JANUARY 1931 KUDZU IN ALABAMA By R. Y. BAILEY AND E. L. MAYTON AGRICULTURAL EXPERIMENT STATION OF THE ALABAMA POLYTECHNIC INSTITUTE M. J. FUNCHESS, Director AUBURN CIRCULAR 57 CONTENTS Page KUDZU AS A HAY AND GRAZING CROP-3 Feeding V alue -- -- --- -- - -- -- - -- -- - - - - - 3 Grazing-'3 Green Feed for Poultry ----- -- -4 Y ields of H ay -- -- - -- - -- -- - -- - -- -- - - - 4 Effect of Time and Frequency of Cutting on Yields of K udzu H ay ---------------------------- 6 W hen to Begin Mowing ----------------- _ -- 6 H a rv estin g -- -- -- -- -- - -- -- -- -- -- -- - -- -- -- -- -- - 7 KUDZU FOR SOIL IMPROVEMENT ----------------------- 7 CULTURAL M ETHODS ---------------------------------- 7 SOIL AND FERTILIZER REQUIREMENTS OF KUDZU ----- 9 Soil R equirem ents ---------------------------- 9 F e rtiliz e rs -- -- -- - -- -- -- -- -- -- - -- -- -- -- -- -- -- - 9 K U D ZU A S A PE ST -------------------------------------- 9 S U M M A R Y - -- -- -- --- - -- -- -- -- - -- --- - -- -- - -- -- -- -- -- -- --10 Kudzu in Alabama By R. Y. BAILEY, Assistant Agronomist and E. L. MAYTON, Assistant in Agronomy THERE is a need for a perennial forage plant which will pro- duce large yields of hay, which is adapted to grazing by livestock, and which is sufficiently drouth-resistant to pro- duce high yields when other crops fail. Kudzu has shown more promise of meeting these requirements than any other plant now being grown in Alabama. Kudzu is a perennial legume which is known locally in Ala- bama as "Porch Vine" or "Telephone Vine" and is used exten- sively as a shade plant around farm houses. As a forage plant, kudzu, in either the green or cured state, is eaten readily by all classes of livestock. In feeding value it compares favorably with other legumes. KUDZU AS A HAY AND GRAZING CROP Feeding Value.--A comparison of the feeding values of kudzu and alfalfa in both the cured and green states is presented in Table 1. A study of the table reveals the fact that kudzu in both states has a silghtly higher feeding value than alfalfa. Table 1.-Comparative Feeding Values of Kudzu and Alfalfa.(1) Total dry Digestible nutrients in 100 pounds matter in Crude Carbo- 100 pounds protein hydrates Fat Total Kudzu hay 92.9 11.4 39.8 1.2 53.9 Alfalfa hay 91.4 10.6 39.0 0.9 51.6 Green kudzu 30.6 4.2 13.9 0.5 19.2 Green alfalfa 25.3 3.3 10.4 0.4 14.6 (1) Henry and Morrison's "Feeds and Feeding". Seventeenth edition, 1920. Grazing.-All classes of livestock graze kudzu readily and a field of it may be used effectively as a temporary pasture when regular summer pastures fail on account of drouth. The De- partment of Animal Husbandry and Dairying at the Alabama Experiment Station has done some preliminary grazing work with this plant. During the severe drouth of July 1930, the milk flow of dairy cows was maintained by changing them from grass pasture to kudzu a part of each day. Unfortunately, the area was too small for the number of cows used and no record was obtained which would indicate the grazing capacity of an acre of kudzu. No unpleasant odor or flavor of milk resulted from grazing kudzu. Observation of kudzu which has been grazed and results of mowing experiments to date indicate that it should not be grazed closely throughout the growing season. However, the most de- sirable time for grazing this crop and the extent to which it may be grazed will be determined by additional experiments. In order to maintain a stand, it may be necessary to allow kudzu one year out of every three or four to recover from the effects of mowing or grazing; this would more likely be necessary on poor land than on rich land. Green Feed for Poultry.-Another use for this crop is as a summer green feed for poultry. Although it would probably not be well adapted as a grazing crop in poultry yards, due to its heavy growth, kudzu may be cut from the field and fed through- out the growing season. It would be especially valuable during periods of extremely dry weather when other green crops fail. Yields of Hay.