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Phosphorus (P) fertilizer is a significant cost in crop production. Understanding the mechanisms behind P fertilizer–soil–crop interactions can enhance phosphorus use efficiency (PUE) and increasing yield. We conducted a rice cultivation bucket experiment in red soil (pH = 5.9) and lime concretion black soil (pH = 7.8) and applied single superphosphate (SSP), calcium magnesium phosphate (CMP), diammonium phosphate (DAP), triple superphosphate (TSP), ammonium polyphosphate (APP), and a control group (CK, no P fertilizer). We analyzed rice P uptake and utilization patterns, evaluated the impact of varying P fertilizer formulations on rice root morphology, yield, and PUE, and investigated changes in soil P pools. In red soil, the APP treatment produced the greatest total root length, rice yield, PUE and increased soil Olsen-P, NaHCO3-Pi at anthesis. In lime concretion black soil, the TSP and APP treatments had the highest rice yields and increased Olsen-P, H2O-P, NaHCO3-Pi at anthesis. Moreover, the TSP treatment had the greatest total root length and root surface area at anthesis and the APP treatment had the largest PUE. Random forest regression analysis revealed that residual-P and Olsen-P significantly impacted rice yield in red soil and lime concretion black soil, respectively. We recommend using APP in red soil and TSP and APP in lime concretion black soil for rice cultivation to optimize soil P pool characteristics and root morphology for nutrient uptake, ultimately leading to the highest yields and PUE.

Identifying molecular markers linked to tobacco bacterial wilt resistance is crucial for developing resistant tobacco varieties, thereby enhancing tobacco production and quality. In this two-year study, we evaluated the tobacco bacterial wilt disease index (TBWDI) in a mapping population of 78 tobacco accessions using SSR/InDel markers across 1377 marker loci. Two association models, GLM_Q and MLM_Q + Kinship, were used for association analysis. By considering multiple environments, selection thresholds, and phenotype values, we identified 19 reliable marker loci (P = 7.07-E05–4.98-E02) that explained 5.37–19.10 % of the phenotypic variation. Among these, we selected 11 accessions with high resistance to tobacco bacterial wilt, each containing at least one excellent locus. The models predicted five hybrid combinations whose offspring aggregated additional excellent loci. Additionally, one locus was identified during quantitative trait loci mapping, with accessions carrying this locus exhibiting significantly different TBWDI values from those without it, confirming its reliability and stability. A candidate gene (LOC107795335) was also identified downstream at 17.58 Kbp of the locus. Our study pinpointed reliable loci associated with bacterial wilt resistance, identified important materials for breeding resistant tobacco varieities, and predicted the best hybrid combinations for low disease indexes. The results of our study offer invaluable theoretical insights for breeding varieties with high and stable resistance.

Oilseed rape (Brassica napus L.), also known as canola, is particularly sensitive to high temperatures during flowering. However, the impacts of heat stress during male and female gametophyte development, several days before anthesis and fertilisation, remain unclear. In this study we selected two cultivars, AV-Ruby and YM11, which exhibited different responses to heat stress in a previous study. Precise transient heat stress (maximum 32 ℃ day /22 ℃ night) or control (maximum 25 ℃ day /15 ℃ night) treatments were applied to evaluate the impact of heat stress during male and female gametophyte development on subsequent floret fecundity after pollination. We measured floret fecundity by pod set, number of seeds per pod and average seed size. Heat stress during male gametophyte development reduced pollen viability and germination rate, and resulted in fewer pods and seeds per pod on the main stem. However, despite these negative impacts, pollen tubes successfully traversed the style and were visible at a high percentage of ovules in both heat stress and control treatments. When heat stress was applied to the female gametophyte in the first five buds on the main stem, subsequent floret fecundity was reduced in the lower main stem, while florets in the upper main stem exhibited higher fecundity than in the control treatment. Heat stress during sporogenesis and/or gametogenesis in male and female organs across two cultivars had a lasting negative impact on subsequent floret fecundity, observed as a reduction in the number of pods and seeds per pod, but had no impact on average seed size.

