Low Soil Research Articles

Exploring Genetic Variability in Rice for Yield Improvement under Low Phosphorus Soil Conditions

Phosphorus (P) is an essential macronutrient for all living organisms. P deficiency in soils is a major limiting factor for crop growth in rice and reduces yield. Understanding genetic variability for low P tolerance is crucial for improvement of rice genotypes for this stress. This study was conducted under low soil P and normal conditions to evaluate genetic variability in yield and its associated traits among rice genotypes. The experimental material consists of 91 F2:3 mapping population along with two checks, planted in a low P and normal plot at ICAR-IIRR, Hyderabad. Traits assessed included days to 50% flowering, plant height, total number of tillers, number of productive tillers per plant, flag leaf length, flag leaf width, panicle length, total number of grains per panicle, spikelet fertility, single plant yield, shoot length, root length, root volume, dry root weight, dry shoot weight and root to shoot ratio. ANOVA analysis suggested, mean sum of squares due to test genotypes were significant (p<0.01) for most of the traits under study. Plant height, number of tillers per plant, number of productive tillers per plant, flag leaf length, number of grains per panicle, spikelet fertility, single plant yield, shoot length, root volume, shoot dry weight, root dry weight and root to shoot ratio possessed high GCV and PCV values under low P condition. Genetic advance as per cent of mean for all traits possessed high genetic advance as per cent mean except for days to 50% flowering which showed medium GAM under low P condition. The genotypes showed varied response to genetic variability, heritability and genetic advance as per cent mean for days to 50% flowering (low), plant height (high), number of productive tillers per plant (high), panicle length (medium to high), flag leaf length (high), flag leaf width (medium to high), number of grains per panicle (high), spikelet fertility (high), single plant yield (high), root volume (high), shoot dry weight (high), root dry weight (high) and root to shoot ratio (high) under low P condition. This study identified these traits with high genetic variability and heritability, which are useful for developing P efficient rice cultivars and selection based on these traits would improve the rice for low soil P tolerance.

Survival of 13 Forage Legumes in Contrasting Environments of Central Otago, New Zealand

ABSTRACTThe lack of suitable perennial and annual forage legumes strongly constrains the productivity and sustainability of upland grasslands in New Zealand. Legumes support sustainable grassland production through nitrogen fixation and increased yields. However, traditional legume species such as white clover (Trifolium repens L.) struggle to persist within New Zealand's upland climatic and edaphic conditions characterised by acid, low fertility soils and short growing seasons. To address this challenge, we assessed the survival of 13 forage legume species over 2 years at three field sites across Central Otago, capturing the districts varied precipitation and temperature profiles. Legume survival rates, biomass and weather data were measured. Notably, lotus (Lotus pedunculatus Cav.) exhibited 100% survival over the 2 years on high altitude acidic, low fertility soils, whereas other perennial legume species showed limited persistence (0%–55% survival) and low biomass production. Crimson clover (Trifolium incarnatum L.) had the greatest Year 1 establishment and biomass of annual legumes species at low and medium rainfall sites. Moreover, strong Year 1 seed set and subsequent regeneration in Year 2 were observed for crimson clover, striated clover (Trifolium striatum L.), and subterranean clover (Trifolium subterraneum L.) (cvs. Denmark and Narrikup). These findings underscore the potential of these annual legume species in dryland environments due to their regeneration capacity before summer drought onset. Climate emerged as a pivotal determinant influencing the viability of less resilient species across all trial locations. Lotus and crimson clover are alternative legume species with the potential to enhance sustainable grassland productivity in New Zealand's upland farming systems.

Identification of Environmental Factors Influencing the Population of Endangered Epilobium hirsutum L. in Korea

Epilobium hirsutum has been identified as a Class II endangered species in Korea. Therefore, there is an urgent need to develop habitat conservation and improvement strategies for the protection of E. hirsutum. In this study, we aimed to evaluate the environmental characteristics of E. hirsutum habitats and identify key environmental factors influencing the population size. To this end, we conducted field surveys and performed a spatial data analysis to collect data on 38 environmental characteristics associated with the population size of E. hirsutum. We performed factor and path analyses to identify the environmental factors influencing the population size and the correlations between the population size and environmental factors. The common factors identified in both analyses were the average temperature in March, available P, soil pH, and soil humidity. Therefore, to manage E. hirsutum habitats or create alternative habitats, areas with a low air temperature and high soil moisture must be selected. It is necessary to remove tall plants and amend soils with alkaline fertilizers containing P. Additionally, it may be effective to implement a management strategy that induces vegetative propagation and seed germination by replacing agricultural waterways made of concrete with those made of rock and soil.

