Autumn Soil Research Articles

Influence of autumn soil moisture over Kalimantan Island on following winter precipitation over southern China

Influence of autumn soil moisture over Kalimantan Island on following winter precipitation over southern China

The specifics оf тhe development оf soil flushing during spring snowmelt in the arable land of the northern zone of the Krasnoyarsk forest-steppe

The results of studies of soil flushing and accumulation in the period 2009–2017 in the northern part of the Krasnoyarsk forest-steppe in areas with high intensity of erosive and accumulative processes are presented. A wide range of erosion values from meltwater has been established – from 0.4 to 25 mm for the spring period. The results of the application of a refined Regional model for calculating potential flushing for the northern part of the Krasnoyarsk forest-steppe are presented. The analysis of meteorological factors and conditions of the underlying surface affecting the distribution of values of melt runoff, flushing and accumulation of soils on arable massifs located on inclined watershed surfaces is carried out: the specificity of the distribution of meltwater flows determines the formation of zones of extreme erosion along the perimeter of arable land in the lower parts of the slope – up to 15–20 mm of soil layer. In conditions of low slope steepness, the effect of relief on erosion is largely determined by the high slope lengths and melt water flow lines. The distribution of flushing values over the area of arable land shows a close correlation with the values of snow accumulation and soil moisture. The spatial and temporal patterns of the influence of the previous autumn soil moisture on the intensity of erosion have been established: the values of flushing increase with increasing soil moisture, the average values of erosion correlate with the values of autumn soil moisture in dynamics over the years of field observations. Special soil protection measures have been proposed for sites with the most intensive flushing in the research area.

Soil bacterial communities affected by land-use types in a small catchment area of the Balaton Uplands (Hungary).

Changes resulting from different tillage practices can affect the structure of microbial communities, thereby altering soil ecosystems and their functioning. The aim of this study was to explore and compare the physical, chemical properties and bacterial community composition of soils from different land use types (forest, grassland, vineyard, and arable field) in a small catchment. 16S rRNA gene-based amplicon sequencing was used to reveal the taxonomic diversity of summer and autumn soil samples taken from two different slope positions. The greater the anthropogenic impact was on the type of land use, the greater the change was in soil physical and chemical parameters. All sample types were dominated by the phyla Pseudomonadota, Acidobacteriota, Actinobacteriota, Bacteroidota and Verrucomicrobiota. Differences in the relative abundance of various bacterial taxa reflected the different land use types, the seasonality, and the topography. These diversity changes were consistent with the differences in soil properties.

Pulp mill sludges as a solution for reducing the risk of mineral nitrogen leaching from agriculture

Nitrogen (N) from agricultural systems contributes to the eutrophication of waterbodies through leaching. Incorporating organic material with a high carbon-to-nitrogen (C/N) ratio, such as mixed pulp mill sludges (PMSs), into the soil in autumn could reduce the amount of leachable N. This study tested the potential of composted and lime-stabilised mixed PMSs (CPMS and LPMS) in reducing the concentration of mineral N in the soil, and thus the risk of N leaching from arable land in the boreal region using a two-year field experiment. To better understand the mechanisms of the PMSs for influencing mineral N concentration in soil, the impact of PMSs with different quality on the reactions of N in the soil was investigated in a laboratory incubation study. In the field experiment, nitrate-N (NO3--N) concentration was lower with PMSs compared to mineral fertilisation and the control during the first autumn and the following spring after PMS application. The undersowing of Italian ryegrass reduced the NO3--N concentration in the soil during the first autumn. In the incubation experiment, PMSs reduced the soil ammonium-N (NH4+-N) concentration at the beginning of the experiment and the soil NO3--N concentration throughout the experiment compared to a mineral fertiliser treatment and an organic fertiliser. Increased soil respiration in PMS-treated soils indicated increase in microbial activity, and thus immobilisation of soil NO3--N and NH4+-N due to PMSs addition. These results suggest that PMSs have the potential to reduce N leaching from agricultural soils. However, the immobilisation of N must be considered when planning the nutrient requirements of the following crops.