Groundwater irrigation (GWI) decreases soil temperature and increases crop growth duration and water consumption. Optimizing sowing dates offers a cost-effective solution to mitigate these effects. This study evaluated five sowing date treatments for spring maize: GWI on April 20 (GW420), April 25 (GW425), April 30 (GW430), May 5 (GW505), and May 10 (GW510), with surface water irrigation (SWI) on April 20 (SW420) as the control. The evaluated parameters included soil temperature at 5 cm depth (T5), soil-temperature-calculated growing degree days (GDDs), actual crop evapotranspiration (ETc-act), leaf area index (LAI), grain filling, grain yield, and crop water productivity (WPc). GW420 decreased daily maximum T5 by 1.8°C (P

Uneven precipitation during the growing season and frequent seasonal droughts on the Loess Plateau in Northwest China adversely affect crop production and water use efficiency. While plastic mulching (PM) has been used to alleviate water stress, few studies have examined the traits maize cultivars need to adapt to the altered water environment under PM and achieve high yields. A two-year field experiment was conducted to assess the root characteristics and aboveground growth traits of three widely used high-yielding maize cultivars—Zhengdan 958 (ZD), Huanong 138 (HN), Heboshi 122 (HBS)—under no mulching (NM) and PM conditions. Among the three cultivars, HBS had the highest root system indices—root length density (RLD), root surface area density (RSD), and root biomass—in the topsoil (0–40 cm), followed by ZD and HN under both NM and PM conditions. Under NM, HBS_NM treatment exhibited strong water absorption, improving photosynthesis and yield, making it suitable for drought conditions. Under PM, topsoil moisture increased significantly, with root system indices increasing by 22.5–36.1 % for RLD, 30.2–36.1 % for RSD, and 25.2–36.5 % for root biomass across the cultivars compared to NM. While ZD_PM did not have the highest root system indices under PM, it exhibited higher green leaf area index (4.5–7.5 %), chlorophyll content (2.8–8.6 %), and photosynthetic rate (6.0–14.5 %), resulting in the highest aboveground biomass and yield among the treatments. These findings suggest ZD is better adapted to the enhanced soil moisture under PM. Future research should focus on breeding genotypes that thrive under PM conditions, emphasizing traits such as larger leaf areas and higher photosynthetic rates to boost crop productivity in rainfed areas.

Soil thermal conductivity (λ) is required to investigate coupled heat and water transport in disciplines such as agriculture, hydrology and engineering. Parameterization schemes or models of λ are also the critical input parameter for various numerical simulation programs like the widely used HYDRUS, one of the most commonly used models for mimicking water, heat, and solute transport. However, λ has not received enough attention in HYDRUS, and it remains unclear how different λ schemes affect the simulated soil water and thermal regimes. Thus, we programmed 24 λ schemes (including two built-in schemes) used in mainstream land surface, hydrological, and soil–vegetation–atmosphere transfer models into HYDRUS-1D (freezing module) to assess the effects of different λ schemes on soil temperature and water content simulations under freezing–thawing. The results showed that the 24 λ schemes performed differently in the simulation of soil temperature within 1 m below ground, with eight λ schemes, i.e., de Vries 1963 scheme/DV1963 (R=0.99), Camillo and Schmugge 1981/CS1981 scheme (R=0.98), Desborough and Pitman 1998/DP1998 scheme (R=0.97), Cass et al. 1984/CS1984 scheme (R=0.96), Shmakin 1998/SA1998 scheme (R=0.95), Dharssi et al. 2009/DI2009 scheme (R=0.95), Becker et al. 1992/BB1992 scheme (R=0.95), Hubrechts 1998/HL1998 scheme (R=0.94), performing superiorly to the built-in λ schemes. This study highlights the importance of choosing appropriate λ schemes in soil water and heat simulations.

Accurate monitoring of fertilizer concentration and variable irrigation components is crucial for achieving precision irrigation through variable-rate fertigation. However, technological and cost constraints pose challenges in effectively managing mixed variable-rate fertigation. This study addresses these challenges by integrating machine learning (ML) with easily monitored physical parameters, such as electrical conductivity (EC), pH, and temperature, to predict fertilizer solution components and concentrations in mixed variable-rate fertigation. Cubic spline interpolation (CSI) was used to enhance the training dataset. Six ML algorithms—Multivariate Linear Regression (MLR), Support Vector Machines (SVM), K-Nearest Neighbors (KNN), Extremely Randomized Trees (ETs), Multilayer Perceptron (MLP), and Extreme Gradient Boosting (XGB)—were used to develop prediction models, with their performance evaluated using the coefficient of determination (R2), root mean square error (RMSE), and Akaike information criterion (AIC). The Extended Fourier Amplitude Sensitivity Test (EFAST) assessed the sensitivity of the ML models to physical parameters. All of the ML models, except for MLR, particularly SVM, demonstrated superior performance in predicting fertilizer solution components’ concentrations, with R2 values between 0.989 and 0.997 and RMSE values between 0.089 and 0.210. The CSI significantly enhanced model performance, resulting in larger R2 values and smaller RMSE values. The AIC results and sensitivity analysis confirmed the exceptional performance of SVM, emphasizing its suitability for predicting fertilizer components using easily measured physical parameters. The developed ML models offer valuable insights for decision-makers managing irrigation and fertilization in mixed variable-rate fertigation.

