Search Results (36)

The wheat–soybean double-cropping system enables the continuous production of preceding and succeeding crops within the same growing season, providing an important approach for improving arable land-use efficiency, increasing output per unit area, and optimizing cropping structure. In Liaoning Province, where thermal resources and the frost-free period are relatively limited, this system places high requirements on the growth duration, yield stability, and succession compatibility of the preceding wheat crop with the succeeding soybean crop. To identify spring wheat cultivars suitable for this system, field trials were conducted from 2021 to 2023, using three representative ecological regions of Liaoning Province. Ten widely grown spring wheat cultivars were evaluated for major agronomic traits, grain quality, and disease resistance, and their stability and system adaptability were analyzed using a mixed linear model, GGE biplot analysis, and TOPSIS. The results showed clear differences among cultivars in growth duration, wheat yield, and succeeding soybean yield. Liaochun 33 and Liaochun 18 had relatively short growth durations of 78–84 days and 79–83 days, respectively, and showed favorable performance in wheat yield, succeeding soybean yield, and stability. Combined with grain quality, disease resistance, and TOPSIS-based comprehensive evaluation, Liaochun 33 showed the best overall performance, while Liaochun 18 also exhibited strong system adaptability. Overall, cultivar selection for the wheat–soybean double-cropping system in Liaoning Province should shift from single wheat-yield evaluation to overall system-benefit evaluation. Liaochun 33 and Liaochun 18 can be recommended as preferred spring wheat cultivars for this cropping system. Full article

Owing to the high altitude and short frost-free period of the Tibetan Plateau, potato plants are frequently exposed to cold stress (CS), which severely restricts their growth and productivity. Thus, understanding the mechanisms underlying cold tolerance in potato varieties is crucial for breeding improvement. This study aims to investigate the role of caffeic acid in potato cold tolerance and to elucidate the molecular mechanisms underlying the CS response. To achieve this, we conducted comprehensive metabolomic and transcriptomic analyses of KY130 (cold-tolerant) and KY140 (cold-sensitive) potato cultivars under CS at the seedling stage. ELISA results showed that caffeic acid levels were higher in KY130 than in KY140, while CS-KY130 exhibited higher levels than those of CS-KY140. Across all treatments, KY130 showed significantly higher activities of antioxidant enzymes (CAT and SOD) and higher contents of osmolytes (proline, soluble protein, and soluble sugar) than those of KY140. Caffeic acid and naringenin* were identified as candidate metabolites potentially involved in the direct and indirect cold resistance of potatoes. StPAL(Soltu.Atl.03_2G004060, Soltu.Atl.03_2G004070, Soltu.Atl.03_2G008130) and StCSE(Soltu.Atl.04_1G006370 and Soltu.Atl.04_3G005440), identified as upstream regulators of caffeic acid, were associated with the direct and indirect cold resistance of potatoes. KEGG pathway analysis of differentially accumulated metabolites and differentially expressed genes revealed several key metabolic pathways, including “flavonoid-related metabolism,” “lipid metabolism,” and “amino acid metabolism.” This research enhances our understanding of caffeic acid and the molecular mechanisms involved in the response of potatoes to CS, and supports future efforts in potato screening and breeding programs. Full article

