Comparative Study of the Leachates from Syngonium podophyllum using Different Fertilization Techniques and Nitrogen Forms

Abstract

The objectives of this article were to analyze the evolution of the nutrient parameters of the leachates collected from Syngonium podophyllum var. Silver plants cultivated for 20 weeks in a buried greenhouse with four methods of fertilization. The treatments were T₁, standard liquid feeding (SLF) [7.0 mmol L⁻¹ nitrate (NO₃ ⁻) nitrogen (N), 0.3 mmol L⁻¹ phosphorus (P), and 3.5 mmol L⁻¹ potassium (K)] after transplanting; T₂, liquid feeding soluble fertilizer (LFSF) [6.9% NO₃ ⁻ N, 11.1% ammonium (NH₄ ⁺) N stabilized by 3,4-dimethylpyrazole phosphate, 8.0% P₂O₅, and 14.0% K₂O] after transplanting; T₃, controlled release fertilizer (CRF I) (7.4% NO₃ ⁻ N, 8.6% NH₄ ⁺ N, 8.0% P₂O₅, and 12.0% K₂O) applied before planting and half concentration of SLF from 45 days after transplanting; and T₄, controlled release fertilizer (CRF II) (8.5% NO₃ ⁻ N, 7.5% NH₄ ⁺ N, 8.0% P₂O₅, and 12.0% K₂O) applied before planting and half concentration of SLF from 45 days after transplanting. Solution pH, electrical conductivity (EC), NO₃ ⁻ N, NH₄ ⁺ N, K, and P concentrations in the leachate were analyzed weekly. Plant quality was assessed at the end of the trial through objective and subjective parameters. Significant differences among the different fertilization methods were observed. CRF treatments resulted in the greatest nutrient leachate concentration during the first 6 weeks of the study, and afterward it decreased gradually until the end of the cultivation. CRF I showed greater leachate concentrations of N, P, and K than the others during the first half of the study. The concentrations of NO₃ ⁻ N and P from all the fertilizer types were often above the permissible levels cited in the federal Clean Water Act. The best-quality plants were obtained with CRF II, whereas the greatest height and Aerial Dry Weight (ADW) were obtained with CRF treatments and the greatest Root Dry Weight (RDW) was obtained with the NH₄ ⁺ N treatments.

Keywords:

• Ammonium
• controlled release fertilizer
• leaching
• nitrate
• phosphate
• potassium

Acknowledgments

This work is included in the project “Evaluation and Optimisation of New Slow-Release and Soluble + DMPP Inhibitor Fertilizers in Horticultural and Ornamental Crops,” financed by COMPO Agricultura S.L. (Barcelona) and the Department of Agriculture and Fisheries (Junta de Andalucía), Spain.