A major problem in the production of tobacco on acid soils in Kentucky is manganese toxicity, despite the fact that it can be easily prevented. Since manganese toxicity is caused by high levels of soil acidity, prevention of soil acidity by liming is the best method of control. And soil testing is the only way to determine how acid a field has become

Gray, Paul

Sims, J. L.

Wallace, A. M.

Wells, Kenneth L.

English

University of Kentucky

University of KentuckyUKnowledgeAgronomy Notes Plant and Soil Sciences4-1977Field Tests of Some Liming Treatments forGrowing Burley Tobacco on Acid SoilsA. M. WallaceUniversity of KentuckyKenneth L. WellsUniversity of KentuckyJ. L. SimsUniversity of KentuckyPaul GrayUniversity of KentuckyRight click to open a feedback form in a new tab to let us know how this document benefits you.Follow this and additional works at: https://uknowledge.uky.edu/pss_notesPart of the Agronomy and Crop Sciences CommonsThis Report is brought to you for free and open access by the Plant and Soil Sciences at UKnowledge. It has been accepted for inclusion in AgronomyNotes by an authorized administrator of UKnowledge. For more information, please contact UKnowledge@lsv.uky.edu.Repository CitationWallace, A. M.; Wells, Kenneth L.; Sims, J. L.; and Gray, Paul, "Field Tests of Some Liming Treatments for Growing Burley Tobacco onAcid Soils" (1977). Agronomy Notes. 114.https://uknowledge.uky.edu/pss_notes/114ACR(JNlJMYNOTES)UNIVERSITY OF KENTUCKYCOLLEGE OF AGRICULTURELexington, Kentucky 40606COOPERATIVE EXTENSION SERVICEVol. 10. No.5.FIELD TESTS OF SOME LIMING TREATMENTS'I ;'FOR GROWING BURLEY TOBACCO ON ACID SOILSA. M. Wallace, K. L. Wells,_ J. L. Sims, and Paul GrayApril, 1977'A major problem in the production of tobacco on acid soils in Kentucky is manganeseto,;in:.), despite the fact that it can be easily prevented. Since manganese toxicity iscaused by high levels of soil acidity, prevention of soil acidity by liming is the bestmethod of control. And soil testing is the only way to determine how acid a field has be-come.Ideally, a good plan is to follow a crop rotation of 2 years grass-legume sod follow-ed by 2 years tobacco and to apply lime immediately after the last tobacco crop in the ro-tation in sufficient amounts to maintain soil pH adequately (pH around 6.5) for legumesduring the sod part of the rotation. For land which is kept in continuous tobacco, thebest practice is to take a soil sample during late summer so that if results show needfor lime, it can be applied and worked into the field when seeding the winter cover crop.In reality, however, many growers either lime indiscriminately or not at all, and be-come aware of their problem onlyaft.er plant.ing the crop and severe manganese toxicitydamage has occurred. Others wait until spring to have their soil tested, and then applylime too late for obtaining. the most benefit from. its u~e.A few field tests have been conducted during the past few years to test the effect-iveness of fall and spring. application of lime for production of burley tobacco. Table 1shows yield results obtained. on an extremely acid soil (inHial pH was 4.7) in one experi-ment conducted in Ohio County. . ,As shown, plants did not survive wHho~t '!se 9f lime before trEmsplanting. With 1:l.ti1e,good yields were obta,ined, the fall application giving somewhat higher yields than' the'spring applications.' Even though yields were good, soil pH in all plots at the end of thegrowing season was still very· acid. EHher there had' not been enough neut·ral:i.zation bythe ag lime to raise pH appreciably within 6-12, months' timli', or the rate (4 or (j T/A ofag lime) was insufficient. The notable point is that even though there was only slightincrease in soil pH from the ag lime treatments, good yields were obtained where it wasused as contrasted to no yields when lime was not used.The College of Agrlcultureto18i~d,:3:::18 ~~~o~~tJ't~~Ot~~t}:C~~~I~j~~U~O ,:;~~d:or~:~~~Ol:~u~:;i:Q~~~~':i~;n~nd oth6f' '6Tt>wes onlllUNIVERSITY OF KENTUCKY, KENTUCKY STATE UNIVERSITY, U.S. OEPARTMENT OF AGR.ICULTURE, AND KENTUCKY COUNTIES, COOPERATING-2-Table 1. Effect of Time, Source, and Rate of Lime Application on Burley Tobacco -Ohio County, Kentucky, 1974.TreatmentNo LimeAg Lime in Fall, 1973 (4 T/A)£/Ag Lime in Spring, 1974 (4 T/A)l"!Ag Lime in Spring, 1974 (6 riA)Hydrated Lime 3/in Spring, 1974 (2.68 T/A)-Hydrated Lime Sidedressed in Summer, 1974 (0.5 T/A)Soil pH / Yield(Fall, 1974)1. (lbs curedleaf /A)4.0 rf:-/4.9 29435.0 27525.0 27982729o'l/data Av. 3 reps/tmt1Initial soil pH 4.7 in fall of 1973.2Rate recommended on basis of soil test•3Rate is 2/3 that of Ag lime4Plants died soon after transplanting due to extreme acidity. /,'5 /.Even though some plants were alive when· sidedressed, all died.Another test was conducted during 1976 on·a soil in Franklin County which was notas acid initially as the soil in Ohio County. Results from this study are summarizedin Table 2. As shown, a