Fertilizing Tomatoes, Sweet Corn, and Muskmelons in a Three- Year Rotation By J. W. Lloyd «> % ■''**,, UNIVERSITY OF ILLINOIS AGRICULTURAL EXPERIMENT STATION BULLETIN 364 CONCLUSIONS rrr^HE EXPERIMENTS described in this bulletin justify the I following conclusions concerning the fertilizing of musk- -^ melons, tomatoes, and market sweet corn in central Illinois: 1. It is not feasible to substitute cover crops for manure in the production of these vegetables in a three-year rotation on dark- colored silt loam in the Illinois corn belt. 2. Even when used as supplements to manure, fall-sown cover crops plowed under in spring are more likely to reduce than to in- crease the yields of the three crops in question. 3. Manure is essential to the production of satisfactory crops of muskmelons on the type of soil used in this experiment. 4. The yields of all three crops may be increased by supplement- ing manure with limestone, as compared with the use of manure alone. 5. Phosphorus has a very beneficial influence on the yield of to- matoes and in some combinations increases the yield of melons and corn also. 6. Potassium, in the quantities and combinations used in this experiment, is of doubtful benefit to any of the three crops grown. 7. Good crops of tomatoes may be grown on dark-colored silt loam without the use of manure provided phosphorus and nitrogen are adequately supplied thru the use of commercial ferti- lizers. Steamed bone meal and dried blood are good sources of phosphorus and nitrogen for this purpose. 8. The sweet-corn crop is not of sufficient value per acre to justify the use of large quantities of fertilizing material especially for its production. 9. In a three-year rotation of the three crops in question an economical fertilizing program would be to apply manure and lime- stone for melons the first year, steamed bone and dried blood for tomatoes the second year, and no fertilizer for the corn the third year of the rotation. Urbana, Illinois January, 1931 Publications in the Bulletin series report the results of investigations made or sponsored by the Experiment Station Fertilizing Tomatoes, Sweet Corn, and Musk- melons in a Three- Year Rotation By J. W. Lloyd, Chief in Olericulture f |r n^OMATOES, sweet corn, and muskmelons are three im- I portant truck crops that may be grown successfully in the J_Lcorn belt. Each of these crops, however, requires either a relatively rich soil or heavy fertilizing. In the past, truck growers have depended primarily upon stable manure for enriching the soil, but this material has become more difficult to obtain and higher in price since the extensive substitution of motor vehicles for horses. With a view to rinding, if possible, a means of maintaining the soil in suitable condition for the production of tomatoes, sweet corn, and muskmelons without the use of such large quantities of manure as have ordinarily been considered necessary, an experi- ment in soil treatment for these crops was started in 1920 and continued for six years. The crops were grown in a three-year ro- tation on three series of plots so that each crop was grown ever> year. Two full rotations were completed. The experiment included tests to determine the feasibility of supplementing a moderate application of manure with various com- mercial fertilizing materials for the production of these vegetables, the possibility of supplementing manure with leguminous cover crops or even substituting cover crops and commercial nitrogen for manure as a means of supplying organic matter and nitrogen, and the possibility of growing the crops in question by using com- mercial fertilizer alone. PLAN OF THE EXPERIMENT Arrangement of Plots Three series of plots were laid out at Urbana on dark-colored silt loam soil that previously had been used for the production of corn and other field crops without special fertilizing. There were 22 plots in each series. Each plot was 2 by 4 rods in area, thus