Abstmct: Reclamation practices at Navajo Mine involve the establishment of native vegetation on mined lands. Currently, this involves incorporation of a grass hay mulch into the soil following seeding. The mulch retards moisture loss and impedes wind erosion. Reclamation areas are characteristically irrigated for two seasons. In 1992, management of Navajo Mine became interested in finding an alternative to the use of grass hay mulch that would be readily available year to year, be of consistent quality and cost, less expensive to apply, sterile, and as good as or better than hay mulch in its ability to maintain consistent soil moisture. A commercially available chemical product, Desert Bloom Plus, manufactured by Hydra-Soil International, is a possible replacement for mulch. A study implemented in June 1993, sought to compare vegetal performance using mulch and Desert Bloom Plus(DBP) in irrigated and nan-irrigated conditions. Test results indicate a significant positive response of mean total cover, mean perennial grass and mean annual forb cover to irrigation. There were no differences comparing DBP, Mulch, and DBP-Mulch in either irrigated or non-irrigated treatments. Mean total cover and annual forb cover values ofDBP-Mulch treatments tend to be slightly higher than mean total cover and annual forb cover values of Mulch treatments in irrigated and non-irrigated treatments.Additional

Repeated failures in attempts to establish a selection of Atriplex in a non-mined site near the Navajo Mine in New Mexico proved to be due to "damping-off" (black root) of the seedlings, caused by Pythiaceae fungi. The contaminated soil contained more than 1,000 propagules of the fungus per g of soil; stockpiled soil in another area contained an average of 20 propagules per g of soil. Coating the Atriplex seed with fungicide prior to sowing increased seedling establishment more than JOO-fold. Reduced vigor and loss of plants subsequent to seedling-establishment may also be caused by these fungi.

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An irrigation study was established in 1990 to compare the effects of one and two seasons of irrigation on reclamation success.

The arid Southwest is associated with a sparse vegetal cover and highly erosive landscapes. The sparse vegetation is largely the result oflow annual precipitation and the erosion is largely the result of high intensity short duration storms which, at Navajo Mine, most frequently occur in late summer. Storms of this type have high runoff and result in little soil moisture retention.Through special landscape shaping, personnel at Navajo Mine have used several means of harvesting water that are supporting greater plant densities than what is normal to an arid climate and controlling erosion in what were previously highly erosive areas. These features consist of both above and below ground structures that reduce runoff, retain moisture for longer times during drought periods and support vegetation that is suited for controlling erosion. This paper discusses the construction and effectiveness of water harvesting features at Navajo Mine.