Phosphorus Source Affects Phosphorus Leaching and Growth of Containerized Spirea

in HortScience

Commercially propagated `Halward's Silver' spirea (Spiraea nipponica Maxim.) bareroot cuttings and cuttings with substrate around the roots (plugs) were transplanted into 3.8-L containers and fertilized with various P fertilizers to determine the effect of fertilizer source on P leaching and plant growth. The following fertilizer treatments were applied: 1) 100% of the recommended rate of P from controlled-release fertilizer (CRF), consisting of 22N-2.6P-10K; 2) 100% of P from triple superphosphate (TSP, 0N-20P-0K) with N and K provided by 22N-0P-10K CRF; and 3) 50% of P from CRF, consisting of 22N-1.3P-10K, plus 50% of P from TSP (CRF/TSP). The most P leached from cuttings transplanted as plugs or bareroot and fertilized with TSP, while the least P leached from cuttings transplanted as plugs and fertilized with CRF or CRF/TSP. Plants fertilized with CRF/TSP generally had larger root dry weights than did plants fertilized with CRF or TSP. Plants fertilized with CRF had the smallest stem dry weights. Shoot-to-root (S/R) ratio was largest in plants transplanted as plugs in substrate amended with TSP, but cuttings transplanted bareroot into CRF-amended substrate had the highest S/R ratio and the lowest stem P concentration. Incorporation of CRF/TSP into the container substrate can reduce P leaching compared with incorporation of TSP, and can increase root and stem dry weights of plants transplanted as plugs compared with incorporation of CRF.

If the inline PDF is not rendering correctly, you can download the PDF file here.

Contributor Notes

E-mail address:
All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 24 4 1
PDF Downloads 36 16 1