Soil Physicochemical and Metagenomic Analyses of Bacteria and Fungi: Toward Desert Truffle Cultivation in Saudi Arabia

Researchers are exploring plant-based protein sources to address both malnutrition and climate change. Desert truffles are rich in protein (i.e., 20%) and offer a cheaper and more environmentally friendly option. However, desert truffle cultivation is limited by environmental factors like rainfall and soil properties. This study was conducted to understand the soil conditions and microbiomes associated with desert truffles growing in parts of Saudi Arabia. Based on yield, the truffle fields were categorized into high-yield (50 kg/ha annually) and low-yield (2 kg/ha annually) truffle farms. Truffle yield differences were not significantly influenced by most soil physicochemical variables except for total nitrogen (negatively correlated). However, low soil nitrogen alone did not explain yield disparities, as wild truffle fields with low nitrogen also produced fewer truffles. In contrast, truffle yield showed a strong positive correlation with calcium carbonate content. We hypothesized that the unmeasured irrigation schedule was most likely behind the truffle yield differences especially during fruiting season. Furthermore, the high-yield farms had lower bacteria richness and diversity than the low-yield farms. Environmentally important bacteria genera such as Geodermatophilus and Rubrobacter were found in both farms, although more were found in the low-yield one, whereas more Streptomyces were found in the high-yield farm. In addition, fungal alpha diversity was higher in the high-yield farm with the dominance of Sordariomycetes, Dothideomycetes, Eurotiomycetes, and Glomeromycetes.

Temporal variation in soil quality and carbon sequestration potential of different cropping systems in Arid and Semi-Arid parts of South Eastern Kenya

The use of incorrect agricultural methods and utilization of land, excessive inorganic chemical applications, misguided cultivation, and nutrient mining have all contributed to a considerable deterioration in soil health globally. To meet the requirements of growing inhabitants, farmers have turned to unsustainable methods including monoculture, excessive use of pesticides and fertilizers, and increased agricultural intensification. A study to determine the seasonal variation of soil quality under different cropping systems and carbon sequestration potential was done during the years 2018 and 2019 in Kauwi and Zombe Wards of South Eastern Kenya. Five cropping systems namely, vegetable, cereal, fruit, and agroforestry were selected, whereas uncultivated land was considered as control. During the typical long (MAM) and short (OND) rainfall seasons, composite soil samples were taken from the cropping systems at random, making the treatment combinations ten. Each farming system had surface soil samples obtained from a depth of 0 to 15 centimetres. Two-way ANOVA was used to analyze the results. The results revealed that the influence of cropping systems on seasonal variation of soil quality parameters varied significantly (p<0.05). Further, the interaction between cropping systems and seasons significantly influenced soil pH and soil organic carbon. The short rain season registered lower soil pH values across all cropping systems. Soil Organic Carbon was found to be highest in vegetable-based cropping systems during short and long rain seasons. Electrical Conductivity was highest during the long rain season across all cropping systems. Soil bulk density was lowest during the short rains and under uncultivated land. NPK varied significantly across the cropping systems in the different rain seasons. Higher carbon stock was found in the Zombe ward as compared to the Kauwi ward. Carbon density values were noticed to be highest under Vegetable-based cropping systems in both study locations. This can be ascribed to the heavy application of organic and artificial fertilizers by farmers to increase yields and profits. Based on the results, Vegetable and agroforestry cropping systems were found to contain the highest amounts of soil carbon, and therefore, with the potential to sequester the highest amount of soil carbon. Both tiers of government should promote vegetable and agroforestry cropping systems to minimize the effects of climate change

Why are some invasive plant species so successful in nutrient‐impoverished habitats in south‐western Australia: A perspective based on their phosphorus‐acquisition strategies

