.15 5.94 6.42 Ibs. per acre 150 75 200 200 75 50 100 50 75 75 75 150 150 75 75 100 75 100 100 75 300 150 50 200 2 2 3 3 4... 4. 5 5 6 6 7 7 8 8 9 9 10 10 11 11. 12 12 13 13 14 14 15 15 16 16. 17 17 18 18 ... 19 19 20 20 21 21 22 22 23 23 .... 24 24 The relative available phosphorus was measured by the La Matte-Truog method. The pH was determined by the Quinhydrone electrode. The data in this table show the relative phosphorus and pH of the plots at the close of the experiment. value of the increase in yield due to fertilizer less the cost of fertiliz- ing material. The value of each crop was obtained by reducing the yield in pounds to the sales unit employed on the Chicago wholesale market for the given commodity, and multiplying by the estimated price per unit based on an eight-year average (1925-1932) for the period of the year during which the given home-grown product was normally marketed directlv from the field. RESULTS OF EIGHT YEARS' EXPERIMENTS WITH VEGETABLES High Spinach Yields Obtained With Manure Substitutes and Supplements That high yields of spinach may be obtained without the use of large quantities of manure is shown conclusively by results obtained during the eight-year period of experiments with manure, manure supplements, and manure substitutes (Fig. 3). Higher yields were obtained with 10 tons of manure supplemented with either complete fertilizer or with bone meal and potash than with 20 tons of manure 584 BULLETIN No. 421 [December, alone. The use of a complete fertilizer with no manure gave very high yields and was one of the most economical treatments. The 6-8-6 commercial fertilizer used as a supplement with 10 tons of manure gave slightly higher yields than the 4-8-6 treatment with the smaller proportion of nitrogen. When used as a supplement for one-half the FIG. 3. YIELDS OF SPINACH UNDER VARIOUS FERTILIZER TREATMENTS The use of a complete commercial fertilizer without manure (Plot 4) re- sulted in higher yields than the use of manure alone (Plot 1). Ten tons of manure supplemented by a 6-8-6 fertilizer (Plot 6) or by bone meal and potash (Plot 16) produced higher yields than 20 tons of manure (Plot 1). manure, superphosphate was more effective than either bone meal or rock phosphate. When no manure was used, complete fertilizers were needed for high spinach yields. Plot 4 treated with 4-8-6 and Plot 15 treated with blood, bone meal, and potash gave high yields, while Plots 9, 10, 19, and 21 treated with incomplete fertilizers gave relatively low yields (Table 2). When the single element nitrogen was applied without applications of phosphorus and potash, an overbalance of nitro- gen resulted, and the yields were low and uneconomical. When used in connection with other fertilizers, nitrogen was an important factor in increasing yields, blood and bone meal together giving higher yields than either nitrogen or phosphorus alone. The use of lime alone for spinach gave a very economical increase, but did not give yields com- parable to those obtained from the use of fertilizer mixtures or super- 79J5] SUBSTITUTION OF COMMERCIAL FERTILIZERS FOR MANURE 585 TABLE 2. SPINACH: YIELDS WHEN FERTILIZED WITH MANURE, MANURE PLUS SUPPLEMENTS, AND MANURE SUBSTITUTES (Average for eight years) Plot Treatment per acre Average yield per Moo acre Increase over adjoining check Odds Acre- value of increase less cost of fertilizer* 1 Manure 20 tons Ibs. 95.7 Ibs. 57.3 184:1 $246.80 3 Supplements Manure 10 tons 4-8-6 90.5 52.1 127: 230.97 6 Manure 10 tons 686 101.5 58.3 184: 259.93 24 22 13 Manure 10 tons rock phosphate.. . . Manure 10 tons superphosphate . . . Manure 10 tons bone meal 73.3 84.7 71.5 43.2 54.6 29.2 216: 184: 103: 180.20 243.31 115.60 16 4 Manure 10 tons, bone meal, potash . . Substitutes 4-8-6 100.7 97.7 61.9 54.5 70:1 184:1 273.68 253.54 9 Nitrogen 48.5 11.2 8:1 38.65 10 Nitrogen, limestone 51.5 11.0 8:1 35.05 12 Blood, bone meal 76.9 36.4 59:1 153.67 15 Blood, bone meal, potash . . 92 1 49.8 70:1 215.15 7 Li mestone 50.2 12.9 47:1 61.80 19 Superphosphate 64.7 19.7 713:1 88.71 21 Rock phosphate 53 8.0 14:1 24.40 18 Superphosphate, limestone 71.2 32.4 184:1 149.31 Average of check plots 39 4 The cost of each fertilizer treatment was based on the average price of each kind of fertilizer for the eight years 1925-1932. phosphates. Lime should be applied as a maintenance treatment when needed. Spinach is very sensitive to acidity, so that on acid soil the addition of limestone would be expected to give a good increase. The use of 200 pounds of potash in addition to dried blood and bone meal or manure and bone meal gave increases in yield of spinach which were both economical and significant. Plot 15 treated with dried blood, bone meal, and potash gave nearly 20 percent higher yields than Plot 12 treated with dried blood and bone meal, and Plot 16 treated with manure, bone meal, and potash gave 40 percent higher yields than Plot 13 treated with manure and bone meal (Table 2). When used alone as a substitute for manure on the spinach plots, superphosphate gave much better results than rock phosphate used in the same way. Rock phosphate has been shown to be much more available to vegetable crops when used in connection with manure than when used without manure. Limestone and superphosphate gave higher spinach yields than superphosphate alone. Lettuce Highly Responsive to Balanced Fertilizers Greater increases in yield of leaf lettuce than of any other crop in this experiment were obtained by the use of fertilizers. Where no 586 BULLETIN No. 421 [December, fertilizer was used, the plants were stunted and made very slow growth. This stunting usually became apparent about two weeks after the plants were up; from then on most of the fertilized plots rapidly gained over the check plots until, by the time of cutting, differences as great as 900 percent sometimes existed between adjoining plots. The yield of lettuce on Plot 1, receiving the basic treatment of 20 tons of manure, was higher than the yield on any of the six plots treated with 10 tons of manure supplemented with some form of commercial fertilizer, but the difference was in no case very great (Table 3). Thus the amount of manure may be reduced one-half and TABLE 3. LETTUCE: YIELDS WHEN FERTILIZED WITH MANURE, MANURE PLUS SUPPLEMENTS, AND MANURE SUBSTITUTES (Average for eight years) Plot Treatment per acre Average yield per Moo acre Increase over adjoining check Odds Acre- value of increase less cost of fertilizer 1 Manure 20 tons Ibs. 247.7 Ibs. 161 >9999:1 $161.40 3 Supplements Manure 10 tons 486 . 