THE UNIVERSITY OF ILLINOIS LIBRARY G30V , terialis responsive for The person charging this ma unaH ^ ^ drawn ils return >o the I'^'V J d below, on or before the Late. ti M *aB8l JAN 1 5 1991 JAN282CI 3 L161-0-1096 Fertilizer Experiments With Ten Market-Garden Crops in Cook County, Illinois Spinach, lettuce, beets, peas, beans, tomatoes, peppers, carrots, po- tatoes, and cauliflower By J. W. LLOYD and E. P. LEWIS UNIVERSITY OF ILLINOIS AGRICULTURAL EXPERIMENT STATION BULLETIN 377 CONTENTS PLAN OF EXPERIMENTS RESULTS OF FIRST FIVE YEARS' WORK ........................... 6 Fertilizers Greatly Improved Yields of Spinach ........................ 6 Lettuce Showed Increase Following Treatment ........................ 10 Nitrogen Increased Yield of Beets .................................... 13 Peas Responded to Commercial Fertilizer Without Manure ............ 15 Complete Fertilizer Gave Good Yields of Beans ....................... 17 Tomato Yields Doubled With Superphosphate and Manure. . . ......... 21 Peppers Showed Benefit From Superphosphate ........................ 25 Phosphorus With Manure Gave Good Yields of Carrots .............. 28 Potato Yields Showed Wide Variations ......................... ..... 29 Commercial Fertilizer Gave High Cauliflower Yields .................. 31 Manure Substitutes Proved Value With All Ten Crops ............... 33 SUMMARY.. 36 Urbana, Illinois February, 1932 Publications in the Bulletin series report the results of investigations made by or sponsored by the Experiment Station Fertilizer Experiments With Ten Market- Garden Crops in Cook County, Illinois By J. W. LLOYD, Chief in Olericulture, and E. P. LEWIS, Associate IN COOK COUNTY, Illinois, are concentrated approximately three thousand farmers producing vegetable crops far more than in any similar area in the state. While dairying is also carried on, vegetable growing predominates and is gradually pushing the other more extensive system out into neighboring counties. The extensiveness of the vegetable industry in Cook county and adjacent areas, and the importance of the problems confronting vege- table growers of the district led the Illinois Legislature, in 1923, to appropriate funds for the establishment of an agricultural experiment station in this part of the state to deal primarily with problems con- cerned with the growing of vegetables. The responsibility for the conduct of the work was placed with the University of Illinois. After thoro study of the situation and examination of many tracts of land, an area consisting of twenty acres in Section 29, Maine town- ship, Cook county, was purchased by the University for the purposes described. The land is typical truck-garden soil, and at the time it was taken over by the University was in a good state of cultivation. It is located two miles from the Des Plaines railway station, 20 miles northwest of the "Loop," on the Chicago and North Western Railway, less than a mile from state highway U. S. 45 ; thus it is easily access- ible to Station workers as well as to visitors. Fertilizer experiments have received the preponderance of the at- tention at this branch station because of the high state of fertility required in such an intensive system as truck farming. Heavy appli- cations of plant food must be made, and these cannot be obtained in ways that are practical in general farming. In the past, truck farmers have depended almost entirely on the supply of manure from Chicago to maintain this high productivity, but with amounts from this source growing less and less each year, growers have found it necessary to turn to other forms of fertilizer. The problem of fertilizing has been increased by the fact that most of the old gardening area near the city limits has been taken over by real estate companies, and growers have had to move to new land BULLETIN No. 377 [February, !> * = m Z N S H H H - '- 3 V m^ ID 3 I a IE S3I3S I S3lb3S 1932] FERTILIZER EXPERIMENTS WITH TEN MARKET-GARDEN CROPS 5 which is much lower in productivity and which does not have the ad- vantage of previous years of heavy manure fertilizing. The object of the experiments reported herein was to ascertain the response of various vegetable crops to different fertilizer treatments, particularly to test the effectiveness of commercial fertilizers as sub- stitutes for and as supplements to animal manure'. PLAN OF EXPERIMENTS Arrangement of Plantings The tests reported herein involve seven acres of land divided into 96 plots. Two series of market-garden crops are planted. In Series I are included five early-maturing crops spinach, leaf lettuce, beets, peas, and beans. In Series II are included five late-maturing crops tomatoes, peppers, carrots, potatoes, and cauliflower. Each year, after the five early crops are removed, a cover crop is seeded on the land occupied by Series II, and this is plowed under about May 1 of the next year before the late crops are planted. The land occupied by the late crops is plowed in the fall without cover crops and is used early in the spring for planting the early crops. In this way the two series are rotated and organic matter is supplied in alternate years. Excellent growth of cover crop has been obtained in every case. Arrangement of Plots The 96 plots used for these experiments are laid out in eight tiers, twelve plots in each tier (Fig. 1). A space 11 feet wide is left between the plots in a tier, and an alley 8 feet wide separates the different tiers. Each plot is 50 feet wide and 43.5 feet long, or essentially % acre. Five crops are 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 duplicate Plots 1 to 24 in fertilizer treatment as well as in crops. Both series of plantings receive exactly the same fertilizer treat- ments, the only difference between them being that in Series I the five early crops are planted thru each of the 48 plots and in Series II the five late crops are planted thru each of the 48 plots. Series I occupied the location shown in Fig. 1 in 1925, 1927, and 1929. The detailed planting of one plot in each series is shown in Fig. 2. Treatment of Plots Sixteen different soil treatments and 8 check plots receiving no treatment are duplicated for each series of plantings. These treat- 6 BULLETIN No. 377 [February, ments are indicated by the following outline. The quantities stated represent the rate of application per acre. Plot 1. 20 tons manure 2. Check 3. 10 tons manure, 500 Ibs. 4-8-6 1 4. 1,000 Ibs. 4-8-6 1 5. Check 6. 10 tons manure, 500 Ibs. 6-8-6 1 7. 3 tons limestone 8. Check 9. 200 Ibs. nitrate of soda, 300 Ibs. dried blood 10. 200 Ibs. nitrate of soda, 300 Ibs. dried blood, 3 tons limestone 11. Check 12. 500 Ibs. dried blood, 500 Ibs. bone meal 13. 10 tons manure, 500 Ibs. bone meal 14. Check 15. 500 Ibs. dried blood, 500 Ibs. bone meal, 200 Ibs. muriate of potash 16. 10 tons manure, 500 Ibs. bone meal, 200 Ibs. muriate of potash 17. Check 18. 800 Ibs. superphosphate, 3 tons limestone 19. 800 Ibs. superphosphate 20. Check 21. 2,000 Ibs. rock phosphate 22. 10 tons manure, 800 Ibs. superphosphate 23. Check 24. 10 tons manure, 2,000 Ibs. rock phosphate Except in the case of limestone, each of the materials mentioned above has been applied annually. Limestone was applied only in 1925 and 1927. Plots 3, 6, 13, 16, 22, and 24, where manure was supplemented with other fertilizers, received half of what is considered a normal appli- cation of manure when manure is used alone 10 tons to the acre. RESULTS OF FIRST FIVE YEARS' WORK Fertilizers Greatly Improved Yields of Spinach Response of spinach to fertilizer applications was very pronounced, as is indicated by the yields shown in Table 1. On all check plots, where no fertilizer was used, the plants were stunted, of extremely poor quality, and in many cases unsalable. The highest average yield 2 was produced from the use of 10 tons 'These fertilizers were home-mixed. In each case half the nitrogen was derived from nitrate of soda and half from dried blood. The phosphorus was supplied from superphosphate and the potassium from muriate of potash. 'Yields were based on weight of all plants regardless of salable qualities. 