Impact of Application Rates of Pre-planting Liming Fertilizers on Changes in Soil Chemical Properties and Growth of 'Melody Yellow' Pansy in Plug Production

Abstract. Objective of this research was to investigate the influence of liming fertilizers on changes in soil chemical properties and growth of pansy ‘Melody Yellow’ in plug production. To achieve this, dolomite (DO) with 0, 1.0, 3.5, 8.0 or 13.0 g･L -1 and calcium carbonate (CC) with 0, 2.0, 2.5, 3.0, 3.5, or 4.0 g･L -1 in application rate were incorporated into peatmoss + vermiculite (1:1, v/v) during the formulation. The treatments of 3.5 g･L -1 of DO and 2.5 or 3.0 g･L -1 of CC had acceptable range of soil solution pH such as 5.6-6.2. Faster rising of pH was observed in root media containing CC rather than those of DO, indicating higher solubility of CC. The soil Ca concentrations in all treatments of CC were 2 times as high as those of DO. The treatments of 3.5 or 8.0 g･L -1 of DO had the highest soil Mg concentrations, but all treatments of CC had lower soil Mg concentrations than control indicating that additional applications of Mg fertilizers are required. The elevated application rate of DO or CC resulted in the increase of fresh and dry weight; however, plant heights were not influenced by application of liming fertilizers. The results of tissue analysis showed that application of DO or CC influenced the Ca and Mg contents, but did not influence the contents of other nutrients such as N, P, Fe, Mn, Zn and Cu.