Taking sustainable agriculture measures is critical to effectively cope with the effect of the increasing population on water shortage. Straw mulching and reduced tillage are the most successful measures adopted in arid and semi-arid regions which affect crop production by changing the crop environment. This review focuses on the effects of tillage and mulching on the soil environment, including soil organic matter, soil moisture, soil temperature, soil microorganisms, soil enzyme activity, soil fertility, soil carbon emissions, pests, weeds, and soil erosion. In addition, water use efficiency and crop production are discussed under different tillage measures. Straw mulching can increase soil organic matter content, adjust soil moisture, and prevent water loss and drought; however, it can also lead to an increase in pests and diseases, and change the structure of the soil microbial community. Straw mulching can significantly enhance WUE (water use effectively) and yield. Reducing tillage maintains soil integrity, which is conducive to soil and water conservation, but could negatively impact crop yield and WUE. Precise field management measures, taken according to crop varieties and local conditions, not only ensure the high yield of crops but also protect the environment.

Excessive inorganic fertilizers are one of the main causes of nitrous oxide (N₂O) emissions. Organic fertilizers can not only reduce the use of nitrogen (N) fertilizers by increasing soil organic matter but are also safe for the environment. The partial replacement of nitrogen (N) fertilizers with organic fertilizers can potentially reduce N₂O emissions. To illuminate the best ratio for the nitrogen replacement of inorganic fertilizer, the present experiment was conducted in dryland areas of central Gansu Province and different portions of inorganic N fertilizers (200 kg ha⁻¹); i.e., 0, 50, 37.5, 25, and 12.5% were replaced with commercial organic fertilizers to test their effects on soil physicochemical properties, the grain yield of maize, N₂O emissions, and the diversity of ammonia-oxidizing archaea (AOA) and bacterial (AOB) communities. Results showed that the maximum N₂O emission was obtained by 100% inorganic fertilizers and the lowest was obtained at the control (no fertilizer). Substituting inorganic fertilizers with organic manure not only reduced N₂O emissions but also improved soil organic carbon content and soil moisture and typically improves grain yield and biomass. The highest reduction in N₂O emissions was recorded by 50% substitution. Furthermore, 37.5% and 12.5% substitutions did not reduce the grain yield and biomass compared to 100% inorganic fertilizer, and a 37.5% substitution performed better in improving soil fertility. Organic fertilizer increased the amoA copy number of AOA but decreased that of AOB. Nitrososphaera (AOA) and Nitrosospira (AOB) were the most dominant ammonia-oxidizing communities. Structural equation modeling indicated that AOB contributes more N₂O emissions than AOA and is more sensitive to changes in pH, moisture, and NO₃⁻−N, and the input of organic fertilizers may affect AOB by influencing soil physicochemical traits. In summary, replacing a reasonable proportion (37.5%) of inorganic fertilizers with organic manure improves soil fertility, reduces N₂O emissions, and stabilizes production.

Improving the water-use efficiency (WUE) of crops is the most effective way to increase yields in semi-arid regions. Field research was carried out based on a long-term experiment initiated in 2001, aimed to explore the mechanisms of different tillage practices effects on grain yield and WUE of spring wheat. Tillage practices in the research including conventional tillage (CT), no tillage with no straw mulching (NT), conventional tillage with straw incorporation (TS), and no tillage with straw mulching (NTS). The effects of tillage practices on soil’s physical and chemical properties, dry matter accumulation, grain yield, dynamics of stress-related substances, and WUE were observed. Soil and plant samples in this research were collected in 2020 (wet year), 2021 (dry year), and 2022 (dry year). The results indicated that NTS improved the soil’s physical and chemical properties. The NTS treatment had the lowest soil bulk and pH and the highest total N, NO₃^--N, and available P. Throughout the whole growth stage, soil water content in the NTS and TS treatments were significantly higher than that of CT by 8.77–20.40% and 2.19–18.83, respectively. Averaged catalase (CAT), peroxidase (POD), and soluble protein across the three years with NTS and TS were significantly increased by 1.26–25.52% compared to CT. Meanwhile, the NTS treatment had the lowest malondialdehyde (MDA) content among the different tillage practices. NTS maintained the highest dry matter accumulation throughout the whole growth stage among different treatments; it was increased by 10.47–73.33% compared with CT. The average grain yields and WUE of NTS across the three years were 6.09–30.70% and 6.79–40.55% higher than other tillage practices, respectively. It is concluded that NTS influences dry matter accumulation and water-use efficiency during the whole growth stage of spring wheat by improving the soil’s physicochemical properties and modulating spring wheat substances related to stress, which in turn promotes yield formation.

Cadmium (Cd) contamination poses a significant threat to wheat productivity and food safety. This study demonstrates that TaMAN7-4B, which encodes an endo-β-mannanase involved in the metabolism of cell wall mannans, is significantly upregulated in response to Cd stress, thereby enhancing Cd tolerance by increasing the root cell wall mannan content and facilitating Cd sequestration. Furthermore, we identified the transcription factor TabZIP27 as a direct regulator of TaMAN7-4B expression. TabZIP27 is phosphorylated by the kinase TaCIPK16, which stabilizes TabZIP27 by suppressing its proteasome-dependent degradation. This phosphorylation event subsequently promotes the transcription of TaMAN7-4B, resulting in enhanced Cd binding within the root cell walls and reduced translocation of Cd from roots to shoots. Our findings elucidate a novel regulatory module, TaCIPK16-TabZIP27-TaMAN7-4B, which governs Cd accumulation in wheat, thereby providing potential targets for the breeding of low-Cd cultivars.

Accurate monitoring of photosynthetic phenotypes is fundamental for breeding high photosynthetic-efficiency wheat cultivars, and UAV remote sensing provides an effective approach for their large-scale identification. However, single photosynthetic parameters are limited in comprehensively evaluating crop photosynthetic efficiency. This study integrated multiple photosynthetic phenotypic parameters using principal component analysis (PCA) and the CRITIC objective weighting method (PCA-CRITIC) to construct a Comprehensive High Photosynthetic-Efficiency Phenotypic Index (CHPPI) for winter wheat. Concurrently, multispectral vegetation indices (MSVI), RGB vegetation indices (RGBVI), texture features (TF), and their combination, Comprehensive Multispectral-Visible-Texture Features (CMVTF), were extracted from UAV multimodal remote sensing data. Based on these features, four feature selection methods, namely PCC, VIP, SPA, and UVE, were evaluated in combination with five machine learning algorithms, including KNN, DT, SVR, RF, and XGBoost, to precisely estimate the CHPPI across key growth stages. The results demonstrated that the CHPPI exhibited significant cultivar variations across growth stages. Cultivars SH06144 and Liangxing19 consistently maintained high photosynthetic efficiency levels. The fused feature set CMVTF derived from multimodal remote sensing data outperformed individual feature categories, and the feature subset selected by the UVE method most significantly enhanced model accuracy. Regarding algorithms, the ensemble-based XGBoost and RF models markedly surpassed traditional machine learning algorithms. Specifically, the CMVTF-UVE-XGBoost model achieved the optimal comprehensive performance, yielding an R² of 0.862, an RMSE of 0.032, and an MAE of 0.027 on the testing set, with its spatial distribution estimations highly consistent with measured values. This study provides robust technical support for the rapid and large-scale screening of high photosynthetic-efficiency wheat breeding materials.