-Dublicdato CIRCULAR 75 OCTOBER 1936 ThL Value of Lime in a Two-Yep -Rotation on Sand Mountain A PROGRESS REPORT Uooa ,LMO '"'SOIL SAND t/'\OLNTAIN F~RELATED AIREA I r I fC i~~C ftf~- ,'" t; :~'r ct~~':; :. ..,L;.~~~~;s?';5-fXT~i~5;~,,,..;~.Cc it; ;~G'' ;~-..-.r~r~~ ~t~~~r;;5 t?; if; if; ~ ~f;I I;:f~ ~~ -~~.:;rf~ ~.~s~ C .t i- ft; ~f~t~? - ;f~ :'r;t.. ;' .. ir.~~ ~~~ ; : p/ex~Ns~AY~f~f~~rf?::";-~-.;;~5"';:;;.~~f;;~-'.:L~ urt sA ; I .i~t~:~~it~:.if~~~~r,?i:T.~::.-;s ..r;? ~5,.. f ;:.:I5I5'.~s~I ' lg~91~ t.rz,~ I t.~ WALX~rZrs"... -TII~~;.~tIi ~'~~~t 'iS ~ 5~; ~2~CZ~ Contents HOW MUCH LIME TO USE PER ACRE ............................. RECOMMENDATIONS AS TO THE AMOUNT OF LIME TO ADD FOR THE TWO-YEAR ROTATION DOES LIME PAY WHEN FERTILIZERS ARE USED?................ DO LEGUMES PAY WHEN FERTILIZERS AND LIME ARE USED IN A TW O-YEAR ROTATION ? ................................ KINDS AND GRADES OF LIME TO USE ............................ HOW TO LIME THE SOILS FOR TWO-YEAR ROTATIONS S U M M A RY ----------------------------------3 6 6 8 9 10 - -10 The Value of Lime in a Two-Year Rotation On Sand Mountain' A PROGRESS REPORT in growing cotton and corn with SHOULD lime berotation on the Sand Mountain sectionlegumes and on in a two-year used In order to answer this the related soil areas of Alabama? question, field tests with lime were begun at the Sand Mountain Substation in 1930, and it is the purpose of this paper to report the value of lime during the six-year period, 1930-1935. The results reported herein are intended for the soils of the area shown on the cover. The most practical type of farming for this section, from the standpoint of profitable operation and the maintenance of soil fertility, is that by which soil improvement crops are grown in a rotation with cotton and corn. Thus a two-year rotation of cotton, vetch, corn and soybeans has been the cropping system used to determine the value of lime. Previous results showed that the profit from cotton and corn production on Sand Mountain was increased by the use of proper commercial fertilizers 2 and, as will be shown below, the profits may be further increased by the use of lime in a two-year rotation. It is generally known that lime is necessary for plant food and as a preventive and corrective of soil acidity. The lime content of the sandstone soils of the Sand Mountain section is extremely low and becomes lower each year through losses by leaching and crop removal. Legumes grown in the two-year rotation feed heavily on lime and make their best growth on non-acid soils. The fact that non-acid-forming fertilizers do not increase the acidity of the soil does not remove the need for lime on these soils. HOW MUCH LIME TO USE PER ACRE Outline of Tests.-In order to determine the amount of lime to apply, two methods of liming were used. Small additions of 200, 400, and 600 pounds per acre applied every other year in the drill were compared with larger applications of 1,000, 2,000, and 3,000 pounds per acre broadcast once in ten years. Unlimed plots were used for checks and all plots received 600 pounds of 6-10-4 fertilizer per acre during the two-year rotation The tests reported herein were outlined by Director M. J. Funchess Acknowledgment: and conducted by R. C. Christopher, superintendent of the Sand Mountain Substation, The manuscript was prepared by James on Hartsells fine sandy loam. Crossville, Alabama, A. Naftel. 2 Alabama Agricultural Experiment Station Circular 70. 1 of which none was applied to the corn. Vetch and soybeans were grown as soil improvement crops and dolomitic limestone was used in these tests. Field Results from Small Additions of Limestone in the Drill. was found that 200 pounds of limestone per acre in the -It drill was not sufficient to obtain the greatest profit, that 600 pounds was too much lime, but that 400 pounds gave the greatest profit from cotton and corn. The figures for the six-year period are given in Table 1. The increase per acre from the 400pound addition of lime in the drill was approximately 150 pounds of seed cotton and 7 bushels of corn. This increase from lime gave an average annual profit of $6.16 per acre (average of cotton and corn) after the cost of lime was deducted. The profits were based on seed cotton at 4 cents per pound, corn at $1 per bushel, and limestone at $5 per ton. The average yearly profits are more clearly shown in Figure 1. It may be seen from this information that when this method is used 1 ton of lime is sufficient for 5 acres in the two-year rotation. How the additions of small amounts of limestone in the drill compare with the larger ten-year broadcast application is important and is shown below. Field Results from Ten-Year Applications of Limestone Applied Broadcast.