Influence of soil organic matter content on leaf minerals, fruit quality, and soil chemical properties in ‘Gamhong’/M.9 apple orchard

This research was conducted to find out the effect of soil organic matter (SOM) on the seasonal changes of leaf mineral content, fruit quality attributes, and soil chemical properties in 'Gamhong'/M.9 apple orchard. Leaf, soil, and fruit samples were collected over a period of three years (2014-2016) from 60 'Gamhong'/M.9 apple orchards in Yeongju and Mungyeong areas of Korea. Leaf samples were collected every month from the middle of the shoot from May to August, and the rhizosphere soil samples were collected in July. Based on the SOM content, the samples were grouped into five different categories. There were no significant differences between the ranges of SOM content in terms of fruit quality attributes. However, positive correlation (r=0.51**) was observed between SOM and soil available phosphate content. In addition, leaf phosphorous (P) from May to July was observed to be affected by SOM content. In conclusion, long time over-application of livestock manure can lead to soil phosphate accumulation and high phosphorus uptake by apple trees.