1932] FERTILIZER EXPERIMENTS WITH TEN MARKET-GARDEN CROPS 7 TABLE 1. YIELDS OF SPINACH WITH VARIOUS FERTILIZER TREATMENTS I Plot Treatment Yield per acre 1925 1926 1927 1928 1929 Average 1 3 4 6 7 9 10 12 13 15 16 18 19 21 22 24 Manure (20 tons) Ibs. 2 930 4 000 3 140 3 150 2 630 225 320 2 533 2 353 2 061 4 683 5 870 3 175 721 4 820 6 180 1 079 Ibs. 3 881 3 821 3 690 4 317 965 1 078 1 225 2 595 3 295 2 670 4 944 2 497 2 207 1 529 3 988 3 954 1 114 Ibs. 1 518 1 477 2 504 1 886 1 144 933 912 1 907 1 628 2 058 2 595 1 664 1 419 994 1 677 1 405 1 044 Ibs. 17 800 16 070 15 030 17 290 5 730 7 950 8 090 11 270 19 500 16 240 14 890 10 060 9 950 8 720 13 450 13 480 5 240 Ibs. 7 210 9 970 11 450 8 490 5 560 4 780 5 460 10 740 7 450 10 960 7 520 7 570 8 130 7 540 8 650 7 770 4 610 Ibs. 6 668 7 063 7 026 7 026 3 206 2 993 3 201 5 809 6 445 6 598 6 926 5 532 4 976 3 901 6 517 6 570 2 617 4-8-6 Manure, 6-8-6 Lime Nitrogen Nitrogen, lime Manure, bone Blood, bone, potash Manure, bone, potash Superphosphate, lime Superphosphate Manure, superphosphate Manure, rock phosphate Average of check plots The yields from treated plots in the case of all crops reported in this publication were calculated in reference to the two nearest check plots according to the formula f$(C + $4Ci + J$Ci) N, where C = average of all checks, Ci = adjacent check, and Cj = check separated by one treatment. The theoretical yield of each plot, were it untreated, was calculated by dividing N by the average of the checks (Q and expressing the result on a percentage basis. The corrected yield for each treated plot was then derived by dividing the actual yield by the theoretical yield as above expressed. (See Hayes and Garber, "Breeding Crop Plants," pp. 66-67.) of manure supplemented with 500 pounds of complete fertiliser (Plot 3). The use of 20 tons of manure gave good yields, as might be ex- pected, but was excelled by four other treatments. The results show that 1,000 pounds of 4-8-6 fertilizer is capable of replacing 20 tons of 120 100 80 60 40 20 20 TONS MANURE 346 c 22*2 7 9 K) 12 13 15 16 18 19 2\ 22 24CHKS. & & n. a 4 % % 2 2 5 FIG. 3. YIELDS OF SPINACH FROM VARIOUS FERTILIZER TREATMENTS The yield from Plot 1, treated with 20 tons of manure, has been taken as 100 and the yield from each of the other plots calculated in relation to it. A complete commercial fertilizer without any manure produced practically the same yield as 10 tons of manure supplemented with half the quantity of fertilizer. BULLETIN No. 377 [February, TABLE 2. ESTIMATED MONEY RETURNS FROM VARIOUS FERTILIZER TREATMENTS WITH SPINACH (Average values per year for five years 1925-1929) Plot Treatment Cost of fertilizer per acre 1 Value of treatment based on increase over check plot* Returns from fertilizer for each dollar invested 1 Manure (20 tons) $40.00 $202 55 $5 06 3 Manure, 4-8-6 31.38 222 30 7 08 4 4-8-6 22.76 220.45 9 69 6 Manure, 6-8-6 34.74 220 45 6 34 7 Li me 3.00 29.45 9 81 9 23.10 18 80 81 10 Nitrogen, lime 26.10 29 20 1 12 12 Blood, bone 39.70 159.60 4 03 13 32.20 191 40 5 94 15 45.90 199 05 4 33 16 Manure, bone, potash 38.40 215.45 5.61 18 Superphosphate, lime 10.72 145 . 75 13.59 19 7.72 117.95 15 27 21 Rock phosphate 16.00' 64.20 4.01 22 Manure, superphosphate 27.72 195.00 7.03 24 Manure, rock phosphate 36.00 197.65 5.49 l Based on 1930 prices. "The value of the crop was obtained by dividing the yield in pounds by 12 (the weight of a bushel) and multiplying by 60 cents, the estimated price per bushel based on a five-year average for July on the South Water Market, Chicago. manure in the production of spinach (Fig. 3). In three out of five years higher yields were obtained with this commercial fertilizer treat- ment than with manure, and in the other two years the yields did not show wide differences. From the standpoint of economy the commer- cial fertilizer treatment, owing to the high price of manure, was even more favorable (Table 2) than the manure treatment. Where 10 tons of manure was used, it was not necessary to use any higher concentration of nitrogen in the supplementary fertilizer than that contained in a 4-8-6 mixture. Commercial nitrogen alone was not an economical or efficient treat- ment. Plot 9, which received an annual application of 200 pounds of nitrate of soda and 300 pounds of dried blood, produced consistently low yields in comparison with the more balanced treatment given Plot 4. This single-element application, in the absence of sufficient phosphorus and potash, evidently caused an overbalance of nitrogen in the soil, which resulted in the low yield, for in three years of the five this treatment gave lower yields than the check plots. When used in connection with other fertilizers, nitrogen was an important factor in increasing yields. Blood and bone together, for example, gave higher yields than either nitrogen or phosphorus alone. Complete fertilisers used as supplements to one-half the normal application of manure, were more effective than phosphorus alone. Evidently the additional nitrogen in the complete fertilizer was needed. Very little difference in average yields was noted when superphosphate, rock phosphate, or bone meal was used as a supplement to manure. 1932] FERTILIZER EXPERIMENTS WITH TEN MARKET-GARDEN CROPS However, of these three forms of phosphorus, superphosphate gave the most economical yields. Superphosphate alone was quite effective as a fertilizer for spinach. It proved far superior to rock phosphate alone. Spinach apparently was not capable of using, to any great extent, the phosphorus in rock phosphate when no manure was present (Fig. 4). The yields from 20 22 20 21 FIG. 4. REPRESENTATIVE SPINACH PLANTS FROM THREE PLOTS Plants numbered 20 are from Plot 20, an untreated check; 22 is from Plot 22, treated with manure and superphosphate; 21 is from Plot 21, treated with 2,000 pounds of raw rock phosphate. Without manure, the raw rock phosphate was ineffective. superphosphate alone were much lower than from a 4-8-6 mixture, but the low cost of the superphosphate made the returns on the in- vestment extremely high. The yields from this single-element appli- cation were relatively as high at the end of the five-year period as at any time during the experiment. It remains to be seen, however, when the point of diminishing returns will be reached, for long-continued use of phosphate alone would doubtless lead eventually to low yields. The use of limestone on spinach plots gave an increase in yield in four of the five years. This crop is known to be sensitive to an acid condition in the soil. The application of 6 tons of ground limestone during the five-year period gave an average increase of 49 bushels of spinach an acre a year. Measured by increased yields of spinach the 10 BULLETIN No. 377 [February, return for each dollar invested in limestone was $9.81 (Table 2). 1 The addition of limestone to the superphosphate treatment also seemed to increase the yields of spinach, as shown by the results on Plots 18 and 19. Slightly higher yields were obtained from limestone and nitrogen than from nitrogen alone. Potash applied at the rate of 200 pounds of muriate of potash per acre, in addition to manure and bone, substantially increased the yields of spinach in three out of five years as compared with yields from manure and bone. As an average for the five years Plot 16, treated with manure, bone, and potash, yielded 40 bushels more an acre than Plot 13, treated with manure and bone; while Plot 15, treated with blood, bone, and potash, yielded 65 bushels more than Plot 12, treated with blood and bone. However, a large part of the difference in the five-year average yield of Plots 15 and 12 was due to the great differ- ence in yield one year. Lettuce Showed Increase Following Treatment Greater increases in yield of leaf lettuce than of any other crop in this experiment were obtained thru the use of fertilizers. Where no 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, 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. In most years the crop from the unfertilized plots was unsalable. The relative response of leaf lettuce to 16 different fertilizer treatments is shown in Table 3 and Fig. 5. Judging from the minor differences in the average yields of Plots 1, 3, 4, and 6, it is possible to reduce the amount of manure used to one-half, or to eliminate manure entirely and use a high-grade com- mercial fertilizer, without seriously affecting the yield. Nitrogen used alone was not conducive to high yields. The results 'The estimated money returns from the various fertilizer treatments men- tioned in this publication are based on market quotations for the crops extend- ing thru the calendar month in which the given crop was usually harvested, or, in the case of tomatoes and peppers, thru two calendar months. This seemed to be a fairer method of estimating returns than to use the actual price at which a given crop was sold, especially with such crops as spinach, in which the entire crop for the year was harvested in one day and might be sold at a price entirely unrepresentative of the season's average for the product of the locality. However, estimates of this kind are valuable chiefly for purpose of comparison rather than as representations of actual money returns that may be expected, for prices of products and of fertilizers are too variable to be represented by any set of figures 1932] FERTILIZER EXPERIMENTS WITH TEN MARKET-GARDEN CROPS 11 TABLE 3. YIELDS OF LEAF LETTUCE WITH VARIOUS FERTILIZER TREATMENTS 1 Plot Treatment Yield per acre 1 1925 1926 1928 1929 Average 1 3 4 6 7 9 10 12 13 15 16 18 19 21 22 24 Manure (20 tons) Ibs. 1 532 1 052 780 692 685 397 451 600 538 860 716 931 569 219 1 023 1 128 502 Ibs. 805 869 827 1 214 153 155 165 446 647 224 926 629 396 385 908 711 186 Ibs. 4 780 4 005 5 117 4 690 1 709 2 130 3 184 4 775 5 210 4 890 6 265 5 080 4 180 3 632 5 548 4 272 2 197 Ibs. 2 360 3 241 3 409 2 949 1 502 973 1 040 3 528 2 865 3 270 2 124 3 559 3 518 2 486 4 368 2 963 477 Ibs. 2 372 2 292 2 533 2 311 1 017 914 1 210 2 337 2 315 2 311 2 508 2 550 2 166 1 681 2 962 2 269 841 Manure, 4-8-6 4-8-6 Manure, 6-8-6 Lime Nitrogen Nitrogen, lime Blood, bone Manure, bone Blood, bone, potash Manure, bone, potash Superphosphate, lime Superphosphate Rock phosphate Manure, superphosphate Manure, rock phosphate Average of check plots *The yields here reported are based on the weight of all plants regardless of salable qualities. 