-Similar to the case with small additions of limestone, the lowest tenz-YEAR 10-YEAR year application of 1,000 APPLICATIONS pounds per acre was too PfR7r/ APPLICATIONS low for the greatest profit PR and the highest rate, 3,000 6.00 pounds per acre, was too high as compared with the intermediate amount of s.0o 2,000 pounds. The 2,000 pound rate gave an aver4 age annual increase per acre over the unlimed "3 plot of approximately 130 pounds of seed cotton and 2.8 bushels of corn as shown The profit in Table 1. from this treatment on cotton and corn amounted to $6.32 per acre annually. / This is clearly shown in Figure 1. Should the farmer add 400 pounds of limeevery in stonedrill the 20 200 400 600 OUNas OF LIME PER ACRE 1000/ 3 stonedrill every the in other year or apply 1 ton FIGURE 1.-How Much Lime to Apply as Shown by the Profit from Cotton and Corn in a TwoYear Rotation. TABLE 1.-eut Annual cost of lime per acre from Different Amounts and Methods of Applying Lime in the Sand Mountain Substation. a Two-Year Rotation on Amount of lime per acre Yield Lb's. Seed Cutton Value Inof crease infrom crease lime Lbs. RLbs. u~hl~~t I -LAII~ Average annual results per acre for the 6-year period 1930-1935 Soybeans' Vetch' Corn Average anInInValue Int$ for~nual profit crease Yield crease of cr ease PrftYil from corn from from Profit' Yield infrom rftYil and cotton' lime lime lime crease Lbs. Lbs. Lbs. Lbs. $ $ Bus. $ $ 2 Bus. -- -4.3 Small 2-year applications of lime 0 200 400 600 -~--0 0.25 0.50 I 0.75 I 1,419 45 1,464 153 1,572 I 1,544 I I 125 1.80 II I 5.00 6.1 2 4,185 5,788 7,187 6.70 7.2 2 32.9 5.6' I 4.2 5 I 32.4 I 6.7 I 6.70 I 5.95 I 7,700 Large 10-year applications of lime 1.5!5 -- 25.7 30.0 7.20 ---4.30 4.05 1,603 3,002 3.515 -I 4,101 4,142 5,216 5,349 - 41 1,115 1.248 iI 2.80 6.16 5.10 0 1,000 2,000 3,000 0 0.25 0.50 0.75 1,419 1,525 1,550 1,500 106 131 81 4.24 5.24 3.24 3.99 4.74 2.49 32.9 34.1 35.9 7.2 8.4 10.2 7.20 8.40 10.20 6.95 7.90 9.45 4,185 6,674 8,117 8,282 2,489 3,932 4,097 4,101 4,815 5,388 5.858 714 1,287 1.757 5.47 6.32 5.97 'Pounds green weight per acre. '5-Year average. 'Profit based on lime at $5 per ton, seed-cotton at 4 cents per pound, and corn at $1 per bushel. broadcast once in ten years to increase the profits from the twoyear rotation? This is discussed below. Discussion of Small Two-Year Additions as Compared With Large Ten-Year Applications.-On the basis of a 5-acre field in a two-year rotation, the lime cost would amount to $5 when 400 pounds per acre is added or $25 when 1 ton per acre is added; however, the 1-ton application is for a ten-year period, while the 400-pound rate is for only two years. Over a ten-year period the same amount of lime is applied with both methods of liming. It would be necessary to make five applications during the ten-year period when using the small amount in the drill, but this may be mixed directly with the fertilizer and applied. In this way the more frequent applications of the small amounts would cost very little more in labor than the 1-ton application once in ten years. The advantage of the 1-ton broadcast application of lime is that the liming for a ten-year period is done at one time and requires no further labor cost. It may be concluded that either method may be used depending on the individual circumstances of the farmer; perhaps more farmers could afford the cost of 400 pounds for a two-year period than the 1-ton application for a ten-year period. RECOMMENDATIONS AS TO THE AMOUNT OF LIME TO ADD FOR THE TWO-YEAR ROTATION Add 400 pounds of high-grade finely ground limestone every two years in the drill or broadcast 1 ton per acre of high-grade finely ground limestone (or its equivalent) once every ten years. DOES LIME PAY WHEN FERTILIZERS ARE USED? Plan of Tests.-The following fertilizers were compared with and without lime: 1, superphosphate alone, 2, superphosphate and muriate of potash, and 3, superphosphate, muriate of potash, and nitrate of soda. Plots which received no fertilizer were used for checks. Two tons per acre of high-calcium limestone was applied in October 1929 to the limed plots. Results of Tests.