The high-latitude cold regions of northeastern China present scarce thermal resources, exhibit a short frost-free period, and lack high-yielding maize (Zea mays L.) varieties suitable for dense planting. These factors have long constrained the realization of maize yield potential under dense planting conditions. This study investigated the effects of intercropping maize varieties with different growth periods on the photosynthetic performance, yield formation, and interspecific competition. The long-season varieties Zhengdan958 (ZD958) and Xianyu335 (XY335), which are representative of the region, were intercropped with the shorter-season variety Yinongyu10 (YNY10), six intercropping row ratios (6:6, 4:4, 2:2, 1:1, 0:1, and 1:0) were set, and monoculture plots (0:1 and 1:0) were used as the controls. The results indicated that as the row ratio decreased in the intercropped plots, the leaf area index, relative leaf chlorophyll content, photosynthetic rate, stomatal conductance, and transpiration rate increased while the intercellular CO₂ concentration gradually decreased compared with those in the monoculture plots. Simultaneously, dry matter accumulation, allocation, transport efficiency, 100-kernel weight, number of kernels per ear, and grain yield progressively increased, reaching maximum values at a 1:1 intercropping row ratio. Conversely, YNY10 in the intercropped plots exhibited opposite trends in these parameters. The land equivalent ratios for all intercropped row ratios exceeded 1. During the 2023–2024 growing season, the composite population grain yield was significantly higher (p < 0.05) at an intercropping row ratio of 1:1 for ZD958 (4.11–4.26%) and XY335 (3.54–3.65%) compared with the monoculture treatments, demonstrating the strong yield advantage of intercropping. Furthermore, in the intercropping systems, ZD958 and XY335 exhibited positive aggressivity and a competitive ratio greater than 1, thus showing stronger competitive ability than YNY10. Moreover, the increased grain yield of ZD958 and XY335 effectively compensated for the ecological disadvantages of YNY10, thereby leveraging the synergistic effects of close planting and intercropping patterns to promote improvements in maize composite population productivity. Full article

Climate change is expected to have significant effects on crop yield in the Canadian Prairies. The objective of this study was to investigate these possible effects on spring wheat, barley and canola production using the Decision Support System for Agrotechnology Transfer (DSSAT) modelling platform. We applied 21 climate change scenarios from high-resolution (0.22°) regional simulations to three modules, DSSAT-CERES-Wheat, DSSAT-CERES-Barley and CSM-CROPGRO-Canola, using a historical baseline period (1985–2014) and three future periods: near (2015–2040), middle (2041–2070), and far (2071–2100). These simulations are part of CMIP6 (Coupled Model Intercomparison Project Phase 6) and have been processed using statistical downscaling and bias correction by the NASA Earth Exchange 26 Global Daily Downscaled Projections project, referred to as NEX-GDDP-CMIP6. The calibration and validation results surpassed the thresholds for a high level of accuracy. Simulated yield changes indicate that climate change has a positive effect on spring wheat and barley yields with median model increases of 7% and 11.6% in the near future, and 5.5% and 9.2% in the middle future, respectively. However, in the far future, barley production shows a modest increase of 4.4%, while spring wheat yields decline significantly by 17%. Conversely, simulated canola yields demonstrate a substantial decrease over time, with reductions of 25.9%, 46.3%, and 62.8% from the near to the far future, respectively. Agroclimatic indices, such as Number of Frost-Free Days (NFFD), Heating Degree-Days (HDD), Length of Growing Season (GSL), Crop Heat Units (CHU), and Effective Growing Degree Days (EGDD), exhibit significant correlations with spring wheat. Conversely, precipitation indices, such as very wet days and annual 5- and 10-day maximum precipitation, have a stronger correlation with canola yield changes when compared with temperature indices. The results provide key guidance for policymakers to design adaptation strategies and sustain regional food security and economic resilience, particularly for canola production, which is at significant risk under projected climate change scenarios across the Canadian Prairies. Full article

Frost is one of the most frequent, intense, and influential agrometeorological disasters that occurs frequently in Northeast China. The study of the spatiotemporal changes of ground frost is of great significance for farmers and policymakers in Northeast China, as it can inform decisions related to crop selection, planting schedules, and the development of regional climate adaptation plans. In this study, the spatiotemporal changes of frost indices (last spring frost (LSF), first fall frost (FFF), and frost-free period (FFP)) in Northeast China were analyzed from 1961 to 2020. Then, we investigated the mutation characteristics of the frost indices and their correlation with geographical factors. The results revealed that (1) the LSF, FFF, and FFP in Northeast China were concentrated at 120–140 DOY, 260–280 DOY, and 110–170 days, respectively. The spatial distribution of frost indices exhibited significant spatial heterogeneity. (2) The LSF, FFF, and FFP showed significant trends of advancement, delay, and extension, with trends of −1.94 days/10 a, 1.72 days/10 a, and 4.21 days/10 a, respectively. (3) More than 80% of the LSF, FFF, and FFP of the sites showed trends of advancement, delay, and extension, with greater variability in the central part of Heilongjiang Province. (4) The FFF and FFP experienced an abrupt change in the late 1990s. (5) The correlation between latitude and LSF, FFF, and FFP was the strongest, with correlation coefficients of 0.77, −0.79, and −0.78, respectively. This study provides a comprehensive understanding of the changing characteristics of ground frost indices that impact agricultural production in Northeast China against the backdrop of climate change. The findings hold significant scientific value in guiding the adaptation of agricultural production layouts in Northeast China to the evolving climatic conditions. Full article