'Yield records for 1927 are not reported because of a very poor stand of plants that season. indicate that in the absence of sufficient phosphorus and potash, nitro- gen in liberal quantities is not desirable. Limestone, while not nearly so effective as fertilizer treatments in promoting high yields, showed economical increases over 'the checks owing to the low cost of the material (Table 4). Lettuce is known to be very sensitive to acidity; higher yields might therefore be expected 140 120 20 FIG. 5. RELATIVE YIELDS OF LETTUCE FROM VARIOUS FERTILIZER PLOTS Nitrogen, in the absence of the other elements, was ineffective. The yield from the plot treated with 20 tons of manure was taken as 100, and yields of other plots were based on it. 12 BULLETIN No. 377 [February, TABLE 4. ESTIMATED MONEY RETURNS FROM VARIOUS FERTILIZER TREATMENTS WITH LEAF LETTUCE (Average value per year for four years 1925, 1926, 1928, and 1929) Plot Treatment Cost of fertilizer per acre 1 Value of treatment based on increase over check plot 1 Returns from fertilizer for each dollar invested 1 Manure (20 tons) $40.00 $57.41 $1.43 3 Manure, 4-8-6 31.38 54 41 1 73 4 4-8-6 22.76 63.45 2 78 6 Manure, 6-8-6. 34.74 55.12 1.58 7 Lime 3.00 6 60 2 20 9 Nitrogen 23.10 2.73 .11 10 26.10 13 83 53 12 Blood, bone 39.70 56.10 1 41 13 Manure, bone 32.20 55.27 1.71 15 45.90 55 12 1 20 16 Manure, bone, potash 38.40 62.51 1 62 18 10 72 64 08 5 98 19 7.72 49 68 6 43 21 Rock phosphate 16.00 31.50 1.96 22 27 72 79 53 2 86 24 Manure, rock phosphate 36.00 53.55 1.48 'Based on 1930 prices. ! The value of the crop was obtained by dividing its total weight in pounds by 8 (the weight of a box) and multiplying by 30 cents, the estimated price per box based on South Water Market quotations for June over the five-year period. from the application of lime to acid soils. Limestone was also effec- tive in causing increased yields when used in connection with super- phosphate and also when used with nitrogen. In these experiments phosphorus appeared to be the most important 24 22 19 C-20 FIG. 6. REPRESENTATIVE LETTUCE PLANTS FROM Six PLOTS Treatments were as follows: Plot 24, 10 tons manure and 2,000 pounds rock phosphate; Plot 23, check; Plot 22, 10 tons manure and 800 pounds super- phosphate; Plot 19, 800 pounds superphosphate; Plot 20, check; Plot 21, 2,000 pounds rock phosphate. The lettuce showed great response to applications of phosphorus, especially as a supplement to manure. 1932] FERTILIZER EXPERIMENTS WITH TEN MARKET-GARDEN CROPS 13 element in the fertilizing of leaf lettuce (Fig. 6). Superphosphate alone gave very economical returns, altho the yields were not so high as from some of the more balanced treatments. As a supplement to manure, superphosphate, four years of the five, gave higher yields than either rock phosphate or bone meal similarly used. When the amount of manure was reduced one-half, complete fertilizers were no more effective as supplements than was superphosphate. Rock phosphate used without manure was not an effective source of phosphorus. Nitrogen Increased Yield of Beets Beets showed a very marked response to commercial fertilizer without the use of any manure (Table 5). An annual application of TABLE 5. YIELDS OF BEETS WITH VARIOUS FERTILIZER TREATMENTS' Plot Treatment Yield per acre 1925 1926 1927 1928 1929 Average 1 3 4 6 7 9 10 12 13 15 16 18 19 21 22 24 Manure (20 tons) Ibs. 35 300 39 030 32 810 32 300 37 060 11 420 13 270 30 760 37 600 32 450 33 450 29 000 24 430 16 180 18 680 32 100 19 750 Ibs. 49 780 44 180 65 260 64 900 39 900 49 730 53 250 47 350 52 800 53 750 62 675 50 925 48 490 46 012 53 065 42 620 37 470 Ibs. 27 100 32 785 39 035 35 315 34 220 32 835 33 015 36 245 26 580 35 385 33 550 34 050 32 950 30 110 31 400 32 745 26 750 Ibs. 59 525 81 555 78 700 69 700 59 250 60 150 66 050 80 850 49 625 58 150 54 625 38 575 50 370 38 675 51 750 44 860 45 510 {65. 25 780 33 515 45 165 28 020 31 725 45 865 36 250 34 985 32 395 52 985 39 095 25 540 33 445 34 530 37 765 33 810 31 050 //.---. 39 497 46 213 52 194 46 047 40 431 40 000 42 367 46 038 39 800 46 544 44 679 37 618 37 937 33 101 38 532 37 227 32 106 Manure, 4-8-6 4-8-6 Manure, 6-8-6 Lime Nitrogen Nitrogen, lime Blood, bone Blood, bone, potash Superphosphate Manure, superphosphate Manure, rock phosphate Avenge of check plots 'Yields are expressed as weight of both root and top, since the crop was sold as bunched beets. Only beets of marketable size are included. 20 tons of manure an acre produced lower yields than many of the other treatments. When half this amount of manure was supple- mented with 500 pounds of 4-8-6 or 6-8-6 fertilizer, higher yields were obtained; and when all the manure was replaced by 1,000 pounds of 4-8-6 fertilizer, the yields were still higher. Nitrogen used alone gave an average increase in the yield of beets of approximately 4 tons an acre over the check plots, or a 25-percent increase, which is a greater increase for this material than shown by any other crop in the experiment (Fig. 7). When used as a supple- ment to manure, a higher concentration of nitrogen than that in a 4-8-6 fertilizer was not profitable (Table 6). Limestone gave a very economical increase in beet yields. The beet is classed with those vegetables which are very sensitive to soil acidity, 14 BULLETIN No. 377 [February, TABLE 6. ESTIMATED MONEY RETURNS FROM VARIOUS FERTILIZER TREATMENTS WITH BEETS Plot Treatment Cost of fertilizer per acre 1 Value of treatment based on increase over check plot 1 Returns from fertilizer for each dollar invested 1 Manure (20 tons) $40.00 $50.81 $1.27 3 Manure, 4-8-6 31.38 96.98 3.09 4 4-8-6 22.76 138.09 6.06 6 Manure, 6-8-6 34.74 95.84 2.75 7 Li me 3.00 57.23 19.07 9 Nitrogen 23.10 54.27 2.34 10 Nitrogen, lime 26.10 70.54 2.70 12 Blood, bone 39.70 95.78 2.41 13 Manure, bone 32.20 52.89 1.64 15 45.90 99.26 2.16 16 Manure, bone, potash 38.40 86.43 2.25 18 Superphosphate, lime 10.72 37.89 3.53 19 7.72 40.08 5.19 21 Rock phosphate 16.00 6.84 .42 22 Manure, superphosphate 27.72 44.17 1.59 24 Manure, rock phosphate 36.00 35.20 .97 'Based on 1930 prices. *The value of the crop was obtained by taking 55 percent of the gross weight of roots and tops as representing the weight of the roots, dividing this figure by 60 to get the yield of roots in terms of bushels, and multiplying by 75 cents, the average price per bushel for the month of July on the South Water Market, Chicago, for the five-year period. This seemed to be the only way of determining the price of the product based on weight, since the bunched product was actually sold by count rather than weight, and all yield records were in terms of weight. The various seasons and various treatments had little influence on the relative weight of tops and roots. Weighings of samples at various times served as the basis for taking 55 percent of the total weight as representing the weight of the roots. and the limestone evidently improved conditions for its growth. From the standpoint of returns for each dollar invested in fertilizing ma- terials, limestone was more effective than any other treatment. Phosphorus brought less favorable response from beets than from most of the other crops in this experiment. An application of 2,000 pounds of rock phosphate each year gave very slight increase over no treatment. Superphosphate gave a greater increase than rock phos- phate, but the increase was not comparable to that obtained from the more balanced treatments. 140 120 22* i .i 2 z .4 a. 4 a % % i a a FIG. 7. RELATIVE YIELDS OF BEETS FROM VARIOUS FERTILIZER PLOTS A complete commercial fertilizer, without manure, gave the highest yield. These yields are based on the yield from the plot treated with 20 tons of manure taken as 100. 