Changes in Pond Bottom Soils During the First Ten Years of Use
A STUDY TO DETERMINE CHANGES IN POND BOTTOM SOIL COMPOSITION HAS BEEN IN PROGRESS AT THE MARION, ALABAMA NATIONAL FISH HATCHERY FOR MORE THAN TEN YEARS. THIS REPORT GIVES THE FINDINGS OF ANALYSES FOR CALCIUM, PHOSPHORUS, POTASSIUM, PH, NITROGEN, AND ORGANIC CARBON. SAMPLES WERE TAKEN PERIODICALLY FROM THE SAME LOCATIONS WITH THE LAST ONES TAKEN TEN YEARS AFTER THE INITIAL FLOODING. DURING THE PERIOD, PH GENERALLY CHANGED FROM ACID TO NEUTRAL LEVELS. PHOSPHORUS INCREASED IN SOME PONDS AND DECREASED IN OTHERS. ONE UNFERTILIZED POND SUPPORTED A LUXURIANT GROWTH OF NAJAS SP. AND CHARA SP. EVEN THOUGH NO AVAILABLE PHOSPHORUS WAS MEASURED IN THE SOIL SAMPLE. ORGANIC NITROGEN AND CARBON INCREASED APPRECIABLY WITH NITROGEN INCREASING AT A GREATER RATE. THE CARBON/NITROGEN (C/N) RATIO NARROWED IN 11 OF 12 PONDS.