Morphological traits related to flag leaves are determinant traits influencing plant architecture and yield potential in wheat (Triticum aestivum L.). However, little is known regarding their genetic controls under drought stress. One hundred and twenty F8-derived recombinant inbred lines from a cross between two common wheat cultivars Longjian 19 and Q9086 were developed to identify quantitative trait loci (QTLs) and to dissect the genetic bases underlying flag leaf width, length, area, length to width ratio and basal angle under drought stress and well-watered conditions consistent over four environments. A total of 55 additive and 51 pairs of epistatic QTLs were identified on all 21 chromosomes except 6D, among which additive loci were highly concentrated in a few of same or adjacent marker intervals in individual chromosomes. Two specific marker intervals of Xwmc694-Xwmc156 on chromosome 1B and Xbarc1072-Xwmc272 on chromosome 2B were co-located by additive QTLs for four tested traits. Twenty additive loci were repeatedly detected in more than two environments, suggestive of stable A-QTLs. A majority of QTLs involved significant additive and epistatic effects, as well as QTL × environment interactions (QEIs). Of these, 72.7 % of additive QEIs and 80 % of epistatic QEIs were related to drought stress with significant genetic effects decreasing phenotypic values. By contrast, additive and QEIs effects contributed more phenotypic variation than epistatic effects. Flag leaf morphology in wheat was predominantly controlled by additive and QEIs effects, where more QEIs effects occurred in drought stress and depressed phenotypic performances. Several QTL clusters indicated tight linkage or pleiotropy in the inheritance of these traits. Twenty stable QTLs for flag leaf morphology are potentially useful for the genetic improvement of drought tolerance in wheat through QTL pyramiding.

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.

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%, WUE_r by 11.27%, and WUE_b 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, WUE_r, and WUE_b 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.

A reduction in emissions of nitrous oxide (N₂O), one of the three major greenhouse gases, is important for achieving environmental sustainability and carbon neutrality goals. Agricultural fields are the primary source of N₂O emissions, and their management measures influence greenhouse gas emission reductions and the greening of agriculture. Among these practices, cover cropping plays a key role in promoting sustainable agricultural production as a major cropping technique for efficient water use and increasing crop yields in water-scarce regions worldwide. The present paper systematically reviews the influence of various soil environmental factors, such as soil temperature, moisture, pH, carbon, and nitrogen contents, as well as nitrogen cycle-related enzymes, microorganisms and mulching practices, including general mulching and straw mulching, on N₂O emissions from agricultural fields. This review suggests that future research should explore the long-term effects of different mulching materials and their application rates and durations on soil N₂O emissions. Furthermore, a networked mathematical model for causal analysis should be employed in future research to elucidate the relationships among soil environmental factors, nitrogen cycle microorganisms, and soil N₂O production and consumption. These future studies will help to deepen our understanding of nitrogen cycling processes in agroecosystems with the aim of developing environmentally friendly agricultural technologies and promoting green and sustainable agricultural development.

Introduction: Water scarcity is a critical constraint limiting potato production in semi-arid rainfed areas. Mulching practices are recognized as effective water conservation strategies; Here, we investigated the effects of mulching practices on soil moisture and their impact on potato yield. Methods: A two-year field experiment (2018 – 2019) was conducted with five treatments, traditional bare-land planting without mulching (CK); large ridges and small furrows with only ridges mulched with black plastic film in fall (FPM); a partial-field mulching using whole cornstalks in straw mulching strips that alternate with planting strips without mulch in fall (FSM); large ridges and small furrows with only ridges mulched with black plastic film in spring (SPM); a partial-field mulching using whole cornstalks in straw mulching strips that alternate with planting strips without mulch in spring (SSM). We measured soil water storage (0–200 cm), yield, water-use efficiency (WUE), and stage-specific water consumption (WC). Results: Study results demonstrated that SSM and SPM significantly increased soil water storage (0–200 cm) by 6.7% and 8.4%, yield by 14.7% and 25.1%, and water-use efficiency (WUE) by 9.2% and 14.3%, respectively, compared to CK. Compared to spring mulching, the fall mulching outperformed in improving soil water retention and yield, increasing soil water storage by an average of 10.2% vs. 4.9%, and fresh potato yield by 17.8% vs. 11.8%. SSM and SPM reduced water consumption (WC) during the early growth stage (planting-to-budding) by 8.2–9.8%, conserving water for later use. This conserved water was then available during the critical yield-forming period, leading to increased WC during budding-to-tuber expansion by 10.3–11.3%. SSM increased WC more than FSM (12.3% vs. 10.2%), while FPM increased WC more than SPM (20.3% vs. 13.1%). Discussion: The findings indicated that both the straw strip mulching (SM) and plastic film mulching (PM) optimized the water consumption structure. Fall mulching generally outperformed spring mulching because it captured and conserved autumn and winter precipitation more effectively, resulting in higher soil water storage at planting. Both straw and plastic film mulching improve water use and potato yields, with fall application were most effective. However, for sustainable production, straw strip mulching is recommended, as it offers both high crop yields and significant environmental benefits.