1932] FERTILIZER EXPERIMENTS WITH TEN MARKET-GARDEN CROPS 15 Muriate of potash used at the rate of 200 pounds an acre as a supplement to manure and bone gave an economical increase in beet yields. Beets are known to be heavy feeders on potash and the high tonnage removed per acre makes this crop very exacting. It is true that quite a large amount of the potash removed from the soil is con- tained in the tops ; but as the tops are usually removed with the roots, the bunched product being much more in demand than the roots alone, this fact does not lessen the need for potash applications. For the production of bunched beets commercial fertilizers are fully as effective as manure. Of the single-element applications nitrogen was most effective in promoting high yields, while superphosphate produced the most eco- nomical increases in yield. Peas Responded to Commercial Fertilizer Without Manure The yearly yields of garden peas are shown in Table 7. A thousand pounds of 4-8-6 fertilizer per acre produced the great- est average yield of pods. This treatment gave consistently high yields except for the first year. TABLE 7. YIELDS OF PEAS WITH VARIOUS FERTILIZER TREATMENTS 1 Plot Treatment Yield per acre 1925 1926 1927 1928 1929 Average 1 3 4 6 7 9 10 12 13 15 16 18 19 21 22 24 Manure (20 tons) Ibs. 382 952 614 430 768 008 030 818 519 900 828 728 783 786 2 023 2 182 1 508 Ibs. 3 043 3 488 3 753 2 829 1 263 2 659 2 622 2 960 2 717 2 295 2 273 2 853 2 440 2 304 2 697 2 557 2 263 Ibs. 3 540 4 309 5 820 4 410 4 152 4 770 3 746 6 180 3 562 4 410 3 698 4 775 4 790 3 266 4 970 4 310 3 340 Ibs. 6 315 6 417 6 625 5 305 3 662 4 078 4 263 5 950 7 170 6 015 5 618 5 030 4 720 5 139 5 845 5 715 3 928 Ibs. 4 987 5 650 6 325 5 855 4 049 4 515 4 128 5 659 5 465 6 185 5 800 6 295 6 430 4 988 6 480 5 245 4 015 Ibs. 3 855 4 363 4 827 3 966 2 979 3 606 3 358 4 511 4 087 4 161 3 843 4 136 4 033 3 497 4 203 4 002 3 Oil Manure, 4-8-6 4-8-6 Manure, 6-8-6 Lime Nitrogen Nitrogen, lime Blood, bone Manure, bone Blood, bone, potash Manure, bone, potash Superphosphate, lime Superphosphate Rock phosphate Manure, superphosphate Manure, rock phosphate Average of check plots 'Yields based on weight of marketable pods; unfilled pods at end of season were not included. The second highest average yield was produced from the use of blood and bone without any potash. The use of 20 tons of manure per acre was not conducive to con- sistently high yields, altho in two of the five years good yields were obtained. However, when 10 tons of manure was supplemented with 500 pounds of 4-8-6 fertilizer, quite high yields resulted. Fairly good, tho somewhat smaller yields were secured from the plot treated with 16 BULLETIN No. 377 [February, 10 tons of manure supplemented with 1,000 pounds of 4-8-6 fertilizer or 800 pounds of superphosphate. When used as supplements to manure, rock phosphate and bone meal were somewhat less effective than superphosphate. Nitrogen used alone was not a profitable fertilizer for peas on the dark-colored soil of Cook county (Table 8). Nitrogen in excess of available phosphorus and potassium retarded the growth of plants as well as total yield of pods. Some nitrogen is evidently needed, how- ever, as shown by the higher yields from the 4-8-6 mixture as com- pared with the yields from the phosphorus plots. The fact that Plot 3 yielded more than Plot 6 indicates that the amounts of nitrogen con- tained in a 4-8-6 mixture used at the rate of 1,000 pounds an acre as a supplement to manure are sufficient for the production of peas. Limestone applied at the rate of 3 tons an acre in 1925 and again in 1927 (making a total of 6 tons for the five-year period) gave no increase in average yields over the check plots. Also, the addition of limestone to superphosphate was not profitable (Table 9). When lime- stone was applied with nitrogen, the average yield was reduced rather than increased as compared with that from the use of nitrogen alone. Superphosphate showed a very economical increase when used alone at the rate of 800 pounds an acre (Table 8). The average yearly increase over the checks for the five-year period was more than 1,000 pounds an acre. The average increase from rock phosphate over the same period was 486 pounds. The use of sufficient available phos- phorus appears to be an important factor in producing high yields of peas. TABLE 8. ESTIMATED MONEY RETURNS FROM VARIOUS FERTILIZER TREATMENTS WITH PEAS Plot Treatment Cost of fertilizer per acre 1 Value of treatment based on increase over check plot 1 Returns from fertilizer for each dollar invested 1 Manure (20 tons) $40.00 $35.16 $ .88 3 Manure, 4-8-6 31.38 56.33 1.79 4 4-8-6 22.76 75.66 3.32 6 Manure, 6-8-6 34.74 39.79 1.14 7 Lime 3.00 -1.33 -.44 9 Nitrogen 23.10 24.79 1.07 10 Nitrogen, lime 26.10 14.45 .55 12 Blood, bone 39.70 62.50 1.57 13 Manure, bone 32.20 44.83 1.39 15 Blood, bone, potash 45.90 47.91 1.04 16 Manure, bone, potash 38.40 34.66 .90 18 Superphosphate, lime 10.72 46.87 4.37 19 7.72 42.58 5.51 21 Rock phosphate 16.00 20.25 1.26 22 27.72 49.66 1.79 24 Manure, rock phosphate 36.00 41.29 1.14 'Based on 1930 prices. The value of crop was obtained by dividing the yield in pounds by 24 (the weight of a bushel) and multiplying by $1.00, the estimated price per bushel based on a five-year average for July on the South Water Market, Chicago. 1932} FERTILIZER EXPERIMENTS WITH TEN MARKET-GARDEN CROPS 17 . Potash, whether used as a supplement to manure and phosphorus or blood and phosphorus, did not give an increased yield of peas as an average for the five years. 140 120 220 FIG. 8. CORRELATION OF WEIGHT OF PODS WITH WEIGHT OF PLANTS IN GARDEN PEAS GROWN UNDER SIXTEEN DIFFERENT SOIL TREATMENTS Large yields were associated with large development of the plants. The yield from the plot treated with 20 tons of manure was taken as 100. The pods were harvested at two pickings each year. There was an interval of ap- proximately one week between the pickings. Two years, 1926 and 1927, the vines were pulled and weighed at the time of the second picking; any un- filled pods were weighed with the vines. This graph is based on the average weights of pods and vines for those two years. The correlation between yield of pods and green weight of plants grown under 16 different soil treatments is shown in Fig. 8. It will be noted that the various fertilizers produced about the same relative increase in weight of vine growth as in weight of pods. The three highest-yielding plots, Plots 4, 12, and 3, also produced the heaviest growth of vines. Likewise the three lowest-yielding plots, Plots 7 21, and the untreated checks, produced the smallest vine growth. These tests show that high yields of peas may be obtained thru the use of commercial fertilizer applications without manure on the type of soil used in this experiment. Of the single-element applications superphosphate was the most profitable treatment. Higher yields were obtained from the use of a complete fertilizer without manure. As a supplement to 10 tons of manure an acre, phosphorus alone was nearly as effective as a complete fertilizer. Complete Fertilizer Gave Good Yields of Beans Results of experiments with green beans from the 16 different soil treatments show that high yields can be obtained without the use of manure or with one-half the amount of manure commonly used. Of 18 BULLETIN No. 377 [February, TABLE 9. YIELDS OF GREEN BEANS WITH VARIOUS FERTILIZER TREATMENTS 1 Plot Treatment Yield per acre 1925 1926 1927 1928 1929 Average 1 3 4 6 7 9 10 12 13 15 16 18 19 21 22 24 Manure (20 tons) Ibs. 1 384 2 462 1 352 1 404 1 289 693 1 074 1 800 1 800 1 402 2 070 2 071 2 146 1 592 1 347 2 340 1 044 Ibs. 2 676 1 555 2 347 1 559 1 907 1 244 801 1 830 1 853 1 023 1 733 1 953 2 177 1 694 3 167 1 929 1 057 Ibs. 3 259 2 719 2 991 2 866 1 415 2 018 1 865 1 964 3 264 2 479 3 260 2 448 2 667 2 548 3 949 2 913 1 921 Ibs. 4 363 6 325 6 920 6 888 2 489 3 175 3 212 5 863 5 065 4 938 5 435 3 399 2 310 2 758 5 109 4 802 2 901 Iftft, 5 095 4 855 5 250 4 960 2 555 2 530 2 570 4 425 4 965 5 260 5 510 4 300 4 990 3 330 6 090 5 240 2 637 Ibs. 3 355 3 583 3 772 3 533 1 931 1 932 1 904 3 177 3 389 3 020 3 602 2 834 2 858 2 384 3 932 3 445 1 912 Manure, 4-8-6 4-8-6 Lime Nitrogen Blood, bone Manure, bone Superphosphate, lime Manure, superphosphate Manure, rock phosphate Average of check plots l Yields based on weight of marketable pods. Small, undeveloped pods remaining after the last picking were not included. the 16 different plots 7 produced yields greater than the full manure treatment as an average for the five-year period (Table 9). The highest yields were obtained from the use of 10 tons of manure supple- FIG. 9. RELATIVE YIELDS or GREEN BEANS FROM VARIOUS FERTILIZER PLOTS Top row: Plot 19, superphosphate; untreated check; Plot 21, rock phos- phate. Middle row: Plot 22, manure and superphosphate; untreated check; Plot 24, manure and rock phosphate. Bottom row: Plot 22, manure and super- phosphate; untreated check; Plot 1, manure alone. The favorable influence of phosphorus is clearly shown. 