222 1 136.0 1428:1 140.57 6 Manure 10 tons 686 211.8 126.5 1249:1 126.43 24 22 13 Manure 10 tons rock phosphate Manure 10 tons superphosphate. . . . Manure 10 tons bone meal. 201.1 245.5 245 3 94.1 138.5 117.8 >9999:1 255:1 191:1 81.80 143.41 117.10 16 4 Manure 10 tons, bone meal, potash . . . Substitutes 4-8-6 234.8 223 9 123.3 138.6 832:1 369:1 118.18 154.44 9 Nitrogen 98.9 15.4 21:1 2.15 10 Nitrogen, limestone 102.9 3.5 1:1 15.75 12 Blood, bone meal 219.9 120.5 216:1 122.47 IS Blood, bone meal, potash 260.2 132.7 104:1 132.05 7 Limestone 94.3 10.9 14:1 10.60 19 Superphosphate 216 8 83.2 88:1 94.31 21 Rock phosphate 141.4 7.8 1:1 6.00 18 Superphosphate, limestone 221.5 110.0 587:1 124.81 Average of check plots 111 4 supplemented with commercial fertilizer without serious reduction in lettuce yield (Fig. 4). All seven of the fertilizer treatments which in- cluded manure gave highly significant odds over the untreated checks. Of the various supplements used with manure, superphosphate and bone meal gave the highest lettuce yields and superphosphate the most economical lettuce yields. The results show that 10 tons of manure applied annually supplied sufficient nitrogen and potash for the production of lettuce, and that more economical yields were obtained by supplementing the manure with superphosphate than by supple- menting with complete commercial fertilizers. When no manure was 79J5] SUBSTITUTION OF COMMERCIAL FERTILIZERS TOR MANURE 587 used, complete fertilizers produced higher lettuce yields than the single-element treatments, as shown in Table 3. Plots 4 and 15, which received no manure but which were treated with complete fertilizers, gave lettuce yields comparable to those on Plot 1. Nitrogen used alone gave the lowest lettuce yields of any of the treatments, indicating that on the black soil of the type used in these 300 250 Q 200 Q. 150 _l UJ 100 50 LETTUCE : CHECK TREATED PLOTS 1 2 34 56 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 id) m CO en u 2 2^ 5-J zz 52 ~- "~ 52 ^ Z 2 2 FIG. 4. YIELDS OF LETTUCE UNDER VARIOUS FERTILIZER TREATMENTS The highest yield was produced by Plot 15 which was treated with a com- plete fertilizer but no manure. tests, phosphorus is a more limiting factor than is nitrogen. However, when used with phosphorus, nitrogen was beneficial, as shown by the good yields obtained with blood and bone meal on Plot 12 (Table 3). The use of limestone for lettuce gave a slight increase in yield over the adjacent check plot, altho the increase was not significant. The adjacent checks were only very slightly acid so that little increase was to be expected. Lettuce is known to be sensitive to acidity, and on soils of high acidity this treatment would doubtless result in a much greater yield increase. Phosphorus used alone increased the yield of lettuce, but only the increase from the superphosphate was significant. That lettuce requires a balanced fertilizer, especially in regard to nitrogen and phosphorus, is shown conclusively by the results given in Table 3. When manure is not economical, complete fertilizers, such as the 4-8-6 ratio, may be used just as effectively, provided organic matter is supplied in the form of cover crops. 588 BULLETIN No. 421 [December, Nitrogen Increased Yield of Beets All sixteen treatments with beets over the eight-year period gave some increase in yield over the untreated checks. The fairly wide range in the increases resulting from the different treatments is shown in graphic form in Fig. 5. The beet yield on Plot 1, treated with 20 tons of manure an acre, and the yields of the six plots treated with 10 tons of manure sup- plemented with some form of commercial fertilizer show large in- creases over the untreated checks, with very significant odds (Table 4). The difference between treatments was not great, altho all plots 450 400 M Q 300 a. 3200 O 6? 100 BEETS PLOTS 1234567 TREATED BS! 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 !S 9: OL o o CD cD _J **"* *** *" "" /\ zz cos cos ;> - 2 2 CO ' 9999: 51.57 6 Manure 10 tons, 686 395. 141.7 >9999: 46.33 24 22 13 Manure 10 tons, rock phosphate Manure 10 tons, superphosphate. . . . Manure 10 tons, bone meal 329.8 343.4 340.8 111.5 125.1 91.4 2499: 832: 184: 25.40 39.31 20.20 16 4 Manure 10 tons, bone meal, potash . . . Substitutes 4-8-6 359.9 417.3 127.5 164.0 1666: >9999:1 34.28 66.04 9 Nitrogen 304.1 81.4 262:1 27.85 10 Nitrogen, limestone . . . 310.6 76.2 32:1 21.85 12 Blood, bone meal 334.0 99.6 1110:1 26.47 15 Blood, bone meal, potash 396.7 147.3 >9999: 45.95 7 Li mestone 275.2 52.5 1110: 25.80 19 Superphosphate 314.7 76.2 151: 32.31 21 Rock phosphate 259.8 21.3 8: - 3.80 18 Superphosphate, limestone 313.1 81.7 525: 32.31 234 8 addition to manure and bone meal, gave an increase of 19.1 pounds over Plot 13, which received manure and bone meal but no potash. Of the nine plots on which manure substitutes were used, only three Plots 4, 12, and 15 gave higher yields than the plot treated with 20 tons of manure (Table 4). The two plots (4 and 15) treated with complete fertilizers gave much higher yields than the plots re- ceiving incomplete treatment. Beets are heavy feeders and respond definitely to available fertilizer. Potash added to the blood-and-bone-meal treatment at the rate of 200 pounds of muriate of potash an acre gave an increase of 62.7 pounds in the yield of beets. Beets are known to be heavy feeders of potash, and the high tonnage of beets removed from an acre makes frequent replacement of potash necessary. A large amount of the potash removed from the soil is contained in the tops and can be re- turned to the soil if the tops are used as fertilizer. The tops, however, are usually left on the beets so that they can be bunched. Nitrogen used alone caused a significant increase over the beet yield of the adjoining check, and the increase was greater than for most of the other nine crops. However, it was not great enough nor economical enough to warrant the use of nitrogen in place of a com- plete fertilizer such as the 4-8-6 mixture used on Plot 4. 