Soil Evaluation Methods for Calcium for Peanut (Arachis hypogaea L.)Production in the Coastal Plain

摘要

Successful peanut production requires adequateCa in the pegging zone. Soil testing for Cabased on pegging zone samples provides scientificbasis for Ca supplementation for peanut,but concerns regarding inaccuracy of certain soiltesting methods have been brought up byprevious studies; therefore, reevaluation ofroutine soil testing methods for Ca on peggingzone samples is necessary. The objective of thisstudy was to evaluate relationships and predictabilityof four major soil tests including Mehlich1 (M1), Mehlich 3 (M3), 1 N neutral ammoniumacetate (AA), and 0.01 M sodium nitrate (SN)for Ca, K, and Mg for peanut production inCoastal Plain soils common in the major peanutproducing regions of the Southeast. Resultsshowed that the four tests extracted variedamount of Ca, K, and Mg from soil. Soiltreatments that included an addition of gypsumor lime reduced availability of soil K and Mg.Correlations were strong among soil K and Mgdetermined using M1 and M3, but the relationshipwas weak between M1 and SN. Applicationof gypsum shortly before soil sampling hadminimal effect on correlations among the fourtests; however, application of lime led to weakercorrelations. In unamended or gypsum-treatedsoils, M1 is an adequate index of soil availableCa for peanut. The M1 test may overestimatesoil available Ca if soil is recently limed;therefore, any of the other three soil tests maybe used in such cases. The AA test for Ca had thebest relationships to peanut yield, grade, andseed Ca concentration, followed by M1.