1932] FERTILIZER EXPERIMENTS WITH TEN MARKET-GARDEN CROPS 19 mented with 800 pounds of superphosphate in three out of five years. One year the highest yield resulted from the use of 10 tons of manure supplemented with 500 pounds of 4-8-6 fertilizer, while in the other year 1,000 pounds of 4-8-6 without manure gave the greatest yield. The use of 20 tons of manure alone usually gave good yields, but phosphorus in addition to that contained in the manure had a tendency to promote greater production (Fig. 9). The results indicate that where 10 tons of manure are used to supply half the fertility, super- phosphate is fully as effective a supplement as is a complete fertilizer. Higher concentration of nitrogen than a 4-8-6 mixture did not increase the yield when used in connection with manure. The highest yields obtained without the use of any manure resulted from the use of a complete fertilizer. TABLE 10. ESTIMATED MONEY RETURNS FROM VARIOUS FERTILIZER TREATMENTS WITH BEANS Plot Treatment Cost of fertilizer per acre 1 Value of treatment based on increase over check plot 1 Returns from fertilizer for each dollar invested 1 Manure (20 tons) $40.00 $108.22 $2.70 3 Manure, 4-8-6 31.38 125.32 4.00 4 4-8-6 22.76 139.50 6.12 6 Manure, 6-8-6 34.74 121.57 3.50 7 Lime 3.00 1.42 .47 9 Nitrogen 23.10 1.50 .06 10 Nitrogen, lime 26.10 -.60 -.02 12 Blood, bone 39.70 94.87 2.39 13 Manure, bone 32.20 110.77 3.44 15 Blood, bone, potash 45.90 83.10 1.81 16 Manure, bone, potash 38.40 126. 75 3.30 18 Superphosphate, lime 10.72 69.15 6.45 19 Superphosphate 7.72 70.95 9.16 21 Rock phosphate 16.00 35.40 2.21 22 Manure, superphosphate 27.72 151.50 5.46 24 Manure, rock phosphate 36.00 114.97 3.19 'Based on 1930 series. The value of the crop was obtained by dividing the yield in pounds by 8 (the weight of a box) and multiplying by 60 cents, the estimated price per box based on a five-year average for August on the South Water Market, Chicago. Applications of nitrogen without other fertilizer resulted in low yields, as in the case of most other crops in the experiment. Single- element applications of superphosphate gave good returns for the amount of money invested in the material (Table 10). However, the more balanced treatments resulted in much higher yields. The use of ground limestone resulted in increased yields the first two years but in decreased yields the last three years as compared with the untreated check plots. For the five-year period the application of limestone was not profitable. Beans are considered tolerant to add conditions in the soil, and it therefore is not surprising that no con- sistent beneficial results were apparent from the use of the limestone. Superphosphate was more effective than either bone meal or rock 20 BULLETIN No. 377 [February, TABLE 11. GREEN WEIGHT OF BEAN PLANTS AND PERCENTAGE OF CROP MATURING AT FIRST PICKING Plot Treatment Green weight of plants per acre 1 Percent of crop maturing at first picking 1 1 Manure (20 tons) Ibs. 4 290 percl. 28.2 3 Manure, 4-8-6 3 950 29.9 4 4-8-6 4 010 28.7 6 Manure, 6-8-6 4 050 23.3 7 Lime 2 700 31.5 9 2 680 27.8 10 Nitrogen, lime : 2 460 27.5 12 Blood, bone 3 380 27.4 13 3 320 36.4 15 3 480 31.6 16 Manure, bone, potash 4 410 27.9 18 3 630 33.9 19 3 450 22.7 21 Rock phosphate 2 940 32.3 22 4 760 26.4 24 4 190 26.7 Average of check plots 3 080 29.2 'Three-year average, for the years 1925, 1926, and 1929. 'Five-year average. phosphate as a supplement to manure. When used without manure, superphosphate was much more effective than rock phosphate. A marked correlation existed between green weight of plants and weight of pods. 1 In general the heavier the growth of vines the greater the yield, as shown in Fig. 10. The high nitrogen plots had a slight tendency to increase vine growth at the expense of pods. The lowest yielding plots produced the lightest weight of plants. The effect of particular fertilizers on the earliness of maturity was 120 FIG. 10. CORRELATION OF WEIGHT OF BEAN PODS WITH WEIGHT OF PLANTS Weights of pods and of plants from Plot 1, treated with 20 tons of manure per acre, were taken as 100, and the products from other plots calculated in reference to them. There is a fairly close relation between yield of pods and size of plant. 'At the time of the last picking, the plants were pulled and weighed. Any small, undeveloped pods left on the plants at this time were weighed with the plants. 1932] FERTILIZER EXPERIMENTS WITH TEN MARKET-GARDEN CROPS 21 slight. Those plots which received optimum fertilizer applications produced the heaviest yield of pods at the first harvest. The percent- age of total pods maturing at the first harvest was fairly uniform on most plots, including the checks (Table 11). The increase in yield on the high-yielding plots was due both to an increase in number of pods per plant and an increase in the actual size of pods. The high-yielding plots produced pods which were longer and more filled out than those produced by plots less favorably treated. This is an important consideration in the sale of the product. Tomato Yields Doubled With Superphosphate and Manure Response of tomatoes to fertilizer treatment was quite pronounced, the high-yielding plots producing approximately double the yield of the untreated check plots. Yields from the 16 different fertilizer treat- TABLE 12. YIELDS OF TOMATOES WITH VARIOUS FERTILIZER TREATMENTS 1 Plot Treatment Yield per acre 1925 1926 1927 1928 1929 Average 1 3 4 6 7 9 10 12 13 15 16 18 19 21 22 24 Manure (20 tons) Ibs. 34 180 30 470 31 180 33 430 12 980 17 100 14 790 30 220 26 670 23 670 37 500 33 000 30 780 15 520 39 310 30 130 17 920 Ibs. 39 500 37 750 33 550 27 580 20 030 10 870 10 960 36 380 25 330 26 650 36 630 31 890 32 680 14 250 36 040 37 860 9 460 Ibs. 31 570 33 290 39 780 45 490 12 650 13 070 16 610 31 780 31 380 31 920 38 260 27 730 25 580 26 250 40 230 34 330 16 210 Ibs. 36 980 41 490 40 700 40 280 24 000 19 210 21 990 45 650 40 950 38 550 44 160 42 730 39 980 23 380 53 200 45 680 20 460 Ibs. 57 210 63 150 59 150 61 650 36 530 40 620 37 050 47 850 52 150 55 200 59 300 49 370 49 980 44 070 55 400 53 830 39 220 Ibs. 39 890 41 230 40 870 41 690 21 240 20 170 20 280 38 380 35 300 35 200 43 170 36 940 35 840 24 690 44 836 40 370 20 650 Manure, 4-8-6 4-8-6 Manure, 6-8-6 Lime Nitrogen Nitrogen, lime Blood, bone Manure, bone Blood, bone, potash Manure, bone, potash Superphosphate, lime Superphosphate Rock phosphate Manure, superphosphate Manure, rock phosphate Average of check plots 'The yield record includes marketable ripe fruits and also full-sized green fruits picked at end of season. ments and the average of all check plots, for the five-year period, are given in Table 12. Plot 1, which received 20 tons of manure annually, produced good yields thruout the test. The average yield from this manure treatment was nearly double that from the check plots. On Plot 3 half the manure was replaced by a 4-8-6 commercial fertilizer, and slightly higher average yields were produced. On Plot 4 all the manure was replaced by commercial fertilizer, and here the yields were slightly lower than on the half-manure and half- fertilizer plot but slightly higher than on the plot receiving manure alone. The use of a commercial fertilizer higher in nitrogen than a 4-8-6 22 BULLETIN No. 377 [February, formula gave a slight increase in yield, but the increase was not sufficient to pay for the additional cost of the material. Limestone at the rate of 3 tons an acre in alternate years gave an increase over check plots of approximately 600 pounds an acre. This increased production was worth slightly more than the cost of the material. The tomato is tolerant to an acid condition of the soil, and lime is evidently not an important factor in affecting the yield. When nitrogen was used alone, extremely low yields were obtained. In most years the yield was practically the same as from the check plots, and in no case did the increase pay for the cost of fertilizer. While the experiment shows by the yields from the first four plots that the tomato responds well to liberal applications of nitrogen in the presence of sufficient amounts of phosphorus and potash, it is evident that nitrate alone tends to produce low yields. On the other hand single-element applications of phosphorus in the form of superphosphate gave very economical increases in yield (Fig. 11). Altho the yield from superphosphate alone was not so high as from some of the more balanced treatments, the low cost of treatment was responsible for a very high return on the investment in fertilizer (Table 13). Over a longer period of time this might not hold true, for a deficiency in the nitrogen and potash might result. However, these results indicate that phosphorus is the most important element in the fertilization of the tomato in northern Illinois. CHK 19 CHK 21 FIG. 11. REPRESENTATIVE YIELDS OF TOMATOES FROM FOUR TREATED PLOTS COMPARED WITH YIELDS FROM UNTREATED CHECK PLOTS Treatments were as follows: Plot 4, 1,000 pounds 4-8-6 commercial ferti- lizer; Plot 9, 200 pounds nitrate of soda and 300 dried blood; Plot 19, 800 pounds superphosphate; Plot 21, 2,000 pounds rock phosphate. The high yields from a complete commercial fertilizer, without manure, are clearly shown. 