Trehalose (Tre) is a non-reducing disaccharide found in many species, including bacteria, fungi, invertebrates, yeast, and even plants, where it acts as an osmoprotectant, energy source, or protein/membrane protector. Despite relatively small amounts in plants, Tre concentrations increase following exposure to abiotic stressors. Trehalose-6-phosphate, a precursor of Tre, has regulatory functions in sugar metabolism, crop production, and stress tolerance. Among the various abiotic stresses, temperature extremes (heat or cold stress) are anticipated to impact crop production worldwide due to ongoing climate changes. Applying small amounts of Tre can mitigate negative physiological, metabolic, and molecular responses triggered by temperature stress. Trehalose also interacts with other sugars, osmoprotectants, amino acids, and phytohormones to regulate metabolic reprogramming that underpins temperature stress adaptation. Transformed plants expressing Tre-synthesis genes accumulate Tre and show improved stress tolerance. Genome-wide studies of Tre-encoding genes suggest roles in plant growth, development, and stress tolerance. This review discusses the functions of Tre in mitigating temperature stress—highlighting genetic engineering approaches to modify Tre metabolism, crosstalk, and interactions with other molecules—and in-silico approaches for identifying novel Tre-encoding genes in diverse plant species. We consider how this knowledge can be used to develop temperature-resilient crops essential for sustainable agriculture.

This study investigated the impact of stress modifiers in intercropping systems on seed yield and yield components, physiological traits, and antioxidant activity of safflower (Carthamus tinctorius L.) and chickpea (Cicer arietinum L.) under rainfed (water deficit) conditions. The experimental design included three stress modulator levels [control, 1 mM salicylic acid (SA), and 10 mM selenium (Se)] and five planting patterns [intercropping one row of safflower and two rows of chickpeas (1S:2C), two rows of safflower and four rows of chickpeas (2S:4C), and three rows of safflower and five rows of chickpeas (3S:5C), and sole cropping of safflower (Ss) and chickpea (Cs)]. The results revealed that Ss treated with Se produced the highest safflower biological yield (4,905.50 kg ha−1) and seed yield (1,259.50 kg ha−1), while Cs produced the highest chickpea biological yield (2,799.67 kg ha−1) and seed yield (852.44 kg ha−1), followed by Cs treated with SA (2,419.25 kg ha−1 and 764.83 kg ha−1, respectively). Conversely, the 3S:5C intercropping ratio (IR) with Se application recorded the highest safflower oil content (32.08%), while Ss treated with Se produced the highest oil yield (358.62 kg ha−1). The 2S:4C configuration with Se application produced the highest unsaturated fatty acid (oleic and linoleic acids) concentrations in safflower, while 2S:4C and 3S:5C treated with Se produced the highest chlorophyll a and chlorophyll b contents in safflower and chickpea. Furthermore, 1S:2C and 2S:4C treated with SA or Se produced the highest proline and total soluble sugars in safflower and chickpea. The SA and Se treatments in the intercropping systems increased catalase, ascorbate peroxidase, and superoxide dismutase activities compared to the respective control plants (sole cropping) and enhanced oil contents, fatty acid composition, physiological traits, and antioxidant properties. These results underscore the potential of intercropping systems coupled with stress modulator treatments as a sustainable approach for safflower and chickpea cultivation under rainfed conditions.