590 BULLETIN No. 421 [December, Limestone used alone (Plot 7) gave an increase in beet yield which was very economical owing to the low cost of this material. Beets are known to be fairly sensitive to acidity, so that on acid soils some increase would be expected from an application of limestone. Phosphorus used alone was not an effective fertilizer for beets under the conditions of this experiment. Altho increased yields fol- lowed applications of phosphorus, much higher yields were secured from well-balanced treatments. That beets require large amounts of fertilizer is evidenced by the fact that some response to all fertilizer treatments was obtained. This bears out the practical experience of many growers who claim that the drain on the soil from beets is readily noticed on the following crop unless considerable fertilizer is used to offset the loss. Complete fertilizers proved capable of replacing 20 tons of manure, but the use of incomplete fertilizers generally resulted in yields that were lower than those from the manure treatment. When a part of the manure was replaced by commercial fertilizers, higher yields re- sulted than when phosphorus was used as a supplement. Manure Alone Gave Uneconomical Increases With Peas The response of peas to fertilizer treatment was not so pro- nounced as was that of spinach and of lettuce, altho all treatments gave some increase in yield. Average plot yields from each treatment and the adjacent untreated check are represented graphically in Fig. 6. The use of manure alone was not an economical treatment for peas, according to the yields given in Table 5. When half the manure was supplemented with a complete commercial fertilizer or with phos- phorus, yields were increased. Of the various supplements used, super- phosphate gave the highest and most economical increase in yield. Peas do not respond to supplementary treatment with potash. In fact, the yields were reduced slightly when extra potash was used, as shown by a comparison of Plots 13 and 16. As a supplement to manure, superphosphate was more effective as a source of phosphorus than either raw rock or bone meal. The relative effectiveness of various commercial fertilizer appli- cations compared with the basic treatment of 20 tons of manure is shown in Table 5. Plots 4 and 15, receiving the two complete ferti- lizer treatments, were more productive than the manured plot, as were also the plots receiving superphosphate and those receiving blood and bone meal. In the absence of manure, superphosphate w r as much more effective and economical than raw rock phosphate as a source of 1935] SUBSTITUTION OF COMMERCIAL FERTILIZERS FOR MANURE 591 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 FIG. 6. YIELDS OF PEAS UNDER VARIOUS FERTILIZER TREATMENTS Yields from the use of manure supplemented by superphosphate (Plot 22), and from the use of dried blood and bone meal (Plot 12) were practically iden- tical, and were larger than any of the other yields. TABLE 5. PEAS: YIELDS WHEN FERTILIZED WITH MANURE, MANURE PLUS SUPPLEMENTS, AND MANURE SUBSTITUTES (Average for eight years) Plot Treatment per acre Average yield per Hoo acre Increase over adjoining check Odds Acre- value of increase less cost of fertilizer 1 Manure 20 tons Ibs. 40.7 Ibs. 5.4 88:1 $-23.00 3 Supplements Manure 10 tons, 4-8-6 44.6 9.3 184: - .43 6 Manure 10 tons, 6-8-6 41.5 8.8 21: - 3.67 24 22 13 Manure 10 tons, rock phosphate.. . . Manure 10 tons, superphosphate. . . Manure 10 tons, bone meal 42.5 48.0 43.9 15.7 21.2 10.4 103: 88: 70: 13.20 36.31 2.80 16 4 Manure 10 tons, bone meal, potash . . Substitutes 4-8-6 38.5 45.9 8.0 13.2 47: 302: -10.92 22.14 9 Nitrogen 36.4 6.4 127: 2.85 10 Nitrogen, limestone 36.2 3.1 6: 10.15 12 Blood, bone meal 47.8 14.7 587: 17.87 15 Blood, bone meal, potash 41.1 7.9 87: - 8.85 7 Limestone 33.1 3.1 14: 7.00 19 Superphosphate 42.5 14.1 713: 34.31 21 Rock phosphate 34.5 6.1 26: 3.20 18 Superphosphate, limestone 44.5 14.3 587: 32.31 A verage of check plots 31.2 592 BULLETIN No. 421 [December, TABLE 6. PEAS: EFFECT OF VARIOUS FERTILIZERS ON YIELD, EARLINESS, SIZE OF PODS, AND GREEN WEIGHT OF PLANTS Plot Treatment per acre Average yield of pods per Moo acre* Weight of pods at first harvest 1 " Weight per 100 pods c Green weight of plants per Moo acre* 1 Manure 20 tons Ibs. 42.0 Ibs. 14.69 gms. 502 Ibs. 38.7 3 Manure 10 tons, 48-6 44.2 17.18 551 46.1 4 4-8-6 44.5 19.09 497 45 7 6 Manure 10 tons, 686 40.2 16.99 460 41.9 7 Limestone 34.9 14.02 442 31.7 9 37.3 16.83 489 32.8 10 Nitrogen, limestone 37.8 15.66 493 32.8 12 50.1 21.36 543 48.8 13 41.9 25 26 502 43 4 15 39.4 20.68 500 41 5 16 Manure 10 tons, bone meal, potash 36.3 19.96 480 39.0 18 43.5 18.83 492 42 1 19 40.8 19.90 462 38.5 21 Rock phosphate 31.8 19.30 486 28.8 22 49.5 24.51 577 48 8 24 Manure 10 tons, rock phosphate 43.4 22.48 477 42.0 Average of check plots 31.2 14.47 479 28.8 Based on data for five years. b Based on data for eight years. c Based on data for one year. 170 160 PLOTS FIG. 7. CORRELATION OF WEIGHT OF PEA PODS WITH WEIGHT OF PLANTS Fertilizers that increased the yield of pods increased the growth of plants in about the same proportion. The broken line in the above graph represents the weight of pods and follows a trend very similar to that of the unbroken line representing the weight of plants. The weight of pods and of plants from the check plots were used as the base (100). 1935] SUBSTITUTION OF COMMERCIAL FERTILIZERS FOR MANURE 593 phosphorus for peas. The greatest returns from fertilizer without manure were from superphosphate alone. The use of 200 pounds of muriate of potash did not increase the yield of peas, as Plot 12 gave higher yields than Plot 15. Limestone gave an average increase of 10 percent in yield over the check, altho the odds of 14:1 are not significant. The effect of fertilizers upon the increased quality of pods was observed each year but measured in 1929 only. The pods from the plots which received optimum fertilizer treatment were larger and better filled. The weight per hundred pods from each plot in 1929 is shown in Table 6. The use of fertilizers increased the yields of early peas. All check plots produced much lower yields at the first picking than the plots receiving a complete fertilizer or receiving manure supplemented with fertilizer. Plots that received phosphorus in addition to manure pro- duced the highest yield at the first picking. The correlation between yield of pods and the green weight of plants grown under sixteen different soil treatments is shown in Fig. 7. This graph is based on data for the years 1926, 1927, 1930, 1931, and 1932. In the other three years the