comprizing exactly one-twentieth of an acre. Border strips Yz rod wide separated adjacent plots, and driveways 1 rod wide separated the different series. The plots in each series were numbered from 1 to 22 and the corresponding plots in the three series received identical treatment. Bulletin No. 364 [January, Fertilizing Materials Used Treatment of the various plots was as follows: Plot Treatment 1. Manure 2. Manure, limestone 1 3. Manure, limestone, bone meal 4. Manure, limestone, bone meal, potassium sulfate 5. Bone meal, dried blood, potassium sulfate 6. Check 7. Cover crop, manure, limestone 8. Cover crop, manure, limestone, bone meal 9. Cover crop, manure, limestone, rock phosphate 10. Cover crop, manure, limestone, superphosphate (acid phos- phate) 11. Cover crop, manure, limestone, bone meal, potassium sulfate 12. Cover crop, limestone, bone meal, nitrate of soda 13. Cover crop, limestone, bone meal, dried blood, potassium sul- fate 14. Check 15. Cover crop, limestone 16. Cover crop, limestone, bone meal 17. Cover crop, limestone, rock phosphate 18. Cover crop, limestone, superphosphate (acid phosphate) 19. Cover crop, limestone, bone meal, potassium sulfate 20. Check 21. Poultry manure 22. Cover crop, limestone, bone meal, ammonium sulfate OTests showed that the soil used in this experiment had a limestone requirement of 2 to 2V2 tons an acre.) Table 1. — Amounts of Fertilizer Applied in Experiments With Tomatoes, Muskmelons, and Sweet Corn Fertilizer Per acre Per plot Frequency of application 10 tons 2 tons 500 pounds 1000 pounds 500 pounds 200 pounds 500 pounds 300 pounds 220 pounds 1 ton }4 ton 200 pounds 25 pounds 50 pounds 25 pounds 10 pounds 25 pounds 15 pounds 11 pounds 100 pounds Poultry manure annually The quantities of the various fertilizing materials used, whethe applied alone or in combination, are given in Table 1. Methods of Applying the Materials The first application of limestone was made in the spring, after plowing, while the other application (three years later) was mad< 1931] Fertilizing Tomatoes, Sweet Corn, and Muskmelons 5 in the fall and worked into the soil while preparing the seed bed for the cover crops. The manure was invariably applied broadcast in the spring shortly before plowing, while the other fertilizers, with the exception of sodium nitrate, were applied broadcast after the plowing and were thoroly mixed with the surface soil by disk- ing and harrowing. The nitrate of soda was applied as top dress- ings in three equal applications at intervals of two weeks, beginning after the respective crops had been planted from 3 to 4 weeks. The plots designated as receiving cover-crop treatment were seeded to the cover crop each year after the vegetable crop had been harvested. Hairy vetch alone was used for the cover crop wherever it could be sown early enough to make a good growth before winter. Early sowing was possible following the sweet corn but seldom following the other two crops. Where late sowing was necessary, a mixture of equal parts of hairy vetch and rye was used. Whether used alone or in combination the vetch was sown at the rate of 40 pounds an acre. The object of using the rye in the late sowing was to afford the small vetch plants as much winter protection as possible, and to make sure of having a supply of humus to plow under in the spring even if the late sown vetch should be winterkilled. The cover crops were plowed under at dates varying from April 20 to May 9 in the different series and different years. At the time of plowing the cover crop was usu- ally from 12 to 18 inches tall. Over 10 tons of green material per acre was sometimes plowed under. Distances of Planting For planting the tomato plots, large, pot-grown plants were used. These were set in rows 5]/£ feet apart with the plants 4 feet apart in the row, making 96 plants to the plot. At the begin- ning of the experiment the melons were planted in hills the same distance apart