Abstract Invasive plants are a major cause of the global biodiversity crisis; it is therefore crucial to understand mechanisms that contribute to their success. South‐western Australia is a global biodiversity hotspot with extremely low soil phosphorus (P) concentrations. In this region, a large proportion of native plant species release carboxylates that mobilise soil P. Many widespread invasive plant species in south‐western Australia are arbuscular mycorrhizal (AM). We hypothesised that some of these invasive AM plant species exhibit similar P‐acquisition strategies as native carboxylate‐releasing P‐mobilising species which allows them to thrive in P‐impoverished soils. To test this hypothesis, we collected 23 common invasive species in the field and assessed their leaf manganese concentration [Mn], relative to that of native reference species at different locations, as a proxy for carboxylate release. In addition, we cultivated seven of the invasive species in hydroponics at different P supply to measure their root carboxylate exudation. Furthermore, we measured leaf P concentration and photosynthetic P‐use efficiency (PPUE) of five invasive species in the glasshouse. In the field investigation, almost all invasive species exhibited significantly higher leaf [Mn] than the negative references, which do not release carboxylates, indicating carboxylate release of the invasive plants. Leaf [Mn] of a few invasives even exceeded that of positive references, which exhibit significant carboxylate release, indicating substantial carboxylate release of these invasives. All glasshouse‐grown invasive species with high field leaf [Mn] released root carboxylates under low P supply. Most of the tested invasive plant species also exhibited greater PPUE than native plants under low P supply. Invasive AM plant species exhibited root exudation of carboxylates as a P‐acquisition strategy, which very likely allows their successful invasion of severely P‐impoverished habitats. Read the free Plain Language Summary for this article on the Journal blog.

EVALUASI STATUS KESUBURAN TANAH PADA BEBERAPA JENIS PENGGUNAAN LAHAN DI DESA PENGERAGOAN, KECAMATAN PEKUTATAN, KABUPATEN JEMBRANA

This research was carried out in Pengeragoan Village, Pekutatan District, Jembrana Regency, from July to September 2023. The aim of this research was to determine the chemical properties of soil and determine soil fertility status classes and provide direction in land management according to the level of soil fertility status for each type. Land use in Pengeragoan Village, Pekutatan District, Jembrana Regency. The types of land use that exist include coffee plantations, cocoa plantations, coconut plantations, mixed plantations, natural forests, teak forests and rice fields. Sampling was carried out compositely on several existing land use types, namely coffee plantations (Tki), cocoa plantations (Tko), coconut plantations (Tka), mixed plantations (Tc), natural forests (Tha), teak forests (Tj), and rice field (Ts). Determination of soil fertility status is carried out by measuring soil chemical properties parameters, namely soil Cation Exchange Capacity (CEC), Base Saturation (KB), P-total, K-total and C-organic. The research results show that the soil fertility status in several types of land use falls into the criteria of high, medium and low. Natural forest and mixed garden land use types have high soil fertility status. The land use types of coffee plantations, cocoa plantations and teak forests have medium soil fertility status. The land use types of coconut plantations and rice fields have low soil fertility status. The management direction recommended from the results of evaluating soil fertility status and several supporting soil chemical properties for each type of land use is the need to add N and P nutrients to the land use types of coffee plantations, mixed plantations and natural forests. In the types of land use of cocoa plantations, coconut plantations, teak forests and rice fields, it is necessary to add nutrients N, P and organic materials in the form of plant litter and organic fertilizer.

Influence of Annual Ryegrass (Lolium multiflorum) as Cover Crop on Soil Water Dynamics in Fragipan Soils of Southern Illinois, USA

Fragipans are dense subsurface soil layers that severely restrict root penetration and water movement. The presence of shallow fragipan horizons limits row crop production. We hypothesized that the roots of cover crop might improve soil physiochemical properties and biological activity, facilitating drainage and increasing effective soil depth for greater long-term soil water storage. To evaluate annual ryegrass as one component of a cover crop (CC) mix for promoting the characteristics and distribution of soil water, on-farm studies were conducted at Marion and Springerton in southern Illinois, USA. Soil samples were collected at 15 cm increments to 60 cm (Marion) and 90 cm (Springerton) depths during the fall of 2022. Both sites had low total soil carbon and nitrogen contents and acidic soil pH (≤6.4). A soil water retention curve was fitted using the van Genuchten equation. At Springerton, the CC treatment increased saturated (thetaS) and residual (thetaR) soil water contents above those of the no cover crop (NCC) at the 60–75 cm and 75–90 cm depths. Changes in volumetric soil water content were measured using a multi-depth soil water sensor for the Springerton site during late July to early August of the soybean growing phase of 2022; NCC had higher soil water than CC within the 0–15 cm depth, but CC had higher soil water than NCC at the 30–45 cm depth. These findings indicate that cover crop mix has the potential to improve soil water movement for soils with restrictive subsoil horizon, possibly through reducing the soil hydraulic gradient between the surface and restrictive subsurface soil layers.