weight of the plants was not re- corded. The various fertilizers produced about the same relative in- crease in weight of vine growth as in weight of pods. There is no evidence in these data to support the theory that an abundance of nitrogen tends to promote excessive growth of vines and low yield of pods. The results for the eight-year period show that commercial ferti- lizers with cover crops are capable of producing yields of peas compa- rable to yields obtained under the manure treatment. The response of peas to available phosphorus is greater than to either nitrogen or potash. When some manure is used, superphosphate alone is sufficient as a supplement. Beans Varied Widely in Response to Different Fertilizer Treatments Results of fertilizer tests with beans over the eight-year period 1925-1932 show a wide range in response to various treatments. The average increase for each fertilized plot over the adjoining check is shown graphically in Fig. 8. Most of the treatments gave economical increases (Table 7). The yields on plots treated with 10 tons of manure supplemented with some form of commercial fertilizer differed only slightly from the yield on Plot 1 treated with 20 tons of manure (Table 7). Of the 594 BULLETIN No. 421 [December, various supplements used, bone meal and potash (Plot 16) gave the largest increase in yield over the adjoining check, but the lower cost of superphosphate as a supplement made the treatment given Plot 22 slightly more profitable. None of the plots receiving treatment without manure produced yields as high as the basic manure treatment, tho the yields on Plots PLOTS i 2 345 t. Q. Q. a z z m (Q Ea 2 CD (D m 5 ^ FIG. 8. YIELDS OF BEANS UNDER VARIOUS FERTILIZER TREATMENTS The yields from plots treated with 10 tons of manure supplemented with 4-8-6 fertilizer (Plot 3), bone meal (Plot 13), and superphosphate (Plot 22) were slightly greater than the yield from Plot 1 treated with 20 tons of manure. 4 and 15, treated with complete fertilizers, were only slightly lower. The increase in Plot 4 over the untreated checks was more economical than the increase from the manure treatment. The limestone plot showed a lower yield than the adjoining check and than the average of the checks. Beans are not sensitive to acid soils and unless very excessive acidity existed, little increase from lime could be expected. The use of nitrogen alone was not effective; the increase over the adjoining check was slight and the odds were not significant. More- over, the cost of treatment exceeded the value of the increase. The plot which received nitrogen and lime was not profitable. The use of 200 pounds of potash in addition to blood and bone meal (Plot 15) gave a slight increase in yield over the use of blood and bone meal alone (Plot 12). Phosphorus used alone, either raw rock or superphosphate, gave an economical yield increase, altho the yields were much lower than from more balanced treatments. SUBSTITUTION OF COMMERCIAL FERTILIZERS FOR MANURE 595 TABLE 7. BEANS: YIELDS WHEN FERTILIZED WITH MANURE, MANURE PLUS SUPPLEMENTS, AND MANURE SUBSTITUTES (Average for eight years) Plot Treatment per acre Average yield per Moo acre Increase over adjoining check Odds Acre- value of increase! less cost of fertilizer 1 Manure 20 tons Ibs. 32.5 Ibs. 10.7 384:1 S40 . 40 3 Supplements Manure 10 tons 486 34.2 12.4 713:1 63 57 6 29 7 8 6 69-1 33 13 24 Manure 10 tons rock phosphate 30.0 9.0 166: 32 00 22 13 Manure 10 tons superphosphate Manure 10 tons bone meal 33.8 33.5 12.8 11.2 384: 138: 66.31 53 80 16 Manure 10 tons bone meal, potash 33.0 13.5 1110: 65.48 4 Substitutes 4-8-6 30.5 9 4 57: 51 94 9 Nitrogen 20.4 .9 2: -10.55 10 Nitrogen, limestone 18.2 2.2 7: 36.95 12 Blood, bone meal 29.5 9.1 384: 40 27 15 Blood, bone meal, potash 30.1 7.8 28: 24.95 7 Limestone 19.0 .5 4: 6 60 19 Superphosphate 24.7 5.6 44: 32.31 21 22.8 3 7 44:1 11 80 18 Superphosphate, limestone 24.4 4.9 57:1 23.91 Average of check plots 20.6 200 FIG. 9. CORRELATION OF WEIGHT OF BEAN Poos WITH WEIGHT OF PLANTS Large yields of pods were associated with large plant growth. Using the weight of pods and of plants from the check plots as the base (100), the rela- tive weights of pods and of plants from the treated plots were as indicated. 5% BULLETIN No. 421 {December, When no manure is used, complete fertilizer treatments are neces- sary for high bean yields. When some manure is used, good yields may be secured from the use of either phosphorus or a complete fertilizer as a supplement. With beans, as with peas, fertilizers that increased the yield of pods increased the growth of plants in about the same proportion (Fig. 9). The optimum treatments increased the weight of pods at the first harvest. Superphosphate Gave Most Economical Yield of Tomatoes Response of tomatoes to fertilizer treatment was very pronounced, all but four treatments giving considerable increase in yield over the adjoining check plot (Fig. 10). 500 [ 10 11 13 14 15 16 17 18 19 20 21 22 2324 Fie. 10. YIELDS OF TOMATOES UNDER VARIOUS FERTILIZER TREATMENTS Plot 22 treated with 10 tons of manure supplemented with superphosphate produced the highest yield whether measured by yield of ripe fruit alone or of the ripe and green fruit combined. The yields on plots treated with 10 tons of manure supplemented with some form of commercial fertilizer did not differ significantly from the yield on Plot 1, treated with 20 tons of manure, so that the most economical of these treatments may be considered the best (Table 8). Plot 22, which received 10 tons of manure supplemented with superphosphate, gave the highest yield, the greatest increase, and most economical returns in this group. The average increase from this treatment was more than 104 percent. The results show 19351 SUBSTITUTION OF COMMERCIAL FERTILIZERS FOR MANURE 597 TABLE 8. TOMATOES: YIELDS WHEN FERTILIZED WITH MANURE, MANURE PLUS SUPPLEMENTS, AND MANURE SUBSTITUTES (Average for eight years) Plot Treatment per acre Average yield per Moo acre Increase over adjoining check Odds Acre- value of increase less cost of fertilizer 1 Manure 20 tons Ibs. 435.3 Ibs. 170.2 >9999:1 $102.00 3 Supplements Manure 10 tons, 4 86 .... 