as the tomatoes, but on account of the heavy vine growth the second season the distance was changed to 5i/£ by 5}/£ feet for the third and subsequent years. Thus there were 72 hills to each plot after the first two years. The corn was planted in hills 40 inches apart each way. Five kernels were planted in each hill and the stalks thinned later to 3 in a hill. Varieties Used The variety of melon used thruout the experiment was the Pol- lock Ten-Twenty-Five. The Bonny Best tomato was used the 6 Bulletin No. 364 [January, first four years, but it was so severely attacked by Fusarium wilt the fourth year that the wilt-resistant strain of New Century was substituted in the fifth and sixth years. Golden Giant sweet corn was grown the first three years but did not prove well adapted to this locality; and, beginning with the fourth year, the Howling Mob was substituted. The original planting of corn the last year of the experiment was of this variety, but on account of dry weather it failed to produce a stand of plants. Replanting was therefore necessary, and in the absence of sufficient seed of this variety, the Narrow Grain Evergreen was substituted since it was then too late in the season to secure a fresh supply of the Howling Mob seed. Care and Harvesting of the Crops The crops were given good cultivation, and the tomatoes and melons were sprayed or dusted as often as necessary for protection from insects and foliage diseases. About a month after planting, the melons were thinned to two plants in a hill. The melon vines were trained lengthwise of the rows to facilitate cultivation, spray- ing, and harvesting. The tomatoes were grown without artificial support of any kind. As soon as any ripe fruits appeared, harvesting of the tomatoes and melons was started, and pickings were made at frequent in- tervals as long as any marketable fruits were available. The har- vesting of the corn was usually made in three pickings. Grading Products and Recording Yields The tomatoes and melons gathered at each picking were graded into No. l's, No. 2's, and culls on the basis of the grades described in Bulletins 144 1 and 124 of this Station. The corn was separated into two grades — marketable and culls. Each grade in all products was weighed separately, and the melons and ears of corn were counted as well as weighed. In reporting yields in this publication only the products of marketable grade are considered, and for the sake of brevity only the six-year aver- ages are given rather than the yields for each of the six years. In order to show the influence of a given fertilizing material the yields of all plots to which that material was applied are- grouped in a table for comparison with yields from plots which re- ceived similar treatment, with the exception of the one material under consideration in each case. 'Bulletin 144 is no longer available. 1931] Fertilizing Tomatoes, Sweet Corn, and Muskmelons 7 RESULTS OF EXPERIMENT Manure Increased Yields of All Three Crops In all combinations manure increased the yields of melons and corn, and except in two combinations, increased the yields of to- matoes also (Table 2). When used alone, manure increased the yield of tomatoes 2.92 tons per acre as compared with the average from the untreated check plots. This is an increase of over 33 percent. If all combinations in which manure entered are considered, the manure showed more influence on the melons than on either of the other crops. The average increase in the yield of melons ap- parently due to manure was 29 percent; of corn, 16 percent; and of tomatoes, 10 percent. Cover Crops Reduced Yields The use of cover crops to supplement manure combined with other treatments almost invariably reduced the yields, the only exception being melons grown on land treated with manure and lime in addition to the cover crop (Table 3). Here the increase was 631 pounds an acre, or approximately 8 percent. The average de- crease