Effects of Dolomitic Lime on Growth and Nutrient Uptake of Buddleia davidii ‘Royal Red’ Grown in Pine Bark

Abstract

Buddleia davidii Franch. ‘Royal Red’ was grown in pine bark amended with 0.0, 2.4, 4.7 or 9.5 kg/m3 (0.0, 4.0, 8.0, or 16.0 lbs/yd3) dolomitic lime. Growth characteristics responded quadratically to dolomitic lime with those plants receiving 2.4 kg/m3 having the greatest shoot and root dry weights and inflorescence numbers. Plants grown in 4.7 kg/m3 had the greatest shoot lengths. Concentrations of Ca and Mg in leaves of plants grown in containers without dolomitic lime amendment were below that recommended for normal growth of B. davidii. Leaf concentrations of N, S and Mn showed quadratic responses to dolomitic lime additions. Media pH and concentrations of NO3, Al, B, Mn and P also showed quadratic responses. Media Zn concentrations showed a linear response. Although all dolomitic lime amendments tested improved growth of Buddleia davidii ‘Royal Red’, the incorporation of 2.4 kg/m3 produced maximum growth and inflorescence quantity.

Micronutrient Availability from Steel Slag Amendment in Pine Bark Substrates

“…This could be at least partially the result of the increased pH observed with higher incorporation rates of steel slag. For example, Gillman et al (1998) reported reduced butterfl y bush growth in pine bark substrates amended with greater than 2.4 kg•m -3 (4 lb•yd -3 ) dolomitic lime. Butterfl y bush root ratings responded similarly to SDW with respect to the two control groups and slag rate.…”

Dolomitic Lime Amendment Affects Pine Bark Substrate pH, Nutrient Availability, and Plant Growth: A Review

“…For example, Altland et al (2015) using a 80 pine bark : 20 peatmoss (by volume) substrate showed a curvilinear response in pH to DL rate over the range of 0 to 4.8 kgÁm -3 , but doubling or tripling the rate up to 14.3 kgÁm -3 resulted in little or no additional change. Likewise, Gillman et al (1998) reported a pH increase in 100% pine bark from 4.4 up to 6.1 with 4.8 kgÁm -3 DL, but only up to 6.4 when the rate was doubled to 9.5 kgÁm -3 . Harvey et al (2004) reported that 3.6 kgÁm -3 DL raised pH of a 3 pine bark : 2 peatmoss : 1 sand (by volume) substrate from 3.7 to 6.2, whereas more than doubling the rate up to 9.5 kgÁm -3 only raised the pH an additional 0.9 units up to 7.1.…”

“…Walden and Epelman (1988) Chrustic and Wright (1983) reported that shoot N was higher in 'Helleri' holly (Ilex crenata), 'San Jose' juniper (Juniperus chinensis), and 'Rosebud' azalea (Rhododendron obtusum) at lower DL rates and attributed greater growth of these crops a low lime rates to greater N, phosphorus (P), and K availability. Gillman et al (1998) reported 'Royal Red' butterfly bush (Buddleia davidii) foliar N was highest in nonlimed controls; however, trends in shoot N with increasing DL rates did not follow a clear pattern. In contrast, Nash et al (1983) reported similar shoot N levels among limed and nonlimed photinia (Photinia •fraseri).…”

“…Nash et al (1983) suggested that increased growth of photinia with increasing DL rates was due to the greater quantity of Mg 2+ available for uptake, and was not related to pH. Gillman et al (1998) reported that butterfly bush root and shoot growth, as well as flower number, increased with DL compared with nonlimed controls. They attributed the increased growth to increased amounts of Ca 2+ and Mg 2+ from the DL available for plant uptake.…”

“…G round pine bark pH ranges from 4.1 to 5.1 before amendment with other components or fertilizers (Brown and Pokorny, 1975;Gillman et al, 1998;Wright et al, 1999aWright et al, , 1999b. Limestone is traditionally used to raise the pH of pine bark substrates to between 5 and 6.5, a range that is thought to be most conducive for growth of most plants.…”