Experimental Study on Seasonal Ground-Coupled Heat Storage and Harvesting in Cold Regions

In recent years, global efforts toward sustainable energy have intensified, aiming to reduce carbon emissions and boost energy efficiency. Heating in winter and hot water for hygiene are essential, especially in cold climates where heating demands significantly impact household energy consumption. This study examines a city in western Inner Mongolia, characterized by a severe cold climate and unique geology. A test system with dual U-shaped buried pipes for ground source heat storage and extraction was constructed, utilizing two layout schemes. Drilling tests measured formation parameters, highlighting how pipe layout and soil characteristics influence heat storage. Short-term 5-day cycles and cross-seasonal 60-day cycles were tested. Results showed upper soil suited for frequent short-term storage, while lower soil favored long-term energy retention. Increasing buried pipes raised soil temperature and storage capacity, enhancing thermal stability in short-term cycles. However, while the long-term storage capacity improved, heat loss also rose. Effective ground source heat pump design in cold regions should consider environmental temperatures, pipe optimization, soil characteristics, and heat storage duration to achieve stable, efficient operation.

Tracing nitrogen use efficiency of diverse Canadian spring wheat cultivars.

Decades of wheat breeding have provided growers with numerous high-yielding options, but it is unknown if these yield improvements are likewise characterized with improved nitrogen use efficiency (NUE). Fertilizer nitrogen (N) is an ever-increasing expense, so improving NUE by reducing the requirement for N fertilizer without risking yield and quality is necessary. The goal of our research is to identify cultivars and associated traits that may improve NUE while maintaining productivity. We compared 25 spring wheat cultivars over a three-year period (2020, 2021, 2022) at two field sites differing in background soil N level for the ability to use fertilizer-N and allocate it to the grain. To do so, we employed the 15N stable isotope technique to trace the flow of fertilizer-N and determine the 15N recovery efficiency (15NRE). The 15NRE in the grain averaged 25.0% at the higher soil N site, and 15.5% at the lower soil N site. At the higher soil N site only, dwarfing alleles (Rht-B1b) were associated with greater 15NRE. Grain 15NRE was positively associated with yield, grain N content, and the 15N harvest index (15NHI) at the high soil N environment, but never at the low soil N environment. Our findings support the notion that the genetic development of high yielding semi-dwarf cultivars also translates into an improved ability to recover fertilizer-N-but this outcome is only expressed only under rich soil N conditions. Cultivars that simultaneously produced higher 15NRE and yields, grain N, or 15NHI differed by environment; possibly suggesting different mechanisms for improving crop NUE depending on background soil N level. Ultimately, cultivar-specific 15NRE information, including that presented here, will be useful breeders to design new crosses and approaches aimed at increasing NUE for spring wheat.

Rainfall and Soil Moisture Jointly Drive Differences in Plant Community Composition in Desert Riparian Forests of Northwest China

