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1. chinaXiv:202110.00019 [pdf]

Effects of different ridge-furrow mulching systems on yield and water use efficiency of summer maize in the Loess Plateau of China

CHEN Pengpeng; GU Xiaobo; LI Yuannong; QIAO Linran; LI Yupeng; FANG Heng; YIN Minhua; ZHOU Changming
Subjects: Geosciences >> Geography

Ridge-furrow film mulching has been proven to be an effective water-saving and yield-improving planting pattern in arid and semi-arid regions. Drought is the main factor limiting the local agricultural production in the Loess Plateau of China. In this study, we tried to select a suitable ridge-furrow mulching system to improve this situation. A two-year field experiment of summer maize (Zea mays L.) during the growing seasons of 2017 and 2018 was conducted to systematically analyze the effects of flat planting with no film mulching (CK), ridge-furrow with ridges mulching and furrows bare (RFM), and double ridges and furrows full mulching (DRFFM) on soil temperature, soil water storage (SWS), root growth, aboveground dry matter, water use efficiency (WUE), and grain yield. Both RFM and DRFFM significantly increased soil temperature in ridges, while soil temperature in furrows for RFM and DRFFM was similar to that for CK. The largest SWS was observed in DRFFM, followed by RFM and CK, with significant differences among them. SWS was lower in ridges than in furrows for RFM. DRFFM treatment kept soil water in ridges, resulting in higher SWS in ridges than in furrows after a period of no water input. Across the two growing seasons, compared with CK, RFM increased root mass by 10.2% and 19.3% at the jointing and filling stages, respectively, and DRFFM increased root mass by 7.9% at the jointing stage but decreased root mass by 6.0% at the filling stage. Over the two growing seasons, root length at the jointing and filling stages was respectively increased by 75.4% and 58.7% in DRFFM, and 20.6% and 30.2% in RFM. Relative to the jointing stage, the increased proportions of root mass and length at the filling stage were respectively 42.8% and 94.9% in DRFFM, 63.2% and 115.1% in CK, and 76.7% and 132.1% in RFM, over the two growing seasons, showing that DRFFM slowed down root growth while RFM promoted root growth at the later growth stages. DRFFM treatment increased root mass and root length in ridges and decreased them in 0–30 cm soil layer, while RFM increased them in 0–30 cm soil layer. Compared with CK, DRFFM decreased aboveground dry matter while RFM increased it. Evapotranspiration was reduced by 9.8% and 7.1% in DRFFM and RFM, respectively, across the two growing seasons. Grain yield was decreased by 14.3% in DRFFM and increased by 13.6% in RFM compared with CK over the two growing seasons. WUE in CK was non-significantly 6.8% higher than that in DRFFM and significantly 22.5% lower than that in RFM across the two growing seasons. Thus, RFM planting pattern is recommended as a viable water-saving option for summer maize in the Loess Plateau of China.

submitted time 2021-10-11 Cooperative journals:《Journal of Arid Land》 Hits7669Downloads405 Comment 0

2. chinaXiv:201906.00048 [pdf]

Effects of land use and cover change on surface wind speed in China

LI Yupeng
Subjects: Geosciences >> Geography

The surface wind speed (SWS) is affected by both large-scale circulation and land use and cover change (LUCC). In China, most studies have considered the effect of large-scale circulation rather than LUCC on SWS. In this study, we evaluated the effects of LUCC on the SWS decrease during 1979–2015 over China using the observation minus reanalysis (OMR) method. There were two key findings: (1) Observed wind speed declined significantly at a rate of 0.0112 m/(s?a), whereas ERA-Interim, which can only capture the inter-annual variation of observed data, indicated a gentle downward trend. The effects of LUCC on SWS were distinct and caused a decrease of 0.0124 m/(s?a) in SWS; (2) Due to variations in the characteristics of land use types across different regions, the influence of LUCC on SWS also varied. The observed wind speed showed a rapid decline over cultivated land in Northwest China, as well as a decrease in China's northeastern and eastern plain regions due to the urbanization. However, in the Tibetan Plateau, the impact of LUCC on wind speed was only slight and can thus be ignored.

submitted time 2019-06-20 Cooperative journals:《Journal of Arid Land》 Hits8768Downloads1610 Comment 0

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