Microbiocenosis of the Permafrost Soils of Transbaikalia under Agriculture Use

An understanding of how the involvement of soils in agricultural turnover affects soil microbiocenosis has been attained. The aims of this study were to investigate the number of the main groups of microorganisms in microbial complexes, the carbon of microbial biomass and the enzymatic activity in permafrost soils under the influence of tillage. The presented data can provide an insight into the stability of the microbiome in region’s soils under agricultural influence. The significance of the study lies in obtaining new data on the microbiocenosis of permafrost soils, which will make it possible to reveal the orientation and intensity of microbiological processes during their agricultural use. The study uses the classical methods used in soil science and soil microbiology, which are characterized by accuracy and reliability. The general characteristics of the microbiocenosis of different types of the studied region’s soils have been revealed. The quantity of bacteria, including actinomycetes and fungi, in the studied soils was determined. The variability of indicators in time and space is shown. The number of bacteria was revealed to reach its maximum in the autumn period in grey forest non-podzolised soils, and the indicator decreases in the following manner: forest—10.6 billion cells/g, arable land—5.1 billion cells/g, virgin land—2.6 billion cells/g. The lowest indicator of bacterial abundance—0.5 billion cells/g was found on arable permafrost meadow chernozemic soil. A comparatively low bacterial content is characteristic of chernozem meal-carbonated: 1.9 billion cells/g on virgin land and 2.1 billion cells/g on arable land. The length of actinomycete mycelium is dynamic according to the seasons of the year. The maximum length of actinomycete mycelium was observed in grey forest non-podzolised soil (forest) in the autumn period—830 m/g. The maximum length of fungal mycelium was also observed in grey forest non-podzolised soil (forest) in autumn—1200 m/g. In arable variants, the length of fungal mycelium is high in grey forest non-podzolised soils and meadow permafrost soils. In chernozems and permafrost meadow chernozemic soils (virgin and arable) the index is much lower. Assessment of catalase activity showed that the studied soils are poor or moderately enriched in this enzyme. Relatively high invertase activity was found in all variants.

Mode and experiments of a straw ditch-burying returning and maturing in cold region of Northeast China

The current agronomic model of returning straw litter to soil (straw returning) involves crushing and mixing the straw with soil, which leads to shallow burial and ineffective decomposition of the straw. To address this issue in the cold region of Northeast China, this study proposed a method of burying and composting rice straw in furrows for returning to the field, and developed a matching machinery. Based on long-term experiments of burying straw in soil in spring and autumn, in this study, the operating parameters, postoperative straw decomposition effects, and influence of soil bulk density were analyzed. The results showed that the straw returning rate was inversely proportional to the forward speed and proportional to the furrow opening rotation speed and exhibited an increasing-then-decreasing trend with increasing collecting rotation speed. Taking into account both straw returning rate and operational efficiency, the recommended optimal operating parameters for the machinery unit were a forward speed of 0.4 m s−1, a raking speed of 180 r min−1, and a ditching speed of 420 r min−1. Under the spring model of burying straw in soil, straw treated with the composting agent was more likely to be fully decomposed in a short period, with a maximum total decomposition rate of up to 97.23%. Burying straw in soil effectively reduced soil bulk density, and straw returning in spring was more conducive to improving soil physical properties than straw returning in autumn. The value of this research lies in the integration of agricultural machinery and agronomy, providing insights for the development and design of related equipment, as well as offering a new approach for the effective treatment and utilization of straw in cold regions.

Residue and soil dissipation kinetics of chloroacetanilide herbicides on rice (Oryzae sativa L.) and assessing the impact on soil microbial parameters and enzyme activity.

