Soil frost control: agricultural adaptation to climate variability in a cold region of Japan

Abstract

Agriculture, Environmental control, Environmental optimization, Frozen soil, Snow management, Weed removal, Potatoes,

Effects of saturated hydraulic conductivity on volunteer potato (Solanum tuberosumL.) tuber survival

“…A close relationship between k s_min and the survival rate except for the data of Shihoro in 2010-2011and Taiki in 2011-2012 (Fig. 3) implies that k s_min controlled the surface soil moisture condition and determined the survival rate in most of the study field.…”

“…The survival rate of potato tubers might also be determined by the pore space volume in the surface soil layer because the diffusivity of soil air, which controls the amount of fresh air supplied from atmosphere to soil, increases with its air phase ratio (Osozawa 1987). Nevertheless, no significant relationship was found between the survival rate and the porosity of the surface layer (A p or A layers) even when excluding the data from Shihoro in 2010-2011and Taiki in 2011-2012. The macro-porosity of the surface layer was not related to the survival rate either, despite the exclusion of those two values (R = 0.05).…”

“…3) implies that k s_min controlled the surface soil moisture condition and determined the survival rate in most of the study field. In other words, the data for Shihoro in 2010-2011and Taiki in 2011-2012 (Fig. 3) imply that they might exist below the linear relation on the scatter diagram between the survival rate and k s_min when potato tubers are killed by cold temperatures in winter or poor drainage caused by factors that are unrelated to k s .…”

“…Saturated hydraulic conductivity effects on the potato tuber survival rate Potato tubers might not sprout because of the low temperature (Hirota et al 2011) or high humidity (Letnes 1958) of the surrounding soil. Yazaki et al (2013) reported the threshold of soil temperature to kill potato tubers was -3°C.…”

“…In the Tokachi region, a main crop production area in Japan, soil frost depth has decreased during the last 20 years because of the increase of the period during which soil is insulated from the cold air by thick snow cover (Hirota et al 2006). Boydston et al (2006) and Hirota et al (2011) reported that potato tubers (Solanum tuberosum L.) are killed when ambient soil temperatures drop below approximately -3°C. Higher soil temperatures of the surface soil layer in recent years have facilitated overwintering of potato tubers left in the field at harvest time before winter.…”