Climate Change in China Semi-Arid Region and Potato Sowing Dates Adaptation.

Abstract: Climate change in temperature and precipitation are expected to affect crop development, yield, and agricultural production practices sowing date are also likely changed. In field trials carried out during four growing seasons (2010-2013) in semi-arid China, impacts of sowing dates on the development of potato (Solanum tuberosum L.) with five target sowing dates (from last April to early June) were analyzed. The objectives of this study were to evaluate the effects of sowing dates and primary climatic variables (temperature, precipitation) during the growing season on potato growth, development and yield, explore the flexibility in the potato sowing dates, and determine the optimal sowing date for potato to better adapt to climate change in the study area based on the climate conditions. Results showed that potato yield was significantly affected by sowing dates, both potato total yield and marketable yield were strongly increased with the earlier sowing dates. Delayed sowing time shortened the duration of potato development period, and the thermal time over the potato growing season also decreased as the sowing date delayed. Both leaf area index (LAI) and dry biomass of potato showed a high relationship with the thermal time after sowing. Based on the long-term weather record, the flexible sowing date for potato in the study area was from early May to early June, and the optimal sowing date was found to be between May 10 and May 27 based on the precipitation condition. Climate warming could affect the sowing date, and it was found that the length of the flexible sowing period in the study area has increased at a rate of 5.1day/decade over the past 50 years. Keywords: Inner Mongolia, sowing date, potato, yield, thermal time