The present investigation determines the persistence of herbicides like butachlor and pretilachlor in Indian soil, and their impact on soil biological properties including microbial biomass carbon (MBC), total microbial population numbers, and enzyme activities. Butachlor was degraded faster in autumn rice soil (t1/2 of 10-13days) than in winter rice soil (half-life of 16-18days). The t1/2 of pretilachlor in winter rice was 12-16days. Regardless of the seasons under cultivation, no pesticide residue was detected in rice at harvest. Herbicides induced an initial decline (0-14th days after application) in MBC (averages of 332.7-478.4gg-1 dry soil in autumn rice and 299.6-444.3gg-1 dry soil in winter rice), microbial populations (averages of 6.4cfug-1 in autumn rice and 4.6cfug-1 in winter rice), and phosphatase (averages of 242.6-269.3μg p-nitrophenol g-1 dry soil h-1 in autumn rice and 188.2-212.2μg p-nitrophenol g-1 dry soil h-1 in winter rice). The application of herbicides favored dehydrogenase (averages of 123.1-156.7g TPF g-1 dry soil in autumn and 126.7-151.1g TPF g-1 dry soil in winter) and urease activities (averages of 279.0-340.4g NH4 g-1 soil 2h-1 in autumn and 226.7-296.5g NH4 g-1 soil 2h-1 in winter) in rice soil at 0-14th DAA. The study suggests that applications of butachlor and pretilachlor at the rates of 1000gha-1 and 750gha-1, respectively, to control the weeds in the transplanted rice fields do not have any negative impact on the harvested rice and associated soil environment.

The effect of tillage methods on the cellulose-decomposing activity of the soil and on crop yields in crop rotations

In the conditions of the Chuvash Republic in a long-term stationary experiment there has been studied the effect of crop rotations (grain- fallow and green manure) and methods of primary tilling of soil (by the plow PLN-3-35 to the depth of 24-26 cm; by the combined unit KOS-3.0 to 14-16 cm; by the disc header BDM-4-3.2 to 10-12 cm without autumn tilling) on the cellulose-decomposing activity of the soil by the method of setting up flax linen and on the crop yield. The article provides 2016-2020 data. It has been established that plowing increased the total soil porosity (55.3…63.5 %) and provided maximum decomposing of flax linen (42.9…51.3 %). Absence of primary soil tilling led to the statistically significant decrease in the porosity (50.8…59.3 %) and cellulose-decomposing activity (36.1…43.9 %). Maximum yield of crops in crop rotation was obtained by cultivation according to traditional plowing. When replacing plowing by subsoil tillage the use of combined stubble cultivator KOS-3.0 was the best variant. Primary tillage of soil to the depth of 14-16 cm using KOS-3.0 unit instead of plowing led to the significant yield decrease (by 0.29 t/ha) of spring vetch only. Among other cultures of crop rotation there was no significant yield decrease. Complete rejection of autumn soil tillage led to 16-25 % yield loss in grain crops. Plowing to the depth of arable layer (24-26 cm) as primary autumn tillage of soil increased the fertility indicators of dark-gray wooded soil (its total porosity, cellulose-decomposing activity) and yield of cultures in crop rotation. But when changing over to resource saving technologies for primary autumn tilling of soil under grain crops the combined unit stubble cultivator KOS-3.0 should be used.

Impact of Snowmelt Conditions on the Isotopic Composition of the Surface Waters of the Upper Ob River during the Flood Period

For many of the Siberian rivers, and the Upper Ob in particular, 70–80% of the volume of the annual water runoff is formed during the spring flood. Thus, factors influencing the formation of water runoff during the spring flood are paramount. We explain changes in the isotopic composition of the Upper Ob surface waters by changing different components’ contribution to the runoff water discharge over the spring flood period. We suggest estimating the time of meltwater flow from the Upper Ob watershed to the outlet section using the difference between the date of the complete melting of the snow cover in the catchment area and the date of the maximum light isotope composition of water in the outlet section. We show that a sharp short-term weighting of the isotopic composition of water in the river at the end of the first phase of the flood may be associated with the influx of autumn soil moisture, displaced from the soils by snowmelt waters.

Inter-seasonal connection of typical European heatwave patterns to soil moisture

Although prolonged heat periods have become a recurring feature of European climate, little knowledge is available on dominant spatial patterns of heatwaves and their influence on moisture-related processes. Increased knowledge will help to improve heatwave and drought prediction and mitigation. This study uses hierarchical agglomerative clustering to derive nine dominating spatial heatwave patterns from a 50-member regional climate model (Canadian Regional Climate Model version 5, CRCM5-LE). The heatwave patterns correspond well with clusters derived from an observational data set (E-OBS) and with extreme historical heatwave events. Moreover, we analyse the occurrence of heatwaves in the identified spatial patterns regarding a soil moisture deficit present before and after the event. We show that negative soil moisture anomalies in the preceding winter/spring (JFMA) can serve as a predictor for heatwaves in South Europe. For North Europe, we find a negative correlation between the number of heatwave days in summer and autumn (OND) soil moisture content.

