Korean Journal of Soil Science and Fertilizer ISSN:0367-6315(Print) 2288-2162(Online) 한국토양비료학회 학회지

An estimation of optimal requirement of additional N by cropping pattern and growth stage is very important for greenhouse watermelon. The objectives of this study were to estimate an amount of optimal additional N based on growth, N uptake and yield of watermelon. In order to achieve these goals, we performed the study at farmer’s greenhouse with a fertigation system and watermelon was cultivated three times (spring, summer and autumn) in 2015. The levels of additional N were set up with x0.5, x0.75, x1.0 and x1.5 of the NO₃-N-based soil-testing N supply for watermelon cultivation. The trends of growth and N uptake of watermelon markedly differed from cropping pattern; spring (sigmoid), summer and autumn (linear). The yield of watermelon was the highest at summer season and followed by autumn and spring. Also, the x1.5N showed a significantly higher yield compared to other N treatments. On the basis of growth, N uptake and yield of watermelon, we estimated an optimal level of additional N by cropping pattern and growth stage as follows; 1) spring (transplanting ~ 6 WAT : 6 ~ 14 WAT : 14 ~ harvest = 5 : 90 : 5%), summer (transplanting ~ 4 WAT : 4 ~ 8 WAT : 8 ~ harvest = 25 : 50 : 25%) and autumn (transplanting ~ 4 WAT : 4 ~ harvesting : 50 : 50%). In conclusion, nutrient management, especially N, based on cropping pattern and growth stage was effective for favorable growth and yield of watermelon.

Optimal additional N supply by cropping pattern- and growth stage-based on growth and N uptake of watermelon.