Journal of Sustainable Agriculture and Environment最新文献

Organic fertilisers enhance crop drought resilience by improving nitrogen (N) and phosphorus (P) use efficiency and soil-plant water relations. However, the underlying mechanisms governing their effects across different drought timings in wheat under sandy soils remain unclear. This 120-day controlled-environment experiment assessed how compost, sheep manure, and their combinations applied at 25 g kg⁻¹ ameliorate wheat yield under drought (35%WHC; −10 kPa) imposed at two timings: early- (tillering, 20 DAS) and late-stage drought (heading, 60 DAS) in a sandy soil. The manure alone and combined amendments (CM₅₀SM₅₀ ≈ CM₂₅SM_75, ≈CM₇₅SM₂₅ > SM₁₀₀) retained more soil moisture compared to the compost alone treatment. Compared with the control, compost and the half-half-blend with manure increased grain yield by up to 2.3-fold under early drought and only 1.4-fold under late drought. The compost-rich treatments increased root N uptake by 2.6–3.5 fold and sustained grain-based N utilisation efficiency during early drought. Manure-rich treatments showed higher P uptake, but P utilisation efficiency remained lower compared with the compost-rich treatments across drought timings. During early drought, half-half-blend increased soil organic carbon by 90%, and plant available water by 21% over the unamended control. Compost-rich treatments improved microbial N mineralisation under early drought by increasing microbial biomass nitrogen by 8.1-fold and nitrate-N by 2.4-fold. The Partial Least Squares Path Modelling analysis confirmed the relationship between field capacity, microbial activity, nutrient availability, and grain yield. Oveall, manure-rich treatments enhanced moisture retention, while compost-rich treatments balanced nutrient acquisition and utilisation by rapid P supply from manure with sustained N mineralisation from compost, enhancing wheat resilience more under early than late drought. Therefore, we recommend compost and manure combination as a potential approach to increase dryland wheat yield during early-stage droughts in sandy soils.

Silique number is an important yield trait in rapeseed. Identifying the genetic loci and analyzing the molecular mechanism of this trait are of great significance for increasing rapeseed yield. In this study, we conducted a quantitative trait loci (QTL) analysis for silique number using a recombinant inbred line (RIL) population, and detected seven QTLs for silique number across two environments, explaining 5.97%–9.05% of the phenotypic variation. The transcriptome sequencing analysis of extreme lines with more silique and less silique showed sulfur and glycosyl compounds metabolism is crucial for flower bud differentiation in shoot apical meristem (SAM) of rapeseed. By integrating the QTL mapping results with transcriptome data, we identified four candidate genes involved in regulating silique number, including BnaA06g27290D, BnaA06g27360D, BnaC06g10070D and BnaC06g10100D. The findings not only enhance the understanding of the genetic and molecular basis of silique formation but also provide valuable genetic loci and gene resources for molecular breeding aimed at yield improvement in rapeseed.

Assessing the impact of climate change is crucial for addressing the challenges of sustaining and increasing rice production. This study employed the APSIM model driven by climate data from 27 global climate models under SSP245 and SSP585 emission scenarios to evaluate climate change effects on irrigated and rainfed rice in three key rice-growing regions (Rangpur, Bogura, and Rajshahi) in northwest Bangladesh. Relative changes in climate variables, rice yield, and yield components were analysed for the near future (NF: 2031–2065) and far future (FF: 2066–2100), compared to a baseline period (1988–2022). Results indicate a substantial increase in temperature during FF under the SSP585 scenario, with maximum temperature rising by up to 3.3°C (3.1°C) and minimum temperature up to 3.7°C (3.3°C) during irrigated (rainfed) rice seasons. This increase could shorten the growth period of irrigated and rainfed rice by up to 18 days and 10 days, respectively, under SSP585. Rice yields were projected to increase in the NF by up to 14.7% (irrigated) and 6.5% (rainfed) under SSP245. However, yields were expected to decline in the FF by 21% (irrigated) and 11% (rainfed) under SSP585 scenario. These projected yield changes are primarily explained by variations in spikelet number (NSP) and spikelet fertility (SPFERT) across locations. While projected climate conditions enhance NSP by 22% (irrigated) and 11% (rainfed) due to increased CO₂ concentration and solar radiation, SPFERT was projected to decline sharply, by up to 47% and 35% in irrigated and rainfed rice seasons, respectively, in the FF under SSP585. The change in SPFERT was largely attributed to the change in elevated maximum temperatures during the anthesis period across the locations. While yields may increase in NF, an adaptation strategy is needed to sustain rice production during far future in Bangladesh.