Effect of the most severe summer-autumn droughts on the yield of winter wheat on different precursors in the arid conditions of the Eastern Caucasus

Relevance. To study regularities of severe droughts influence and to develop measures on decreasing their negative consequences on crop capacity are important tasks of arable farming. Methods. A long-term experiment was laid in the Prikumskaya experimental station in 1969. The research was conducted in the 6-field grain and fallow crop rotation in the years with HC 0,12–0,30 in July – October. The aim of the research was to study the effect of the most severe droughts of the summer-autumn period on the moisture supply, growth, development and yield of winter wheat on background of bare fallow and semi-fallow in the arid zone of Stavropol Territory. Results. The reserves of productive moisture in the 1 m layer of soil in autumn for sowing on background of bare fallow in 4, semi-fallow – in 5 out of 7 years were below the norm, and in 3 years on non-fallow predecessor were completely absent. This leads to a significant or complete delay of seedlings, weak plant development, thinning and formation of a reduced number of productive stems for harvesting, and this indicator of the structure largely determines the value of the crop. By spring, the moisture content on background of fallow in 3 (43%) and semi-fallow in 4 years (57%) was lower than the average annual value. Of the 7 years in 3 severe summer-autumn droughts were combined with varying degrees of aridity in the spring-summer period. Yields of winter wheat averaged 3.71 t/ha on background of bare fallow and 1.85 t/ha on semi-fallow but in some years ranged from 2.74 to 5.68 and from 1.06 to 2.79 t/ha, or by 2.1–2.6 times, respectively. The size of a yield on background of fallow is by 2 times higher, than that on non-fallow; that testifies to expediency of application of fallow and of its stabilizing role in droughty conditions.

Extraction, Antioxidant Activity and Identification of Flavonoids from Root Tubers of Kosteletzkya virginica

Kosteletzkya virginica (K. virginica) is used for revegetation of salt-affected coastal tidal flats and as a raw material of biodiesel. K. virginica root tuber, a biowaste with low economic value, is rich in bioactive compounds. This study aimed to extract and identify flavonoids from K. virginica root tubers. The optimal extraction conditions were 1/25 (w/v) solid/liquid ratio, 40% ethanol concentration at 40°C for 60 min. Under these conditions, 65.2 ± 3.7 mg/g total flavonoid content was extracted from the roots, which were collected from salinized soil in late autumn of the third year. Antioxidant activity was evaluated through 1,1-diphenyl-2-picrylhydrazyl, hydroxyl radical, and superoxide anion scavenging assays. The extracted flavonoids exhibited antioxidant activity in a dose-dependent manner. Five flavonoids, glucoliquiritin apioside, licoisoflavone B, 5-methoxy-7,8-diprenyl- flavone, 7,2′-dihydroxy-6,8-dimethyl-4′,5′-methylenedioxyflavan, and 5,7,4′-trihydroxy-3′-methoxy-6,8-di-Cmethylflavanone, were identified by ultra-performance liquid chromatography–tandem mass spectrometry. Our results suggest that the flavonoids of K. virginica root tubers might be potent antioxidants and can be effectively applied as an ingredient in food and natural medicine.

Ecological plasticity of winter wheat yield when cultivating on different predecessors in arid conditions of Eastern Caucasus