437 6 172.5 >9999:1 114.57 6 Manure 10 tons, 686 432.5 183.2 3332:1 120.83 24 22 13 Manure 10 tons, rock phosphate . . . Manure 10 tons, superphosphate. . . Manure 10 tons, bone meal 402.3 451.9 375.6 170.9 220.5 123.7 4999:1 3332:1 4999:1 106.70 154.31 72.80 16 4 Manure 10 tons, bone meal, potash . . Substitutes 4-8-6 423.1 424.6 184.1 175.3 > 9999:1 4999:1 117.58 127.14 9 Nitrogen 261.1 36.3 27:1 13.35 10 Nitrogen, limestone 272.3 19.4 9:1 - 4.15 12 Blood, bone meal 410.1 157.2 4999:1 102.87 IS Blood, bone meal, potash 376.9 125.0 1249:1 70.15 7 Limestone 282.4 57.6 25:1 45.00 19 Superphosphate 372.2 135.0 4999:1 102.81 21 Rock phosphate 289.8 52.6 184:1 28.20 18 Superphosphate, limestone 382.0 143.0 2499:1 106.31 243 9 that when manure was used, phosphate was fully as effective as was a complete fertilizer, altho the yields were not so consistent. As a supplement for half the manure, superphosphate was more effective than either bone meal or rock phosphate. The 6-8-6 mixture used with manure gave slightly better results than the 4-8-6 mixture used with manure, when compared with the adjoining check. Since the soil used in this experiment was a black soil high in organic matter, and the 6-8-6 fertilizer was applied in ad- dition to 10 tons of manure, it is evident that tomatoes respond favor- ably to liberal applications of nitrogen. These data indicate that the large quantities of manure formerly used in fertilizing soil for tomatoes are unnecessary; more economical yields are obtained when half the manure is supplemented with phosphorus. Plots treated with manure substitutes gave more varied results than plots treated with manure supplements (Table 8). None of the substitute treatments produced yields as high as did the basic manure treatment. The 4-8-6 fertilizer used in place of manure gave prac- tically the same yield as the basic manure treatment. The 4-8-6 yield was more economically produced, however, because of the lower cost of the fertilizing materials. 598 BULLETIN No. 421 [December, The lowest yields in the test were on Plots 9 and 10 treated with nitrogen without phosphorus or potash. The increase over adjacent checks was too slight to be significant. Where nitrogen and lime were used, the value of the increase was less than the cost of the fertilizer. The use of nitrogen is important in the fertilization of the tomato when phosphorus is added, but when the phosphorus content is limited, nitrogen alone fails to produce economical yields (Table 8). The use of potash on Plot 15 as a supplement to the blood- and- bone-meal treatment of Plot 12 did not give any increase in tomato yield, altho the potash used on Plot 16 as a supplement to manure and bone meal gave an increase of 47.5 pounds over the yield on Plot 13 treated with manure, bone meal, and no potash (Table 8). 200 FIG. 11. CORRELATION OF TOTAL TOMATO YIELD WITH NUMBER OF FRUITS PER PLANT Large yields were associated with large numbers of fruits per plant rather than with any great difference in average size of fruits. Limestone gave a small increase in yield, which was quite eco- nomical owing to the low cost of material, altho the increase was too low to be significant, since the odds were only 27:1. Superphosphate used alone and with lime was the only single- element fertilizer which gave economical yields. Rock phosphate used without manure is apparently too slowly available to the tomato plant to be of much value. The wide difference in tomato yields with the various fertilizer treatments was due more to the increase in size of plant and number 1935-} SUBSTITUTION OF COMMERCIAL FERTILIZERS FOR MANURE 599 TABLE 9. TOMATOES: EFFECT OF VARIOUS FERTILIZERS ON YIELD, EARLINESS, NUMBER OF FRUITS PER PLANT, AND SIZE OF FRUIT (Average for eight years) Plot Treatment per acre Average yield per Moo acre Weight of fruit matured first half of season Average number fruits per plant Average weight per fruit 1 Manure 20 tons Ibs. 435.3 Ibs. 55.4 50.1 Ibs. .267 3 437.6 56.8 50.4 .272 4 4-8-6 424.6 61.3 48.1 .275 6 Manure 10 tons, 686 432.4 54.6 50.6 .280 7 Limestone 282.4 33.6 27.5 .272 9 Nitrogen 261.1 22.7 25.8 .274 10 Nitrogen, limestone 272.3 25.5 26.7 .269 12 Blood, bone meal 410.1 52.8 45.3 .280 13 Manure 10 tons, bone meal 375.6 46.8 46.0 .263 15 Blood, bone meal, potash 376.9 42.8 43.9 .266 16 18 Manure 10 tons, bone meal, potash. . . . Superphosphate, limestone 423.1 382.0 39.0 44.8 48.4 43.2 .263 .271 19 Superphosphate 372.2 41.8 41.6 .267 21 Rock phosphate 289.8 30.3 29.5 .273 22 Manure 10 tons, superphosphate 451.9 64.2 51.0 .283 24 Manure 10 tons, rock phosphate 402.3 55.4 47.2 .267 Average of check plots 234.9 25.0 26.5 .265 of fruits per plant with the favorable treatments than to an increase in weight of individual fruits. The correlation of number and weight of fruits with total yield is shown in Fig. 11 and Table 9. The largest number of fruits per plant was on the manure and superphosphate plot (Plot 22), which also gave the largest yield. Plots 7, 9, 10, and 21 yielded much smaller numbers of fruits than the other treated plots and also gave low total yields. All plots showed a close correlation between total yield and number of fruits. Altho no data were recorded, observation in the field showed that the size of top growth was also closely correlated with number of fruits. Plants with the most rank growth produced the greatest number of fruits and, in turn, high total yields. Fertilizer applications affected the earliness of maturity to some extent, as shown in Table 9. Where part of the manure was supple- mented by either superphosphate or a 4-8-6 fertilizer, some increase in weight of fruit produced during the first half of the season occurred. There was also an increase in production of early fruit where a 4-8-6 fertilizer was used without manure. The results of these tests show that where manure is difficult to obtain or too costly to be practical, equally high tomato yields may be obtained thru the use of high-grade commercial fertilizers, either as a supplement to half the manure or as a substitute for the entire 600 BULLETIN No. 421 [December, amount. When some manure is used, a supplement of superphosphate may be used to good advantage. Phosphorus Important Fertilizer for Peppers The response of green peppers to various fertilizer treatments, while similar to that of the tomato, was somewhat smaller (Fig. 12). Plots 22, 3, and 6 treated with 10 tons of manure an acre and, re- spectively, superphosphate, 4-8-6 fertilizer, and 6-8-6 fertilizer, gave higher yields than Plot 1, which received the basic treatment of 20 tons of manure (Table 10). The use of potash in addition to manure and