The water-intensive conventional winter wheat–summer maize (WM) double cropping system in the North China Plain (NCP) has significantly decreased the groundwater table. To address this issue, we undertook a two-year field experiment to explore the potential and mechanisms of water-saving and yield increase of five newly designed diversified crop rotations incorporating spring crops (sweet potato, soybean, peanut, spring maize, and millet) into cereal crops compared with the conventional WM (as control). The results revealed that the five diversified crop rotations significantly decreased annual actual crop evapotranspiration by 7–12% and net groundwater use by 21–31% compared to the conventional WM. Sweet potato and peanut-based rotations significantly enhanced annual average equivalent yields up to 32% and economic benefit (+50%, +7%) while improving water productivity by 24–68% compared to WM. Shallow-rooted crops (sweet potato, soybean, peanut, and millet), when used as the preceding crop, improved soil water storage in the 0–180 cm soil layer at the start of the succeeding wheat planting season by 3–9% compared to the conventional WM. These shallow-rooted crops mainly concentrated their root systems in the 0–120 cm soil water, particularly the top 80 cm, complementing the deeper root systems of wheat, which extended down to 180 cm. Consequently, this optimal soil water use regime in diversified crop rotations increased the leaf area index and aboveground biomass of the succeeding wheat and maize crops, increasing total grain yields by 4–11%. Thus, introducing shallowed-root annual crops as preceding crops to the current WM rotation is beneficial for decreasing irrigation inputs, enhancing overall crop productivity, and mitigating groundwater table decline in the NCP.

Irrigation is a common practice in agriculture to increase crop yield. However, the impacts of irrigation on microbial-mediated processes that influence soil carbon (C) pools and crop yield remains largely unknown. Therefore, we conducted a 2-year field experiment to investigate the effects of low (I1, 80% field capacity, 80%FC), medium (I2, 90%FC), and high (I3, 100%FC) irrigation upper limits on rhizosphere soil bacterial community, soil organic carbon (SOC) content, and wheat yield. The results showed that as the irrigation upper limit increased, the α-diversity of the bacterial community decreased. The bacterial community structure significantly differed across various irrigation upper limits. As the irrigation upper limit increased from low (80%FC) to medium (90%FC) or high (100%FC), the abundance of copiotrophic taxa (Proteobacteria, Actinobacteria, Bacteroidetes) decreased, and oligotrophic taxa (Acidobacteria) increased, enhancing the decomposition of persistent C pools. In the second year of the irrigation experiment, the I2 and I3 treatments significantly decreased microbial biomass carbon (MBC), SOC content (by 4.62–7.30%), and the microbial quotient (MQ) compared to I1. Wheat straw biomass and grain yield also decreased as the irrigation upper limit increased from 80%FC to 100%FC, with key bacterial taxa (Proteobacteria, Actinobacteria, and Chloroflexi) and functional processes (glycan biosynthesis and metabolism; folding, sorting, and degradation; translation; transport, and catabolism) playing key roles in wheat grain formation. Our findings indicate that adjusting irrigation levels affects the rhizosphere soil bacterial communities, and that the lowest upper limit of irrigation application (80%FC) is associated with maximum crop yield and microbial diversity.

The growth and yield of crops have been significantly affected by abiotic stresses. Although respiratory metabolism is integral to plants, its understanding within the context of stress adaptation remains limited . While the rice genome contains three Aconitase genes, their specific roles in abiotic stress tolerance and plant development remain largely unexplored. This study aimed to characterize the Aconitase gene family in rice, shedding light on the evolution of Aconitase and its involvement in diverse developmental processes, as well as its response under various abiotic stress conditions. Phylogenetic analysis indicated the evolutionary relationship between rice Aconitase genes and those of other plant species. The prediction of promoter cis-elements revealed the presence of diverse cis-acting elements associated with the response to abiotic stress within the Aconitase gene family. In addition, an analysis of public RNA-seq data indicated the potential involvement of Aconitase genes in various developmental processes and mechanisms related to stress tolerance. Further, qRT-PCR confirmed the expression patterns of Aconitase genes. Expression analysis revealed differential expression of Aconitase genes under cold, drought, ABA, and salt stresses. Elevated levels of the OsAco1 transcript resulted in a phenotype that exhibited increased tolerance to salt stress. Biochemical analysis revealed higher Aconitase activity in the overexpressed line compared to the control plant. Furthermore, the overexpressed line exhibited improved growth and lower H2O2 levels than the control plant following a 2-hour exposure to 200 mM salt stress. These findings suggest a potential role of Aconitase in enhancing salt stress tolerance. Moreover, they lay the foundation for further exploration into the precise involvement of Aconitase in plant developmental processes under various stress conditions, with the ultimate aim of developing salt-tolerant rice cultivars.

