Yields of rainfed potato (Solanum tuberosum L.) in China’s semiarid region are restricted by limited precipitation. Climate change could cause significant fluctuation in the rain-fed agricultural production due to the spatiotemporal changes in temperature and precipitation. As adjusting sowing dates proved to be an important management technique for improving grain yields, we examined how potato production can be improved by altering planting date in China’s semiarid region, thus improving potato adaptation to climate change. Field trials with five target sowing dates (from late April to early June) were carried out in Inner Mongolia, China during four growing seasons (2010–2013), and the effects of sowing dates on potato development, yield and water use efficiency (WUE) were estimated. Results showed that although delayed sowing shortened the duration of potato growth period, non-significant thermal time differences after flowering stage was found among the treatments. However, greater precipitation was shown in three intermediate treatments. Potato yield was significantly affected by sowing dates, and intermediate sowing dates showed greater yield compared to the earlier or later sowing dates. Delayed sowing dates significantly improved WUE in a drier year. As for a normal year, earlier sowing dates promoted WUE because of less water consumption, but these increases came at the cost of reducing yields. Under the current climate conditions in the study area, the flexible sowing time for potato was determined as from early May to early June, and optimum sowing time was between 10 May and 27 May. In conclusion, adjusting sowing date affected duration, thermal time, and precipitation over potato growth period, and the optimal sowing date exhibited higher yield by obtaining greater precipitation, which could improve potato adaption to climate change.

Home Search Collections Journals About Contact us My IOPscience You may also be interested in: Radiological impact of surface water and sediment near uranium mining sites K Ivanova, Z Stojanovska, V Badulin et al.

Xinjiang is currently the most dominant cotton (Gossypium hirsutum L.)‐growing region in China and possesses abundant radiation resource. The cultivation techniques such as wide and narrow row‐spacing and high density are widely adopted to obtain high cotton yield in the region. However, the region is facing some problems including poor light transmittance in the field and low exploitation for light resources under the current planting pattern which impedes further growth in cotton yields. Therefore, it is essential to develop some cultivation practices to increase radiation use efficiency (RUE) and cotton yields in Xinjiang. Here we conducted a field experiment to quantify the effects of row spacing pattern and plant density on RUE, intercepted photosynthetically active radiation from May to August (IRAR_5–8), and lint yield during 2017 and 2018. In this study, we designed two row‐spacing configurations (R₁, wide and narrow configuration, 66 cm + 10 cm; R₂, uniform row‐spacing configuration, 76 cm) and six plant densities (4.5, 9.0, 13.5, 18.0, 22.5, and 27.0 plants m⁻²). The RUE, lint yield, and number of bolls were higher in R₂ than R₁ by 4.1–5.9, 2.5–4.8, and 9.1–14.2%, respectively. The RUE significantly increased with plant density, but lint yield stabilized at 18.0 plants m⁻². Moreover, RUE had more significant positive effects on boll number and lint yield. Overall, we found that R₂ combined with optimal plant densities (13.5–18.0 plants m⁻²) would be an effective strategy to achieve higher RUE and yields in the Xinjiang cotton system.

Based on 541 Landsat images between 1988 and 2016, the normalized difference vegetation indices (NDVIs) of the wetland vegetation at Xitugou (XTG) and Wowachi (WWC) inside the Dunhuang Yangguan National Nature Reserve (YNNR) in northwest China were calculated for assessing the impacts of climate change on wetland vegetation in the YNNR. It was found that the wetland vegetation at the XTG and WWC had both shown a significant increasing trend in the past 20–30 years and the increase in both the annual mean temperature and annual peak snow depth over the Altun Mountains led to the increase of the wetland vegetation. The influence of the local precipitation on the XTG wetland vegetation was greater than on the WWC wetland vegetation, which demonstrates that in extremely arid regions, the major constraint to the wetland vegetation is the availability of water in soils, which is greatly related to the surface water detention and discharge of groundwater. At both XTG and WWC, the snowmelt from the Altun Mountains is the main contributor to the groundwater discharge, while the local precipitation plays a lesser role in influencing the wetland vegetation at the WWC than at the XTG, because the wetland vegetation grows on a relatively flat terrain at the WWC, while it grows on a stream channel at the XTG.

Climate change has changed the distribution of climate resources in crop growing season, and caused some impacts on agricultural production. Based on daily meteorological data collected at 71 meteorological stations in Northeast China, trends at multi‐temporal scales (decadal, annual, monthly, and 10‐day) and spatial patterns of heat resources [temperature, frost‐free period (FFP)] and solar radiation resources [growing season's sunshine hour (GSS)] are estimated over the period 1961–2012.The period of 2000–2012 has been successively warmer than the previous decades with higher mean values for both temperature and FFP, and temperature had an abrupt increasing change in the 1980s. An increasing trend was identified for the daily mean temperature in the study area, with the trend value (0.30 °C decade⁻¹) double the global warming rate (0.14 °C decade⁻¹). As the last frost date advanced by 1.9 days decade⁻¹ in spring and the first frost date delayed by 1.6 days decade⁻¹ in fall, FFP increased by 17.9 days in recent 52 years with the average trend value of 3.5 days decade⁻¹. Temperature in February exhibited the highest increasing rate; furthermore, the maximum temperature trends occurred in the last 10 days of February at most stations. Daily sunshine hours decreased in June, July, and August, but GSS showed small changes at decadal and annual scales because of the prolonged FFP.In summary, climate change has prolonged FFP, increased the heat resource, and slightly changed solar radiation resource during crop growing season, which is beneficial for agriculture in Northeast China.