Relevance. The selection of the best winter wheat precursors that provide low yield variability in contrasting years is an important task of farming.Methods. Studies were carried out in 2017–2021 at the Prikumskaya Experimental Breeding Station in a 6-field crop rotation, where winter wheat was placed on bare and full fallow and semifallow. The aim of the research was to evaluate the precursors in different nutritional backgrounds from the position of low variability of yield, ecological stability and high adaptability to the conditions of the arid zone of the Stavropol Territory.Results. The hydro-thermal coefficient of summer-autumn period was 0,22 and of spring-summer period — 0,06 units drier than the average summer value. The pre-sowing period was especially unfavorable (HTC = 0.22). The stocks of productive moisture in a meter layer of soil in autumn were considerably below the norm on bare fallow in 40% of years of experiment and on other predecessors — in 80% of years. Yield of winter wheat varied from 2.43 to 4.46 t/ha on bare fallow on control, 2.86 to 4.93 t/ha — on fertilized variant, 1.98 to 4.72 and 2.15 to 5.35 t/ha— on ful fallow, 0.59 to 2.19 and 0.64 to 2.44 t/ha — on semifallow. And the environmental conditions index ranged from –0.51 to +1.52 and –0.64 to+1.43; from –0.90 to+1.84 and –1.10 to +2.10; from –0.72 to + 0.88 and –1.19 to +0.79 respectively. Maximum yields in all nutritional backgrounds were obtained on bare and full fallow. Only 1 year out of 5 was favorable as it had positive environmental conditions index values. The environmental plasticity ranged from 1.67 to 3.04. The highest yield variability (47.1%) and maximum stress tolerance (–1.6 –1.98 t/ha) was observed for the half fallow Semifallow. Bare fallow was the most flexible under stress conditions of cultivation as it had the highest yield (2.94–3.50 t/ha) and the lowest variability (26.4%) compared to other precursors.

ВМІСТ МІНЕРАЛЬНИХ ЕЛЕМЕНТІВ У ПЛОДАХ LYCOPERSICON ESCULENTUM MILL. ЗА ВПЛИВУ РЕКУЛЬТИВАНТУ КОМПОЗИЦІЙНОГО TREVITAN

The article presents the results of research on the effect of the Trevitan® composite recultivator on the elemental composition and ratio of macroelements in the fruits of the F1 Talent edible hybrid tomato. Field experiments with edible tomato were carried out in the conditions of the Western Forest Steppe of Ukraine on meadow-chernozem medium loam soils in 2021. The soil of the experimental field was characterized by a neutral reaction (pH=7,12), a low content of mobile compounds of macronutrients, and of trace elements (Fe, Mn, Cu, Zn). In the studies, Trevitan® composite recultivator was used – a product of organic origin for rapid soil regeneration, processing of seeds and planting material of various agricultural crops, acceleration of plant growth and development. Trevitan® is a liquid with a pH=7.5-10.9 and a mass fraction of organic matter of 50-80 % on the dry substance of the preparation. Trevitan® was applied by autumn soil treatment before plowing, seed and plant treatment during the growing season. 
 The use of Trevitan® compound recultivator in the technology of growing the Talent hybrid tomato influenced the indicators of the content of macro- and microelements, mainly by increasing their content. The content of Nitrogen, Potassium and Magnesium in the fruits of experimental plants compared to the control increased by 21,0, 31,6 and 43,3%, respectively. The amount of nitrogen in the fruits did not exceed the permissible level, which is an important characteristic of the quality of the fruits. It has been established that the use of Trevitan® composite recultivator helps to improve the mineral composition and biological value of tomato fruits, to increase the content of Manganese, Copper, Zinc and Potassium in them, while optimizing nutrition in the soil-plant system.

Prolonged Effect of Forest Soil Compaction on Methanogen and Methanotroph Seasonal Dynamics.

Methane (CH4) oxidation by methanotrophic bacteria in forest soils is the largest biological sink for this greenhouse gas on earth. However, the compaction of forest soils by logging traffic has previously been shown to reduce the potential rate of CH4 uptake. This change could be due to not only a decrease of methanotrophs but also an increase in methanogen activity. In this study, we investigated whether the decrease in CH4 uptake by forest soils, subjected to compaction by heavy machinery 7years earlier, can be explained by quantitative and qualitative changes in methanogenic and methanotrophic communities. We measured the functional gene abundance and polymorphism of CH4 microbial oxidizers (pmoA) and producers (mcrA) at different depths and during different seasons. Our results revealed that the soil compaction effect on the abundance of both genes depended on season and soil depth, contrary to the effect on gene polymorphism. Bacterial pmoA abundance was significantly lower in the compacted soil than in the controls across all seasons, except in winter in the 0-10cm depth interval and in summer in the 10-20cm depth interval. In contrast, archaeal mcrA abundance was higher in compacted than control soil in winter and autumn in the two soil depths investigated. This study shows the usefulness of using pmoA and mcrA genes simultaneously in order to better understand the spatial and temporal variations of soil CH4 fluxes and the potential effect of physical disturbances.

