Davis, J. V.

Haby, Vincent A.

Leonard, Allen T.

English

Texas A&amp;M Repository

    PUBLICATIONS 1990 NUTRIENT SCREENING FOR ALFALFA RESPONSEv. A. Haby, J. V. Davis, and A. T. LeonardSUMMARYAlfalfa (Medicago sativa) production on Alfisols and Ultisols in the EastTexas Timberlands is hindered by a number of problems which include soil acidityand nutrient deficiencies. This greenhouse-pot study nutrient screening techniquewas conducted to determine response of 'Cimarron' alfalfa to the main effects ofphosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), sulfur (S), zinc (Zn),copper (Cu), boron (B), and molybdenum (Mo) in a randomized complete blockdesign with 4 replications. Three selected rates of each nutrient were applied tosoil from the Ap (0-6") horizon of the Darco series (loamy, siliceous, thermic,Grossarenic Paleudult). Soil incorporated treatments consisted of a check with nonutrients applied, all nutrients applied at the Ix rate, and all nutrients applied atthe 2x rate. In addition, the zero and the 2x rates of each individual nutrient weretested at the Ix rate of the other B nutrients. All nutrients except Mo contributedto increased yield in various cuttings. Calcium as Ca(OH)2, and S, P, K, and Znaffected alfalfa yield most strongly. Zinc decreased yield. This study suggestedthat limestone, P, K, and S should be applied to the field for alfalfa production onthe Darco soil.INTRODUCTIONLivestock, dairy, and horse producers in the East Texas Timberlands aredependent on interstate shipment for alfalfa hay. In addition, this area lacks awarm season perennial legume which could be grown in association with Coastalbermudagrass. Coastal bermudagrass interseeded with alfalfa could improve foragequality while reducing the requirement for fertilizer N on soils which have a highleaching potential for ground water contamination by NOs. Soil problemsprohibiting alfalfa production in this region include soil infertility and acidity. Theobjectives of this study were to determine the most yield limiting nutrients foralfalfa production on the Darco soil, and to determine the rates of each nutrient toapply in future field studies with alfalfa.PROCEDURESSoil was collected from the Darco series Ap horizon (plow depth) and airdried. Plant essential nutrient elements and rates studied, including source, and37percent concentration are shown in Table 1. The mass of each nutrient applied to9 kg (19.84 lb) of soil is presented in Table 2. Treatments 1, 2, and 3 were allnutrients applied at the zero rate, at the Ix rate, and at the 2x rate, respectively.Each individual nutrient was tested at its zero and 2x rate with all other nutrientsapplied at their Ix rate. A treated soil mass of 2.2 kg (4.85 lb) was placed into15.2 em (6 inch) diameter plastic pots. The soil was saturated to field capacity for1 d to allow the chemicals to begin to equilibrate. 'Cimarron' alfalfa was seededinto the pots and thinned to 10 plants per pot. The pots were watered daily asneeded. Greenhouse temperature was set at 20"C. The first harvest was collected85 d after seeding. Succeeding harvests were collected at 30 day intervals. Datawere statistically analyzed using micro SAS.RESULTSSoil test data indicate that the Darco soil Ap horizon was deficient in N, P,K, Mg and B (Table 3). Calcium tested in the moderate level. Sulfur and themicronutrient cations tested high. Soil pH indicated moderate acidity.Statistical analysis of