Extreme rainfall and soil moisture play important roles in the survival, community composition, and ecosystem function of desert plants. This study focused on arid desert riparian forests ecosystems in the Ebinur Lake Basin of Xinjiang, China. We analyzed the effects of rainfall and soil moisture on species composition, indicator species, β diversity, species turnover, and nestedness using three consecutive years of community surveys. A zero-model combined with a Bayesian framework was used to explore the response of species turnover and nestedness to soil moisture and rainfall, and variance decomposition was used to quantify the relative importance of spatial distance, rainfall, and soil factors in determining species composition. The results indicated the following: (1) when rainfall was high, the richness and abundance of annual herbaceous plants increased. The proportion of the community based on richness (32%) and abundance (58.1%) of annual herbaceous plants in 2016 was higher than that in 2015 and 2017. The Jaccard, Bray–Curtis, and Chao indexes of the community in years with higher rainfall were significantly higher than in years with lower rainfall; however, a lag effect was also observed. (2) Soil factors explained 5% of the changes in community composition, rainfall explained 12% of the changes in community composition, and spatial distance, soil factors, and rainfall jointly explained 32% of the changes in community composition. (3) We also showed that high soil moisture leads to greater β diversity than low soil moisture. Rainfall had the greatest explanatory power on the measured values of β diversity (19.6%) and species turnover (38%), and the factor with the greatest explanatory power for species nestedness was the interaction between rainfall and soil moisture (26.2%). Our findings indicate that drought and rainfall drive differences in plant community composition, with rainfall playing a dominant role. These results provide a basis for understanding the impact of extreme rainfall events on arid ecosystem functions.

Soil Organic Matter Influences Citrus Growth, Nutrient Uptake, and Root System Architecture

Florida citrus production faces multiple challenges, including low nutrient retention, low soil organic matter (SOM) and, more importantly, the devastating impacts of citrus greening, which is a bacterial disease that impacts root growth and nutrient uptake. Growers are exploring management practices to improve SOM and hoping to enhance tree health, nutrient uptake, and yield. Despite these efforts, research of the effects of SOM on citrus root systems and nutrient absorption remains limited, particularly that defining a target SOM range for optimal production. This study investigated the influence of varying SOM levels on citrus tree root system architecture, biomass, and nutrient uptake. This experiment was conducted in a greenhouse where 1-year-old ‘US-942’ rootstocks were assigned to a completely randomized experimental design and exposed to one of six experimental treatments with differing levels of SOM as the growing media [0% (control), 1%, 2%, 3%, 5%, or >10% (100% compost)]. Each pot was considered an experimental unit and replicated six times (n = 6), for a total of 36 seedlings. The results indicated that although root biomass did not change significantly, lower SOM levels resulted in longer roots with greater surface area and volume, likely because of increased soil exploration for nitrogen. Higher SOM treatments, however, showed improved leaf nutrient content, with increased nitrogen, phosphorus, and potassium uptake. In conclusion, the results of this study indicate that 3% SOM may be ideal for citrus because it positively impacted both root system architecture and nutrient uptake, which are both of primary concern because of citrus greening. Further research is necessary to establish critical SOM thresholds and evaluate the effects under field conditions and in combination with different irrigation and fertilizer regimes.

Carbon dioxide fluxes and the dominant role of vegetation in recently created and reference Gulf Coast marshes

AbstractCoastal wetlands are one of the most productive ecosystems on Earth with the capacity to sequester large amounts of carbon dioxide (CO2). Wetland loss due to anthropogenic and natural causes reduces the carbon (C) storage capacity and potentially releases previously fixed C in biomass and soil to the water column and atmosphere through decomposition. Coastal wetland restoration has the potential to mitigate some of the C losses depending on the balance of C fluxes. However, the role of vegetation and environmental conditions in governing rates of C accumulation in restoration sites is not well resolved. The purpose of this study was to examine seasonal C fluxes, specifically, gross ecosystem productivity (GEP), ecosystem respiration (ER), and net ecosystem exchange (NEE) of CO2 in unvegetated and vegetated (Spartina alterniflora) areas of a 2‐year old created marsh, and S. alterniflora and Spartina patens communities in a “natural” reference brackish marsh. S. alterniflora‐dominated areas were sinks for CO2 in both the newly created and reference marsh with an average CO2 uptake rate of 7.0 ± 1.0 μmol m−2 s−1. The unvegetated areas in the newly created marsh and S. patens areas in the reference marsh had approximately net neutral CO2 fluxes. S. alterniflora areas of the created marsh had similar carbon fluxes to that in the reference marsh, despite a much lower soil organic matter content. Because vegetation develops much faster than soil properties, restored marshes can be a C sink equivalent to natural marshes as soon as the marsh is vegetated. Ecosystem productivity and C assimilation in S. alterniflora areas of the reference marsh were enhanced by lower elevations (up to 6 cm) and higher soil bulk density (up to 0.28 g cm−3). At similar elevations, S. alterniflora in both the created and reference marshes was a greater C sink than S. patens areas of the reference marsh. Our findings illustrate that establishment of vegetation is critical to promoting C sink functions in created marshes and, notably, species do matter.