1932} FERTILIZER EXPERIMENTS WITH TEN MARKET-GARDEN CROPS 23 TABLE 13. ESTIMATED MONEY RETURNS FROM VARIOUS FERTILIZER TREATMENTS WITH TOMATOES Plot Treatment Cost of fertilizer per acre 1 Value of treatment based on increase over check plot 1 Returns from fertilizer for each dollar invested 1 Manure (20 tons) $40.00 $240.50 $6.01 3 Manure, 4-8-6 31.38 257.25 8.19 4 4-8-6 22.76 252.75 11 10 6 Manure, 6-8-6 34.74 263.00 7.57 7 Li me 3.00 7.37 2.45 9 Nitrogen 23.10 6.00 .26 10 Nitrogen, lime 26.10 4.62 .17 12 Blood, bone 39.70 221.62 5.58 13 Manure, bone 32.20 183.12 5.68 IS Blood, bone, potash 45.90 181.87 3.96 16 Manure, bone, potash 38.40 281.50 7.33 18 Superphosphate, lime 10.72 203 . 65 18.98 19 Superphosphate 7.72 189.87 24.59 21 Rock phosphate 16.00 50.50 3.15 22 Manure, superphosphate 27.72 302 . 32 10.90 24 Manure, rock phosphate 36.00 246.50 6.84 'Based on 1930 prices. *The value of the crop was obtained by dividing the yield in pounds by 60 (the weight of a bushel) and multiplying by 75 cents, the estimated price per bushel based on a five-year average for August and September on the South Water Market, Chicago. Rock phosphate without manure gave very low yields in four of the five years. When used as a supplement to manure, better results were obtained, but in four out of five years superphosphate gave higher yields. It is evident that the tomato plant is capable of making better use of phosphorus in the form of superphosphate than in the form of rock phosphate, under the conditions of this experiment. Potash does not appear to be as important as nitrogen or phos- phorus for tomatoes, but on land which has been cropped with root crops and cabbage it would doubtless be a more important factor than on the land used in this experiment. Plot 16, which received 200 pounds of muriate of potash in addition to 10 tons of manure and 500 pounds of bone meal, was a very consistent high-yielding plot and was never lower than fourth in total yield. It yielded consistently higher than Plot 13, treated with manure and bone, without the potash. On the other hand, potash usually gave negative results where no manure was used. The wide variation in yield from the various fertilizer treatments is caused more by the increase in number of fruits per plant under the favorable treatments than by the increase in weight of individual fruits. The correlation of number and weight of fruits to total yield is shown in Fig. 12 and Table 14. In constructing Fig. 12, Plot 1 was taken as 100 for size, number, and total yield; the results from the other 15 plots are expressed in relation to that plot. The largest number of fruits per plant was on the manure plot, while the smallest number was on the nitrogen plot. Plots 7, 9, 10, and 21, which gave consistently low yields, also showed a great reduction 24 BULLETIN No. 377 [February, TABLE 14. EFFECT OF FERTILIZERS ON TOMATO YIELDS, INCLUDING SIZE OF FRUITS, NUMBER OF FRUITS, AND EARLINESS OF MATURITY (Based on five-year average) Plot Treatment Average weight of individual fruits Average number fruits per plant Percent of crop ripening during first half of harvest 1 Manure (20 tons) grams 126.3 66.2 perct. 19.5 3 Manure, 4-8-6 128.5 54.3 19.8 4 4-8-6 130.0 59.7 18.9 6 Manure, 6-8-6 136.7 61.4 18.1 7 Lime 130.0 28.4 13.0 9 125.0 25.2 15.3 10 Nitrogen, lime 122.0 26.4 11.4 12 Blood, bone 136.3 56.1 16.2 13 129.0 54.5 18.5 15 Blood, bone, potash 126.7 52.0 19.3 16 Manure, bone, potash 127.2 53.4 19.0 18 Superphosphate, lime 133.5 43.3 20.5 19 124.0 44.7 22.6 21 Rock phosphate 128.9 32.3 12.8 22 Manure, superphosphate 133.6 56.6 20.0 24 Manure, rock phosphate 125.0 60.4 19.7 Average of check plots 123.1 30.9 15.0 in number of fruits per plant. In fact there is a marked correlation of number of fruits set to total yield. Altho no data are available, ob- servations in the field showed that size of top growth was closely cor- related with number of fruits. Plants with the most rank growth of tops produced the greatest number of fruits and in turn a high total yield. On the other hand, the average weight of individual fruits from the various plots did not vary to any great extent. The greatest 120 100 TOTAL YIELD NUMBER OF FRUITS SIZE OF FRUITS 1346 cb Yield records are based on marketable fruit. No record was taken of the number or weight of partially developed fruits at frost time. 26 BULLETIN No. 377 [February, TABLE 16. ESTIMATED MONEY RETURNS FROM VARIOUS FERTILIZER TREATMENTS WITH GREEN PEPPERS Plot Treatment Cost of fertilizer per acre 1 Value of treatment based on increase over check plot 1 Returns from fertilizer for each dollar invested 1 Manure (20 tons) $40.00 $64.03 $1.60 3 Manure, 4-8-6 31.38 63.56 2.02 4 4-8-6 22.76 67.13 2 94 6 Manure, 6-8-6 34.74 74.03 2.13 7 Lime 3.00 3.73 1.24 9 Nitrogen ' 23.10 13.40 .58 10 Nitrogen, lime 26.10 6.90 .26 12 Blood, bone 39.70 80.06 2.01 13 32.20 37.90 1 17 IS Blood, bone, potash 45.90 28.40 .61 16 Manure, bone, potash 38.40 43.16 1.12 18 10.72 57.66 5 37 19 Superphosphate 7.72 39.66 5.13 21 Rock phosphate 16.00 10.63 .66 22 Manure, superphosphate 27.72 97.33 3.51 24 Manure, rock phosphate 36.00 67.90 1.88 'Based on prices for 1930. The value of the crop was obtained by dividing the yield in pounds by 24 (the weight of a bushel) and multiplying by 80 cents, the estimated price per bushel based on a five-year average for August and September on the South Water Market, Chicago. raw rock phosphate nor bone meal was comparable to superphosphate as a supplement for manure. Also, superphosphate alone was superior to rock phosphate as a source of phosphorus. Fertilizer high in nitrogen, such as 6-8-6, gave higher yields than the medium nitrogen, when used to supplement manure. When used alone, however, nitrogen was not conducive to high yields and resulted in a loss of money (Table 16). Plot 12, which received 500 pounds of dried blood and 500 pounds of bone meal, produced a higher aver- TOTAL YIELD ......NUMBER OF FRUITS SIZE OF FRUITS 5 2 FIG. 13. RELATION OF NUMBER OF PEPPERS PER PLANT AND SIZE OF FRUITS TO TOTAL YIELD Differences in yield were influenced more by number than by size of fruits. The yield of Plot 1, treated with 20 tons of manure per acre, was taken as 100. 1932] FERTILIZER EXPERIMENTS WITH TEN MARKET-GARDEN CROPS 27 age yield than manure supplemented with a complete fertilizer, but not so high a yield as manure supplemented with superphosphate. The relation of total yield to number of fruits per plant and size of individual fruits is shown in Fig. 13. The total yield was affected more by the number of fruits than by differences in the size of the TABLE 17. EFFECT OF FERTILIZERS ON PEPPER YIELDS, INCLUDING SIZE OF FRUITS, NUMBER OF FRUITS, AND EARLINESS OF MATURITY (Based on five-year average) Plot Treatment Average weight of individual fruits Average number fruits per plant Weight of fruit maturing during first half of season Percent of crop maturing during first half of season 1 Manure (20 tons) grams 69.3 6.06 Ibs. 149.4 perct. 19.5 3 Manure, 4-8-6 67.0 6.28 169 2 23.6 4 4-8-6 76.2 6.11 192.0 24.8 6 Manure, 6-8-6 72.9 6 48 208 5 26 4 7 Lime 67.9 4.06 105.7 12 4 9 Nitrogen 68.4 4.31 88.3 9.8 10 Nitrogen, lime 62.9 4 44 83 7 9 1 12 Blood, bone 67.0 7.01 182.8 21.7 13 Manure, bone 63.4 5.77 110.4 15.3 15 Blood, bone, potash 66.6 4.36 105.8 12.1 16 Manure, bone, potash 65.3 6.39 148.6 14.8 18 Superphosphate, lime 67.9 6.12 186.8 22.7 19 70.2 5.20 179 5 23.9 21 Rock phosphate 64.3 4.87 77.2 9.1 22 Manure, superphosphate 77.1 7.83 218.0 24.8 24 Manure, rock phosphate 66.6 6.57 144.9 18.2 Average of check plots 64.3 4.08 83.8 9.7 fruits (Table 17). Those fertilizers which produced the highest total yields produced larger plants with more fruits, while the size of the fruits did not vary nearly so much. Certain fertilizers, however, had a tendency to increase the size of the fruits. The factor of earliness is often more important than total yield with market-garden crops, as the price declines rapidly when the bulk of the crop comes on the market. Complete commercial fertilizers and superphosphate were conducive to earliness, while rock phosphate was less effective in the production of early peppers. The influence of various fertilizers on earliness is shown in Table 17. When the variation in cost of the fertilizer treatments is considered (Table 16), it will be noted that certain plots showed a much greater economic return than others. The greatest returns for each dollar invested in fertilizer were from superphosphate and superphosphate and lime. Superphosphate also added greatly to the returns from manure. The high cost of dried blood reduced the net returns from Plot 12, in spite of the high yield. Limestone, while not producing a great increase over the check plots, showed a good return for the cost of treatment. 