Semiarid bunchgrasses accumulate molybdenum on alkaline copper mine tailings: assessing phytostabilization in the greenhouse

AbstractPhytostabilization is the use of plants and soil amendments to physically stabilize and remediate contaminated mine wastes and to control wind and water erosion in semiarid environments. The aim of this study was to evaluate two native bunchgrass species’ (Pseudoroegneria spicata and Festuca campestris) biomass accumulation and metals uptake response to locally available soil amendments (compost, wood ash and wood chips) to determine their suitability for phytostabilization at an alkaline copper mine tailings site in British Columbia, Canada. In the greenhouse, bunchgrasses important as forage for livestock and wildlife were grown in tailings with various ash–compost–wood chip combinations and evaluated using a randomized complete block design with 13 treatments and 10 replicates. Plants were harvested after 90 d, and tissues were analyzed for root and shoot biomass. Tissue samples (n = 3) from three treatment subsets (ash, compost, blend) were selected for elemental analysis. Biomass increased with increasing compost applications, and the response was greatest for P. spicata. Shoot molybdenum exceeded the maximum tolerable level for cattle and was significantly higher when grasses were grown on the ash treatment (183–202 mg kg−1) compared to the others (19.7–58.3 mg kg−1). Translocation and root bioconcentration factors were highest on the ash treatment (2.53–12.5 and 1.75–7.96, respectively) compared to the other treatments (0.41–3.43 and 1.47–4.79, respectively) and indicate that both species are ‘accumulators.’ The findings suggest that these bunchgrasses were not ideal candidates for phytostabilization due to high shoot tissue molybdenum accumulation, but provide important considerations for mine restoration in semiarid grassland systems.

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Influence of Nitrogen and Potassium on Three Zoysiagrasses

HortScience ◽

10.21273/hortsci.33.3.516b ◽

1998 ◽

Vol 33 (3) ◽

pp. 516b-516

Author(s):

James N. McCrimmon

Keyword(s):

Gulf Coast ◽

Block Design ◽

Nutrient Content ◽

Zoysia Japonica ◽

Tissue Samples ◽

Color Quality ◽

Randomized Complete Block Design ◽

Color Density ◽

Minimal Research ◽

Micronutrient Fertilizer

Zoysiagrass has great potential for use in the Gulf Coast states as a turfgrass. There has been minimal research on the nitrogen (N) and potassium (K) fertility response of zoysiagrass and the effect on turf color, quality, and nutrient content. The objective of this study was to evaluate the effects of N and K fertility on zoysiagrass. A study was conducted on three zoysiagrasses: Zoysia japonica × Z. tenuifolia Willd. ex Trin. (`Emerald'); Z. japonica Steud. (`Meyer'); and Z. matrella. The N and K treatment combinations consisted of high (H) and low (L) rates of N and K at the following levels: N levels of 454 and 227 g N/92.9 m2 per month and K levels of 454 and 227 g N/92.9 m2 per month. The treatment combinations were (N and K): HH, HL, LH, and LL and were applied in two split applications monthly from July through November. The study was a randomized complete-block design with three replications. All plots received two applications of a micronutrient fertilizer (late June and August), were irrigated as needed, and maintained at a height of 3.8 cm. Color, density, texture, uniformity, and quality were determined visually for each month. Plant tissue samples were collected (September) and analyzed for macronutrient and micronutrient contents. There were significant differences for color, density, and quality in the following months: September (color and density); October (quality); and November (color and quality). There were differences in leaf texture for all months. There were significant differences for N, magnesium (Mg), and K contents but there were no differences for any micronutrient. This study indicated that all three zoysiagrasses provided acceptable color and quality during the summer and fall, and that N and K rates affected N, K, and Mg contents in the plant.

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