Plant microorganisms are an essential component of the host and perform critical functions in plant development and health. Emerging evidence shows that plants use their root exudates to recruit beneficial microbes that protect them against abiotic and biotic stresses, including diseases. However, the metabolic responses of plant under pathogen infection remain underexplored. In this study, using a manipulative experiment, we employed amplicon sequencing and untargeted metabolomics to investigate the response of rhizosphere microbial communities and metabolites of root exudates to potato-wilt disease caused by Ralstonia solanacearum (RS) across two developmental stages (vegetative and tuber bulking). Our results revealed that β-diversity showed distinct shifts in bacterial and fungal communities between healthy and diseased plants. Higher relative abundance of bacterial taxa from genera, Bradyrhizobium, Cadidatus, Paenibacillus and the fungal genus Terramyces were observed in the rhizosphere of healthy plants. Similarly, Burkholderia spp and the fungal Apiotrichum spp dominated the rhizosphere of diseased plants across the developmental stages. Further compared to healthy plants, microbial functional potentials and metabolomic profiles of root exudates linked to pathogen resistance were significantly enhanced in diseased plants. Particularly, metabolites from alkaloids, triterpenoids and polyketides were enriched in disease plants and exhibited associations with microbial groups known to influence host immunity, nutrient acquisition and stress adaptation. We observed that variations in disease index were associated with the identified enriched metabolites. Our integrative analysis provides evidence for multifaceted signalling, sensing between plants, pathogens and beneficial microbiota that may shape plant health status and microbiome assembly under pathogen pressure. These insights not only advance our understanding of crop pathophysiology but also lay the foundation for developing targeted biological strategies or metabolic markers for early disease detection and sustainable crop protection.

The increasing frequency and unpredictability of adverse growing conditions pose significant challenges to crop productivity and ecosystem sustainability. Early-stage vigour strongly influences crop establishment and yield potential, making it essential to understand sorghum responses for developing resilient cultivars. This study examined physiological, morphological and biomass responses of 12 grain sorghum hybrids/inbreds to high temperature (HT), low temperature (LT), drought (DS), salinity (SS), low nitrogen (LN) and elevated CO₂ (eCO₂) comapred to control (CNT). Stomatal and non-stomatal traits were assessed to determine their contribution to early growth performance. LT emerged as the most detrimental stress, causing the largest reductions in above-ground biomass (76%) and canopy temperature regulation, while HT, SS, DS and LN also negatively affected shoot growth to varying degrees (> 20%). DS increased root biomass, whereas LT suppressed both shoot and root biomass. In contrast, eCO₂ had a minimal impact, with traits remaining largely comparable to those in CNT. Genotypes responses varied with stress: inbred SC35 maintained tolerance across multiple stresses, while RTx430 and LGS06B19 were highly susceptible. These results demonstrate that abiotic stresses significantly constrain early sorghum growth and development, with LT (chilling) being the most limiting factor. Identifying and using genotypes with broad early-stage stress tolerance, such as SC35, will accelerate development of stress-resilient cultivars under increasingly unpredictable growing conditions. Future work on combined stress effects is essential for developing multi-stress resilient sorghum.

Mangroves in arid environments represent unique ecological niches that support a diverse range of microorganisms. Endophytic bacteria residing within host plants play a crucial role in promoting plant growth by enhancing pathogen resistance and alleviating environmental stress. Identifying novel stress-tolerant strains, specific to arid environments, is essential for expanding the repertoire of plant growth-promoting bacteria (PGPB). In this study, we investigated the saline tolerance of the endophytic bacterium strain E1, previously isolated from the root of Avicenna marina (grey mangrove). Whole-genome sequence (WGS), phylogenetics and average nucleotide identity (ANI) analysis were performed. The strain exhibited high salinity tolerance, growing in conditions up to 11% NaCl, and was phylogenetically closely related to Bacillus cereus. Genome analysis revealed multiple PGP-related genes, including those involved in nitrogen fixation, phosphate and potassium solubilization, and iron siderophore transport. Additionally, genes associated with detoxification, hormone biosynthesis (Including Indole-3-Acetic acid and cytokinin), salt and heat stress tolerance, as well as volatile compound production, were identified. A greenhouse assay with tomato plants was conducted to assess the ability of strain E1 to alleviate saline stress (50, 100, and 150 mM NaCl) and its impact on spectral indices, antioxidant enzymes, and electrolyte leakage (EL). Inoculation with strain E1 significantly enhanced all measured growth parameters, including shoot and root length and weight (both fresh and dry) as well as leaf area. These improvements were reflected in elevated spectral indices, increased antioxidant enzymes, improved cell stability, and reduced EL compared to control and NaCl-treated plants. These findings highlight Bacillus cereus strain E1 as a promising, stress-tolerant endophyte for arid agriculture, capable of promoting tomato growth through multiple mechanisms under challenging environmental conditions.

