ENO - v CIRCULAR 73 MARCH 1935 The Black Locust in Alabama By L. M. WARE AGRICULTURAL EXPERIMENT STATION OF THE ALABAMA POLYTECHNIC INSTITUTE M. J. FUNCHESS, Director AUBURN, ALABAMA CONTENTS PAGE INTRODUCTION----- 3 EXPERIMENTAL-4 Behavior in G ullies ----------- ---------- -- ------ - 4 Behavior on Old Fields------------------------------ 5 Behavior as a Crop-----------------------------------------------6 Behavior and Cost Considerations when Intercropped --11 DISCUSSION OF USES-----------------------------------------------11 Use in Erosion Control-------------------------------------------11 Production of Fence Posts -------------------------------------- 13 SUMMARY ------------------------------------------------------------- 14 LITERATURE CITED ------------------------------------------------- 115 The Black Locust in Alabama By L. M. WARE, Horticulturist (Robinia pseudoacacia) has been quite generally recognized as one of the best adapted of all species of trees for planting on eroded hillsides and gullied lands. It has also been generally recognized as a plant which is able to grow on rather poor sites and one which demands little or no attention. Mattoon (1), referring to the black locust, states: "Its strong spreading root system and rapid development gives it first place among all trees in ability to check erosion in gullies and on steep hillsides." He advises against planting on very sandy, very wet, or very acid soils. Meginnis (2), in describing the black locust, states: "It is not only particularly well adapted for growth on most eroded sites and exposed clay subsoils much too poor for agricultural use, but, like most legumes, it also builds Tillotson (5), in disup the soil by contributing nitrogen." cussing this species for forest plantings in the eastern United States, says: "It grows on poor, sandy, gravelly, or clay soils." Rehder (3), describing the characteristics of the black locust and a closely related species, states: "They are not particular as to the soil and they do well even on poor sandy soil and dry locations." Turner (6), describing the behavior of the black locust in Arkansas, reports: "This species grew exceedingly well on strongly acid soil at the Fruit and Truck Branch Experiment Station." It was emphasized in the report that the successful growth of the locust on acid soil was contrary to current belief. Sargent (4), gives the distribution of the black locust as follows: "The slopes of the Appalachian Mountains, central and southern Pennsylvania to northern Georgia; in southern Illinois; now widely naturalized in the United States east of the Rocky Mountains and perhaps indigenous as a low shrub in northern and western Arkansas and in Oklahoma." Mattoon (1) states that the locust has been generally recommended for planting from the New England States south to Georgia and west to Texas, Missouri, and Illinois. Since 1927 the Alabama Experiment Station has made 10 different experimental plantings of the locust at various points in the State. These plantings have definitely shown that the locust in Alabama does not behave according to the generally accepted opinions expressed in literature and commonly held by people in other sections. Because the locust has been so highly regarded as a plant for use in erosion control and in reforestation programs and because its behavior in this State has been different from the behavior one might expect, a brief re- THE BLACK locust fIen 1' cond I'litint Thi is doot i in' i the11 l et' I th at tei result EXPERIMENTAL tEt 'xp eri et a in and l' Th ltt fou ) ing ~l. o il l xpeimen Ftid usall s iii y in eve '1 ' of yt ande twxo Iin 19ti4. ll' wer t orac( auar(' Jttuk'ee antd Alexania:i the two madii~e ini 19:81 Xere mahde Behavior in Gullies.-Both of the expeeiunietal il ntthy.5 stled '> i'enta 92 aoi te taion xt it pit lace weeloaedo nr>1wara xelis I'ei'0(t'I tsha llm Sit I(s) e l an , wee iTh . pott i i in tf t he -- tilliesi anud no . j typicatl planit in onet) ot these' plant- 4 ing is abou plantt fe til' ihi hiht r'I x't sto pl t g' tilt giln ich~ ii ttit de tl lo ito t'het i 'pint n ' tl f lt oil) to three years of age. lIn 19381 the upper half' ol the area %x-,us clearedl. and the locust cut to the grOLn1l. The seteIlill" plants on the lower area have disappeared with the exception li' a f'e«x whichI App ear as brush be neath pines that niow sta nd '.() feet in height. O)n the up~oper area th ere is a scattered standl o)f locust wxhic h h as b een produneed from sprouts originating tiom t h old pl~Ia nts: these p)la nts. th erefore. haxve nine-vear root Sstemsi andl ooui yea' tolps. Griowth is better on the tupper area of this planitinig thani in the first planting described,. although still Snsat isaict oiv . The ax erage height of the pilanits on the area xhith wit ac lear4'd x as 7.3 feet and the aiverage dliameteir 1.1)2 inches after foul'r ears' gro xxt h of the spirouts. Behavior on Old Fields.