Yield and Nitrogen Use Efficiencies (NUEs) in Open-Field Pepper: Effect of Different Types of Basal Fertilizer and Fertigation Ratio

With an increasing concern of fertilizer-saving crop production system, an optimal nitrogen (N) management strategy is strongly required to attain both sustainable crop production and environmental sustainability. Therefore, we employed an open-field pepper production system to investigate soil nitrate variation, pepper growth and yield and nitrogen use efficiency (NUE). The following fertilization treatments were established; three types of fertigation ratio, basal and topdressing (100:0, 50:50 and 30:70), and three types of basal fertilizers, chemical fertilizer (CF), slow release fertilizer (SRF) and livestock compost (LC)+CF as a ratio of 50:50. The CF 50:50, which is widely practiced by farmers in South Korea, was used as a control group to compare with other treatments. Soil nitrate from transplanting until 36 days after transplanting (DAT) ranged from 20 to 60 mg kg -1 except for CF 100:0 and SRF 100:0, indicating significant higher concentrations. Compared to the control, marketable pepper yield was significantly greater, and the difference was not observed by both fertigation ratio and the types of basal fertilizer. The NUE (fruit yield/N applied, kg kg -1 ) was significantly higher in CF 100:0, LC+CF 50:50 and LC+CF 30:70, and higher N availability (NutE) showed in fertigation ratio (50:50) and basal fertilizer (LC+CF). Our results clearly represented that the combined application of LC+CF as a basal fertilizer with 50:50 of fertigation ratio could achieve the benefits of sustainable yield, higher NUE and reduced potential soil nitrate leaching in an open-field pepper production system in South Korea.