a and ba horizonsa1a2a3ababatementabc soilabioticabiotic factorabrasionabsorbed waterabsorptanceabsorptionabsorption activeabsorption lossabsorption passiveacac soilaccelerated erosionaccess tubeacclimatizationaccommodationaccretionaccumulationaccumulatoracetylene block asseyacetylene reduction assayacidacid gasacid mine drainageacid rainacid soilacidic cationsacidic precipitationacidificationacidifying substanceacidity activeacidity exchangeacidity exchangeableacidity freeacidity potentialacidity reserveacidity residualacidity salt replaceableacidity totalacidoidacidophilousacreacre foot