-The tw\o pilanti ngs made at the Exper'imnt 'Station ini 19383 werte lotated on o)1( cultivaltedl fields. Onle lanitiiig xxas madeolt' an o)1( field oftlogoxv fertility" and slightas lv- eroded : the other plalntinig "vx made on a low area oft tair lertilitx-. The' soil on both are'as was sandIy 14am. and bo4th plaiitThe land xxas not p~rep~aredl and no ine's \\ ele haledltt alike. the plants. Grass wxas remov ed trom the to Itix atioii xwa i gien base of each planut onte dutrinig the first year xvith a hoe. In Hi -u le 2 is shownl the size of one of the largest lpla nts fotund in the first of th ese txxo plantings two veais afteri tranlsp~lantiing: It maY bie the pilanti is. therefore. three vealrs old from seed. se(1n from the rodl that this plunt is about 1.8 feet tall. In this planting the average height oft the l 1ants, afIter thrlee seasoins' giroxxth, xwas 9) inches and the ax'r ' (diameter at the base xvus '..erage .19 inthes; on(lly 6i p)er '('lt of the pP~llants wxere alix e at the time the measur ements wxere madle. In the 1 p1llanltinug, located on the 1 econ , Z better soil, the plants txxo veal's a ftei tranuspla nti ng ax eraged 2.69) feet in h eight and .8)7 i nthes in lht'le. dliam et er at th isbooth (On the Etxpeorimenital Fil ds. ofl the plantings made ill * y.x , NI(I;B:°- 1980), the one at Tusk egee, the ohrat Alexalidria. failed. They with out lpreplaration ot land oi' three veal's bolactit'allv' all planits xx'eie dead anid the f'exx xxhit'h wxere alix e xxere still unable to makte their wax'a T1')icxl i~;II' .t' frm s'hed: no pr'epill itixWoi oca cdI oi old field. abioxvt the glass. In all of these exp~erimenits where the locuist. has Ibeeni plantedl fertility andl on sites generally surggestedl for loculst plantings, they hav\e fai led. In no instance has special pie parVation b~een given the land or special attention giv en the plants. It is doubtful if the locust in general pilantings onl sim ilar soils aid sites and sim ila rly handled xw ill behaxve anyv on1 soils of low or tair diftferenlt. Behavior as a Crop.-Failuore of the locust in all of the earlier expleriments ledl to a different type) of experiment in 19:14. This experim enlt w\as designedl to dletermine Just howr the locust m ust he hanrd led f or satisfactor glow th . The soil selected toi the experim enlt was a l oa my san1d( of low fertil itvy. The wvholIe area was prepared hy biea king broadcast . Eight diffeieint treatmnirts were giv en. 'T'hese trieatm ents are indicated ini Table 1.In Treatment No. 1. iio cultix atiori was giv en and no fertilizer was added. In Treatment No. 2. three sAllow cultixvations weregix en but no feil iz wS added. In Treatments Nos. 8., 4. 5. IV 6. 7, and 8, cultix atiori wxas giv en and tertilizers adlded as follow-s: to Treatment No. 8., only p~hosplhorus: to 'Treatment No. 4, lihosliliolus aind nitrog.en: to Treatmnients No s. .5, 6. 7. a nd 8. pihospihoius, nitrogen. andl potash. lIn Treatmiient No. 6. theF7 amon)tit of fertilizer applied wxas I >I A ' The one halt the standard. standarad fertilizer for each lanllt w as .82 pounds ot suplelpihostphate, .22 p~ound~s oft nitrate ~of sodl~. aand .06 piouinds of nuliat e of ootash. In T reatm ent N\o. 7, small pilants were used lr. and iin No. 8. summer pruning wals gix en. lanrts. exceplt ini N))o. 7. w ere 18 to 80f inches in height wxhen prlarnted. No prun-, ig wais g-i en in ;imy t reatmerit l except No. 8. The seeds wvere l' lanirted on .June 183 in oider to iy *g piroduice p~lanits riot too large tor tranispl antin bi wxinter. lants y xxere trarnsplantedl in Jarnar.Jeaso lemniets amudl photo grapl~hs i , wxere made ini late .1ulu-. The .~ platai 18 no n h, ~V F IG dlistanice fromi camera to pilant xx-i5 the saime for all photopared no lticn- r graphs excep~t in Figur'e 1. 1ion; no feliiliz, r The '-rowth made under the dlifferent treat ments is summariz ed in Table 1. Data for three of the earl ier p~lant ings are included. Tlvpical p~lants grown undIer several selectedl treatments are shown in Figures 3,. 4. 