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Seedlings are a crucial part of the plant community and the basis of vegetation restoration and regeneration. Grazing and climate change are two main factors contributing to vegetation changes in semiarid grasslands. However, the effects of grazing on seedling emergence with rainfall variation are not clearly understood. This study aimed to address how seedling abundance and the emergence dynamics of annuals respond to grazing with rainfall changes in different years. We conducted a seedling investigation experiment in a grassland along a grazing intensity gradient (light grazing—LG; moderate grazing—MG; heavy grazing—HG) in contrasting wet and dry years. The results showed that MG increased the seedling richness of grasses and forbs in the wet year, but increasing grazing resulted in a decline in forb richness in the dry year. Seedling abundance of grasses was enhanced under MG, while seedling abundance of forbs was higher under HG. The monthly emergence dynamics were generally in a single peak pattern, but the peak time of seedling emergence for forbs advanced under HG. Seedling abundance of whole annuals increased with grazing in the wet year but was much higher under MG in the dry year. Our results suggest that more judicious grazing management based on rainfall variation and functional composition of the plant community should be undertaken to facilitate grassland restoration. [ABSTRACT FROM AUTHOR]

Water scarcity threatens the sustainability of irrigated agriculture in semi-arid regions, and ridge-furrow planting systems (RFPS) can be a prospective rainwater harvesting approach. In this study, we aimed to develop a promising water-saving strategy to boost maize productivity and water use efficiency (WUE). In 2017, we carried out a field experiment to study the effects of various RFPS with multiple irrigation levels on the yield-water relationship of maize (Zea mays L.). Eleven treatments were set up: RFPS with film mulching on both ridges and furrows and without water supply after seed emergence, abbreviated as QF; RFPS with film mulching on continuous ridges, abbreviated as MD, including SMD, MMD, and LMD (S, M, and L—three water supply (irrigation plus precipitation) levels of 650 mm, 500 mm, and 350 mm during the whole growing season); RFPS without film mulching, abbreviated as DD, including SDD, MDD, and LDD; conventional flat planting with no film mulching, abbreviated as GG, including SGG, MGG, and LGG; localized full irrigation (actual amount of irrigation excessively exceeding the quantity needed), abbreviated as NM. A positive linear relationship (R2 = 0.95–1), a quadratic curve, and a negative linear relationship were observed between the irrigation water level and actual crop evapotranspiration (ETc), grain yield, and WUE, respectively. The ETc of QF (292 mm) was substantially lower than that of the other treatments (p < 0.01), saving 649 mm of irrigation water and increasing the yield by 2.24% compared with those of NM. Meanwhile, the WUE and irrigation water use efficiency (IWUE) of QF reached maximums of 6.3 and 47.36 kg m−3, respectively, which were significantly higher than those of other treatments (p < 0.001). The results showed that planting in an RFPS with film mulching on both ridges and furrows (a ridge-to-furrow ratio of 50:30, with a 38 mm irrigation level) is suitable for maize to obtain high yield and reduce irrigation water use significantly. [ABSTRACT FROM AUTHOR]