Most chickpea cultivation occurs in rainfed environments, where unpredictable rainfall leads to drought stress, consequently reducing growth and productivity. Fast and robust image-based screening methods would greatly facilitate drought tolerance research. In this study, an experiment was conducted in a climate-controlled environment, using radio frequency-enabled ID (RFID) tagged plant carriers on Lemnatec's high-throughput phenotyping platform. The agro-physiological characteristics of six chickpea genotypes under drought stress conditions imposed at the early podding stage were explored. Using non-destructive techniques, including Red, Green, and, Blue (RGB), Near-Infrared (NIR), Infrared (IR), and chlorophyll fluorescence (Fv/Fm) imaging, data was captured at various stages of drought stress, quantified as the fraction of transpirable soil water, using LemnaGrid software. Traits such as plant phenology, yield, yield components, and physiological parameters (e.g., leaf temperature and photosynthetic characteristics) for both drought-stressed and well-watered plants were recorded manually. Seed yields ranged from 9.9 to 18.1 g plant−1 under WW, and 2.6–13.7 g plant−1 under DS. DS decreased yield the most in ICC 1882 and RSG 888 (73.7%) and the least in ICC 4958 (24.3%) relative to WW. Our findings revealed significant genotype × water treatment interactions for all manually recorded traits. Moreover, strong positive correlations were observed between manually recorded and image-based traits, i.e., between aboveground dry weight and projected area, aboveground dry weight and convex hull area, plant height and caliper length, photosynthetic rate, and chlorophyll fluorescence, stomatal conductance and NIR reflectance, IR thermometer temperature and IR imaging temperature. Notably, the strong positive correlations between NIR reflectance and stomatal conductance, and between chlorophyll fluorescence and photosynthesis, underscore the immense potential of harnessing image-based screening methods in breeding programs to enhance drought tolerance.

Sesame (Sesamum indicum) is an important indigenous oilseed crop but its growth and productivity are severely affected by abiotic stresses. Class III peroxidases are key stress related enzymes that exclusively occur in plant kingdom, however, their specific involvement in sesame remains largely unexplored. The present study aimed to identify the PRX gene family in sesame and elucidate their role in conferring drought stress tolerance in contrasting sesame accessions. Through genome-wide analysis of the PRX gene family, 45 non-redundant members (designated SiPRXs) were identified which were unequally distributed on 13 sesame chromosomes. Motif analysis revealed highly conserved peroxidase domains in all SiPRX proteins. To validate the function of identified SiPRX family members, sesame accessions were phenotyped under drought stress and irrigated conditions. The contrasting drought-tolerant and drought-sensitive accessions were used to study the relative transcript abundance of the selected 15 SiPRX genes by quantitative real-time PCR.Expression analysis revealed differential expression of SiPRX genes between drought-tolerant and drought-sensitive accessions, which was consistent with their physiological responses to drought stress. Our findings provide comprehensive insights into the genomic characterization of the SiPRX gene family in sesame with special reference to drought stress tolerance. These results emphasize the potential utility of SiPRX genes in enhancing drought resilience in sesame with implications for crop improvement strategies.

Plastic film mulch systems are used widely in arid areas, and the associated tillage measures affect soil properties, root and crop growth, and nutrient uptake. However, much debate surrounds the most suitable tillage method for plastic film mulch systems. We conducted a two-year field experiment to explore the impact of three tillage treatments - rotary tillage before ridge–furrow plastic film mulch (MR), no-tillage before ridge–furrow plastic film mulch (MZ), and plow tillage before ridge–furrow plastic film mulch (MP) - on soil total nitrogen, available nitrogen, root stratification structure, nitrogen transfer and utilization, and maize yield. The results showed that MP had better soil quality than either MR or MZ over 2019 and 2020, with higher nitrate-nitrogen and total nitrogen in the 0–40 cm soil layer. MP improved the soil physicochemical properties more than the other treatments, producing significantly higher root numbers and root biomass for the aerial and underground nodal roots than MR and MZ. At harvest, MP had the highest root biomass density, root length density, and root surface area density in the different soil layers (0–20, 20–40, and 0–40 cm). Significant correlations occurred between root biomass and aboveground nitrogen accumulation during maize growth. During grain filling, MP had the greatest nitrogen transfer amount, significantly increasing root and aboveground nitrogen transfer by 19.63–45.82% and 11.15–24.56%, respectively, relative to the other treatments. MP significantly produced 1.36–26.73% higher grain yields and a higher grain crude protein content at harvest than MR and MZ. MP also had higher values for the nitrogen harvest index, nitrogen uptake efficiency, and partial factor productivity of nitrogen fertilizer than MR and MZ. In conclusion, plow tillage combined with a ridge–furrow plastic film mulch system facilitated maize root development and improved nitrogen utilization, thereby increasing maize yield more than the other treatments.