Grapevine is a highly climate-sensitive plant. In the last few decades, an increase in the number and area of vineyards has been observed in the country, with the Zielona Góra region pioneering this revival. A comprehensive analysis of climatic and agroclimatic indicators for grapevines was conducted to assess the possibilities and limitations in this region. Based on data obtained from the Institute of Meteorology and Water Management—National Research Institute (IMGW-PIB) for stations in Zielona Góra, nine key indicators were identified. The analysis of agroclimatic conditions for the Zielona Góra winegrowing region from 1951 to 2022 revealed significant changes in air temperature, length of the vegetative period, and number of frosts. The average annual air temperature increased, while the number of days with temperatures below 8 °C decreased. The extension of the vegetative period (starting earlier and ending later) favours grapevine cultivation. The increase in temperature during the vegetative period and the lengthening of the frost-free period have a beneficial effect on grape production in the Zielona Góra region. Full article

Fruits, garden plants, and agricultural crops grown in Poland exhibit wide variations in their sensitivity to frost, particularly in early spring. In the case of frost, generally, the yield and quality are reduced, and sometimes, entire plants can be destroyed. This article characterizes the occurrence of ground frosts (at 5 cm agl) and air frosts (at 200 cm agl) in Poland gathered from 52 meteorological stations affiliated with IMGW-PIB between 1971 and 2020. To assess the real risk of frost to plants, the variability of this phenomenon was analyzed per thermal growing season (defined as air temperature >5 °C), rather than in traditional calendar terms as presented in most studies. In the climatic conditions of Poland, the growing season is characterized by a reported 28 days with ground frost and 13.3 days with air frost, approximately. In spring, the last ground frost disappears, on average, on a country scale, on May 14, and air frost on April 27. In turn, in autumn, the first ground frost is recorded, on average, on 1 October and air frost on 14 October. On the basis of the selected characteristics of frost and the growing season, four areas of potential risk of ground and air frost in the growing season, as well as in spring, were determined with the use of cluster analysis. Full article

Soybean downgrading due to immature (green and semi-green) color at harvest, caused by frost conditions, poses a significant loss to producers and processors. After harvest, drying and storage are important for preserving the quality of the harvested produce. This study investigated the impact of drying on color change in harvested immature soybeans and the effect of the soybean moisture content, storage environment (temperature, light, and aeration), and storage period on color change and oil quality of immature soybeans. Soybeans were harvested at three different maturity stages: R6 (green) and R7 (semi-green) in pods and R8 (fully matured) in seed. The soybeans in pods were dried, shelled, and conditioned to moisture contents of 12% and 17% (wet basis) prior to storage in 12 storage chamber (box) environments. The chambers were built to have four environments of “light” and “no light” with and without aeration and were stored at temperatures of either 4 °C or 23.5 °C for 24 weeks. Samples were taken every 2 weeks for 2 months and then bimonthly in storage. Soybean color change during drying and their chlorophyll, color, peroxide value (PV), and free fatty acid (FFA) status in storage were determined. Visual observation showed that R6 (green) soybean color faded after 48 h drying, which was supported with a colorimeter reading as the “a” value increased from −8.89 to −3.83 and −8.89 to −1.71 with 37 °C and 27 °C drying temperatures, respectively. The ANOVA analysis showed that light had the greatest contribution (~81%) to the color change compared to the other three storage environment factors of temperature (~9.1%), aeration (~8%), and moisture content (~1.5%) with <10% separate effects. During storage, the R6 green and R7 semi-green soybean color continued to fade with color a-values that exceeded the initial values of the R8 matured (control) by 353% and 350%, respectively, by the end of the storage period. Low amounts of peroxide and free fatty acids (FFA) were recorded throughout the storage period. Only the FFA of 17% M.C. soybeans stored at 23.5 °C exceeded acceptable limits at the end of the storage period. Exposing immature (green and semi-green) soybeans to light resulted in the fading of the green color. Seed producers in regions prone to frost can extend harvest time by allowing immature soybeans to field-dry. Full article

