Evaluating Kaolin Clay as an Amendment to Container Substrates

Transcription

1 Evluting Kolin Cly s n Amendment to Continer Sustrtes Jmes T. Midcp nd Theodore E. Bilderck Deprtment of Horticulture - Athens & Rleigh The University of Georgi & North Crolin Stte University Nture of Work: Amending pine rk continer mixes with cly hs een suggested s wy to improve the wter holding cpcity of the mix s well s providing method of holding nutrients tht normlly re rpidly leched from potting mixes. A loclly mined Kolinite cly could provide chep nd uniform source of cly mendment. The ojective ws to test kolin cly rtes in the potting sustrte on vriety of continer plnts. Test plnts included those tht were susceptile to nutritionl deficiencies s well s fst growing plnts tht ecome pot ound therefore might enefit from incresed wter holding cpcity lte in the production yer. A locl kolin cly product ws otined from Thiele Kolin Compny. The RC32 kolin cly is very fine hydrous luminum silicte. The prticle size is less thn 2 microns. The sustrte tretments were 1) Control - stndrd potting mix of 9:1 Pine Brk:Snd, 2) % RC32 in the stndrd mix, 3) % RC32 in the stndrd mix nd 4) % RC32 in the stndrd mix. The cly tretments were sed on volume of the sustrtes. Five continer nursery crops were selected nd re listed elow: Cupressocypris leylndii -- Leylnd Cypress Lgerstroemi Zuni -- Zuni Crpe Myrtle Ligustrum jponicum recurvifolium -- Wvylef Ligustrum Loropetlum chinense rurum Ruy -- Ruy Loropetlum Rhododendron Girrd Hot Shot -- Girrd Hot Shot Azle On April, 2, plnts were potted into trde gllons. Osmocote -4-8 t #/yd 3 nd dolomitic lime t 4#/yd 3 were incorported into the sustrtes. Twenty replictes were used for ech tretment nd two gurd rows were plced round the ech crop. Tretments were rndomized within ech crop. Plnts were mintined under norml nursery conditions through out the tril. On Novemer 6, 2 the plnt tops were cut t the sustrte surfce, gged nd dried. The top dry weights were recorded nd used to compre the tretments. Results were compred y ANOV nd mens were seprted y the Student-Newmn- Keuls test. In Octoer 2 the physicl properties of the sustrte tretments were determined y Dr. Bilderck nd re discussed in the results. Results nd Discussion: The tretment results for the top dry weights for ech crop re shown in Figures 1-4. The Ruy Loropetlum crop sustined hevy plnt loss in mid too lte summer. The

2 Girrd Hot Shot Azles lso suffered from plnt loss, ut not s severe. No losses occurred in the other crops. The stndrd nursery sustrte of 9:1 Brk:Snd produced significntly more top growth thn ny of the cly tretments for the zle, crpe myrtle nd loropetlum crops. There were no significnt tretment differences for the leylnd cypress nd ligustrum crops. The cly mended sustrtes were not different from the stndrd nursery sustrte. The physicl properties showed decrese of totl porosity s the mount of RC32 kolin incresed over the control up to % RC32 (Tle1). The ville wter ws low for the % nd % RC32 tretments while the % nd control were similr. The unville wter ws low for the % nd % RC32, while the control ws similr to the % tretment. The ction exchnge cpcity of ll the RC32 tretments ws greter tht the control. The physicl properties suggest the kolin filled pore spce s the rtes incresed. Kolin did decrese ville wter t the % nd % levels nd improved the ction exchnge cpcity. Significnce to the Industry: RC32 Kolin cly ws not effective in improving plnt growth over the control 9:1 Brk:Snd sustrte. The cly tretments decresed plnt growth in three crops when compred to the stndrd sustrte. At this time, the RC32 Kolin cnnot e recommended s component in Brk:Snd mixes. Tle 1. Physicl properties of Kolin cly mended continer sustrtes. *Sustrtes Totl Pore Spce Air Spce Continer Cpcity Aville Wter Unville Wter Bulk Density Ction Exchnge BS 9:1 % % % 83% 3% 48% 18% 3% % 43% 4% 12% 33% % 44% 41% 12% 29% % 39% 44% % 24% * Sustrtes: PB=Pine Brk, BS=Brk:Snd, BN=Brk:Mini Nuggets, nd BC=Brk:Cly. Bulk Density in g/cc. Ction Excnge Cpcity in Meq/ cm.

3 Figure 1. Response of Girrd Hot Shot Azle to four production sustrtes. c Sustrtes 9:1 Brk:Snd % Cly % Cly % Cly Figure 2. Response of Zuni Crpe Myrtle to four production sustrtes. 4 3 Sustrtes 9:1 Brk:Snd % Cly % Cly % Cly

4 Figure 3. Response of Leylnd Cypress to four production sustrtes Sustrtes 9:1 Brk:Snd % Cly % Cly % Cly Figure 4. Response of Wvylef Ligustrum to four production sustrte 3 Sustrtes 9:1 Brk:Snd % Cly % Cly % Cly

5 Figure. Response of Ruy Loropetlum to four production sustrtes c Sustrtes 9:1 Brk:Snd % Cly % Cly % Cly