bone meal gave no increase in yield and a lower profit (Plots 13 and 16) than manure no 100 PEPPERS FRUITS MATURING DURING FIRST HALF OF SEASON FRUITS MATURING DURING "~ SECOND HALF OF SEASON 3 4 5 6 7 8 9 10 11 2 13 14 15 16 17 18 19 20 21 23 24 Six * x x 2u29999:l $32.00 3 Supplements Manure 10 tons, 4-8-6 270.6 74.4 109:1 34.17 6 Manure 10 tons, 686 258.3 75.1 4999:1 32.53 24 Manure 10 tons, rock phosphate 305.9 93.7 587:1 44.60 22 Manure 10 tons, superphosphate 327.4 115.2 1428:1 69.31 13 Manure 10 tons, bone meal 295.2 76.7 666:1 35.80 16 4 Manure 10 tons, bone meal, potash. . . . Substitutes 4-8-6 337.8 249.6 113.1 66.4 216:1 369: 61.28 38.14 9 Nitrogen 204.6 27.0 105: 6.25 10 Nitrogen, limestone 197.2 .9 1: -19.55 12 Blood, bone meal 239.1 41.0 243: 7.27 15 Blood, bone meal, potash 272.1 53.6 18: 12.35 7 Li mestone 178.9 1.3 1: - 1.80 19 Superphosphate 254.8 42.1 399: 26.31 21 Rock phosphate 233.8 21.1 9: 2.20 18 Superphosphate, limestone 235.0 10.3 3: - 3.69 202 9 tive as complete fertilizers. Superphosphate was superior to either bone meal or rock phosphate as a source of phosphorus to supplement the manure. None of the manure substitutes produced yields equal to those obtained with manure alone, altho Plot 4, which received a 4-8-6 fertilizer at the rate of 1,000 pounds an acre, gave a more economi- cal increase (Table 12). Since Plots 4 and 15 gave the highest in- creases in yield over adjoining checks, we may conclude that when no manure is used, higher yields of carrots may be expected from com- plete fertilizer than from incomplete fertilizer. Limestone gave only a slight increase over the adjoining check 604 BULLETIN No. 421 [December, (Plot 7), while nitrogen and lime together (Plot 10) gave a decrease in yield. Carrots are not especially sensitive to acid soils and, since the soil used in this test was not very acid, little response to lime- stone could be expected. Carrots responded more to potash than most of the crops in this experiment. Two hundred pounds of muriate of potash caused a substantial increase in yield when used to supplement manure and 350 . 300 to O 250 O Q. Z 2OO O uj 150 O 100 a 50 CARROTS PLOTS 1 234567 _| D CD (O 2E 2 9999: 1666: 127: -18.95 5.61 13.50 16 4 Manure 10 tons, bone meal, potash. . . Substitutes 4-8-6 52.7 53 2 18.0 11 1 302: 3332- -12.57 26 9 Nitrogen 36 3 2.9 3: 13.90 10 Nitrogen, limestone 35.0 2.0 11: 24.52 12 Blood, bone meal 44 2 3.5 6: 21.01 15 Blood, bone meal, potash 48.5 .5 1: 27.23 7 Limestone 42 3 7 7 60: 16.00 19 Superphosphate 47.6 10.2 32: .97 21 Rock phosphate 46 5 2 1 3: 2 90 18 Superphosphate, limestone 44.2 8.0 127: 5.56 Average of check plots 36 8 608 BULLETIN No. 421 [December, treatment without manure was more effective than any of the other treatments without manure. The manure and superphosphate treat- ment gave significant and economical increases thru the eight-year period. Manure Supplements Proved of Value With All Ten Crops From these experiments it is evident that economical yields can be obtained by using commercial fertilizers as a supplement to or as a substitute for manure (Tables 15 and 16). With all ten crops, as TABLE 15. RELATIVE YIELDS OF FIVE EARLY, SHORT-SEASON CROPS OF SERIES I UNDER VARIOUS FERTILIZER TREATMENTS Plot Treatment Spinach Lettuce Beets Peas Beans 1 Manure 20 tons 100 100 100 100 100 3 Supplements Manure 10 tons 4-8-6 95 90 118 110 105 6 Manure 10 tons 6-8-6 106 86 123 102 91 24 Manure 10 tons rock phosphate 77 81 103 105 92 22 Manure 10 tons superphosphate 88 100 107 118 104 13 Manure 10 tons bone meal 75 99 106 108 103 16 4 Manure 10 tons bone meal, potash. . . Substitutes 4-8-6 105 102 95 90 112 130 95 113 101 93 9 Nitrogen 51 40 95 89 63 10 Limestone, nitrogen 54 42 97 89 56 12 Blood, bone meal 80 87 105 118 91 15 Blood, bone meal, potash 96 105 124 101 93 7 Limestone 52 38 85 81 59 19 Superphosphate 68 87 98 105 76 21 Rock phosphate 55 57 81 85 70 18 Limestone, superphosphate 67 89 98 109 75 Average of check plots 41 45 73 77 63 high or higher yields were obtained when a part of the manure was supplemented by either superphosphate alone or by 500 pounds of a complete fertilizer than when the full amount of manure alone was used. For the eight-year period, 1,000 pounds of commercial fertilizer used to replace all the manure gave somewhat lower, altho with most crops, more economical yields than resulted from the use of manure alone. The value of some manure in the fertilizing of vegetable crops is demonstrated by the fact that with all crops the group of plots which received a commercial fertilizer supplement for one-half the manure produced higher average yields than the group of plots which received only the substitutes for manure. With a few crops, especially the short-season vegetables, complete fertilizer alone gave the highest yields. When no manure was used, complete fertilizers seemed neces- 1935-] SUBSTITUTION OF COMMERCIAL FERTILIZERS FOR MANURE 609 sary to produce high yields of most crops. However, with all crops, superphosphate used alone gave economical increases. The combination of blood and bone resulted in good increases. Another significant fact brought out by these experiments is the extremely poor showing of nitrogen alone. With all crops except cauliflower, the two nitrogen plots (9 and 10) were among those having the four lowest yields. When phosphorus was applied with the TABLE 16. RELATIVE YIELDS OF FIVE LATE, LONG-SEASON CROPS OF SERIES II UNDER VARIOUS FERTILIZER TREATMENTS Plot Treatment Tomato Pepper Carrot Potato Cauliflower 1 Manure 20 tons 100 100 100 100 100 3 Supplements Manur 10 tons, 486 101 103 94 105 112 6 Manur 10 tons, 686 99 104 92 110 123 24 22 13 16 4 Manur 10 tons, rock phosphate . . Manur 10 tons, superphosphate.. . Manur 10 tons, bone meal Manure 10 tons, bone meal, potash Substitutes 4-8-6 93 104 86 97 98 97 111 99 97 96 109 117 105 120 87 88 119 107 100 101 123 134 133 150 146 9 Nitrogen 60 81 73 69 127 10 Limestone, nitrogen 63 78 70 66 109 12 Blood, bone meal 94 99 85 84 132 IS Blood, bone meal, potash 86 88 97 91 100 7 Limestone 65 88 64 80 79 19 Superphosphate 86 83 91 90 104 21 Rock phosphate 66 78 83 88 92 18 Limestone, superphosphate 111 99 84 84 94 Average of check plots 56 74 72 70 73 nitrogen, good yields were obtained. Beets, spinach, peppers, cauli- flower, and potatoes showed greater response to high nitrogen treat- ment in combination with the other elements than the