28 BULLETIN No. 377 [February, Phosphorus With Manure Gave Good Yields of Carrots Carrots responded readily to fertilizer treatment, particularly to manure supplemented with phosphorus. Of the 16 plots treated with different fertilizers 6 produced higher yields than the plot treated with 20 tons of manure, while 9 produced lower yields. The relative response of carrots to different fertilizer treatments is given in Table 18 and Fig. 14. TABLE 18. YIELDS OF CARROTS WITH VARIOUS FERTILIZER TREATMENTS' PW 1 field per acr e 1926 1927 1928 1929 Average 1 Manure (20 tons) Ibs. 13 060 Ibs. 9 990 Ibs. 27 050 Ibs. 65 450 Ibs. 28 887 3 Manure, 4-8-6 11 230 10 410 25 820 61 450 27 227 4 4-8-6 11 030 12 230 25 490 60 750 27 375 6 Manure, 6-8-6 12 620 11 170 26 550 69 150 29 872 7 Li me 2 751 9 140 20 650 55 900 22 110 9 9 080 9 090 28 070 59 050 26 322 10 Nitrogen, lime 8 940 7 800 22 350 50 700 22 447 12 Blood, bone 10 460 10 090 20 150 67 600 27 075 13 12 290 9 090 36 800 62 500 30 170 IS Blood, bone, potash 9 960 9 140 36 150 66 700 30 487 16 Manure, bone, potash 14 100 8 490 38 500 61 900 30 747 18 Superphosphate, lime 9 470 10 140 32 320 59 500 27 857 19 Superphosphate 8 370 10 510 38 050 57 500 28 607 21 Rock phosphate 10 200 7 150 29 860 50 900 24 527 22 16 350 10 770 38 850 69 500 33 867 24 Manure, rock phosphate 19 340 8 170 35 800 64 200 31 877 Average of check plots 7 640 7 070 24 150 40 540 19 850 'Yields are based on weight of marketable roots after they were topped. An annual application of 20 tons of manure gave an increase of practically 41/2 tons an acre over the average of the check plots. When a 4-8-6 commercial fertilizer was used at the rate of 1,000 pounds an acre, the increase was slightly less. The use of 500 pounds of a 6-8-6 fertilizer in addition to 10 tons of manure gave an increase of more than 5 tons an acre over the average from the check plots. 120 100 FIG. 14. RELATIVE YIELDS OF CARROTS FROM VARIOUS FERTILIZER TREATMENTS The plot treated with manure and superphosphate showed the highest yield. The yield from the plot treated with 20 tons of manure was taken as 100. 1932} FERTILIZER EXPERIMENTS WITH TEN MARKET-GARDEN CROPS 29 Limestone failed to produce consistent increases in yield. Nitrogen used alone produced some increase in yield but not so great an in- crease as the more balanced fertilizers. Superphosphate used alone (Plot 19) produced a very economical increase in yield (Table 19). The highest yields resulted from the use of manure and phosphorus. Superphosphate was superior both to bone meal and to raw rock phosphate when used in combination with manure. TABLE 19. ESTIMATED MONEY RETURNS FROM VARIOUS FERTILIZER TREATMENTS WITH CARROTS Plot Treatment Cost of fertilizer per acre 1 Value of treatment based on increase over check plot 1 Returns from fertilizer for each dollar invested 1 Manure (20 tons) $40.00 $90 37 $2 25 3 Manure, 4-8-6 31.38 73.77 2 35 4 4.8-6 22.76 75 25 3 30 6 Manure, 6-8-6 34.74 100.22 2 88 7 Lime 3.00 22.60 7.53 9 Nitrogen 23.10 64 72 2 80 10 Nitrogen, lime 26.10 25.97 .99 12 Blood, bone 39.70 72.25 1.82 13 Manure, bone 32.20 103 20 3 20 15 Blood, bone, potash 45.90 106.37 2 31 16 38.40 108 97 2 83 18 Superphosphate, lime 10.72 80 07 7 46 19 Superphosphate 7.72 87.57 11.34 21 Rock phosphate 16 00 46 77 2 92 22 Manure, superphosphate 27.72 140.17 5.05 24 Manure, rock phosphate 36.00 120.27 3.34 'Based on 1930 prices. The value of the crop was obtained by dividing the yield in pounds by 70 (the weight of a sack) and multiplying by 70 cents, the estimated price per sack based on a five-year average for October on the South Water Market, Chicago. The use of 200 pounds of muriate of potash resulted in a slight financial gain when used in addition to blood and bone. In general, carrots showed a greater response to nitrogen than most other crops in the experiment. Plot 6, which was treated with a high nitrogen fertilizer in addition to 10 tons of manure, outyielded Plot 3, which received a fertilizer with a medium nitrogen content, in each of the four years. Ten tons of manure with 800 pounds of super- phosphate produced the highest average yield. Potato Yields Showed Wide Variations Yields from 16 different fertilizer treatments with potatoes varied from approximately 21 to 105 bushels an acre. In four out of five years the highest yield resulted from the use of 10 tons of manure and 800 pounds of superphosphate (Table 20). This treatment also gave by far the highest average yield for the five-year period (Fig. 15). The second highest average yield was produced on Plot 6, which received a 500-pound application of 6-8-6 fertilizer in addition to 10 tons of manure. The potato requires considerable nitrogen, as is shown 30 BULLETIN No. 377 [February, TABLE 20. YIELDS OF POTATOES WITH VARIOUS FERTILIZER TREATMENTS* Plot Treatment Yield per acre 1925 1926 1927 1928 1929 Average 1 3 4 6 7 9 10 12 13 15 16 18 19 21 22 24 Manure (20 tons) Ibs. 2 861 2 928 2 571 3 494 1 868 2 005 2 116 1 843 2 320 3 198 3 694 2 471 2 287 2 176 3 809 2 939 2 090 Ibs. 2 522 2 221 3 043 4 716 3 423 1 432 1 386 2 756 3 346 1 239 2 430 3 186 4 221 1 795 5 899 2 277 1 320 Ibs. 4 057 4 484 3 738 3 538 2 079 2 470 2 329 2 960 4 163 2 798 3 027 2 012 2 358 2 903 3 201 3 025 2 310 Ibs. 3 589 4 264 4 261 3 641 2 336 1 553 1 677 3 509 4 236 3 224 4 450 3 221 2 376 3 526 6 296 4 404 2 312 Ibs. 3 715 3 970 3 845 4 185 3 015 1 515 2 335 3 355 3 455 3 895 4 130 3 450 2 890 2 900 5 005 3 920 2 763 Ibs. 3 349 3 573 3 492 3 915 2 544 1 795 1 969 2 885 3 504 2 871 3 566 2 868 2 826 2 660 4 842 3 313 2 159 Manure, 4-8-6 4-8-6 Manure, 6-8-6 Lime Blood, bone Manure, bone, potash Rock phosphate Manure, superphosphate Average of check plots 'Yields are based on weight of marketable tubers only; small tubers not included. by the fact that the yields from Plot 6 were higher than from Plot 3, which received a 4-8-6 mixture in addition to 10 tons of manure. Ni- trogen, however, in excess of available phosphorus and potassium, was not conducive to high yields, as evidenced by the results from Plot 9, which received nitrogen alone, and Plot 10, which received nitrogen and lime. i FIG. 15. RELATIVE YIELDS OF POTATOES FROM VARIOUS FERTILIZER TREATMENTS By far the highest yield was from the plot treated with manure and super- phosphate. The yield from the plot treated with 20 tons of manure was taken as 100. 1932] FERTILIZER EXPERIMENTS WITH TEN MARKET-GARDEN CROPS 31 Twenty tons of manure on Plot 1 gave an increase of approxi- mately 20 bushels an acre over the check plots, but this was not an economical increase owing to the high cost of the material. The re- turn for each dollar invested in the manure was only 49 cents (Table 21). When half the manure was replaced by 500 pounds of commer- cial fertilizer, the yields were higher but still not profitable. One thousand pounds of commercial fertilizer on Plot 4 gave an average yield practically equivalent to that on Plot 3, where 10 tons of manure was used together with 500 pounds of the same kind of fertilizer. TABLE 21. ESTIMATED MONEY RETURNS FROM VARIOUS FERTILIZER TREATMENTS WITH POTATOES Plot Treatment Cost of fertilizer per acre 1 Value of treatment based on increase over check plot* Returns from fertilizer for each dollar invested 1 Manure (20 tons) $40.00 $19.83 $ .49 3 Manure, 4-8-6 31.38 23.56 .75 4 4-8-6 22.76 22 21 .97 6 Manure, 6-8-6 34.74 29.26 .84 7 Lime 3.00 6.42 2.14 9 Nitrogen 23 10 6 06 26 10 Nitrogen, lime 26.10 3.16 .12 12 Blood, bone 39.70 12.10 .32 13 32 20 22.41 .69 15 Blood, bone, potash 45.90 11.86 .25 16 Manure, bone, potash 38.40 23.45 .61 18 10.72 11.81 1.10 19 Superphosphate 7.72 11.11 1.44 21 Rock phosphate 16.00 8.35 .52 22 Manure, superphosphate 27.72 44.71 1.61 24 Manure, rock phosphate 36.00 - 19.23 .53 'Based on 1930 prices. 