5, and 6. The contrast between plants grown undecr the different treatments is striking. The plantis grow n one Year on prepared soil ev en though not c ultiv ated or' fertilizedl were almost as tall as the eight-year-old pla nt s gr(own in the first planting. They were consid erab~ly larg(r than those grown :3 years on unplreparedl soil. It shoul1h le niotedl hoer marked wvas the response in growvth of the locust to each better treatment. The differences in growth are probably more strIikingly shown by the photographs than by the table since no growth. m easu rem ent giv en indic ates accurately the volume of The basal area, or the cross section area of the p~lant I'Ill'ItI. I. J'Laiit l: mnto from seed; Iind prIep~ard; (tltiN (tloli Vi\ve no fer~t iizer'. at the base. probablv represents miore nearl'v the relative size of plant than anI other of the measurements giv en in the table. The proans set on piep)aredl landl but tineultix ated and u iifertilized had a n ax elage height of 3.88 feet andi an average dha meter at the base of .9inches 138 months from the (late of seeding. la nts w hic h w ere cli ivated in addition to being p~lantedl on preplared landi but which receix ed no fertilizer were, as inidicated by, relativ e basal areas, 2.27 times as large as those similarly- handled but not cuiltix ated; cultivaitioni thus more than dob~lled the size of laints. Conitinuling the use ot the basal1 area as gut index of size, the plants receix ing phosphorus in addlitionl to c ultix atioll Were 3 times as large. thoe lec ei ing p hosphorus It 1 II SiI t I fl added. >e-;land pi vl)ii'ed ctti\'8t inn fli\fn; turd0 tis t hose retttim as latgtc as plIanits n~ 1itr'ogen, phosphorus, and pootas-h weret 7(07 wh icth hadl Itttl\ ezd nol cultiva tioni o1 fer- bettttr Uor th. An ete mI fore str iking- conltrast m1 1 he made(1 b}' it tomlpi iso of thetIhree-vea-old l nants seto tininprepartd lanid and( tllose plalltt(1 onl p)ttpared land. ctlliva ted an1d( ive itO complitte fertilizer. oil ag't wer ttIt timest The bettetr handled plants at 1:1 months a15 to rtlatix t its ,itat. and1( accoing' large2 as thet threto-}-a 1 t Iv-s -e\ oil cen1oil oth tfertilized l ts01: 011 thet lip iioi. tall. had( tut1 tvea\ - d11Z( iametter .5 lfimts basal artas. wert 8)I) tinmts asi 0(ol plts set o( il~0tl unprepare ln.N iltpilanoloits \X er Ii1g othet lug ctivaX ted1 11d 1111l01lO 11( plot. oulx G peri cent werei 4ro mm th st d ho tp c nrd utiain ,gi' I 11(1I~l I. lloo o l1 ando~ nito v n oa c ooo ~'Ill o: ttitioi TABLE 1.-Growth of the Black Locust under Different Treatments. 0-- Treatment No. 1 2 3 4 5 6 7' Age of plants Character of land Treatments.given Land preparation prepared prepared prepared prepared prepared prepared prepared prepared none none none Cultivation none cultivated cultivated cultivated cultivated cultivated cultivated cultivated none hoed once hoed once Fertilizer none none P P+N 1 Height (feet) 3.38 4.97 5.62 6.94 8.14 7.31 5.92 8.08 3.74 2.69 .75 K = .06 Diam. i Basal area (sq. in.) .120 .273 .371 .665 .849 .704 .475 .801 .238 .106 .028 Rel. basal area 1.00 2.27 3.09 5.54 7.07 5.86 3.96 6.67 1.98 .88 .23 (inches) .391 .590 .687 .920 1.04 .947 .778 1.01 .55 .368 .19 13 mo. 13 mo. 13 mo. 13 mo. 13 mo. 13 mo. 13 mo. 13 mo. 9 yrs. 3 yrs. 3 yrs. old field old field old field old field old field old field old field old field gully old field old field P+N+K 2 (P+N+K) P+N+K 83 9 10 11 P+N+K none none none 1P = .32 pounds per plant of superphosphate; N = .22 pounds of nitrate of soda per plant; 2Small plants 6 to 10 inches-all other plants 18 to 30 inches. 3Given one summer pruning. pounds per plant of muriate of potash. TABLE 2.-Growth of Locust and the Yield and Value of Corn and Cotton Grown as Intercrop. Treatment Treatment No. Fertilizer Number of cultivations Intercrop Height Diameter Production' Total value' Net Cost of labor and Cost of materials only' Cost of materials above value of intercrop 1 value' materials' (feet) 3.03 6.76 7.89 7.10 (inches) .32 .86 1.05 .91 8.8 bu. 413 lbs. $ 8.80 16.52 $ 6.10 12.12 $ 4.75 13.25 13.25 13.25 $ 2.00 9.02 9.02 9.02 $ 2.00 2.92 3.103 9.02 1 2 3 4 none NPK'2 NPK 2 NPK' none 3 3 3 none corn cotton none 'On acre basis. Four tenths pound per plant of a 2-8-5 fertilizer applied in 3Less than materials. March and one-tenth pound of nitrate of soda applied in April. 11 Behavior and Cost Considerations when Intercropped.-If it is necessary to handle the locust as a cultivated crop, which requires preparation of land and cultivation and fertilization of the plant, then it is logical to inquire if cotton or corn may not be grown as an intercrop for the first year to bear the cost of materials and operations. It is also of interest to know what effect these two crops might have on the growth of the locust. A study of these points has been made. In this experiment the land was prepared for all treatments. In Treatment No. 1,'there was no cultivation, no fertilization, and no intercrop. In Treatment No. 2, the plants were fertilized and corn was grown as an intercrop; in Treatment No. 3, the plants were fertilized and cotton was grown; in Treatment No. 4, the plants were.fertilized but no intercrop was grown. Each fertilized plant received approximately .4 pound of a 2-8-5 fertilizer in March and .1 pound of nitrate of soda about 6 weeks later. The cotton received 200 pounds of superphosphate, 100 pounds of nitrate of soda, and 25 pounds of muriate of potash; the corn