in yield apparently due to the cover crop when used with manure was 14 percent for tomatoes and 24 percent for corn. The addition of the cover crop to manure and lime or to manure, lime, and bone reduced the yield of tomatoes more than 2 tons an acre. When the cover crop was substituted for manure rather than used as a supplement to manure, the reductions in yield were even greater, the averages being equivalent to 19 percent for tomatoes, 22 percent for melons, and 31.6 percent for corn. The substitution of the cover crop for manure when used in combination with lime reduced the yield of tomatoes more than 3j/2 tons an acre. The unfavorable influence of the cover crop on yields of toma- toes and melons was greatest in a dry season (1925), when the yields from many of the treated plots were less than the average yield of the untreated checks. The greatest reduction in yield due to the cover crop in the dry season was in the melons grown without manure, altho there was also an average reduction of ap- proximately lj^ tons an acre in the yields of both melons and to- matoes compared with the average yields for the five preceding years on corresponding plots where the cover crop was used with manure. The yields of corn in 1925 were not comparable with those Bulletin No. 364 [January. s > cn -h to 1/3 O <* 3 . i/3©i/3O0CN© £ O U Co 1/3 »M t~- Tf t-» 1/) u 3 3 a ++++++ rt s o 1ONOO00CC OOOCOOt^iO V 3 . ^^©©lOCNOO 3 O •o *o "3 Hi ~4 cn-h tstM to ey o S ~ + + + +++ c !§ o OiooOOOiO T* 00 CN «^ CN ~« . 0000^-icO O 5 3 E o * IflNHH CN ++ 1 + 1 + H *« OOOOO 3 . t>» 00 PO <0 r<3 i/i O jg ClCN-tt^©© O ""» f*i f*J 1*5 CN to t*3 03 3 f5 00 O VO "# CN . CN 00 C3 1/3 VO © Co CN0C00CNCN»H "3 * s ""* lOiOO >o lOv© 2 3 c 03 3 S o ID t*» «yj re 00 *© . r-» l~» Cj t-, ^ r*5 3 O 3 6 co r*5 \0 O t-» t^ t* *** t»» t*» CN O -H H o «HtH(SiH(SCN '? o> 2 03 " •X ' "3 «-> 8 E W 03 03 u H •s ;<§*%«§ cjjj^j >>>>>> 00 ■<# . csooovrtioin o to 0\ t*) *-h CN r— 1/3 O "~* f5 «*) "* f*5 f} tv> CO 3 J3 OlCOCNNO . 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OOiOl^r^«5 O 3 ^ lOOO^vOOi'* CJ E ~* O ^< C5*>» CN -h -3 o CNCNCN^CNCN ♦J H £ 03 T3 _a> *> iJ P 8 cu C3 O L^' E mm CD O cd Jj, mm SSSj'jj >>>>>> uuouou ^ o scchiooo E 3 u *J Ci V. 3 2 3 8 <3E3§ O C* O W u w _3 CO cno cnxo csx 3 3 . NOinouit^* co f>ooi-c~Hir)tv>eN O .a a O U £ +++ 1 1 + 1 co O 43 a OO-NMfrTf o 3 JO "3 ifliOiO« S S3 J J J • In h >>>>>> Suuuouu ^j o cn t~- m t-» m t^» m - _ rfCNXXOXX 3 , S O f) »h C) ") "! O to X i-h "* CN r>» t~- O o ""* '*•* CO to CN PC CO CO 8 "IOiONOntJi , rtHfl^m^^O O (o >OOXt^CNlOCN CO 3 i *"* HOMSOOiOMfl C o 43 CO a CO s cu s & CO rt Ojffljtjra CU In h g > > > > > > ^ o W00»Ot>NOM S o a to 0) O > CO rt £ S I ** fc '55 o c co O Pn -r-1 oxxo 8 <*> M ^N IT) 3 In n «hiOM » rt co O^OO B S "~* CN-H CNt^ o o CN CNCN^ o H 3 o 43 CO 1 8 ■■J co CQPQCQ O JJJj > > > > uuu< ^ o ooo s """""* XcnO-O 8 . Of^CN CN co T-.OXCN O ►O U "~* tOCNCN't CO PO PO ■** ~* 8 8 t^ ^(^ PO 1 CQMffl ; JJJ : H > > >s UOOd, — o CN PC CN »1 P- rt^CNCN 1931] Fertilizing Tomatoes, Sweet Corx, and Muskmeloxs 11 Potassium Reduced Yields of Melons Potassium was detrimental to the melon crop, reducing the yields 8, 11, and 12 percent in the different combinations where a direct comparison was possible (Table 6). Fig. 1. — Melon Vines Growing ox Plot Treated With Manure, Lime, axd Boxe (Plot 3) These vines show the vigorous growth characteristic of well-nourished plants. Compare with picture of Plot 6 (Fig. 2) taken the same day, July 8. In only one combination was the yield of corn apparently in- creased by the potassium, and there the increase was only 3 per- cent. 1 The tomato crop was apparently increased about 7 percent by the potassium in one combination but reduced to nearly the same extent in another combination. In the third combination potassium gave an increase of only 2 percent, which is insignificant. Complete Fertilizer Produced Good Tomato Yields In spite of the questionable influence of potassium a complete commercial fertilizer consisting of steamed bone, dried blood, and potassium sulfate produced very good yields of tomatoes (more than 12 tons an acre) and fair yields of corn (Table 6). The in- *It is quite possible that smaller quantities of potassium might have given different results. 