'The value of the crop was obtained by dividing the yield in pounds by 60 (the weight of a bushel) and multiplying by $1.00, the estimated price per bushel based on a five-year average for October on the South Water Market, Chicago. The use of 200 pounds of muriate of potash either with or without manure did not show any significant increase in yield as an average for the five years. Superphosphate alone and with limestone gave increases in yield of between 11 and 12 bushels an acre. Rock phosphate was not so val- uable as superphosphate when used either alone or as a supplement to manure. Commercial Fertilizer Gave High Cauliflower Yields The responses of cauliflower to various fertilizer treatments for one year, 1927, are given in Table 22. This crop was a failure the other four years. The 1927 results indicate that commercial fertilizers are capable of replacing manure, since Plot 4, which received 1,000 pounds of 4-8-6 fertilizer without manure, gave the highest yield. Twenty tons of manure showed a smaller increase over the checks than a straight chemical fertilizer. When half the manure was re- placed by 500 pounds of commercial fertilizer, higher yields resulted 32 BULLETIN No. 377 [February, TABLE 22. YIELDS OF CAULIFLOWER FROM VARIOUS FERTILIZER TREATMENTS, 1927 1 Plot Treatment Yield per acre* 1 Manure (20 tons) Ibs. IS 670 3 Manure, 4-8-6 19 690 4 4-8-6 20 120 6 Manure, 6-8-6 18 300 7 Lime 10 540 9 Nitrogen 14 550 10 Nitrogen, lime 15 030 12 Blood, bone 18 340 13 Manure, bone 16 950 15 Blood, bone, potash 15 270 16 Manure, bone, potash 16 670 18 Superphosphate, lime 13 580 19 Superphosphate 15 700 21 Rock phosphate 15 170 22 Manure, superphosphate 18 300 24 Manure, rock phosphate 15 150 Average of check plots 11 650 ^The cauliflower produced a marketable crop only one year out of the five. Three years the plants ailed in the seed bed, and another year the character of the heads was so poor that no yield records were taken. 'Yields are based on weight of heads as trimmed for market. than from the use of manure alone. The results from Plot 6 as com- pared with those from Plot 3 indicate that a higher concentration of nitrogen than a 4-8-6 mixture is not needed. The plot treated with limestone produced a lower yield than the average of the check plots. The use of nitrogen without phosphorus or potash on Plots 9 and 10 showed a fair increase in yield over the check plots, but the yields were considerably lower than on some of the more balanced treat- ments. Blood and bone on Plot 12 gave the third highest yield. The application of 200 pounds of muriate of potash on Plots 15 140 120 FIG. 16. RELATIVE YIELDS OF CAULIFLOWER FROM VARIOUS FERTILIZER TREATMENTS Exceptionally good yields were secured from a complete commercial ferti- lizer without manure. The yield from the plot treated with 20 tons of manure was taken as 100. 1932] FERTILIZER EXPERIMENTS WITH TEN MARKET-GARDEN CROPS 33 and 16 failed to increase yields above those obtained with correspond- ing treatments from which potash was omitted. Nitrogen and phos- phorus are evidently more important than potash for the produc- tion of cauliflower on the soil used in these experiments. Phosphorus used alone failed to produce yields comparable to those from the more balanced treatments. When used alone, rock phosphate was almost as effective as superphosphate for the produc- tion of cauliflower. As a supplement to manure, however, superphos- phate gave higher yields than either rock phosphate or bone meal. The one season's results indicate that for cauliflower a high- grade fertilizer, such as a 4-8-6 formula, applied at the rate of 1,000 pounds an acre will produce good yields (Fig. 16). Superphosphate used as a supplement to manure is nearly as effective as a complete fertilizer used in the same way. Manure Substitutes Proved Value With All Ten Crops From these experiments it is evident that economical yields of high-quality produce can be obtained by using commercial fertilisers without manure. With all ten crops higher yields were obtained from 10 tons of manure supplemented either with phosphorus or with a complete fertilizer than from 20 tons of manure used alone (Table 23). In fact, with each of the ten crops the average yield obtained from the 20-ton manure treatment ranked lower than fourth among the yields from the different fertilizer treatments. Nine of the ten crops gave higher yields from 1,000 pounds of 4-8-6 mixture than from 20 tons of manure. The value of some manure in the fertilizing of vegetable crops is demonstrated by the fact that with seven of the ten crops grown in these experiments the highest yields were obtained on the plots where 10 tons of manure was supplemented with some form of commercial fertilizer. Six of the seven crops responded as well to manure and phosphorus as to manure and a complete fertilizer. In practically every case where no manure was used, higher yields resulted from a complete fertilizer than from an incomplete fertilizer. Three crops peas, beets, and cauliflower gave the highest yields from 1,000 pounds of 4-8-6 fertilizer without manure. With spinach, beans, and potatoes this treatment gave the second highest yield, while with lettuce the straight 4-8-6 mixture gave the third highest yield. Another significant fact brought out by these experiments is the extremely poor showing of nitrogen alone. With nine of the ten crops, the two nitrogen plots (Plots 9 and 10) were among the five lowest yielding; while with only one crop was the plot treated with super- 34 BULLETIN No. 377 a o H "a g s Q >< iJ O B Average of ten crops 8t^. r e 81/^X^t^^^r^-o ifs^oaov 8^lrO'O-<0 OOvOl^M 8<*5i -H <) 'OOO O C Co cs4 iu 4; ' T w 2: M 1932] FERTILIZER EXPERIMENTS WITH TEN MARKET-GARDEN CROPS 35 phosphate alone among the five lowest yielding. Evidently when the vegetable crops used in these tests are grown on the dark-colored soil of Cook county, nitrogen is not so limiting a factor as phosphorus. However, in the presence of sufficient amounts of available phosphorus and potassium, heavy applications of nitrogen were conducive to high yields of most of these vegetables. . Plot 6, which received a heavy application of nitrogen besides sufficient amounts of phosphorus and potash,. gave consistently high yields. Limestone gave an increase over the check plots with eight of the ten crops, tho with only five crops was the increase significant. Beets, spinach, lettuce, potatoes, and carrots showed the greatest increase for the lime treatment, with respective increases of 22.81, 22.12, 20.92, 17.83, and 11.38 percent. Cauliflower and peas showed decreases of 9.52, and 1.06 percent respectively, while peppers, tomatoes, and beans showed slight increases. With six crops limestone and superphosphate gave higher yields than superphosphate alone, altho with the exception of the spinach, lettuce, and pepper yields the differences were slight. A comparison of rock phosphate and superphosphate as sources of phosphorus for vegetable crops is given by Plots 19 and 21. With each of these ten crops an annual application of 800 pounds of 16- percent superphosphate gave higher yields than 2,000 pounds of rock phosphate. The percentage increases in favor of superphosphate over rock phosphate were as follows: tomatoes, 45.16; lettuce, 28.85; spinach, 27.55; peppers, 25.91; beans, 19.88; carrots, 16.63; peas, 15.32; beets, 14.60; potatoes, 6.24; and cauliflower, 3.49. The great response of all the crops to phosphorus is ample evidence that this material is of much more importance than nitrogen or potash in the fertilization of vegetable crops on the dark-colored soil of Cook county. When used as a supplement to manure, superphosphate was superior both to rock phosphate and to bone meal with eight of the ten vege- tables. Spinach showed a greater response to rock phosphate, while with beets bone meal gave higher yields. The difference between the yield from superphosphate and that from rock phosphate, when used as a supplement for part of the manure, was considerably less than when the two materials were used alone, except in the case of lettuce, potatoes, and cauliflower. The use of 200 pounds of muriate of potash increased the average yields of spinach, beets, and carrots whether it was used to supplement blood and bone or manure and bone. Tomatoes, lettuce, and beans gave considerable increase from potash when used to supplement manure and bone but not when used to supplement blood and bone. The other crops showed no consistent increases from the use of potash. 36 BULLETIN No. 377 SUMMARY 1. Results of fertilizer experiments with ten vegetable crops in Cook county over a five-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 when the greater quantity of manure was used. With most of the crops included in this experiment com- parable yields were secured when the entire amount of manure was replaced by commercial fertilizer. 3. When no manure was used, complete fertilizers were more con- ducive to high yields than incomplete fertilizers. When 10 tons of manure was used, superphosphate was fully as effective as a complete fertilizer with many crops, altho with four of the crops (spinach, peas, beets, and cauliflower) a complete fertilizer gave higher yields than phosphorus as a supplement to manure. 4. Nitrogen alone was not a profitable fertilizer on the dark-colored soil of Cook county on which these experiments were conducted. 5. Limestone increased the yields of most of the crops to some ex- tent, tho with only five of the crops (beets, spinach, lettuce, potatoes, and carrots) were the increases significant. UNIVERSITY OF ILLINOIS-URBAN*