Long-term monitoring of soil chemical properties is the main agricultural practices to improve crop yield and soil fertility. Field monitoring was performed to evaluate the chemical properties of 200 greenhouse soil samples every 4 years from 2000 to 2016 in Gyeongnam province, South Korea. Soil properties such as pH, electrical conductivity (EC), amount of organic matter (OM), available phosphate (P 2 O 5 ), nitrate nitrogen (NO 3 -N), exchangeable potassium (K), calcium (Ca), magnesium (Mg), and sodium (Na) were analyzed. In 2016, the average concentration of soils under greenhouse condition showed 6.8 for pH, 3.52 dS m -1 for EC, 40 g kg -1 for OM, 1,065 mg kg -1 for P 2 O 5 , 154 mg kg -1 for NO 3 -N, 2.35 cmol c kg -1 for K, 12.8 cmol c kg -1 for Ca, 4.0 cmol c kg -1 for Mg, and 0.91 cmol c kg -1 for Na. In addition, the average concentrations of OM, K, Ca, and Na have tended to increase with year. In 2016, the frequency distribution of excessive level of soils under greenhouse condition was 43% for pH, 61% for OM, 94% for P 2 O 5 , 89% for K, 96% for Ca, and 83% for Mg. Soil EC values of green pepper, tomato, and lettuce were significantly higher than those of carrot, strawberry, and squash (p < 0.05), whereas soil pH was significantly lower in the carrot and lettuce than that in the strawberry (p < 0.05). Soil pH was significantly correlated with the EC, NO 3 -N, K, Ca, Mg, and Na. The value of EC was also positively correlated with the OM, P 2 O 5 , NO 3 -N, K, Ca, Mg, and Na. In conclusion, the long-term information on soil chemical properties will be helpful to improve sustainable soil and nutrient management for greenhouse farming.