Emitter clogging restricts the promotion and application of drip irrigation technology for Yellow River water. The influence degree of water quality, flow path structure, and operation time on emitter clogging varies. Thus, we conducted a meta-analysis to examine the impact of sediment concentration, sediment particle size, flow path structure [including length (L), width (W), depth (D), minimum cross-sectional size (min (W, D)), and cross-sectional area (A) of flow path], rated flow rate (Q), and operation time on emitter clogging in drip irrigation using Yellow River water to identify viable strategies for alleviating emitter clogging in Yellow River water drip irrigation. The results showed that using drip irrigation with Yellow River water is feasible, and it is important to vigorously develop efficient agricultural irrigation technologies such as drip irrigation in the Yellow River basin. Sediment concentration is the main factor affecting emitter clogging in the Yellow River water drip irrigation. For sediment concentrations below 0.5 g/L, effective operation could be maintained for up to 450 h. The sediment concentration of Yellow River water drip irrigation should not exceed 1.3 g/L to prevent severe clogging. In addition, irrigation methods should involve short single irrigation times and high frequencies, with increased lateral flushing measures. The traditional assumption that a larger W, D, min (W, D), A, or Q leads to superior anti-clogging performance did not hold universally. Across different sediment concentration and operation time combinations, the emitter’s anti-clogging ability first increased and then decreased with increasing min (W, D), and anti-clogging ability gradually decreased with increasing L. The high anti-clogging min (W, D) is 0.64 mm, and L should be 30–50 mm to reduce the clogging risk while playing a role in energy dissipation. These research findings offer valuable insights for selecting emitters and developing anti-clogging strategies specific to Yellow River water drip irrigation, serving as a solid theoretical basis for enhancing the efficiency and reliability of high sediment-laden water drip irrigation systems worldwide.

Mercury (Hg) contamination is acknowledged as a global issue and has generated concerns globally due to its toxicity and persistence. Tunable surface-active sites (SASs) are one of the key features of efficient BCs for Hg remediation, and detailed documentation of their interactions with metal ions in soil medium is essential to support the applications of functionalized BC for Hg remediation. Although a specific active site exhibits identical behavior during the adsorption process, a systematic documentation of their syntheses and interactions with various metal ions in soil medium is crucial to promote the applications of functionalized biochars in Hg remediation. Hence, we summarized the BC's impact on Hg mobility in soils and discussed the potential mechanisms and role of various SASs of BC for Hg remediation, including oxygen-, nitrogen-, sulfur-, and X (chlorine, bromine, iodine)- functional groups (FGs), surface area, pores and pH. The review also categorized synthesis routes to introduce oxygen, nitrogen, and sulfur to BC surfaces to enhance their Hg adsorptive properties. Last but not the least, the direct mechanisms (e.g., Hg- BC binding) and indirect mechanisms (i.e., BC has a significant impact on the cycling of sulfur and thus the Hg-soil binding) that can be used to explain the adverse effects of BC on plants and microorganisms, as well as other related consequences and risk reduction strategies were highlighted. The future perspective will focus on functional BC for multiple heavy metal remediation and other potential applications; hence, future work should focus on designing intelligent/artificial BC for multiple purposes.

Study region: Changwu Tableland, Chinese Loess Plateau Study focus: Soil water status and water demand are two important factors to influence root water uptake (RWU) patterns, but the mechanisms involved in deep-rooted plants remain unknown. This study addresses this knowledge gap by investigating diurnal variations in RWU patterns for two different-aged apple orchards (7 vs. 19 years) on the Chinese Loess Plateau (CLP). We achieved this by inputting measured plant and soil information into a physical-based numerical RWU model. New hydrological insights for the region: The results showed that the 19-year-old orchard exhibits distinct characteristics compared to the 7-year-old orchard. Specifically, the 19-year-old orchard had less deep soil water content, resulting in lower matric potential and hydraulic conductance. In contrast to cropland soil water, the cumulative deep soil water (>2 m) deficits were 17.6 and 1108.3 mm in the 7-year-old and 19-year-old orchards, respectively. Despite the 19-year-old orchard having 67% of its fine roots below 5 m soil depth, their contribution ratio to total RWU was only 30–40%, indicating less available deep soil water for the older orchard.Sap flow and leaf water potential had bell-shaped diurnal variations, leading to shifting soil water contributions to RWU in the 7-year-old and 19-year-old orchards. These changes were particularly evident when soil water potential in the root zone was heterogeneous, resulting in contrasting RWU patterns during different water demand periods. Notably, the 7-year-old orchard exhibited less water contribution from deep 2–5 m layer and enriched xylem water isotopes at midday with high water demand, while the 19-year-old orchard had more water contribution from deep 5–21.6 m layer and depleted xylem water isotopes. These contrasting RWU variations shed light on the profound impact of orchard age on deep RWU patterns, especially under the varying water demand conditions after CLP afforestation.

