360 The Relationship of Mineral Nutrients in the Rhizoplane, Rhizosphere, and Bulk Soil during the Gorwth of Apple Rootstock Seedlings

Malus hupehensis Reld apple rootstock seedlings and the rhizobox technique were used in this study. The seeds were collected from healthy mature trees at the Wanshougong Forest Farm in Shandong, China, stratified at 0 to 2 °C for 60 days, sown into growing medium with 1/3 loam soil+1/3 silt sand+1/3 compost manure, grown until the three-leaf stage, and then transplanted into rhizoboxes with four plants in each box. The rhizoboxes were inserted into the ground with the top of the boxes levelled with the soil surface. After the root mattress formed in the center of the box, plants were harvested by carefully dividing each box into rhizoplane, rhizosphere, and bulk soil, and mineral nutrients in each part were analyzed. The relationships were tested between the rhizoplane, rhizosphere, and bulk soil for each nutrent. Significant correlations were found for NH + 4 , NO – 3 , K, Mg, Zn, and Cu in the rhizoplane, rhizosphere, and bulk soil. There were significant relationships for P and Ca between the rhizoplane and rhizophere, but not between the rhizoplane or rhizosphere and bulk soil. Fe in the rhizoplane closely related to Fe in the rhizosphere but not to Fe in bulk soil. No correlation was found between the rhizoplane and either rhizosphere or bulk soil, but close correlation existed between rhizosphere and bulk soil for Mn.