Urban Morphology and Surface Urban Heat Island Relationship During Heat Waves: A Study of Milan and Lecce (Italy)

The urban heat island (UHI) effect, marked by higher temperatures in urban areas compared to rural ones, is a key indicator of human-driven environmental changes. This study aims to identify the key morphological parameters that primarily contribute to the development of surface urban heat island intensity (SUHII) and investigates the relationship between SUHII and urban morphology using land surface temperature (LST) data from the Sentinel-3 satellite. The research focuses on Milan and Lecce, analyzing how urban geometry affects SUHII. Factors such as building height, aspect ratio, sky visibility, and surface cover are examined using approximately 1000 satellite images from 2022 and 2023. The study highlights seasonal and diurnal variations in SUHII, with particular emphasis on HW periods. Through multicollinearity and multiple regression analyses, the study identifies the main morphological drivers influencing SUHII in the two cities, specifically the Impervious Surface Fraction (ISF) and Mean Building Height (HM). Milan consistently exhibits higher SUHII, particularly during HWs, while Lecce experiences a negative SUHII, especially during the summer, due to lower urban density, more vegetation, and the low soil moisture around the urban area. Both cities show positive SUHII values at night, which are slightly elevated during HWs. The heat wave analysis reveals the areas most susceptible to overheating, typically characterized by high urban density, with ISF and HM values in some cases above the 90th percentile (0.8 and 13.0 m, respectively) compared to the overall distribution, particularly for Milan. The research emphasizes the importance of urban morphology in influencing SUHII, suggesting that detailed morphological analysis is crucial for developing climate adaptation and urban planning strategies to reduce urban overheating and improve urban resilience to climate change.

Extreme summer drought increased soil detachment capacity of biocrusts in subtropical China

Biological soil crusts (Biocrusts) are considered to have significant effects on soil detachment processes. Increasing extreme droughts are expected to affect the structure and functioning of biocrust ecosystems. However, understanding how biocrust ecosystems will respond to drought requires further investigation in the subtropical region. This study conducted continuously monitoring of understory biocrusts in subtropical China from May to November 2022, analyzed the monthly variation of near-surface characteristics of biocrusts and performed scouring experiments with six flow shear stresses (7.61–21.08 Pa) to assess the monthly variation of soil detachment capacity (Dc) of biocrusts. Finally, we elucidated the complex effects of summer drought (August-September) on Dc of biocrusts. Results showed that summer drought led to significant reductions in biocrust coverage (BC) and biocrust thickness (BT) (P<0.05), as well as notable declines in soil stability (including soil cohesion and Mean weight diameter) and soil nutrient content (including soil organic matter, total Nitrogen, total Phosphorus) (P<0.05), except for a non-significant increase in bulk density (P>0.05). Furthermore, Dc of biocrusts significantly increased by 172.2 % during the summer drought compared to the previous months (P<0.05). These changes of biocrusts are mainly affected by moisture stress more than heat stress. Partial least squares path modeling (PLS-PM) revealed that reduced rain and lower soil moisture increased Dc mainly by diminishing the BC and BT, followed by reducing soil cohesion and soil aggregate stability. The results provide empirical evidence for the cumulatively detrimental effects of future climate on biocrusts and contribute to more comprehensive understanding of biocrusts multifunctionality.

Spatial relationship of weeds with soil properties in wheat field using geostatistical methods

A field experiment was conducted during the agricultural years 2019 and 2020, using a network system with a distance of 2 × 2 m. At each network node, soil, wheat grain yield, seed bank, black grass and wild barley weed density, and biomass were measured. Soil components with high consumption had 0%–55.9% spatial correlation. The association between soil pH and EC was 50.0%–75.2%. The soil texture correlation was 0%–66.5%. The prevalence of black grass and wild barley weeds showed a patchy or clustered dispersion pattern. The kriging interpolated maps also showed a substantial relationship between the first-year seed bank and weed seedling distribution patterns and the second-year weed distribution patterns. Black grass and wild barley weeds were more prevalent in fields with low potassium and soil pH, indicating a spatial connection with soil nitrogen. Wheat grain yield in the field was fragmented, with a 50.2% spatial correlation. In the initial and subsequent years, black grass weed density correlated with grain yield inverse by 81.8% and 78.5%, respectively. Wild barley weed density and grain yield inverse had 53.2% and 63.9% geographical correlations, respectively. The first year's spatial correlation between grain yield and soil nitrogen was 81.6% and the second 80.6%. The association between grain yield and soil phosphorus was 79.4% in the first year and 85.8% in the second. This study suggests that knowing the spatial distribution of soil nutrients and weeds in a field can help determine the best wheat crop management strategy.