Frost killed cover crops induced high emissions of nitrous oxide.

Establishing a cover crop after harvest of a main crop in late summer or early autumn can have several advantages, including weed control, decreased nitrate leaching and an increased potential for carbon sequestration. However, the addition of fresh plant material to the soil in late autumn or winter, either by active termination of the cover crop or by frost damage, could be a risk factor for nitrous oxide emissions, due to the simultaneous occurrence of wet soil conditions and freeze-thaw cycles. We measured field emissions of nitrous oxide from three cover crops - oilseed radish, (Raphanus sativus var. oleiformis), phacelia (Phacelia tanacetifolia) and oats (Avena sativa) - over a 43-day period in winter. All three cover crops were sensitive to frost and died, wilted and started to decompose during this period. The cover crops increased nitrous oxide emissions, relative to controls that were ploughed in autumn, by 1.8, 0.7 and 0.6 kg N2O-N ha-1, for oilseed radish, phacelia and oats, respectively. We conclude that the choice of cover crop species and management options for cover crops need to be further researched to minimise their contribution to nitrous oxide emissions from agriculture.

ASSESSMENT OF CHANGES IN RIVER RUNOFF ZHEM AND OYIL

The article presents the results of work to determine the trend in the flow of the rivers Zhem, Oiyl and results of expeditions to the regions of the river location, conducted in 2021 to assess the ecological state of the river basins under the guidance of a working group of scientistsWater specialists of the Ministry of Ecology, Geology and Natural Resources (MEGCR). The main aim of the work is to assess the trends in the flow of the Zhem and Oiyl rivers. In order to solve these problems, the dynamics of changes in the main meteorological factors that determine the formation of river flow in the region under consideration are considered: the sum of precipitation for the winter period, autumn soil humidification, average annual air temperature and anthropogenic influence on river flow. Genetic analysis of the assessment of changes in flow since the 1950s revealed a disturbance in flow caused by economic activity with the introduction of a dam system in the river basins for estuarine irrigation. On the basis of the above-mentioned studies, the assessment of changes in the flow of the Zhem and Oiyl rivers was carried out respectively by differentiating the mean long-term values of the flow of the conditional-natural period (1935-1950) with the run-off of the period of influence of economic activity (1951-1975) and the period of influence of economic activity in conjunction with the change of climatic factors (1976-2019). It was found that during the combined period of economic activity and changes in climatic factors, compared to the conventional period, the flow of the River Zhem decreased by 49 %, the flow of the river Oiyl by 26 %.

Organic Mulching Increases Microbial Activity in Urban Forest Soil

Interactions between C accumulation, resulting from plant residue mulching, and the accelerated decomposition of litter and soil organic matter due to higher enzyme activities remain poorly understood, particularly in urban forests. Here, the activities of four enzymes associated with carbon (C) and nitrogen (N) cycling after organic mulching were investigated in the rhizosphere and bulk soil of a 15-year-old Ligustrum lucidum urban forest. The enzymatic activities in the rhizosphere were closely correlated to those in bulk soil, however, they were more strongly affected by organic mulching and exhibited faster C and nutrient cycling. Moreover, the activity of urease in the rhizosphere and peroxidase in the bulk soil in autumn, as well as invertase in the rhizosphere in spring, decreased. Microbial C and N were most responsible for the observed increase in invertase activity in spring, during which microorganisms exhibited rapid growth and the highest activities, whereas soil organic C regulated urease activity in winter. Additionally, the activity of dehydrogenase increased by up to 75%; the degree of increase was typically dependent on the mulching amount. Generally, invertase and dehydrogenase activity increased with the abundance of dissolved organic matter and microbial biomass, whereas peroxidase exhibited the opposite trend. Taken together, these findings indicate that organic mulching efficiently increases enzymatic activity, particularly within the rhizosphere, thus accelerating soil C and N cycling. Hence, mulching may represent an effective measure for urban forest management and soil conservation.

