| dc.description.abstract | The objectives of this research are to calculate the value of soil microorganism in slope zone and variation of soil depth class at natural forest ecosystem . The research was conducted in the Laboratory Of Soil Biology and Central Laboratory , Faculty of Agriculture , Univesity of North Sumatera , Medan . The method used is Factorial Complete Random with two factor compared . They are : Factor I , slope class ( V ) and Factor II : depth class ( D ) The result of this research is showing that the highest pH according to slope class is in 0-8 % about 5,80 and lowest pH is in 15-25 % about 5,37 . According to depth class , the highest pH is in 20-30 cm about 5,95 and the lowest is in 0 - 10 cm about 5,27 . The highest amount of soil microorganism according to slope class is in 0 - 8 % about 34,48 x 107 SPK / ml and the lowest is 15-25 % about 33,65 x 10 SPK / ml . According to slope class the highest amount of soil microorganism is in 0 - 10 cm about 47,17 x 107 SPK / ml and the lowest is 20 - 30 cm about 22,08 x 10 ' SPK / ml . The highest production of CO₂ ( respiration ) from soil microorganism based on depth class is in 0 - 8 % about 1,33 kg / day , while the lowest is in 15 - 25 % about 1,10 kg / day . According to depth class , the highest production of CO₂ ( respiration ) from soil microorganism is in 0 - 10 cm about 1,37 kg / day and the lowest is in 20-30 cm about 1,12 kg / hari . The highest organic substance based on slope class is in 0-8 % yaitu about 1,65 % while the lowest is in 8-15 % yaitu about 1,54 % . The highest organic substance based on depth class is in 0 - 10 cm about 2,40 % and the lowest is in 20-30 cm about 0,99 % . | en_US |