This study evaluated the effects of alternative phosphorus (P) sources and soil pH amendments on P fractions and soil chemical properties in two contrasting Brazilian tropical soils. A greenhouse experiment was conducted using a sandy Arenosol and a clayey Ferralsol treated with triple superphosphate (TSP), reactive phosphate (RP), or magnesium thermophosphate (MT), in combination with limestone or wollastonite. The limestone + magnesium thermophosphate treatment improved Ca, Mg and S, availability by up to 28%, 52%, 40%, respectively, in the clayey soil, and available Si (17%) and Mg (65%) were improved in sandy soil, when compared to the conventional treatment (L + TSP). In the sandy soil, labile P fractions increased by 13.7% under TSP + wollastonite and by 24.4% under L + MT, while W + RP increased Ca-bound P by 64.4%. Moderately labile NaOH-extractable P rose by 13%–28% under TSP and MT treatments. Organic P fractions (oP_NaOH0.1) increased by up to 71% with limestone + TSP in the sandy soil. The highest biomass production (48.09 g plant⁻¹) and P accumulation (70.48 mg kg⁻¹) were observed under L + TSP in the clayey soil, whereas sandy soil productivity declined by up to 24.3% under the same treatment due to acidification. Occluded P was 36% higher in the clayey soil. Strong positive correlations were found between labile and moderately labile P, soil pH, CEC and biomass. The integration of silicate-based amendments and alternative P sources showed similar performance to conventional management, indicating that new strategies combining alternative sources may improve soil fertility and sustainability in agricultural production.

Brazil has seen a steady increase in domestic chickpea production, and the crop is expected to gain growing importance across the country. However, solutions for effective pest and disease management remain limited. Many soil-borne phytopathogens that affect other crops can also infect chickpeas, increasing disease incidence due to higher initial inoculum levels. This study aimed to evaluate the effects of concentrated metabolites produced by Rhizobium tropici (CM-RT) on resistance induction and control of Sclerotinia sclerotiorum in chickpeas. Different CM-RT application methods were tested and disease incidence was assessed. Additionally, the relative expression of several defence-related genes was analyzed in CM-RT treated plants. Our results show that root application of CM-RT significantly reduced disease incidence and was statistically equivalent to the commercial elicitor based on acibenzolar-S-methyl. Gene expression analysis revealed the upregulation of key defence genes involved in jasmonic acid, ethylene, and oxidative stress pathways, suggesting a priming effect. These findings suggest that CM-RT can serve as an effective and eco-friendly alternative for disease control by resistance induction in chickpeas.

Arbuscular mycorrhizal fungi (AMF) symbiotically with the roots of most plants play a prominent role in increasing plant growth and yield. However, the mechanistic understanding of how AMF and the phytohormone abscisic acid (ABA) jointly regulate potassium (K⁺) uptake and the expression of K⁺ transporter (KUP) genes in common bean under drought stress remains unclear. In the current study, the effect of symbiotic of Phaseolus vulgaris with Funneliformis mosseae and Rhizophagus irregularis under drought stress and ABA application on the concentration of potassium, phosphorus, and photosynthetic pigment content, soluble sugar content, and KUP transporters expression was investigated. The results revealed that potassium and phosphorus concentrations in root and shoot tissues increased under symbiotic conditions with AMFs. Under normal plant water conditions, symbiotic interaction with F. mosseae increased the potassium content in the shoot by 1.55-fold, and symbiotic interaction with R. irregularis increased the potassium content by 1.64-fold. Also, under drought stress, symbiotic interaction with AMFs was able to increase potassium and phosphorus uptake compared to non-symbiosis. Besides, the photosynthetic pigment content increased in response to symbiotic interaction with AMFs. ABA did not show significant effects on potassium and phosphorus absorption. The expression pattern of PvKUPs revealed that most of these genes are induced in response to symbiosis with AMFs and drought stress. PvKUP3 and PvKUP5 genes were induced more under symbiosis with R. irregularis, and PvKUP11 and PvKUP18 more under symbiosis with F. mosseae. The results of this study provided a preliminary insight into the simultaneous interaction of symbiosis with AMFs and drought stress and the application of ABA on potassium uptake and transport, which will be useful in future studies related to plant-microbe interactions.