LFL: Deep core protocol
Three soil cores are taken down the center of the plot at the north end, south end and middle of plot. A 1 1/4 inch diameter core cylinder (using the probe truck) is pushed down to approximately 3 1/2 feet. If there is no soil compression, any soil beyond 3 ft. is discarded. If there is soil compression, all of the soil beyond 2 ft. is considered the 3 ft. sample.
The probe is marked for each of the depths: 1 ft., 2 ft., and 3 ft. The probe is removed from the ground and inverted. A large screwdriver (or other implement to separate the depths) is used to cut off the 0-1 ft. and put into a pail. The 1-2 ft. is separated and put into another pail. The 2-3 ft. (or 2 ft. to the end) is placed into a 3rd pail.
The cores from each site in the plot are combined in a pail, hand crumbled, run through a ¼ inch screen (to remove rocks) and put into a cardboard soil box. The boxes are labeled with the plot ID, depth and date sampled.
The boxes are then placed (within 2-3 hrs of sampling) into the soils dryer (low temperature convection oven) at 110-140 ° F until dry (at least 48 hrs).
After removal from the dryer, the soils are then ground using a Hammermill Grinder through a 2 mm sieve and placed back into the box.
The soils are then taken to the laboratory for analysis.
Inorganic N (seeSoil Nitrates), Total C and N (see Total CN), and Macro and Micro nutrients (analyzed in Soil & Plant Nutrient Laboratory, A-81 PSSB, MSU) may be analyzed as determined by the LFL manager.