Evaluating Soil Quality for an Environment-Friendly Agriculture in Korea.
Won Kyo Jung, Jung Hui Yoon, Sun Kwan Kim, and Han Kang Kwak. National Institute of Agricultural Science and Technology, 249 Sudun, Suwon Kyunggi, 441-707, South Korea
Intensive soil management for high productivity has long been managed in Korean agriculture. Productivity has only been considered for values of agriculture for past several decades in Korea. For this reason, we have achieved outstanding development of agricultural technologies for self-sufficient of main cereal in a last half century. But, also many negative impacts have found in agricultural field such as soil degradation, soil salinization, soil compaction, nutrient accumulation, eutrophication and water pollution. Without appropriate soil management, these problems will be more severe for Korean agriculture in the future. The objective of this research was to evaluate soil quality for Korean agricultural soils. We have obtained dynamic soil properties, which were considered as major soil properties for crop production for nationwide, for every 4 years since 1999 in flooded paddy, dry field and plastic covered green house field. Soil acidity (pH), soil organic matter (SOM), phosphorus (P), potassium (K), and silicate (Si) were selected to evaluate paddy soil quality and pH, SOM, electrical conductivity (EC), P, and K were selected to evaluate dry field and plastic house soil quality from principal component analysis of soil properties data set. Soil quality index was calculated with selected soil properties for paddy field and dry field differently. Soil quality index was derived from individual soil properties with estimation of contribution rate to crop yield and environmental impact on soils. The results showed that paddy soil quality index was increased after four years from 1999. One of the major reasons of this result was estimated that we have applied reduced chemical application known as environment-friendly agriculture since late 1990's. Generally soil quality index for plastic covered green house and dry field wasn't changed significantly after four years from 2000 and 2001 respectively, but exception was phosphorus. In conclusion, soil quality index may be contributed to evaluate impacts of environment-friendly agricultural practices in Korea.