12 Bulletin No. 364 [January, to O CD S Q n) -J > w 03 > o CD >> a X ~ Ui J C o Q I") /^ CU < U) OS 1 ^ W o. to o U g c/) 0 i/ > 2 OviO 3 + 1 1 H a; N + 1 GO CO 3 0) *«3 o a — t! oo s _o O 'tWJIO o H O t^. ^H r-» t-» cv v£ 5 - | - > CN rt 0) 3 1 1 s 0) 1 1 1 0) H -a o a O 3 o — 3 03 £ VO l~» VO T* c* 3 tfjtfi s o «a» o V C5C5 HfO-H c- 1 CN CN voooo c 3 CN CN 1 B 3 '1 3 <-> a OOvOt^. o Nf^O r- ) 3. o H <-> O 1 CNCNCN 3 O J3 1 o o " s '. 3 o J3 05 00 0) 1 o « j 1 3 OP3J 'o'o > « -fc> o r^vooo s 00O-* (V CNtJh c ■*>T5lO c OvO Ih o OOW) f CO 00 U lOf^f^ "it ■*CN s NNO "* com «oo t IC-H o 00-hCv a OvrH t-- >0 VO Ih N f*5iO CO 6 3 o .-3 o 3 IOVO-H CN | oo t^ 8 OtOifl CN <4-. f^co R) Ov*tf t* 00 a o> 0> too E IOHK) <* 4J •*•* o CNCN CN CN G CN CN .3 J3 _ a o 5 1 ^j \A w Sou J S o > P3U o ^Ov^-i CN »Of*5 S "^ *~ l " 1931] Fertilizing Tomatoes, Sweet Corn, and Muskmelons 13 crease in yield over the untreated checks was 40 percent in the case of tomatoes and 27 percent in the case of corn. Contrasted with the favorable influence on tomatoes and sweet corn, the complete fertilizer was detrimental to the melon crop, reducing the yield 24 percent below the average yield from the check plots. The unfavorable influence of the fertilizer was ap- parent in the unhealthy condition of the vines as well as in the reduced yield. Limestone Improved Yields of All Three Crops Altho in this experiment limestone was applied primarily for the purpose of improving the condition of the soil for the grow- ing of cover crops, the series of plots included two treatments which afforded an opportunity for making a direct comparison of the influence of the lime. When lime was used to supplement manure without any other treatment, the yields of tomatoes were increased 7 percent, sweet corn 14 percent, and melons 25 percent over the yields obtained with manure alone (Table 6). Value of the Products The products of the experimental plots were sold in the local market. The prices varied from season to season and at different times during the same season. The variation in price during the same season was especially marked in the case of tomatoes. Start- ing sometimes as high as 15 cents a pound at the beginning of the harvest, the price gradually declined during a period of about 4 weeks; then local tomatoes usually became abundant and there was a sharp break in the price. Tomatoes picked before the break in price were considered as early tomatoes and those picked after the break, as late tomatoes. The average selling price of the early tomatoes thru the six-year period was 8.7 cents a pound, while the average price of the late tomatoes was only 2.19 cents a pound. The average price of the melons sold was 8.1 cents each, while the average price of the corn was 21 cents for a dozen ears. The value of each crop each year was calculated on the basis of actual conditions prevailing in the local market. The six-year averages are given in Table 7. The net value due to the use of the various fertilizers was determined by subtracting the cost of the fertilizer and the value of the crop produced by the untreated plots from the gross value of the crop grown under a given treatment. The cost of a given treatment varied from year to year depending 14 Bulletin No. 364 [January, I 8 to 03 to •- ►H (1) Q o 55 >» £ X I § Pi *o v - / en H -Q u S3 G O Ph to O cu en S I > £- H to Q i»Onn ■>* o 00 tJ< — oo w> r-t CS CS CS -* rl *-< ~< + + + + + +++++++ + + + + I I I I I I I I I I I I I I I I I II ++++ I ++++++ I +++ I + II N«NOO> C5 O © On u") m no 00 O r^ cs © ■*© •— t--. tJ< ro O ifl-NvOOOiflui 10 1/1 no r~- On 