In-situ estimation of available nutrients through real-time monitoring of electrical conductivity in soil

다국어 초록 (Multilingual Abstract)

Nutrient deficiency reduces crop productivity while excessive fertilizer supply leads to environmental pollution. Therefore, appropriate nutrient management for sustainable agriculture is required through continuous monitoring of soil nutrient levels during crop growth. Since there is no real-time monitoring of soil nutrients, application of indirect monitoring using in-situ electrical conductivity (EC) sensor was evaluated.
The study aimed to evaluate the correlation between EC values measured by an EC sensor and available nutrients in soil during pepper cultivation. Soil was treated with chemical fertilizer, organic fertilizer and composted livestock manure as basal fertilizer. Urea and potassium chloride were applied as top dressing through fertigation. Soil samples were periodically collected, and nutrients were analyzed. Sensor-based EC value was the highest in soil treated with organic fertilizer, followed by chemical fertilizer and composted livestock manure. Fertigation increased EC while overall EC decreased during pepper growth. Sensor-based EC values showed significant correlation with nitrate in soil with correlation coefficient of 0.5 (p < 0.05).
Available phosphorus also showed significant correlation although the coefficient was lower than nitrate. The results indicate that EC sensor can be used as a low-cost and practical means of monitoring available nitrate and phosphate in real-time under field conditions.