Influences of Seasonal Soil Moisture and Temperature on Vegetation Phenology in the Qilian Mountains

Vegetation phenology is a commonly used indicator of ecosystem responses to climate change and plays a vital role in ecosystem carbon and hydrological cycles. Previous studies have mostly focused on the response of vegetation phenology to temperature and precipitation. Soil moisture plays an important role in maintaining vegetation growth. However, our understanding of the influences of soil moisture dynamics on vegetation phenology is sparse. In this study, using a time series of the normalized difference vegetation index (NDVI) from the moderate resolution imaging spectroradiometer (MODIS) dataset (2001–2020), the start of the growing season (SOS), the end of the growing season (EOS), and the length of the growing season (LOS) in the Qilian Mountains (QLMs) were extracted. The spatiotemporal patterns of vegetation phenology (SOS, EOS, and LOS) were explored. The partial coefficient correlations between the SOS, EOS, and seasonal climatic factors (temperature, precipitation, and soil moisture) were analyzed. The results showed that the variation trends of vegetation phenology were not significant (p > 0.05) from 2001 to 2020, the SOS was advanced by 0.510 d/year, the EOS was delayed by 0.066 d/year, and the LOS was prolonged by 0.580 d/year. The EOS was significantly advanced and the LOS significantly shortened with increasing altitude. The seasonal temperature, precipitation, and soil moisture had spatiotemporal heterogeneous effects on the vegetation phenology. Overall, compared with temperature and soil moisture, precipitation had a weaker influence on the vegetation phenology in the QLMs. For different elevation zones, the temperature and soil moisture influenced the vegetation phenology in most areas of the QLMs, and spring temperature was the key driving factor influencing SOS; the autumn soil moisture and autumn temperature made the largest contributions to the variations in EOS at lower (<3500 m a.s.l.) and higher elevations (>3500 m a.s.l.), respectively. For different vegetation types, the spring temperature was the main factor influencing the SOS for broadleaf forests, needleleaf forests, shrublands, and meadows because of the relative lower soil moisture stress. The autumn soil moisture was the main factor influencing EOS for deserts because of the strong soil moisture stress. Our results demonstrate that the soil moisture strongly influences vegetation phenology, especially at lower elevations and water-limited areas. This study provides a scientific basis for better understanding the response of vegetation phenology to climate change in arid mountainous areas and suggests that the variation in soil moisture should be considered in future studies on the influence of climate warming and environmental effects on the phenology of water-limited areas.

Comparing the emergence of Echinochloa crus‐galli populations in different locations. Part I: Variations in emergence timing and behaviour of two populations

AbstractEchinochloa crus‐galli (L.) P. Beauv. is one of the most important weeds. It is distributed worldwide and has adapted to diverse habitats and climatic conditions. This study aimed to compare the emergence patterns of two populations of E. crus‐galli from different environments at 11 locations across Europe and the Middle East. Seeds of the two populations were collected from maize in Italy and from spring barley in Norway and were then buried in soil in autumn 2015. In the spring of 2016, the soil was disturbed around the usual seedbed preparation date in each location and emergence was recorded. The soil was again disturbed a year later and emergence was recorded for a second season. Total emergence, the times of onset, end and to 50% emergence and the period between 25% and 75% of emergence were analysed by two‐way ANOVA and principal components analysis. The Italian population showed a higher emergence than the Norwegian population in Southern locations, while the ranking was reversed in Northern locations. In almost all locations, a tendency to emerge earlier was recorded for the Norwegian population, but the periods from 25% to 75% emergence were similar for both populations. Total emergence, and the times of onset and end of emergence seemed to be mainly under genotypic (plus maternal) control, suggesting there were different temperature thresholds for seedling emergence in each population. Conversely, the duration of emergence seemed to be mainly under environmental control. This research confirms the high variability between populations and suggests the need to continue identifying key characteristics for the development of efficient models for seedling emergence in specific climates and/or latitudes.