-The results from these tests (Table 2) show that lime increased the yields of all four crops regardless of the fertilizers applied. It is seen that with cotton and corn the greatest profit from the lime applications was on the superphosphate-muriate of potash plots. However, the yields on the cotton plots receiving superphosphate, muriate of potash, and nitrogen are the most practical since the yields are much greater from the addition of the nitrate of soda. Two tons of lime per acre was applied in these tests which, as shown above, TABLE 2.-The Effect of Lime on a Two-Year Rotation With Different Fertilizers at Sand Mountain'. Seed Cotton Fertilizer 3 Vetch' Yields Profit from lime $ __ Corn Yields per acre InNo lime Bus. 29.6 Limed Bus. crease from lime Bus. Profit from lime $ Soybeans Yield No lime Bus. 7,850 2 Yields per acre InNo lime Lbs. Limed Lbs. crease from lime Lbs. ____ No lime Lbs. 4,996 8,130 9,882 11,289 Limed Lbs. Limed Bus. Check No Fertilizer 600 lbs. Superphosphate 600 lbs. Superphosphate 75 lbs. Muriate 600 lbs. Superphosphate 75 lbs. Muriate 100 lbs. Nitrate of soda 996 1,128 1,356 1,184 1,595 1,885 56 239 193 1.24 8.56 6.72 8,186 12,684 12,629 39.3 40.0 47.4 44.3 46.4 48.5 5.0 6.4 1.1 4.00 5.40 0.10 8,907 8,202 10,037 10,327 11,066 12,150 1 1,692 J 14,000 lbs. lime per acre applied every 10 years = $10 or $1 annual cost; seed-cotton figured at 4c per pound and corn at $1 per bushel. 2Pounds green weight per acre. 3Fertilizers applied as follows: 2/ minerals applied in fall to vetch, and the remaining 1/3 applied to cotton. No fertilizer was applied to corn except nitrate of soda in the complete fertilizer plot. -- I wvas excessive and henc e reduced the profht frorn lime as comLime is not a substitute for fertilizers, but the proper fertilizers should be used with the lime. pared wvith a 1-ton aplplication. DO LEGUMES PAY WHEN FERTILIZERS AND LIME ARE USED IN A TWO-YEAR ROTATION? Outline of Tests.-Tests w-ere made wvith cotton and corn Nvh ere commnercial f erti lizers and lime Nvere used wvith an ml vxithout legumes in a twvo-year rotation. The fertiliz ers Nvere app liedl to the cotton andl none to the other crops wvith 4,000 poundis of calcareous limestone a pplied broadcast once each ten years. A~ ii11 wh I H thel cottonI anii k ,l() were. filized;& no firtlizer Hci aH l to thle con. ( See sul~or ho phate-nnuiate bil oftTable 2.) Results.-The resulIts fiom these tests on cotton and( coin arec slii in Table :8. It is seen that the leg.tumes in the rotation gave an increase in seedl cotton of 410 p~olnds. The profit oin the cotton from the legumes wvas 1 6.40 per acre. It shoudiI be noted here that the cotton iecei\ ed only 100 pounds of nitrate of sodla in the compl)1ete fertili zer and also li me in each case. Legumes in the rotation increasedl the corn yieldls from 25.6 lbnshels to 41.0 bushels or an increase of 15.4 bushels w\ith a p~rofit ot $12.90 per acre. The alVerage annunal profit for the six-yeai period was $14.65 by growing legumes in the rot ation Nvhen fertilizers and lime wvere used. (JbVionSl V it is Wise and pritable to growv legumes in a two-year rotation wvhen fertIlizers and lime are used. TABLE 3.-The Value of Legumes With Fertilizer and Lime In a Two-Year Rotation of Cotton and Corn at The Sand Mountain Substation. Crop of cotton with N P K L' Increase from legumes 2 Profit Yield Lbs. 1,874 Lbs. 410 $ 16.40 Crop of corn with residual NPKL Yields per acre Increase from legumes Profit Yield With No legumes legumes Bus. 25.6 Bus. 41.0 Bus. 15.4 $ 12.90 Seed cotton yields per acre With No legumes legumes Lbs. 1,464 Average annual profit $ 14.65 1 All fertilizers applied were to cotton and were 600 pounds superphosphate, 75 pounds muriate, and 100 pounds nitrate of soda per acre. Two tons lime per acre was used. 2 Profits were based on cost of vetch at $2.50 per acre and the value of corn at $1 per bushel and seed-cotton at 4 cents per pound; cost of vetch was charged to corn. KINDS AND GRADES OF LIME TO USE Kinds of Lime.