This study was conducted to investigate occurrence and biodiversity of phytoparasitic nematodes in kiwifruit orchards in Korea. Soil samples were collected from 11 locations of Gosung, Goheung, Namhae, Bosung, Sacheon, Suncheon, Wando, Jangheung, Jeju, Jindo, Haenam from April to August, 2008. Phytoparasitic nematodes were found in 115 among 178 soil samples. The major genera of phytoparasitic nematodes on kiwifruit were Meloidogyne spp.(52.2%), Tylenchinae (42.1%), Tylenchus spp. (9.0%), Helicotylenchus spp. (9.0%) and Tylenchorhynchus spp. (6.7%). Ditylenchus spp., Hirschmaniella spp., Trichodorus spp. and Psilenchus spp. were also detected, even though their frequencies were very low. According to the cultivation period, the phytoparasitic nematodes were found as follows; 16.9% of soils under 5 years of kiwifruit cultivation, 10.7% 6~10 years, 23.0% 11~15 years, 3.9% 16~20 years and 5.6% over 21 years respectively. The frequency of phytoparasitic nematodes is higher in the open field (50.0%) than that in plastic houses (13.5%). The frequency of phytoparasitic nematodes was 36.5% in the field where vegetables were previously cultivated and 12.9% in the field where rice was previously cultivated.

Organic kiwifruit orchard soils were compared with conventional ones in Korea. Soil structure of organic soil had higher gaseous and liquous phase as well as soil porosity in the surface soil. Although the nutritional level of each orchards were quite different among soils, the analysis of both system revealed that organic kiwifruit orchard soil had similar or even higher nutrient level (N and organic matter content in surface soil) compared to conventional ones. The organic matter content of deep soil also had the high tendency in deep soil of organic soil. Higher level of nitrogen in organic surface soil is presumably due to the excessive application of organic compost and liquid fertilizer rather than the contribution by grasses such as green manure. Available phosphorous level of organic system was quite high but similar in surface soil of both system, compared to the recommended level. Potassium, calcium and magnesium levels were also enough in organic kiwifruit orchard soils.