Improvements of emergence and tuber yield of potato in a seasonal spring arid region using plastic film mulching only on the ridge

Potato (Solanum tuberosum) is one of the most important economic crops in Yunnan Province (southwest China). However, under rain-fed agricultural conditions, the seeding emergence and yield suffer from seasonal spring drought. In mitigating this problem, field experiments were conducted for 2 years (2015 and 2016) to examine the effectiveness of cultivation patterns for rain-fed potato. Four experiments with different cultivation patterns were carried out: (1) no mulching on ridges and furrows (RFNM-CK), (2) ridge-furrow planting without plastic film mulching after flat planting (RFAF), (3) half mulching only on ridges (RFHM), (4) soil covering after plastic film mulching only on the ridges but not on furrows (RFSM). The temperature of topsoil (0.15 m) was similar among the cultivation patterns. The precipitation and soil conditions were the dominant ecofactors that limited the seedling emergence and yields. RFHM had the best effect on rain harvesting, then improved the topsoil moisture which contributed to good emergence rate and seedling emergence for 14-32 days earlier than CK (P < 0.05). Its superiority also resulted in higher plant height, faster accumulation of dry matter and longer period of yield formation, thereby producing the highest tuber yields (8.3-29.4% higher than CK) and economic benefits in both years. Our results from this investigation revealed that RFHM could be an appropriate cultivation mode to increase the emergency and potato productivity in the rain-fed agroecosystem.