-A well-established planting of kudzu on sandy loam soil at Auburn was cut for hay during the six-year period, 1920-1925. Approximately the same area was cut each year. However, the size of the area varied slightly due to run- ners growing across the borders of the original area. The yields of hay and the number of cuttings made each year are presented in Table 2. Table 2.-Yields of Kudzu Hay at Auburn. Year Number of cuttings Date of cutting Yield of hay per acre Lbs. 1920 1 September 10 5,114 July 28 1921 2 September 2 5,410 August 4 1922 2 September 23 5,240 August 2 1923 2 October 10 5,665 July 29 1924 2 October 10 4,722 July 8 1925 2 August 10 3,100 Average 4,875 The results presented in Table 2 show that during the first four years the yield was never below 5,000 pounds of hay per acre. The low yield in 1925 was due to the fact that during the period from February to August, inclusive, the rainfall was 20.57 inches below normal. When the weather is taken into consider- ation, the yield for 1925 was remarkably high. Another area which was cut twice in 1930, a dry year, pro- duced 5,647 pounds of hay per acre. This area was sandy, but part of it was more moist than average upland. No fertilizers were applied to either of the areas mentioned. andi sa I t Itc r 'a lini hteni x eald iet have pioidued imie than ten bueshels af cooni per acrie . Effect of Time and Frequency of Cutting on Yields of Kudzu Hay.-An experiment was started on Norfolk sandy loam soil at Auburn in 1926 to study the effect of time and frequency of mowing on the growth of kudzu. Plants of uniform size were planted in the spring of 1926 and mowing was started in 1928 after the plants had become well established. The number of cuttings, dates of cutting, and the yields of hay produced in this experiment are presented in Table 3. Table 3.-Effect of Time and Frequency of Cutting on Yields of Kudzu Hay. Pounds of hay per acre Plot Cutting Dates of cutting 3-year No. treatment 1928 1929 1930 average 1 2 Early June 1, August 15 5,749 4,333 1,815 3,966 2 2 Late June 1, October 15 5,374 4,077 2,595 4,015 May 1, July 1, Au- 3 3 Early gust 15 4,256 2,834 1,515 2,868 May 1, July 1, Oc- 4 3 Late tober 15 3,570 4,300 2,366 3,412 May 1, June 1, July 5 4 Early 1, August 15 3,406 2,944 851 2,400 May 1, June 1, July 1, August 15, Oc- 6 5 Late tober 15 3,820 2,829 1,205 2,618 The data presented in Table 3 show that yields declined on all plots, except Plot 4, the second year and on all plots the third year; the loss was greater the third year. The smallest yields were made on plots which received three early cuttings, four cuttings, and five cuttings per year, respectively. In addition to this, observations made in the field during the growing season showed that there was a corresponding thinning of the stand on these plots. Plots cut June 1 and October 15 produced slightly more hay than those cut June 1 and August 15. Although the differences in the average yields were small, the yields declined more rapidly the second and third years on the plots cut June 1 and August 15 than on those which were cut June 1 and October 15. Also, the loss in stand was more pronounced on the plots cut June 1 and August 15 than on those which were cut June 1 and October 15. These preliminary results seem to indicate that October 15 is a more desirable date for the last cutting in the latitude of Auburn than August 15, but this problem is to be studied further in order to determine the best dates of cutting. When to Begin Mowing.-Kudzu should be well established before mowing begins. It should be allowed to grow at least two full seasons before mowing is started. In case the soil is very poor, three seasons may be required before it will be ad- visable to begin mowing. Harvesting.