Natural Fertility And Productivity Differences Of Prime Farmlands In Mississippi

Abstract Three soil series classed as prime farmland in diverse land resource areas of Mississippi were studied. Two pedons each of the Cahaba (Typic Hapludult), Memphis (Typic Hapludalf), and Sharkey (Vertic Haplaquept) series were selected in areas that had not been cultivated for at least 40 years. The series were representative of loamy, silty, and clayey soils, and they had diverse chemical characteristics and water holding capacities. Cation exchange capacities of the surface horizons differed greatly with Sharkey (66 cmol (p+) kg ) > Memphis (19) > Cahaba (7.3). The Cahaba and Memphis surface horizons had H as the dominant exchangeable cation (H > Ca > Mg > K > Na), whereas, Ca was dominant in the Sharkey pedons (Ca > H > Mg > Na > K). Kaolinite was the dominant clay mineral in the Cahaba soils, illite was most abundant in the Memphis pedons, and smectite was dominant in the Sharkey soils. Inherent natural fertility based on greenhouse production of dry matter (wheat) clearly showed the A horizon >...