Abstract Background Weeds reduce wheat yields in dryland farming systems. Herbicides such as metribuzin are commonly used to control weeds. However, wheat has a narrow safety margin against metribuzin. Standing crops such as wheat with weeds in the same field can also be killed by the same dose of metribuzin. Therefore, it is important to identify metribuzin resistance genes and understand the resistance mechanism in wheat for sustainable crop production. A previous study identified a significant metribuzin resistance wheat QTL, Qsns.uwa.4 A.2, explaining 69% of the phenotypic variance for metribuzin resistance. Results Two NIL pairs with the most contrasting performance in the metribuzin treatment and different in genetic backgrounds were compared using RNA sequence analysis, identifying nine candidate genes underlying Qsns.uwa.4 A.2 responsible for metribuzin resistance. Quantitative RT-qPCR further validated the candidate genes, with TraesCS4A03G1099000 (nitrate excretion transporter), TraesCS4A03G1181300 (aspartyl protease), and TraesCS4A03G0741300 (glycine-rich proteins) identified as key factors for metribuzin resistance. Conclusion Identified markers and key candidate genes can be used for selecting metribuzin resistance in wheat.

Tungsten (W) is a rare element and present in the earth's crust mainly as iron, aluminium, and calcium minerals including wolframite and scheelite. This review aims to offer an overview on the current knowledge on W pollution in complex environmental settlings, including terrestrial and aquatic ecosystems, linking to its natural and anthropogenic sources, behavior in soil and water, environmental and human health hazards, and remediation strategies. Tungsten is used in many alloys mainly as wafers, which have wide industrial applications, such as incandescent light bulb filaments, X-ray tubes, arc welding electrodes, radiation shielding, and industrial catalysts. The rigidity and high density of W enable it to be suitable for defence applications replacing lead. In soil, W metal is oxidised to the tungstate anion and occurs in oxidation states from − 2 to + 6, with the most prevalent oxidation state of + 6. However, recently, people have been alerted to the risk posed by W alloys and its particulates, which can cause cancer and have other detrimental health effects in animals and humans. The population is subject to W pollution in the workplace by breathing, ingestion, and dermal contact. Remediation of W-polluted soil and aquatic environments can be accomplished via stabilization or solubilization. Stabilization of W in soil and groundwater using immobilizing agents inhibits the bioavailability of W, thereby preventing the contaminant from reaching the food chain, while solubilization of W in soil involving mobilizing materials accelerates the elimination of W via soil washing and root absorption. Future research opportunities covering risk-based remediation of W pollution in these complex settings are presented.

On the Loess Plateau, unfavorable late-sowing conditions often arise due to late harvests from the previous season or excessive rainfall during the sowing season, which can delay seed germination, reduce tiller numbers, and decrease winter wheat yields. Few studies have explored whether plastic mulching (PM) can mitigate the adverse effects of late sowing. Consequently, we conducted a 3-year field experiment from 2017 to 2020 on the Loess Plateau combining two mulching conditions [PM and no mulching (NPM)] and three sowing times (normal, 10-day late, and 20-day late sowing). We investigated the combined influence of sowing time and mulching conditions on soil hydrothermal status, crop water productivity (WP), and yield. The results revealed that delayed sowing significantly prolonged emergence times and decreased tiller numbers, leaf area index (LAI), root biomass, and aboveground biomass (AGB). The PM increased soil temperatures, advancing wheat emergence and increasing tiller numbers. Plants under PM had higher LAI, root biomass, and AGB than those under NPM. Moreover, PM reduced ineffective transpiration by accelerating the degradation of ineffective tillers, resulting in higher yields without a corresponding increase in evapotranspiration. The beneficial effects extended to spike numbers, thousand-grain weight, and harvest index. Specifically, PM combined with 10-day late sowing increased yield by 12.8 % compared to NPM combined with normal sowing. Furthermore, under 20-day late sowing, PM mitigated yield losses, reducing them from a 28.7 % decline under NPM to a 12.8 % decline when compared to normal sowing under NPM. We conclude that PM completed compensated for the yield loss under 10-day late sowing and partially alleviated losses under 20-day late sowing. Therefore, combining 10-day late sowing (accumulated air temperature before winter > 430 °C d) with PM was the optimal approach for simultaneously improving yield and WP in winter wheat seasons with unfavorable late-sowing conditions.