significant yield increase was obtained from use of lime inthe spring on an initially moderately acid (pH 5.5) soil. Even the 1,000 1b/A top-dressing of fine lime on July 1 when plants were 12-18 inches tall was effective. Sincethe plots which were summer topdressedhad received no lime prior to July 1, their pHand leaf con~ent of manganese should have been similar· to that of the no-lime treatmentjust prior to the July 1 topdressing. And as indicated by the leaf content of manganeseon July 1, there was considerably more manganese in plants growing· on unlimed plots thanon limed plots. Visual manganese toxicity symptoms of plants appeared before July 1,but it was not judged to be severe. This is reflected in the leaf content of manganesewhich, although much greater in un1imed (186 ppm manganese) than in limed plots (50-65ppm manganese), is not as great as that (above 500 ppm manganese) commonly found inleaves of plants showing severe manganese toxicity.)-3-In addition to its effect on leaf yield and manganese concentration, liming alsoincreased leaf calcium and magnesium and slightly decreased leaf phosphorus and pot-assium. The most marked effect was on molybdenum concentrentation, with molybdenumconcentration from the fine lime treatment being nearly double that of no lime. OtherU.K. research has shown that leaf level of molybdenum should be around 0.40 ppm.Results from this study point out that although spring liming of acid soils forburley tobacco production is not considered the best liming practice, it is betterthan not liming at all--even on a soil just moderately acid (pH 5.5). And even alight (1000 lbs/A) application of finely ground lime broadcast over the field and work-ed-in between the rows after visual manganese toxicity occurred was measureably betterthan not liming at all.There are basic principles which should be followed in liming, particularly whenfast reaction is desired (such as spring liming for tobacco). That is, the lime shouldbe mixed with the soil as thoroughly as possible rather than broadcast and turned under.Application after plowing but before discing is a practical way to get good mixing insituations where ground is plowed. If large amounts are to be applied, lime can bemixed deeper into the rooting zone by plowing under half the lime, then broadcastingthe remaining half and discing .it in. The later a person waits to lime before heplants a crop, the more important it is to do as thorough a job as possible in mixinglime into the soil so that acidity around roots of young plants or seedlings will havebeen somewhat neutralized before seeding or planting.From the studies reported here, it was concluded that ag lime is just as effectiveas fine lime or hydrated lime when these are applied in the spring. Sidedressing with1000 pounds per acre of finely ground lime gave an equal response to spring applicationof ag lime on a moderately acid soil (pH 5.5) when it was applied after manganese tox-icity was observed in the field. Sidedressing, however, was no~ effective when thesoil pH was initially extremely acid and when manganese toxicJty symptoms were very se-vere. Sidedressing with lime to correct soil acidity and manganese toxicity in tobaccoshould be done only as a last resort.Manganese toxicity in tobacco is by no/means the only problem caused by acid soils,although it is often the first sign of trouble that the grower observes. The soil pHinfluences the availability of many nutrients to the growing plant. When soils becometoo acid, the improper balance of plant nutrients may effect yields long before thewarning sign of manganese toxicity is observed. Therefore, control of soil acJdity hasa very favorable influence on the production of high yields and quality tobacco.Extension Specialist in AgronomyTable 2. Effect,of Lime on Yield of Burley Tobacco Grown in Acid Soil - Franklin Co., Ky. - 197J!Soil pH(0-6") Soil Mangan- Leaf Content during season~/ Yield2/ Before liming During grow- ese during (July 1) Lbs CuredTreatment -and fertilizing ing season season (ppm) % ppm Leaf/A(April 2) (July 1) (July 1) P K Ca Mg Mn MoNo Lime 5.5 5.0 • 23 0.32 5.10 3.50 0.27 186 0.35 2291Spring Applied Ag Lime (3.5 T/k.3/ *5.5 5.2 14 0.27 4.13 4.37 0.26 65 0.40 2497Spring Applied Fine Lime (3.5 T/A)lI 5.6 5.6 11 0.28 3.83 3.80 0.47 49 0.60 2191Fine Lime Topdressed July 1(0.5 T/A)~ *5.7 --- -- --- -- --- ---- --- --- 2483\~1Av 3 reps/tmt2All tmts received 260 Ibs N/A3Broadcast (recommended rate) over plowed land (April 2) and disced into soil4Broadcast over tobacco (July 1) and roto-tilled into soil5p=phosphorus; K=potassium; Ca=calcium; Mg-magnesium; Mn-manganese; Mo-molybdenumL.S.D. (.05)157*Significantly different from check'-~ ~

Field Tests of Some Liming Treatments for Growing Burley Tobacco on Acid Soils

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Field Tests of Some Liming Treatments for Growing Burley Tobacco on Acid Soils

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