Abstract
Potato has become one of the staple crops to improve food security in North Korea since the late 1990s. However, the potato yield has been stagnated around 11–12 t ha−1 for several decades, and a food shortage is still a primary issue in North Korea. Yield gap analyses were carried out using the SUBSTOR-potato model to quantify the potato yield gaps and explore the potential ways to close the yield gaps in two different cropping seasons in North Korea (early- and main-season potatoes). Yield gaps were estimated to be around 80% for both early- and main-season potatoes. Early-season potato yield was substantially determined by water or nitrogen supplies, depending on the year’s weather condition (i.e., with or without spring drought). Irrigation during the vegetative stage could effectively reduce the year-to-year variation in yield as well as the yield gap (+7.0 t ha−1, +66.1%). Meanwhile, additional nitrogen fertilizer in the early-season potatoes was less effective compared to that in the main-season potatoes. For the main-season potatoes, where precipitation was sufficient, the primary limiting factor of yield was nitrogen supply. Since heavy rainfall aggravated nitrogen leaching, additional nitrogen fertilizer is recommended as a top dressing rather than a basal dressing. Additional top dressing at 50 days after planting with the current amount of nitrogen fertilizer was expected to increase the main-season potato yield by 42.0 t ha−1 (+191.4%). This study highlights that the primary limiting factor of potato yield may differ between the cropping seasons. Therefore, our findings suggest that different agronomic strategies should be applied for different cropping seasons to improve potato production in North Korea, where agronomic resources are limited.
Highlights
Food security has been a primary issue in North Korea for a long period of time
According to the global simulation study using a potato model [3], potato yield in North Korea could be around 30–40 t ha−1 with proper crop management
The early-season potatoes achieved a limited rainfall, during the vegetative stage, with an average of 73 mm across the years and a minimum of 35 mm in 2014
Summary
Food security has been a primary issue in North Korea for a long period of time. Since the 1990s, the productivities of main cereal crops (maize and rice) were reduced due to the limited supplies of fertilizers, pesticides, plastic sheeting, and fuels, partly attributing to the international restrictions on trade. Considering a high potential of potato (Solanum tuberosum L.) as a staple crop, which produces far more carbohydrate than most cereal crops, the area planted with potatoes has extended from 61,000 ha in 1990 to 215,000 ha in 2018 [2] to improve food security. According to the global simulation study using a potato model [3], potato yield in North Korea could be around 30–40 t ha−1 with proper crop management. The experimental yield in Agronomy 2020, 10, 1605; doi:10.3390/agronomy10101605 www.mdpi.com/journal/agronomy
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