-One of the objections to kudzu as a hay crop is the difficulty of mowing. This is especially true of plantings which are being cut the first time. The long vines are caught by the divider board and dragged along by the blade, making it necessary to stop frequently to clear the blade. However, later cuttings are less difficult to make. Although the first cutting is difficult, it may be delayed without serious loss in the quality of hay until the cultivation of other crops is completed and time is not an important factor in the regular farm operations. This plant sheds its leaves very badly when cured in the swath; it should, therefore, be raked into windrows after the leaves are wilted and allowed to remain there until dry enough to put in the barn. Another method of curing is to stack on racks such as are used for soybean and cowpea hay. KUDZU FOR SOIL IMPROVEMENT In an experiment at Auburn kudzu was planted in the early spring of 1916 and turned under in the spring of 1919. The kudzu made little growth in 1916, covered the ground in 1917, and made a dense growth in 1918. From 1919 through 1929, two crops of sorghum hay, four crops of corn, and seven crops of oats were grown on the area devoted to this experiment. The average yields of sorghum hay, corn, and oats are presented in Table 4. Table 4.-Influence of Kudzu on the Yields of Succeeding Crops. Average yields of following crops Plot 2 crops sorghum hay. 4 crops corn. 7 crops oats. Pounds per acre Bushels per acre Bushels per acre 1 No kudzu 3,264 14.7 16.6 2 Kudzu 5,800 34.0 24.5 The results in Table 4 show that the residue from kudzu pro- duced an average increase of 2,536 pounds of sorghum hay per acre in 1919 and 1920. The average yield of four crops of corn following kudzu was more than double the yield on the plot that had not grown kudzu. The average yield of seven crops of oats on the kudzu plot was 7.9 bushels per acre more than that on the plot which had grown no kudzu. In 1929, ten years after the kudzu was turned under, the kudzu plot produced 9.2 bushels of oats per acre more than the plot on which kudzu had never grown. CULTURAL METHODS Kudzu seldom produces seed and, therefore, must be prop- agated by plants which are usually called crowns; these are formed by the vines taking root at the nodes. A good crown has a bud, or growing point, and well-developed, fleshy roots eight I 1(;lIZFi"2 S howing different k~indso ul d(zu plant. Only the two~ on the right ar recom elnedei. orte (1inc h es in Ilength; this developmnlct requ (ires 1 to 01 more ear s ( Figure 8). Some succes sful plantings have been made wxith vine cuttings. but this method usually results in failuore and is not recommWendled. Some growers advertise pl ants and fill 01rders w"ith vine cuttings. Those who order plants should ex- aminell them when they arrive and refuse to accept vine cuttings. If c low 11 ar prl~operll- set betore theyv dryv out, practically all ol them wviii gro w. On the other h and, if theyv ale shi ppled a liog dIistance andI alIlo wed to d ry out before planting, a large per- centage of them will fail to grow. T herefore, it is dlesirabile, wxherev er possible, to obtain crowns locally. One met ho0( of planoting th at h as been utsedl successful lv con- sists in dIiggintg holes a bout 12 inches deep wvith a post-hole dig- gzer andl selling t he crownus, the r oots of wvh ich haxve been cut back to about11 12 inches ill length, in these holes. The soil should lie packed aroundt~ the roots so that the bud ot the plant is left slightly abhove the surifac e. Another net ho0( that h as b~een used (ery successfully is the furrow method. In this method the clr)xx s ar~e set i1n opeln fllTOWs so that the b ud(s are just abiove the sil surf ace. This method req uires less hand labor andI has resultedl ill better first-year griowxth than the post-hole method, (due probably to the fact that the roots are planted whole xithout trimming. C'roxvns ale usually spaced about 10) feet apart each xx ay, wvhich requires 4:35 p~lanlts per acre. A goodI start may lbe madle in less time by, spacing 3 feet ap~art each waxy. This t hic ker spacinug is dIesirable I if 1)lenty of hom e-growxn crowns are axvailable; if they mutst be purchasedl, the thicker spacing is ex- pensiv e. Sintc e kud1(zuI plants are scarcec andl rat her high in price, it is advxisale for tfarImelrs to obtain enough pl1ants to set a small area of' good land wxhich xwill prloducle a dense growtxth in a short lime. From this area crowns may be procured for further planting. An ideal place for such a planting is on low land where soil has been washed in above a terrace or rock dam. A heavy application of manure and phosphate