received 150 pounds of nitrate of soda. Cultivation was given all treatments except No. 1. Each treatment was duplicated and 63 trees were planted in each plot. The results are presented in Table 2. It may be seen that the locust plants were largest in plots where cotton was used as an intercrop and that the cotton produced a crop having a value $3.10 greater than the cost of the locust plants and the fertilizers for the cotton and the locust. This extra value of cotton over the cost of materials was sufficient to allow a reasonable labor charge for preparation of land and cultivation of both crops. This experiment indicates that the labor and materials for starting a crop of locust posts may be taken care of by planting cotton one year as an intercrop. DISCUSSION OF USES These experiments indicate rather conclusively that the commonly accepted ideas that the black locust grows well on poor soils or on eroded hillsides, requires no attention, makes an excellent plant for erosion control, and produces, under unfavorable conditions, valuable posts in a short time, are incorrect under Alabama conditions. The results show, rather, that the locust will fail when planted under unfavorable conditions and given no attention; they will make very rapid growth when planted on prepared land and given some cultivation and fertilizer. Use in Erosion Control.-These results raise certain questions as to the suitability of the locust for some of the purposes to which it has been so commonly thought adapted and to the 12 methods of handling locust planted for these purposes. It is obviously useless to plant the locust on poor, eroded hillsides for the purpose of stopping erosion and producing posts, unless the land is properly prepared and cultivation given until the plants have become established. These operations necessarily increase erosion during the first year or probably the first two years after which time the locust should be of material value in reducing erosion. Where the locust is planted to stop "washes" or gullies already formed, it is equally obvious that some preparation and attention are necessary at least during the first year. It seems likely that mechanical traps which cause accumulation of soil around the plants will produce conditions similar to preparation of the soil. In gullies or on hillsides one-half pound of a complete fertilizer analyzing 6-8-4 (N-P-K) added to each plant should stimulate rapid growth and hasten the establishment of the plants. Given the favorable conditions necessary for good growth, the locust will make extremely rapid growth. This is illustrated by the plant in Figure 6 which is only 13 months old from seed and has only made 5 months growth since transplanting. In established gullies where the cost of preparing these gullies and properly handling the locust is of secondary consideration and where a plant is wanted which will make a quick strong growth, the locust will well meet the requirements. The failure of the locust in Alabama to make satisfactory growth, except where given certain treatments which are costly and require considerable time, raises the serious question of the suitability of the locust for large-scale forest planting in erosion control work in this State. If the proper conditions for successful growth of the locust are supplied, it will require for labor and materials approximately $12 to $14 to establish an acre. This is entirely too costly for general programs involving large areas, and the locust is almost certain to fail unless it is given rather careful attention at least for the first year. Unpublished data at this Station on pines have shown that when planted on eroded hillsides, in washes, and on poor sites, and given no further attention, except fire protection, they have grown rapidly, have been effective in erosion control, and by the eighth year are well on the way toward furnishing a valuable crop of timber. The cost of establishing pines is only a fraction of the cost of establishing black locust because no preparation, no cultivation, and no fertilizer are required for pines. The locust, therefore, does not seem to be as well suited to large-scale plantings as the pine. The locust is furthermore not as valuable for timber purposes as the pine; its uses are more limited and while better adapted to certain purposes than the pine, a limited volume of locust will easily supply the requirements for this species. There is thus little reason for extensive planting of the locust. 13 Production of Fence Posts.