Preserving the authenticity of forest colors is essential to highlight regional characteristics and promote the sustainable development of forest landscapes. However, the factors and mechanisms influencing forest color remain unclear. We quantified 1422 forest color images from 43 parks across seven biogeographic regions in China to capture the forest color composition among regions. A generalized linear mixed-effects model was used to analyze the effects of meteorological and anthropogenic disturbance factors on forest color. Meteorological factors included accumulated sunshine hours, average temperature, accumulated precipitation, frost-free period, average wind speed, and average air quality index. Anthropogenic disturbance factors included park feature indicators (area, elevation, and perimeter-area ratio) and human activity indicators (distance to urban areas, building density, and road density). We calculated p-values and relative effect estimates to determine the sensitivity and degree of sensitivity of color to each factor. The results indicated the following: (1) forest color composition varied significantly among different regions in China with variations observed particularly in the proportions of primary (green), secondary (yellow and yellow-green), and accent colors (orange and blue-green); (2) forest colors were sensitive to all meteorological factors; (3) orange, yellow, purple, and red were all sensitive to anthropogenic disturbance factors; and (4) forest accent colors were more strongly influenced by anthropogenic disturbance factors, particularly park features. To protect the authenticity of forest colors, it is necessary to avoid excessive borrowing of forest color schemes from different regions, control park features, reduce building area within the park buffer zones, and optimize park tourism routes. Full article

Frosts cause damage to plants in field crops and also trees, thus contributing to heavy economic losses in agriculture. One of the consequences of climate warming is the lengthening of the thermal growing season (AT > 5 °C) and acceleration of phenological phases as well as the lengthening of the frost-free period. This favourable element allows the extension of the range of cultivated plants to include plants requiring warmth and a longer development period. The present study concerns the area of Poland. The data on mean and minimum 24-h period air temperature (200 cm above ground level) were obtained from 52 meteorological stations of the Institute of Meteorology and Water Management—National Research Institute (IMGW-PIB) for the period 1971–2020. A day with air frost was identified when the recorded minimum air temperature was below 0.0 °C and the mean 24-h period air temperature was above 0.0 °C. All calculations concerning frosts were limited to the period with mean 24-h period air temperature >5 °C (the growing season) as determined with the Gumiński method. The obtained results show that in the thermal growing season (AT > 5 °C) in Poland, no statistically significant change in the average number of days with air frosts in the period 1971–2020 was found. On average, in Poland, in the years 1971–2020, a lengthening of the thermal growing season by 6.2 days over 10 years was identified. Earlier disappearance of the latest air frosts in spring was identified as 2 to 3 days over 10 years, and the later occurrence of air frosts in autumn as 1 to 4 days over 10 years. The share of severe (−4.1°C ÷ −6.0 °C) and very severe (<−6.0 °C) frosts in the total number of days with air frosts in Poland amounts to, on average, 5.8% in spring and 2.6% in autumn. Full article