Soil Heating Significantly Increases Leaf Magnesium Concentration and Fruit Yield in Tomatoes Produced in a Plastic Greenhouse During Winter

Magnesium (Mg) deficiency frequently occurs in tomato leaves grown in plastic greenhouses during winter in northern China. In this study, field experiments were conducted to test the effects of soil temperature and the potassium (K) fertilizer application rate on tomato K and Mg absorption and fruit yield. The treatments were soil non-heating (control) and soil heating with electric hotlines, with three K2O application rates (180 kg ha−1, 580 kg ha−1, and 980 kg ha−1). The soil heating treatments increased the average soil temperature by 2.1 °C during the day, significantly increasing leaf Mg and chlorophyll concentrations by 21.3% (from 6.86 to 8.32 g·kg−1) and 12% (from 1.25 to 1.40 mg·g−1), respectively, and fruit yield by 5.5% (from 150 to 158.2 t·ha−1) and significantly decreasing the leaf K concentration by 10.5% (from 29.4 to 26.3 g·kg−1). However, the K fertilizer application rate had no significant effect on fruit yield and leaf K and chlorophyll concentrations. Moreover, the soil non-heating treatments showed a significant negative correlation between leaf K and Mg concentrations. Low soil temperature exacerbates K–Mg ion antagonism, which is the main driving factor for Mg deficiency in winter greenhouse tomatoes. Soil heating can significantly promote Mg absorption and improve fruit yield in tomatoes produced in plastic greenhouses during winter. The results of this study provide theoretical and technical support for regulating Mg nutrition in tomatoes grown in plastic greenhouses in northern China.

Ecosystem Services’ Response to Land Use Intensity: A Case Study of the Hilly and Gully Region in China’s Loess Plateau

The hilly and gully region of the Loess Plateau represents one of China’s most ecologically vulnerable landscapes, characterized by severe soil erosion, intensive land use, and pronounced disturbances to the structure and functionality of ecosystem services. Taking Zichang City as a case study, this research integrates grid-scale analysis with the InVEST-PLUS model and bivariate spatial autocorrelation techniques to examine the spatiotemporal dynamics and inter-relations of four critical ecosystem services—carbon storage, water yield, biodiversity, and soil retention—under varying land use intensity scenarios from 1990 to 2035. The findings indicate that (1) between 1990 and 2020, land use intensity in Zichang City steadily declined, exhibiting a spatial distribution pattern typified by central-area clustering and gradual peripheral transitions. (2) Across three development scenarios, the spatial distribution of the four ecosystem services aligned with the patterns observed in 2020, with central areas showing pronounced fluctuations, whereas peripheral regions experienced relatively minor changes. Specifically, from 1990 to 2020, the proportion of low-carbon storage areas increased by 2.89%, and high water yield areas expanded by 9.45%, while the shares of low habitat quality and low soil retention areas decreased by 5.59% and 6.25%, respectively. (3) A significant spatial autocorrelation was observed between land use intensity and the four ecosystem services, with widespread cold and hot spots reflecting dynamic spatial clustering patterns. These results offer valuable insights for optimizing land use strategies, improving ecosystem service performance, and advancing ecological conservation and sustainable development initiatives.