1/5 CS IOONhO »* ^ <— «-> •>* "> *# -HlO>tonO <*) cs ~H CS CS CS ~H — «-• «l ^H +++++ +++++++ I++++ ++ O OO^fvOTf NOOaarf 00 -h r- 00 r^ u-> O uiOOt^rCOO O h CS no o re »■* © o^hooonih cs m oo no no ©» — < ©-*cscs© OOOOOOO oo©ooO\0\ oor-» oo 00 oo fi On >o o O f> »- •>* oo O vOnnOn oc (N r-» vONWON W> -* IT) rt O CJ cs CSr^fiCNN© Ovifl O cscocico-H torctOtONNts cs cs cs cs cs —< ~+ cs HONMfl >* f) tS N O t^ O fOt^MNO OfC On "# i^ t^ -h' no © r- t-~ -h O © O00i>iOrt ©\ no O f» t~» J~» t~- i/nO i/) i/) NO >0 f> in vO to no nO u"> io no t~- ( 1931] Fertilizing Tomatoes, Sweet Corn, and Muskmelons 15 upon the price of the fertilizers. The average cost of each treat- ment per year was used in calculating the net value due to using the fertilizers. Practically all the fertilizer treatments increased the net value of the tomato crop; all except five treatments increased the net value of the melon crop; but not a single treatment increased Fig. 2. — Untreated Melon Plot (Plot 6) Here is shown the weak growth characteristic of poorly nourished melon vines. Yields of melons normally correspond to vigor of vine. the net value of the corn crop. The outstanding plots from the standpoint of combined net value of the three crops were Plot 3, treated with manure, lime, and bone; Plot 2, treated with manure and lime; and Plot 4, treated with manure, lime, bone, and potas- sium sulfate. The potassium in Plot 4 appeared to be a detriment rather than a benefit under the conditions of this experiment, re- ducing the net value of all three crops. Another way of comparing the profitableness of different fer- tilizer treatments is to calculate the increase in the value of the crop for each dollar invested in the fertilizer. Such a comparison of the different treatments involved in this experiment is made in Table 8. Some of the less expensive treatments, such as those used on Plots 16 and 18, were very remunerative on the basis of returns 16 Bulletin No. 364 [January t Table 8.~Difference in Crop Value for Each Dollar Spent for Fertilizer Plot Treatment M ML ML Bo ML Bo K Bo Bl K Check Cv ML Cv ML Bo Cv ML rP CvMLsP Cv ML Bo K Cv L Bo Na Cv L Bo Bl K Check CvL Cv L Bo CvLrP CvLsP CvL Bo K Check PM Cv L Bo amS Tomatoes Melons $5.05 $1.03 6.57 2.83 5.12 1.87 3.90 .87 3.59 -1.70 '.39 2^68 .82 1.01 .37 2.22 .37 1.29 .79 .42 4.92 .00 2.70 - .75 — i ! 75 i'.ii 7.15 1.98 3.03 .66 8.15 - .15 2.19 .90 '."78 -{'.19 .69 -2.72 Corn .75 .19 .25 .32 .61 ■1.04 ■ .55 •1.09 ■ .80 ■1.04 ■1.19 1.16 -i " 6i • .87 ■1.87 •1.30 1.15 •"."67 ■1.63 from each dollar spent for fertilizer, when applied to tomatoes. Some of the more expensive treatments, however, especially those involving the use of manure and commercial fertilizer together, gave very good returns in the tomato crop for the investment in pnpFiK i i tk< ■» -it* ^ - U.< ' ' -'. f. ■■ . ' '-.* ; pp^@i -v'-' A *£*'. -T ■* '. ,~ '■> % Hz& VSF&iKtk&BfFk:- \ ■' - **■' •-^^-"^^feJWplP^S^i I'lM^'Sl W^. Fig. 3. — Tomato Plot Treated With Steamed Bone, Dried Blood, and Potassium Sulfate (Plot 5) The plants are vigorous, and the yield records show that good crops of tomatoes can be produced by this treatment. 1931] Fertilizing Tomatoes, Sweet Corn, and aIuskmelons 17 fertilizer and at the same time yielded a crop of much larger net value to the acre. The highest returns on the investment in ferti- lizer for the growing of melons were from the plots involving the use of both manure and lime. Likewise, the least loss in the corn crop was from the plot treated with manure and lime. RECOMMENDATIONS In view of the failure of sweet corn to respond profitably to any of the fertilizer treatments and the demonstrated possibility of growing good crops of tomatoes without manure, the follow- ing plan is recommended for fertilizing the three crops in question in a three-year rotation on dark-colored silt loam in the Illinois corn belt. Starting with melons, apply limestone and manure. The next