-Although the locust does not appear adapted to general forest plantings it makes an excellent and durable fence post and, when properly handled, offers opportunity to farmers of producing the posts needed on the farm. Where the locust is planted primarily for fence posts and where erosion is of little importance, the planting should be located on land of fair fertility and handled as a cultivated crop for one or two years. After this time it may be left quite largely to take care of itself. In starting the planting, the land should be prepared by turning and the plants set 6 x 6 feet apart, fertilized at the rate of 1/2 pound per plant with a 2-8-4 (N-P-K) fertilizer, and given clean cultivations the first year. Approximately one-tenth of a pound of nitrate of soda should be added about one month after growth has started. Neither the complete fertilizer nor the nitrate should be placed near the plant. Both should be placed about 6 inches from the plant and distributed in a 6 to 8 inch band around each plant. Isolated areas not easily reached when working other fields may be selected as a site for the planting because little attention is required after the first year, and plantings well established need little care. The area on which the locust plants are set should preferably be given over to post production indefinitely for two reasons: first, after the first crop of posts has been cut other crops are quickly produced by sprouts from the stumps; second, the locust is completely removed from an area only with great difficulty because of the strong tendency of the locust to send up new plants from wounded or severed roots. Preliminary studies indicate that some pruning is desirable. About one month after growth starts the first year, the plants should be trained or pruned. Where two or more branches are competing for the central or primary position, each branch should be cut back to one-half its length except the one which is left to assume the central position. The branches which are cut back at this period stop growth until a new mechanism for growth is produced by the formation of lateral buds. During this delay the unpruned branch straightens, and takes the central position; the pruned branches when growth does start have become so reduced in size relative to the unpruned branch that they take secondary positions and become branches of the unpruned branch. During the first winter, another pruning should be given following the principles of the summer pruning. Further experimental work is being done to determine how much pruning should be given to develop a single straight trunk. One acre of locust planted 6 feet x 6 feet will produce 1,210 stems. Approximately 500 pounds of a complete fertilizer in addition to 125 pounds of nitrate of soda will represent approximately $7 per acre invested in fertilizers. If the cost of the 14 plants is added then there has been an outlay of about $9 for 1,200 posts or a cost for material of less than one cent per post. The farmer supplies all other requirements in land and labor. A crop of cotton may be grown the first year between the locust to pay for the fertilizer and plants required to establish the planting. SUMMARY Results based on 10 experimental plantings established at various points in the State have been presented showing the behavior of the black locust on different sites and under different conditions. The results, while not final, seem to establish rather definitely the following points: (1) That the locust planted in gullies, on eroded hillsides, or on old fields will fail where the land has not been prepared and where the plants have received no attention. (2) That the locust planted on old fields of low or fair fertility will make very rapid growth where the land has been prepared, where three cultivations have been given, and where a complete fertilizer has been added. Deduction from the results of these experimental plantings indicate: (1) That the locust used in gullies or on badly eroded areas for erosion control should be planted on prepared land and given the first year sufficient cultivation to remove competing vegetation and sufficient complete fertilizer to induce a vigorous growth. (2) That the cost of establishing the locust satisfactorily makes this species too costly to use in large-scale reforestation programs or for large-scale plantings on abandoned agricultural land. (3) That the locust planted for fence posts should be handled as a crop the first year, the land being prepared, and the plants given two or three cultivations and about four-tenths pound per plant of a 2-8-4 (N-P-K) fertilizer supplemented with .. boufbonie-tenthi of a pound of nitrate of soda. (4) That the cost of plants and materials for establishing a planting of locust for posts should not exceed one cent per post assuming only one post from each plant set, and assuming that no intercrop is grown. (5) That cotton, grown as an intercrop, may be expected to bear the cost of preparing land and cultivating and fertilizing both crops, thus establishing the locust planting with little or no initial cost.