Effects of PBAT/PLA biodegradable film mulching on greenhouse gas emissions in rain-fed maize farmland of Northeast China

Plastic film mulching can effectively increase soil temperature, retain moisture, and enhance crop yield and quality. However, long-term application might pose risks of increased greenhouse gas (GHG) emissions and residual film pollution. Biodegradable film provides a crucial solution to alleviate farmland plastic pollution, but it remains unclear whether biodegradable film can simultaneously enhance crop yields and reduce GHG emissions. Thus, a two-year field experiment was conducted in rain-fed maize farmland of Northeast China. This field experiment included four treatments: BM1 (0.006 mm-thick biodegradable film), BM2 (0.010 mm-thick biodegradable film), PM (0.010 mm-thick traditional plastic film), and CK (non-mulching control). Results indicated that film mulching increased cumulative CO2 emissions by improving soil temperature and moisture. BM1 and BM2 achieved lower cumulative CO2 emissions than PM. N2O emissions were mainly concentrated in the emergence and jointing stages, whose peaks and cumulative values were reduced by film mulching. BM1 and BM2, however, had higher cumulative N2O emissions than PM. All treatments were CH4 sinks, and mulching treatments showed low soil CH4 absorption compared to CK. Additionally, mulching treatments increased maize yield, GWP and GHGI by 4.19 % to 15.89 %, 8.52 % to 52.20 % and − 0.06 % to 45.93 %, respectively, compared to CK. PM showed the highest GWP and GHGI. All mulching treatments improved the net ecosystem economic budget, with increases of 3.03–3.08 thousand CNY ha−1 and 0.35–1.39 thousand CNY ha−1 in 2022 and 2023, respectively, compared to CK. Biodegradable film treatments had higher net ecosystem economic budgets than traditional plastic film treatment. Overall, the biodegradable film can be used to replace traditional plastic film to enhance maize yield while minimizing residual film pollution and GHG emissions in the experimental region.

Effects of different tillage methods on soil properties and maize seedling growth in alternating wide and narrow rows rotation mode in the Songliao Plain of China

The Songliao Plain is the main maize (Zea mays L.) producing region in Northeast China. The no-tillage22NT: no-tillage. (NT) method in alternating wide and narrow rows rotation mode is widely used for maize planting in this region. However, in spring, the NT method in this mode suffer from low soil temperature and high soil water content33SWC: soil water content. (SWC), which severely restrict maize seed germination and seedling growth. We pioneered the research and practice of the ridge tillage44RT: ridge tillage. (RT) method and strip tillage55ST: strip tillage. (ST) method in this mode. We developed a new tillage machine to enable the implementation of RT and ST methods in alternating wide and narrow rows rotation mode, which has not been previously reported in this region. In this mode, the relative research of the RT method and ST method has not been conducted, and the effects of the RT method and ST method on the soil properties and maize seedling growth have not been clarified. Therefore, a 3-year field experiment was conducted at 7 randomly selected experimental sites in this region to research the effects of RT, ST, and NT methods on soil properties and maize seedling growth. During the spring sowing period, for soil pH, organic matter66OM: organic matter. (OM), available nitrogen, available phosphorus, and available potassium, both the RT method and ST method resulted in greater values than the NT method, and there was no significant difference between the RT method and ST method. This indicated that prolonged NT was not conducive to even distribution of OM, resulting in slightly lower available nitrogen, phosphorus, and potassium compared to the RT and ST methods. Within 30 days after spring sowing, for soil temperature, RT method value > ST method value > NT method value; for SWC, NT method value > RT method value > ST method value. For mean seedling emergence time77MET: mean seedling emergence time. (MET), RT method value < ST method value < NT method value; for seedling emergence rate88ER: seedling emergence rate. (ER), plant height, stem thickness, and plant dry weight, RT method value > ST method value > NT method value. Higher soil temperature, more suitable SWC, and better nutrient availability were beneficial in shortening MET, promoting dry matter accumulation, which ultimately increased plant height, stem thickness, and plant dry weight of maize seedlings. In RT, ST, and NT methods, soil temperature and plant dry weight were positively and linearly correlated in the 10–22 °C soil temperature interval. In the RT method and ST method, SWC and plant dry weight were positively and linearly correlated in the 15–24 % SWC interval. In the NT method, SWC and plant dry weight were negatively and linearly correlated in the 27–35 % SWC interval. Moreover, maize yield responses were positive for the RT method and ST method compared with the NT method. The RT method and ST method well solved the problems of low soil temperature and high SWC that existed in NT fields, which affected the early growth of maize seedlings, and ensured the stability and improvement of maize yields. The results suggest that both the RT method and ST method may provide significant improvements over the existing NT method.