alfalfa dry matter showed that P, K, S, B, and Ca asCa(OHh contributed to significant yield increases (P S; 0.05) in harvest 1 (Table 4).At harvest 2, all plant nutrients but Mo significantly increased yield. At harvest3, Mg and B along with Mo ceased to have an effect on yield. Analysis of nutrienteffects on total alfalfa yield indicated that the B effect on harvest 1 carried throughto the total, while the effect of Mg on harvest 2 did not. Regression equations foreach harvest and the total are presented in Table 5. Multiple correlationcoefficients indicated that 68% or more of the variation in yield at all cuttings wasaccounted for by the nutrients indicated as significant in Table 4.The effect of the variable P and K rates on alfalfa yield for individualharvests when the rate of other nutrients which significantly affected yield(probability level s 0.01) was held constant at the Ix rate is shown in Fig. 1 and2, respectively. Response to P was essentially linear and indicated that the ratesselected for this study were inadequate, to maximize yield. Response to K wasquadratic and indicated that maximum yield was attained in the range of 75 to 100kg K ha-l (67 to 89 lb K/ac) for harvests 1 and 3. For harvest 2, yield appeared tobe maximized at 125 kg K haol (112 lb Klac).Total yield response of alfalfa to K, P, S, and Ca is indicated in Fig. 3.Total yield was maximized by approximately 100 kg K (89 lb/ac), 60 kg S (54 lblac),and 1250 kg Ca ha°l (1115 lblac) as Ca(OHh. Total yield response to P was linear.38Not all nutrients increased yield. Increasing rates of Zn significantly loweredalfalfa yield on this soil (Fig. 4 and Table 5).DISCUSSIONResults of this greenhouse nutrient screening test verify that the Darco soilis infertile. To have a chance to effectively produce alfalfa on this soil wouldrequire the application of P, K, S, B, and Ca as a liming material. The use of onlythe Ap horizon limits the application of greenhouse test results to the field,however. Sulfur which had a strong effect on increasing alfalfa yield, increases inconcentration with depth in the Darco soil at this location. Over 800 lb S/ac weremeasured in the top 7 feet of this soil. This does not preclude the application ofS as a starter fertilizer prior to seeding alfalfa.TABLE 1. PLANT NUTRIENTS, APPLICATION RATES, SOURCES, ANDCONCENTRATIONNutrient Application Rates Sources Cone.-------------ltg ha·lt------------ %P 0 56 112 Phosphoric acid 17.48K 0 75 150 Potassium chloride 46.0Ca 0 775 1550 Hydrated lime 62.9Mg 0 33.5 67 Magnesium chloride 11.95Zn 0 3.4 6.7 Zinc chelate 14.5B 0 1.12 2.24 Boric acid 39.65S 0 33.6 67.2 Sodium sulfate 58.0Cu 0 1.12 2.24 Copper chelate 22.57Mo 0 0.21 0.42 Sodium molybdate 14.2tltg hal x 0.8923 = lb/ac39TABLE 2. MASS OF EACH NUTRIENT APPLIED TO THE SOIL FOR 4 REPLICATIONS OF EACH TREATMENTTreatment B Ca K M~ Cn Mo P S Zn----------------------------------------------------------------------~!Jlt~--------------------------------------------------------------------------1 Checlt 0 0 0 0 0 0 0 0 02 All Ix .033 8.628 .732 1.444 .040 .003 1.141 .765 .1223 All 2x .066 17.256 1.463 2.888 .07!J .006 2.281 1.52!J .2434 o B 0 8.628 .732 1.444 .040 .003 1.141 .765 .1225 2x B .066 " " " " " " " "6 o Ca .033 0 " " " " " " "7 2x Ca " 17.256 " " " " " " "8 o K " 8.628 0 " " " " " "!J 2x K " " 1.463 " " " " " It~ 10 0 M~ " " .732 0 " " " " "011 2x M~ " " " 2.888 " " " " "12 0 Cn " " " 1.444 0 " It " "13 2x Cn " " " " .07!J " " " "14 0 Mo " " " " .040 0 " " It15 2x Mo It It It " It .006 " " "16 0 P " " It " " .003 0 " It17 2x P " It " " " " 2.281 " "18 0 S " " " " " " 1.141 0 "1!J 2x S " " " " " " " 1.52!J It20 0 Zn " It " " It " " .765 021 2x Zn " " " " " " " " .243TABLE 3. PLANT AVAILABLE NUTRIENT LEVELS IN DARCO SOILtMacro and Secondary NutrientspH NOs-N P K Ca M~ S......