The development of rainfed dryland agriculture with optimized water use is a priority to ensure food security for the increasing population and the worsening environment. In dryland areas, potato and maize yields have increased under ridge–furrow and plastic-mulching tillage systems, but this has only been observed at low to mid-altitudes. Its effect at high altitude remains unknown.

 Dr. LIU Changan of Xishuangbanna Tropical Botanical Garden (XTBG) and Dr. Kadambot H.M. Siddique of the UWA Institute of Agriculture conducted field experiment from April 2010 to October 2011 at the Semiarid Ecosystem Research Station of the Loess Plateau (36°02′ N, 104°25′ E, 2400 m above sea level), Lanzhou University. The study aimed to determine the effects of ridge–furrow and plastic-mulching tillage systems on potato and maize crops at high altitude in arid regions. They studied the effects of ridge–furrow and plastic-mulching practices on soil water content in various soil layers, soil temperature, crop yield, and water use efficiency (WUE). They then tried to seek the principal factors affecting crop yield in the dryland areas at high altitude.

   When compared with not mulching, mulching ridges can increase soil water content in the 0- to 200-cm soil layer in semiarid farmland at high altitude. When compared with flat-farming practices, the ridge–furrow and plastic-mulching practices did not increase potato crop yield, but did increase big tuber yield and the ratio of big tuber yield to total tuber yield. Higher soil temperatures in the plastic-mulching practice were only observed during early growth, with no significant differences observed between treatments during late growth. The longer growing period from seedling emergence to silking for treatments without mulching led to maize failing to reach maturity due to low soil temperatures in the late growing period. The yield of maize was mainly affected by the temperature in May and not by soil water content before sowing in semiarid farmland at high altitude.

  The study entitled “Does Plastic Mulch Improve Crop Yield in Semiarid Farmland at High Altitude?” has been published online in Agronomy Journal.