on this area will stimulate growth and insure a large crop of plants. The time of planting kudzu has not yet been studied; how- ever, plantings made early in the spring, February 15 to March 15, have been very satisfactory. Kudzu plants make little growth the first year and may be smothered out by weeds or destroyed by rabbits. The young plants may be protected from weeds by planting some cultivated crop between the rows of kudzu the first year. If soybeans are used as the interplanted crop the rabbits will feed on them and do less damage to kudzu plants. SOIL AND FERTILIZER REQUIREMENTS OF KUDZU Soil Requirements.--Kudzu has grown well on soils varying from sandy loams to heavy clays, but has not done well on poor sand. Like other crops it has grown more successfully on good land. Moist land is especially well adapted to kudzu, but noth- ing is known about the effect of water standing on the crop for one or more days in case of overflow by streams. All of the experiments and observations relative to kudzu here reported have been made on non-lime land; therefore, nothing is known of its adaptation to lime soils. The remarkable growth of kudzu on land too poor and rough for other crops, together with its high feeding value, shows be- yond a doubt that there is a place for this crop on Alabama farms. Figures 1 and 2 show kudzu crowding out bushes, briars, and small trees on land which was too poor to produce more than 10 bushels of corn per acre. The possibilities of kudzu on thousands of acres of similar land in Alabama are almost un- limited. The forage that would be produced on this waste land by a crop like that shown would go far toward supplying the feed and pasture needed for successful livestock production. Fertilizers.--No studies have been made at Auburn to de- termine the fertilizer needs of kudzu; all of the plantings dis- cussed in this circular were unfertilized. Some plantings in other parts of the State have been fertilized with phosphate, potash, and manure. Although these plantings are not old enough to warrant definite conclusions, indications are that this plant responds well to phosphorus and manure. KUDZU AS A PEST One of the chief reasons why kudzu has not been grown more generally in Alabama was the prevailing idea that this crop was a dangerous pest. Farmers were told by some agricultural workers that if this plant were allowed to become established in 10 cultivated fields it would be impossible to eradicate it. They were also warned against it on account of the possibility of its spreading to fields where it was not desired. As evidence that this warning is unfounded, kudzu on a small area at Auburn gave no trouble on the adjoining cultivated fields over a period of more than 25 years. This area was plowed in the spring of 1930 for the purpose of obtaining crowns for new plantings, and corn was grown on the land during the summer. The plants which came up on the area did not seriously interfere with the cultivation of the corn. Results of the experiment on time and frequency of cutting indicate that close grazing followed by plowing will eradicate kudzu. SUMMARY 1. Kudzu is a perennial legume which may be cut for hay, grazed by livestock, or used as green feed for poultry. 2. During a six-year period, kudzu produced an average yield of more than two tons of hay per acre without fertilizer. 3. Close grazing or frequent cutting will destroy the stand of kudzu. 4. The growing habits of kudzu make the first mowing diffi- cult. Later cuttings are easier to make. 5. Kudzu turned under in 1919 increased the average yield of two crops of sorghum hay by 2,536 pounds per acre, four crops of corn by 19.3 bushels per acre, and seven crops of oats by 7.9 bushels per acre. 6. Only strong plants, which have not been allowed to dry out, should be planted. Soybeans planted between the rows of kudzu the first year, and cultivated, will protect the young kudzu plants from weeds and rabbits. 7. Kudzu is not a dangerous pest. No trouble was encounter- ed in preventing its spread to adjacent lands over a period of more than 25 years. It may be eradicated by heavy grazing followed by plowing.