Use of synthetic soil aggregates as a containerized growth medium component to substitute peat in the ornamental plant production

摘要

This study investigates characteristics and utilization of synthetic soil aggregates (SA) formed by low productive acidic soil with paper and starch waste for production of French marigold (Tagetes patula) as a partial peat substitution in growing substrate. Five different growth substrates utilized in this study were: (i) Peat only, (ii) peat 75%: SA 25%, (iii) peat 50%: SA 50%, (iv) peat 25%: SA 75%, and (v) SA only. Peat 75%: SA 25% enhanced substrate physical and chemical properties into the established ideal substrate range. Plant height, numbers of flowers, fresh shoot weight, dry shoot weight, root length, fresh root weight and dry root weight of French marigold grown in the substrate of peat 75%: SA 25% increased by 13.28, 23.07, 28.51, 27.41, 6.66, 68.33 and 7.40%, respectively, compared with peat substrate. Peat 50%: SA50% gave similar growth parameters to peat only substrate. Nitrogen (N) content of plants grown in peat 75%: SA25% was higher than peat substrate. Cu, Fe, Mn and Zn concentrations in all plant shoots were in the normal range and well below the phytotoxic range. Therefore, growth substrates with 25% and 50% SA can be recommended as the most effective substrates to substitute expensive and less available peat from an environmental point of view.