year, for tomatoes on the same land, apply steamed bone and dried blood or other organic nitrogen. The third year, grow the corn crop without additional fertiliz- ing, depending upon the residual material from the two previous years to supply the needs of this crop and save the expense of fertilizing. The cornstalks should be disked and plowed under in the early fall, before starting the next rotation. Such a plan is economical of manure, since it requires only 10 tons an acre once in three years, and thus meets modern conditions much better than former methods of fertilizing heavily with ma- nure every year. The quantities of the other materials recom- mended as a result of this experiment are as follows: Limestone, sufficient to meet the limestone requirements of the given soil. Steamed bone meal, 500 pounds an acre. Dried blood, 500 pounds an acre or an equivalent amount of other organic nitrogen. SUMMARY Experiments in soil treatment for the production of tomatoes, sweet corn, and muskmelons in a three-year rotation on dark- colored silt loam were carried on for six years with a view to finding, if possible, a method of fertilization that would produce satisfactory yields of these important truck crops without the use of large quantities of stable manure. Attempts to supplement manure with cover crops or substi- 18 Bulletin No. 364 tute cover crops for manure were disappointing, since the yields were almost invariably reduced by such treatment. Phosphorus proved to be especially important in the production of tomatoes, particularly when the crop was grown without ma- nure. Of the three forms of phosphorus used, steamed bone meal gave the best results. Bone meal, in combination with manure and limestone, increased the yield of melons, but its use was not profit- able. Potassium decreased the yield of melons and appeared to be of little or no benefit to tomatoes or sweet corn under the con- ditions of this experiment. Commercial nitrogen, in the form of nitrate of soda or dried blood, increased the yield of tomatoes but decreased the yields of melons and corn. Ammonium sulfate decreased the yields of all three crops. Dried poultry manure increased the yields of tomatoes and corn. A complete commercial fertilizer, consisting of steamed bone meal, dried blood, and potassium sulfate used without manure or cover crop, increased the yield of tomatoes 40 percent above the untreated check plots and the yield of corn 27 percent. However, this same treatment decreased the yield of melons 24 percent below the check plots. The potassium in the mixture was evidently the element detrimental to the melon crop. Limestone, when used with manure, increased the yields of to- matoes, sweet corn, and melons, 7, 14, and 25 percent respectively, as compared with the use of manure alone. Altho many of the treatments increased the yields of sweet corn, all were so expensive that they were unprofitable with this crop. Based upon the results of this experiment the following method of fertilizing the three crops in a three-year rotation is recom- mended. Starting with melons, apply limestone and manure. The next year, apply steamed bone and dried blood for tomatoes. The third year, grow the corn without additional fertilizing. Other Vegetable Fertilizer Bulletins by the Illinois Station Fertilizer experiments conducted by this Station with various vege- tables have been reported in the following bulletins: Growing Tomatoes for Early Market. 144-B (out of print) Fertilizer Experiments With Muskmelons. 155-B. Tests With Nitrate of Soda in the Production of Early Vegetables. 184-B (out of print) Methods of Fertilizing Sweet Potatoes. 188-B. Some Tests in the Culture of Peppers. 274-B. Fertilizer Experiments With Greenhouse Lettuce and Tomatoes. 286-B. Bush Lima Beans as a Market Garden Crop. 307-B. Fertilizer Experiments With Truck Crops in Southern Illinois. 319-B. Fertilizing Twenty-five Kinds of Vegetables. 346-B.