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To explore the response of soil organic carbon (SOC) and carbon components to surface coverage in wheat fields in semi-arid rainfed regions, a two-year field experiment was conducted under three treatments: straw strip mulching (SM), transparent plastic film mulching (PM) and no mulching (CK). We researched the dynamic feature of soil organic carbon (SOC) and its components at different growth stages of winter wheat under different mulching methods, including microbial biomass carbon (MBC), dissolved organic carbon (DOC), mineralizable carbon (PCM) and easily oxidized carbon (EOC). The results showed that SOC and its components in different soil layers decreased with an increase of soil layer depth. Compared with CK, the SM treatment increased SOC in the 0–40 cm soil layer by 2.83–8.92%, MBC by 12.09–18.40%, DOC by 3.73–9.79%, PCM by 4.82–12.48% and EOC by 6.01–11.68% during the different periods, and an overall increase was greater in the 0–20 cm soil layer than in the 20–40 cm soil layer. The impact of PM on SOC was less significant compared with CK; MBC and PCM had an overall positive effect, and DOC and EOC behaved differently from year to year. In conclusion, SM can improve SOC and its components content in dryland of northwest China, which is conducive to the sustainable management and efficient utilization of maize straw resources and has significant ecological benefits. [ABSTRACT FROM AUTHOR]

To investigate the feasibility of replacing plastic film with straw in semi-arid areas and establishing coordinated cultivation technology for high winter wheat yield and efficient resource utilization, a two-year field experiment was conducted under six treatments, specifically CK (no-mulching), S1 (59% of the field area straw mulched), S2 (50% of the field area straw mulched), S3 (42% of the field area straw mulched), BM (full-cover transparent plastic mulch), and HM (full-cover black plastic mulch). The effects of mulching measures on soil moisture, water consumption characteristics, yield and water use efficiency (WUE) of winter wheat farmland in rain-fed semiarid regions were studied. The results showed that, compared with CK, straw strip mulching reduced total water consumption by 15.39 mm on average, the soil organic carbon content at the 0–40 cm soil layer increased by 4.68%, yield by 6.90%, WUEr by 11.27%, and WUEb by 16.51%. Compared with CK, the total water consumption and soil organic carbon content in each growth period of plastic film mulching were not significantly different, but the yield, WUEr, and WUEb increased by 16.28%, 15.29%, and 25.50%, respectively. Among the three straw strip mulching treatments, treatment S3 had the highest yield, which was equivalent to that of plastic film mulching. The S3 treatment with 42% of the field area straw mulched is recommended in this stusy as the optimal replacement of plastic film mulching in semi-arid environments. [ABSTRACT FROM AUTHOR]

• Mulching significantly increased winter wheat productivity. • The cooling effect may be beneficial to vegetative growth and yield formation. • Mulching reduced the daily variable amplitude of soil temperature. • Mulching showed the warm effect in the season with lower air temperature. Mulching is a major production mode with highly effective use of water in the hydrothermal deficient area of northwest China. However, given the differences in environments and crop species among regions, it is important to further understand whether the mulching-induced changes in soil temperature are beneficial to crop production. Here, we used winter wheat to study the effect of mulching on soil temperature, soil water content, dry matter and yield. Two 3-year field experiments were conducted at two sites over 6 consecutive years (2012–2015 at site 1, and 2015–2018 at site 2) in the semiarid rainfed thermal deficient areas of northwest China. In each experiment, three mulching treatments, including straw strip mulching (SSM), plastic film mulching (PFM) and non-mulching (CK), were tested in a replicated randomized block design. Compared with CK, SSM and PFM significantly increased grain yield by 18.6–69.1 % and 35.5–61.3 % in 2012–2017 growing seasons, except that there was no significant difference in the wet year (2017–2018). In the SSM treatment, soil temperature generally decreased at different growth stages, resulting in a slight decline of 0.9–1.9 ℃ in the 0–25 cm soil layer, whereas in the PFM treatment, soil temperature increased before the jointing stage and decreased subsequently. SSM reduced the daily variable amplitude of soil temperature by decreasing the maximum soil temperature, whereas PFM produced the same effect by decreasing the maximum soil temperature and increasing the minimum soil temperature, which could promote the winter wheat vegetative growth and yield formation in the six experimental years. SSM and PFM decreased accumulated soil temperature from the overwintering stage to maturity stage by 60.1–234.6 ℃ and 30.5–148.5 ℃, respectively. The beneficial effect of the change in soil temperature in SSM and PFM plots expanded the storage capacity of winter wheat. Overall, the moderately cooling effect of mulching was conductive to promoting vegetative growth and expanding storage capacity, ultimately improving crop yield. Our results suggest that SSM can be adopted for sustainable winter wheat production in semiarid rainfed areas under thermal deficient conditions. [ABSTRACT FROM AUTHOR]

Straw strip mulching in maize (Zea mays L.) production is showing a positive effect with the increasing negative effects coming from crop straw and plastic film residues. Therefore, it is imperative to develop comprehensive utilization of straw, and promote the green development of agriculture in rainfed regions. A dryland field experiment was conducted in semiarid northwestern China in 2017 and 2018 and included three treatments: maize straw strip mulching with alternating strips of mulched and non-mulched soil (MSSM), and double ridge-furrow fully mulched soil with white or black plastic film (DRWP or DRBP, respectively). The results show that the interaction between mulching treatment and year significantly influenced maize silage yield, grain yield, biomass yield, aboveground plant water content at silage maize harvest stage, ears ha−1, kernels ear−1, and thousand kernel weight (p < 0.001, p = 0.002, p < 0.001, p < 0.001, p < 0.001, p < 0.001, p < 0.001, and p < 0.001, respectively). For silage, maize growth under straw strip mulching was greater than that of the double ridge mulching system. Silage yield of MSSM was significantly higher than that of DRWP and DRBP, but maize grain and biomass yields under MSSM were significantly lower those under DRWP and DRBP in 2017 and 2018. Compared with the double ridge mulching system, net economic return from silage with MSSM was significantly increased by 28.31% and 20.85% in 2017 and 2018, respectively, and net economic return from grain was 6.67% lower in 2017 and 2.34% higher in 2018. The MSSM treatment exhibited water-temperature coupling; the MSSM treatment significantly reduced soil temperature in the 0–25 cm soil layer by 1.23–2.14 °C and increased soil water storage in the 0–200 cm soil layer by 9.75 and 24.10 mm in 2017 and 2018, respectively, thereby delaying growth development of maize by about 13 days. Therefore, straw mulch can replace plastic film mulch and serve as an environmentally friendly cultivation method for maize in semiarid rainfed regions. [ABSTRACT FROM AUTHOR]