-There are several kinds of liming materials which may be used for agricultural purposes but the tests reported here were made with finely ground calcareous and dolomitic limestones. Either of these forms may be used; however, there is some evidence that the dolomitic lime may be slightly more beneficial since it contains magnesium which is low in many of the soils. The grade and price of the lime should determine the kind of lime to use as will be seen below. Grades of Lime.-The grade and value of any liming material is determined by two factors which are: Composition (total neutralizing power) or purity. (1) Fineness (size of particles or screen test). (2) The composition of the lime is determined by chemical analyses and is reported on the basis of 100 for pure calcareous limestone. On this basis a pure dolomitic limestone may run as high as 108 since it contains magnesium in addition to calcium. The fineness of the limestone is determined by sorting the particles into size groups by means of screens of different meshes or openings per linear inch. The coarser the particles the more slowly the lime becomes available, thus 10- to 20-mesh particles are very slowly available; 20- to 40-mesh, slowly available; 40- to 60-mesh particles, fairly available; and finer than 60mesh particles, readily available within 1 to 3 years after applying to the soil. All agricultural limestone is required by law to have a guaranteed analysis and the value of the particular liming material should be determined accordingly. A high-grade finely ground limestone should be near 90 or above in total neutralizing power, and at least 60 per cent of the lime should be finer than 60-mesh. 10 HOW TO LIME THE SOILS FOR TWO-YEAR ROTATIONS Liming With Small Applications.--The 400-pound rate of calcareous or dolomitic limestone may be added in the drill at the same time the fertilizer is added. In the case where lime is to be added for the winter legume following cotton the drill should be close to the cotton stalks in order that the residue from the cotton fertilizers may be used by the legume crop. Similarly in the spring where the lime is added in the drill for cotton or corn the lime and fertilizer may be applied in one operation a week or ten days before planting. Liming in the Fall With 1 Ton Per Acre on Cotton Land.As soon as the cotton is picked, apply the lime evenly over the entire surface of the soil. Plant the vetch or other winter legume with the proper fertilizer and throw out the middles with a turn plow or "Middle Buster", thus working the lime into the soil and yet not disturbing the fertilizer residue at the cotton stalks; this gives the legumes the maximum effect of the residual fertilizer and the lime. Liming in the Fall With 1 Ton Per Acre Where Cotton Was Not Grown.-On these fields there is usually no fertilizer residue, and the lime may be spread evenly over the field and then the land flat broken with a turn plow or disked. This works the lime into the soil to plow depth, and the land is ready for seeding and fertilizing the winter legume. SUMMARY A summary of this progress report on the value of lime in a two-year rotation of cotton, vetch, corn and soybeans on Sand Mountain is given below. (1) The most profitable two-year addition of lime with proper fertilizers was the 400-pound per acre rate added in the drill; the profit has averaged $6.16 per acre annually during the past six years. The 2,000-pound per acre rate applied once each ten years was the most profitable broadcast application; the average annual profit was $6.32 per acre. (2) Lime increased the yields of all crops in the rotation regardless of the kind of fertilizers used, but was most practical where the cotton received the proper complete fertilizer and the corn received the residue from the superphosphate and muriate; the profit from the lime on the cotton and corn was $6.06 annually in this test. (3) The most important and practical use of lime was obtained when legumes were grown in the rotation of cotton and 11 corn receiving proper fertilizers; the annual profit was $14.65 per acre for the last six years. (4) The kind of lime to use is determined by the grade and price; the value of any liming material is determined by its analysis for total neutralizing power and fineness and these should be guaranteed to the farmer. (5) The lime should be applied for the two-year rotation at the most convenient time, which is usually in the fall before The lime should be well the winter legumes are planted. worked into the soil.