other crops in the test. The use of limestone gave an increase for seven of the ten crops. Beans, carrots, and lettuce showed retarded yields from liming. Only with potatoes, beets, and spinach was the increase in yield from liming significant. Since the acidity of the soil used for this experi- ment did not greatly exceed pH 6.00, little increase in yield from lime would be expected. On soils with a greater degree of acidity, a greater response from lime would doubtless have resulted. Phosphorus, when applied alone, gave a fair increase in yield and the increase was always economically produced. A comparison of the effectiveness of the three sources of phosphorus shows that super- phosphate was superior to either bone meal or rock phosphate when used as a supplement to manure. When used without manure, super- 610 BULLETIN No. 421 phosphate produced higher yields than rock phosphate with all ten crops. The use of potash resulted in varied responses. Four crops spinach, lettuce, beets, and carrots gave consistent increases from the use of 200 pounds of muriate of potash in addition to nitrogen and phosphorus when used without manure. Potatoes and beans showed slightly increased yields, while cauliflower, tomatoes, peas, and peppers showed reduced yields. SUMMARY 1. Results of fertilizer experiments with ten vegetable crops in Cook county over an eight-year period have shown that scarcity and high price of manure need not seriously affect yields of these crops, as commercial fertilizers are capable of replacing manure to a large extent. 2. When half the manure was replaced by commercial fertilizers, even higher yields resulted than from the full manure treatment. When all the manure was replaced by complete fertilizers, the yields were sometimes slightly smaller but, with most of the crops included in this experiment, more economical than yields obtained from the basic manure treatment. 3. When no manure was used, complete fertilizers were more con- ducive to high yields than incomplete fertilizers. When 10 tons of manure, or half the basic application, was used, superphosphate was fully as effective as a complete fertilizer with most of the crops and resulted in more economical yields. 4. Nitrogen alone was not a profitable fertilizer in these experi- ments. When phosphorus was used with nitrogen, good yields were obtained. 5. Limestone gave a slight increase in yield with most of the crops. 12-358,0508698 AUTHOR INDEX 613 AUTHOR INDEX 1. ANDERSON, H. XV. See KADOW 15 2. BARTLETT, R. W. St. Louis Milk Problems With Suggested So- lutions 89-184 3. BAUER, F. C. See PIEPER 24 4. BULL, SLEETER, OLSON, F. C., HUNT, G. E., and CARROLL, W. E. Value of Present-Day Swine Types in Meeting Changed Consumer Demand 257-296 5. BIGGER, J. H. See DUNCAN 10 6. CARD, L. E. See ROBERTS 25 7. CARROLL, W. E. See BULL 4 8. DAWSON, W. M. See ROBERTS 26 9. DECKER, S. W. See LLOYD 19, 20, WEINARD 28 10. DUNCAN, G. H., HOLBERT, J. R., MUMM, W. J., BIGGER, J. H., and LANG, A. L. Illinois Corn Performance Tests: Results for 1934 53-88 11. GILLIS, M. C. See HUELSEN 13 12. HOLBERT, J. R. See DUNGAN 10 13. HUELSEN, XV. A., and GILLIS, M. C. Fertilizer Requirements of Sweet Corn 349-436 14. HUNT, G. E. See BULL 4 15. KADOW, K. J., and ANDERSON, H. W. The Role of Zinc Sulfate in Peach Sprays 205-256 16. KOEHLKR, BENJAMIN. Seed Treatments for the Control of Certain Diseases of Wheat, Oats, and Barley 497-576 17. LANG, A. L. See DUNGAN 10 18. LEWIS, E. P. See LLOYD 21 19. LLOYD, J. W., and DECKER, S. W. Factors Influencing the Refrigeration of Packages of Apples 13-52 20. LLOYD, J. W., and DECKER, S. W. Factors Influencing the Refrigeration of Packages of Peaches 437-464 21. LLOYD, J. XV., and LEWIS, E. P. Substitution of Commercial Fertilizers for Manure in Vege- table Production 577-612 22. MUMM, W. J. See DUNGAN 10 23. OLSON, F. C. See BULL 4 24. PIEPER, J. J., SEARS, O. H., and BAUER, F. C. Lespedeza in Illinois 297-348 25. ROBERTS, ELMER, and CARD, L. E. Inheritance of Resist- ance to Bacterial Infection in Animals: A Genetic Study of Pullorum Disease 465^96 26. ROBERTS, ELMER, and DAWSON, W. M. Effect of Fowler's Solu- tion on Animals 185-204 27. SEARS, O.K. See PIEPER 24 28. WEINARD, F. F., and DECKER, S. W. Effects of Prolonged Storage on Forcing Qualities of Summer-Budded Roses. . . . 1-12 614 INDEX INDEX Agglutination tests, use of in study of disease resistance 485 Alfalfa hay, prices in St. Louis milk- shed 169 Animals, farm, effect of Fowler's solution on 201-202 Apples, marketing and storage, literature on 15-16, 50 APPLES, PACKAGES OF, FACTORS IN- FLUENCING REFRIGERATION OF 13-50 See Contents 14 Summary and Conclusions 48-49 Arsenical spray injury, causes and control of 230-234, 237-247 Bactericide, see Zinc sulfate Barley diseases, control of by seed treatments 512-518, 544-551, 565-566, 568-570 Beans, fertilizer tests with 593-596,608-610 Beef cattle, 1925-1934 prices in St. Louis milkshed 166 Beets, fertilizer tests with 588-590,608-610 Bone meal, as fertilizer for vegetables 580, 582-609 Brown rot of peaches, control of with zinc sulfate 210-214 Butter, prices at Chicago 172 Butterfat, prices in St. Louis milk- shed 166 Carrots, fertilizer tests with 603-604,608-610 Cauliflower, fertilizer tests with. . . . 604-606,608-610 Cereals, seedling diseases of 502 Ceresan treatment for small grains, application of 565-566 Chickens, prices in St. Louis milk shed 167 use of in genetic study of pullorum disease 468-193 Chinese birds, resistance of to disease 474-477 Clover in rotations, effect of on ferti- lizers for sweet corn 355-356,370-426 on check plots 382 Copper carbonate, as seed treatment 563-564 Corn, lodging resistance of tested. . 60,65-87 Corn, prices in St. Louis milkshed. . . . 168 Corn, quality of tested 61-62, 65-87 Corn, variety performance of tested 63,65-88 Corn, yields of tested 60-62, 65-88 Corn hybrids, performance tests with in Illinois 63-88 superiority to open-pollinated varieties 62 Corn performance tests, contribu- tors to 63-64 measure of entries 59-62 numbers and kinds of entries .... 55-56 planting and arrangement of entries 56-58 CORN PERFORMANCETESTS, RESULTS IN ILLINOIS FOR 1934 53-88 Dairy cattle, prices in St. Louis milk- shed 169, 171 Dairy cattle population, in Illinois. . .177 in St. Louis milkshed 176, 177 in United States 177 Dairy rations, cost of in St. Louis area .172 Disease control, biological aspects of studied 486-488 Disease resistance, inheritance of in animals 467-493 Disinfectants, seed, application of 520, 554-556, 563-569 list of compounds tested 519-521 Eggs, prices in St. Louis milkshed. ... 