--...-------...-------------...-------]l]lIIl--...-------------...-...--...--------...----Value 5.9Rating1VL1VL95L508M64L75HMicro Nutrients and SalinityZn Fe Mn en B Na EC------------...--...---------------------]l]lIIl----------------...---------------------------- ctE)IIl1Value.01Rating0.34H9.37H25.7H0.17H0.03L55. VL LtProcedures used in the Texas Agric. Ext. Service Laboratory (Johnson et aI.,1984).41TABLE 4. ANOV FOR ALFALFA RESPONSE TO APPLIED NUTRIENTSElement Cut 1 Cut 2 Cut 3 TotalP *** *** *** ***p2 *** *** NS ***K *** *** *** ***K2 *** *** *** ***Ca *** *** *** ***Ca2 ** *** ** ***B ** * NS **B2 *** * NS **S *** *** *** ***S2 NS *** ** ***Mg NS ** NS *Mg2 NS ** ·NS *Cu NS *** ** **Cu2 NS ** ** **Zn NS *** *** ***Zn2 NS * ** **Mo NS NS NS NSMo2 NS NS NS NSR2 0.86 0.86 0.80 0.88C.V. 4.71 8.24 7.73 5.76*, **, ***Significant at PS; 0.10, 0.05, and 0.01 levels, respectively.NS = not significant42TABLE 5. REGRESSION EQUATIONS AND CORRELATION COEFFICIENTSEquationHarvest No. Equation123123Y = 5.341 - 0.601 B + 0.283 B2 + 0.000272 Ca + 0.0171 K -0.0000820 K2 + 0.0168 P - 0.0000340 p2 + 0.0141 SR2 = 0.79 C.V. =5.3Y = 3.266 + 0.114 S - 0.000975 S2 - 0.267 Ca + 0.0169 K -0.0000585 K2 + 0.00154 Ca - 0.000000561 Ca2 - 0.177 Zn +0.0179 P - 0.0000291 p2R2 = 0.77 C.V. = 9.8Y =5.483 + 0.039 S + 0.0194 K - 0.000101 K2 + 0.00123 Ca -0.185 Zn + 0.00973 PR2 = 0.68 C.V. = 8.9Total 4 Y = 13.572 + 0.190 S - 0.00136 S2 + 0.0437 K - 0.000182 K2 +0.00438 Ca - 0.00000155 Ca2 - 0.428 Zn + 0.0424 P -0.0000551 p 2R2 = 0.81 C.V. = 6.64310,----------------,8"D•>-•-oD- 0at.:E.oD 7....D....a:6~__...,.1,,____=!1,,_~1:,_~~~=__~=__~o 16 32 48 64 80 • 112Phosphorus ratn (kg P 00-1)Fig. 1. Alfalfa r~e to P predicted for eachhorvest by Eq. 1. 2. and 3 In Tobie 5.10"•-DD- Oat"D-•>-.:E.0D....D....a:kg Kha-1x 1.07 = Ib K'!JIc__----~ .Cut 3Cut 160~-2=!:5=-----=50~--:l75=----...,.I~OO=------,-,12~5:--.....,1,...,!.50Potassiu. ratn (kg K 00-1)Fig. 2. Alfalfa response to K predicted for eachhorvest by Eq. I. 2. and 3 In Tobie 5.I g~----L-~;-...L...-__:_I~---L..__::__L=-.1.-...",.Jo 1.7 3.4 5.0 6.7linc rate (kg ho- I )Fig. 4. Alfalfa res~ to ln predicted for thetotal yield by Eq. 4 In Tobie 5.44_211 kg Kbo"l. 1.01- Ib K~/~ I•'4J0250.m-"0 23-..>-. 21::Ekg P110"1. Z. Ib PN~.o27,r-----------i112310 620 030 1240 1550Co rate (kg ho- I )kg Co 1Io"I X .89Z3 :I Ib CoI~o150 0--18-~~ - 48--04------s0P rate (kg ho- I )K10 20 30 - -40- 50- 60 70S rate (kg ho- I )kg S110"1••8DZ3 - Ib S/~19..--_~0250.m"0 23c--..>-. 21%.--i+>-U1Fig. 3. Alfalfa response to rates of individual nutrients as predicted by equation 4. Nutrients entered intoequation 4 were calculated at the Ix rate when not considered for an individual graph.

Nutrient Screening for Alfalfa Response

https://oaktrust.library.tamu.edu/bitstream/1969.1/190145/1/article493.pdf

Nutrient Screening for Alfalfa Response

Abstract

Similar works

Full text

Available Versions

Texas A&M Repository

Nutrient Screening for Alfalfa Response

Abstract

Similar works

Full text

Available Versions

Texas A&amp;M Repository

Texas A&M Repository