Soil contains a diverse fauna and microflora that are vital for maintaining healthy soils and their various ecosystem services. Oribatid mites are typically highly abundant arthropods in the soil and are used as indicators for environmental monitoring. The aim of this study was to determine oribatid mite community response to natural land cover, anthropogenic disturbance, space, and climate in the oil sands region of Alberta, Canada. Our results found that oribatid mite total abundance was significantly reduced by mining, cultivation, and well sites. Species richness was significantly reduced by mining and cultivation. Shannon’s diversity index was significantly higher for all natural land cover types, seismic lines, and forest harvest. Additionally, species diversity was lower under the relative influence of energy-related soft linear disturbances than for naturally vegetated sites and forest harvesting, and was lowered further by anthropogenic disturbances with more impact on soil integrity (cultivation, mines, urban/industrial, road/trail verges, well sites). Abundance, richness, and diversity also increased with increased frost free period and with eastward longitude. Mite community composition included a notable composition difference between lowland habitats and upland forest types, and between natural land cover and intense anthropogenic disturbance types (e.g., mines, cultivation). Our study highlighted oribatid mite communities’ response to natural land cover, anthropogenic disturbance and spatial–climatic factors assessed over broad spatial scales and the potential utility of oribatid mites as ecosystem health indicators under multiple ecological drivers. Full article

Dew is a part of the water cycle of ecosystems and is a source of water and humidity. The climate characteristics of the frost-free period in Northeast China are suitable for dew condensation, and dew is an important factor of water balance in this area. Northeast China is among the most significant warming areas in China, with an obvious “warm and dry” climate trend, which may affect dew condensation. To determine the dew amounts in different ecosystems in Northeast China and the influence of climate change on these amounts, dew condensation in farmland (corn), wetland (Carex lasiocarpa) and urban ecosystems (Syringa oblata Lindl.) was monitored during the growing period (May to October) from 2005 to 2021. The results showed that the annual average number of dew days was 132.8 in a wetland in Fujin, 122.9 in a farmland in Lishu and 118.1 in an urban area in Changchun. The daily dew intensity in the three ecosystems was lowest in May and highest in July and August. The average daily dew intensity was higher in the wetland (0.125 ± 0.069 mm) than the farmland (0.061 ± 0.026 mm) and urban area (0.028 ± 0.009 mm). The annual dew amount was also highest in the wetland (44.09 ± 7.51 mm) compared to the farmland (34.46 ± 3.54 mm) and much higher than that in the urban ecosystem (25.32 ± 3.29 mm). The annual dew in the farmland, wetland and urban ecosystems accounted for 7.92 ± 2.76%, 14.98 ± 5.93% and 6.71 ± 2.66% of the rainfall in the same period, respectively. The results indicated that dew was an important source of water and that wetlands had greater dew deposition than farmlands and urban areas. Considering the climate data during the dew condensation period from 1957 to 2021, the annual dew amount showed a decreasing trend of −0.40 mm/10a (p < 0.05) in Changchun. However, under the joint influence of relative humidity (RH) and wind speed (V), the impact of climate change on dew condensation was not obvious. This study further clarified the impact of climate change on the near-surface water cycle. Full article

Accurately assessing the variation in the frost-free season (FFS) can provide decision support for improving agricultural adaptability and reducing frost harm; however, related studies were inadequate in terms of the Qinghai–Tibet Plateau (QTP). This study analyzed the spatiotemporal changes in the first frost day in autumn (FFA), last frost day in spring (LFS), FFS length and effective accumulated temperature (EAT) during the 1978–2017 period, and their influences on spring wheat potential yield on the QTP, based on daily climatic data and the methodology of Sen’s slope and correlation analysis. The results showed that the annual average FFA and LFS occurred later and earlier from northwest to southeast, respectively, and both the FFS length and EAT increased. From 1978 to 2017, the average regional FFA and LFS were delayed and advanced at rates of 2.2 and 3.4 days per decade, and the FFS and EAT increased by 5.6 days and 102.7 °C·d per decade, respectively. Spatially, the increase rate of FFS length ranged from 2.8 to 11.2 days per decade throughout the QTP, and it was observed to be larger in northern Qinghai, central Tibet and Yunnan, and smaller mainly in eastern Sichuan and southern Tibet. Correspondingly, the increase rate for EAT ranged from 16.2 to 173.3 °C·d per decade and generally showed a downward trend from north to south. For a one-day increase in the FFS period, the spring wheat potential yield would decrease by 17.4 and 9.0 kg/ha in altitude ranges of <2000 m and 2000–3000 m, but decrease by 24.9 and 66.5 kg/ha in the ranges of 3000–4000 m and >4000 m, respectively. Future studies should be focused on exploring the influence of multiple climatic factors on crop production using experimental field data and model technologies to provide policy suggestions. Full article

