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For 12-inch penetration: Number of observations ------------- 20 Mean force applied ----------------- j3 pounds Standard,deviation --------------- 8 pounds Penetration was most difficult at depths of 4 to 8 inches; thereafter, the force required for further penetration generally decreased. Spade. A narrow S-inch aide by 16-inch long spade was also used to measure penetration. The procedure was to place the spade in a vertical position then to stand upon the spade slowly so as to apply a near static pressure, Depths of spade penetration were measured on the mulch-compari- son plots and on the reference area, as follows: For mulch-comparison plots: ~ Number of observations ------------ 20 Penetration ------------------------ 6 inches Standard deviation ----------------- 0.7 inch ' For reference area: Number of observations ----------- 20 Penetration --------------------- 12.4 inches Standard deviation ---------------- 1.5 inches ~ The maximum penetration achieved on mulch-comparison plots xas 8 inches; xhereas, the maxitlum achieved on the reference area xas 16 inches. A shoving motion while standing on the spade pushed it to full depth on the reference area, but seldom to more than 8 inches on the mulch- comparison plots. The spade test would be most readily used to monitor compaction on ~ reclaimed mine areas. DEMONSTRATION OF COt~ACTION The spade test was used to demonstrate sand compaction to John Nelson on April 14, 1980, and to Bob Sill in, Ton Conley and Darryl Arnold on t4ay 14, 1980. RIPPING Although sand compaction during reclamation should be either prevented or corrected before seeding, it would be good to knox whether or not satisfactory results could be obtained by ripping after seeding. For that reason, we had Darryl Arnold rip the west set of mulch-comparison plots (plots 1-6) on May 14, 1880, when the sand xas moist, and the east set (plots 1}-18) on June 18, 1980, xhen the sand was dry. His ripper penetrated to a depth of about 20 inches with ripper teeth spaced 19 inches. Ripping uprooted some of the plants amd lifted the soil surface 5-6 inches. Uproot- ing appeared cost severe with ripping when the sand xas dry. A moderate degree of recovery, mostly by sand dropseed, had been obtained by June 14 • and further recovery by August 25 on plots ripped when the sand was moist. Further observations of recovery are needed in 1981 and subsequent years. ~~ 4