167 FERTILIZER REQUIREMENTS OF SWEET CORN 349-435 See Contents 351-352 index to tables 430-431 literature on 427-429 Recommendations 425-426 Summary. 423-425 Fertilizer tests with sweet corn, plan and scope of 354-370 purpose of 354 mean yields and mean increases in 432^134 Fertilizers, commercial, influence of on maturity of sweet corn 414-119,425 influence of on yield of sweet corn 370^14,423-425 selection of optimum ratios 403-104, 413^14, 419-423 INDEX 615 FERTILIZERS, COMMKRCIAL, SUBSTI- TUTION OF FOR MANURE IN VEGETABLE PRODUCTION . . .577-610 See Contents 578 Summary 610 Food prices, retail, indexes of in St. Louis 101-104, 164 Formaldehyde spray treatment. . 566-567 Formaldehyde sprinkle treatment. . 567-568 FOWLER'S SOLUTION, EFFECT OF ON ANIMALS 185-202 See Contents '.186 Summary of experimental findings . 201-202 Fungicide, see Zinc Sulfate Hogs, prices in St. Louis milkshed. . . 168 Hot-water treatment for seed dis- eases 568-569 Inbreeding, effect of on disease re- sistance studied 473-474 Income, family, as a factor in per- capita milk consumption . . . .99-101 in St. Louis 163 INHERITANCE OF RESISTANCE TO BACTERIAL INFECTION IN ANIMALS : . 465^93 See Contents 466 literature on 489-490 Summary and Conclusions 488 Inoculation of lespedeza 332-334 Lard fat, amount of from different swine types 291-295 LESPEDEZA IN ILLINOIS 297-347 See Contents 300 Summary and Conclusions. . . .346-347 Lespedeza, adaptation of to climate and soil 319-325 cultural practices for 334-341 diseases of 345-346 harvesting of for hay and seed . 341-343 insect damage to 345 literal ure on 347 place of in Illinois agriculture. .308-319 soil treatment, response of crop to 330-334 varieties of, description and history 301-308 variety tests with 325-330 weeds, control of 343-344 yields of, effect of inoculation on 332-334 Lettuce, fertilizer tests with 585-587, 608 610 Limestone, applications of for vege- tables 580,582-610 effect of on lespedeza yields. . .330-331 Manure, substitution of commercial fertilizers for. . . .579-610 Marketing, see Apples, Milk, Peaches, Swine Marketing containers, effect of type on cooling of contents 36-44,454-459 Milk, evaporated, as competitor of whole milk 104-109, 165 average retail prices of 165 Milk consumption, in 14 U. S. cities 94-99, 161 in St. Louis, factors affecting. . . . 99-110, 163 map showing survey of 98 Milk distributors, gross handling margins of 131-135 Milk license, federal, policies under 143-157 Milk market organizations in St. Louis 135-143 Milk prices, basic-surplus plan for. . ..: 125-131 compared with those of other foods 101-104 decline in to producers, reasons for 117-124 gross, paid by distributors 174 net, received by producers 173 paid to producers at Greenville ... 175 Milk producers, number of in St. Louis milkshed 180 questionnaire used in survey of . ... 182 Milk production in St. Louis milk- shed 176, 178-181 Milk sales, St. Louis, ways of in- creasing 110-117 Milk sales areas, population survey of L4 cities 161-162 Nitrogen, as fertilizer for vegetables 580,582-610 effect of on maturity of sweet corn 414-416,418^119,425 effect of on yield of sweet corn . 370-382 efficiency of with sweet corn 382-389,423-424,435 Oat smuts, control of by seed treat- ment 510-512, 534-544, 566-568 Oats, prices in St. Louis milkshed .... 1 70 Peach scab, control of with zinc sul- fate 208-210 Peach sprays, role of zinc sulfate in 206-255 Peaches, harvesting and marketing, literal ure on 440, 464 PEACHES, PACKAGES OF, FACTORS INFLUENCING THE REFRIGERA- TION OF 437^64 See Contents 438 Summary and Conclusions. . . . 462 463 616 INDEX Peas, fertilizer tests with 590-593,608-610 Peppers, fertilizer tests with ....600-603,608-610 Phosphorus, as fertilizer for lespedeza.331 as fertilizer for vegetables. 580, 582-610 effect of on maturity of sweet corn 414-415,417-419,425 effect of on yield of sweet corn . 389-396 efficiency of with sweet corn 397-402,424,435 Population, racial, in St. Louis 164 Pork cuts, difference in due to swine type 278-291,293-295 Potash, as fertilizer for lespedeza. 33 1-332 as fertilizer for vegetables.580, 582-610 effect of on maturity of sweet corn 414-119,425 effect of on yield of sweet corn . 404407 efficiency of with sweet corn 407-413, 424-425, 435 Potatoes, fertilizer tests with. . . .606-610 Prices, see commodity entries Pullorum disease, genetic study of 467-193 Refrigeration, lack of, effect on milk sales 107-109 Refrigeration experiments, with apples 14-49 with peaches 438463 ROSES, SUMMER-BUDDED, EFFECTS OF PROLONGED STORAGE ON FORCING QUALITIES OF 1-10 Contents 2 Summary and Conclusions 9-10 Salmonella pullorum, use of as inocu- lant 469-186, 488, 491-493 SEED TREATMENTS FOR THE CON- TROL OF CERTAIN DISEASES OF WHEAT, OATS, AND BARLEY. 497-5 75 See Contents 498 Summary and Conclusions. . .569-571 Seed treatments for small grains, ap- plication by machine or shovel 554-556 diseases influenced by 502-518 dosage and time in storage tested . . 556-563 effect of on yield 551-554 literature on 500-502, 571-575 Seedling diseases of cereals 502 Soybeans, prices in St. Louis milk- shed 170 Spinach, fertilizer tests with 583-585, 608-610 Spray injury, see Arsenical Spray schedules used in peach tests 254-255 Sprays, literature on 221-223, 237-239, 249-252 ST. Louis MILK PROBLEMS WITH SUGGESTED SOLUTIONS 89-184 See Contents 91-92 index to tables and charts. . . . 183-184 Recommendations 159-160 Summary 158-159 Sweet corn, experiments with ferti- lizer requirements of 353-435 Sweet corn, recommendations for fertilizing of 425-426 SWINE, VALUE OF PRESENT-DAY TYPES IN MEETING CHANGED CONSUMER DEMAND 257-295 See Contents 258 Conclusions 294-295 Swine types, plan of tests to deter- mine market value of 260-275 Tomatoes, fertilizer tests with 596-600,608-610 Vegetables, fertilizers for tested. . 583-610 Wheat, prices in St. Louis milkshed . . 171 Wheat diseases, control of by seed treatments 502-510, 522-534 Zinc, effect of on peach growth.. . 221-236 Zinc sulfate, as corrective for peach spray injury 237-247 Zinc sulfate in peach sprays, as a bactericide 214-221 as a fungicide 208-214 ZINC SULFATE, ROLE OF IN PEACH SPRAYS 205-255 See Contents 206 literature on 249-252 Summary and Conclusions. . .247-248