The backfilling of lime soil in ultra-deep and ultra-narrow foundation trenches is a difficult construction link, and ordinary-cemented soil has drawbacks, including poor strength, impermeability, and frost resistance. To solve these problems, fly ash (FA)–water glass (WG)-composite-cemented soil is developed based on a background project. The three-factor orthogonal tests are conducted on the unconfined compressive strength (UCS) of the composite-cemented soil, and the optimal engineering mix proportion is proposed for the FA-WG-composite-cemented soil. Its UCS is compared with that of cemented soil only doped with FA or WG (FA- and WG-cemented soil). In addition, the cyclic wetting–drying tests, cyclic freeze–thaw tests, and impermeability tests are carried out to study the endurance of the composite-cemented soil in cold regions rich in water. The hydration products of the composite-cemented soil are investigated through scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis, and the curing mechanism of the composite-cemented soil is discussed from the microscopic perspective. The research results indicate that the mixing ratio of cement is crucial to the strength development of the cemented soil; the mixing ratio of FA greatly influences the strength development of the cemented soil in the middle and late stages; the mixing ratio of WG only slightly affects the strength. The ratio of cement, FA, and WG of 9%:12%:3% is the optimal engineering mix proportion of the composite-cemented soil. Compared with ordinary-cemented oil and FA- and WG-cemented soil, the composite-cemented soil shows significantly improved compressive load-bearing capacity. The permeability coefficient of the composite-cemented soil is always obviously lower than that of the ordinary-cemented soil after any curing period. Despite the mass loss, the composite-cemented soil is superior to the ordinary one in overall endurance after wetting–drying and freeze–thaw cycles. Through SEM and XRD analysis, the content of hydration products of the composite-cemented soil is found to be obviously higher than that of ordinary-cemented soil after any curing period, and the hydrates exert stronger cementing action on soil particles in the composite-cemented soil. The contents of C-S-H gel and Aft crystals in the composite-cemented soil are apparently larger than those in the ordinary-cemented soil. Under the alkali activation of WG, the FA produces free SiO₃²⁻ and AlO²⁻, which undergo the polymerization reaction with Ca²⁺ to generate C-S-H gel and C-A-H gel, further promoting the hydration of cement. Full article

Evaluating the impact of different meteorological conditions on apple yield and predicting the future yield in Yantai City is essential for production. Furthermore, it provides a scientific basis for the increase in apple yield. In this study, first, a grey relational analysis (GRA) was used to determine the quantitative relationship between different meteorological factors and meteorological yield which is defined as affected only by meteorological conditions. Then, the comprehensive meteorological factors extracted by a principal component analysis (PCA) were used as inputs for multiple linear regression (MLR). The apple yield accuracy was compared with the lasso regression prediction. Trend analysis showed that the actual apple yield increased annually, but the meteorological yield decreased annually over a long time. Correlation ranking illustrated that the meteorological yield was significantly correlated with the frost-free period, the annual mean temperature, the accumulated temperature above 10 °C, etc. The good consistency between GRA and MLR–PCA showed that the accumulated temperature above 10 °C, the March–October mean temperature, and the June–August mean temperature are key meteorological factors. In addition, it was found that the principal components $F_2, F_4$, and $F_5$ were negatively correlated with meteorological yield, while the principal components $F_1$ and $F_3$ were positively correlated with meteorological yield. Moreover, the MLR–PCA model predicted the apple yield in 2020 as 47.256 t·ha⁻¹ with a 7.089% relative error. This work demonstrates that the principal component regression model can effectively extract information about different meteorological factors and improve the model’s accuracy for analyzing key meteorological factors and predicting apple yield. Full article