Water stress, improper fertilization practices, and agricultural waste pollution severely reduce soil fertility and limit agricultural sustainability on the Loess Plateau. Organic fertilizer application is an efficient method for improving soil water and nutrient availability and grain yield in semi-arid and arid areas. However, the impact of bio-organic fertilizer derived from agricultural waste on soil characteristics and wheat yield and the optimum bio-organic fertilizer substitution rate in semi-humid drought-prone areas remain unclear. A two-year field study was conducted to explore the effect of combined bio-organic and chemical fertilizer application on soil moisture, hydraulic properties, soil structure, soil organic carbon (SOC), total nitrogen (TN), grain yield, and water productivity (WP). Six different treatments were designed: no fertilization (CK), conventional chemical fertilization (CF), and bio-organic fertilizer treatments substituting 25% (OF25%), 50% (OF50%), 75% (OF75%), and 100% (OF100%) of the chemical N fertilizer. From the seedling to over wintering stage, the OF75% and OF100% treatments generally improved soil water storage (SWS) and soil water content (SWC) within the 0–100 cm soil layer compared to the CK and CF treatments across both growing seasons. Bio-organic fertilizer substitution significantly reduced soil bulk density by 4.0–5.6% and enhanced soil porosity by 4.2–5.9% in the 0–40 cm soil layer. Moreover, bio-organic fertilizer substitution significantly increased soil saturated hydraulic conductivity and water content, improved aggregate size distribution, and enhanced SOC and TN contents in both years. The OF75% treatment produced the highest aboveground biomass, yield components, grain yields, and WP, attributed to the improved soil physical environment and nutrient contents. Notably, the OF75% treatment increased the average wheat yield and WP by 21.1% and 24.9%, respectively, relative to the CF treatment across both growing seasons. The measured soil properties strongly correlated with wheat yield, yield components, and WP. Thus, the OF75% treatment is an appropriate and promising fertilization management strategy to alleviate water stress, improve soil properties, and promote crop production in semi-humid drought-prone regions.

Climate warming has increased the frequency of droughts and excessive precipitation, adversely affecting crop growth, particularly under traditional intensive tillage. No-till improves crop tolerance to extreme events by reducing soil evaporation and improving soil structural stability to enhance soil water storage capacity and crop resistance, but long-term mono-no-till cakes the soil, reducing crop yield. Combining intensive tillage with no-till can compensate for some deficiencies arising from conventional tillage or single no-till. A three-year field experiment was conducted in wet (2020) and normal (2019 and 2021, where a drought event occurred in 2021) years to study the effect of tillage practices on summer maize productivity under different precipitation types. Treatments included conventional tillage (CT), no-tillage (NT), ridge cultivation with no-tillage (RNT), and conventional tillage of winter wheat combined with no-tillage of summer maize (NC). Compared with NT, NC and RNT significantly reduced soil bulk density and increased soil porosity in the 0–20 cm soil layer. Compared with CT, NC and RNT significantly improved aggregate stability, NC increased available soil water storage by 19.7% in the dry season (P

Accurately assessing isotope information on water sources and mixtures is essential for determining root water uptake (RWU) patterns. This study investigates the impact of rooting depth and cryogenic vacuum extraction (CVE) on the isotopic composition of deep soil water and RWU patterns in a 19-year-old apple orchard on China’s Loess Plateau. We used a Bayesian mixing model (MixSIAR) to analyze corrected isotopic data from soil and xylem water samples collected at different depths, ranging from 3 m to 21.6 m. Our findings reveal a progressive decline in the isotopic composition of deep soil water by 0.63‰ m–1, which decreased deep soil water contributions to transpiration by 1–12% at different rooting depths. The xylem and soil water isotopes became more enriched after correction, with xylem water isotopes closer to the soil water isotope line and water isotopes enriched in the shallow soil layer. Consequently, the contributions of shallow soil water to transpiration increased after xylem water isotope correction but decreased after soil water isotope correction. Monthly averages of these ratios decreased by 12.8% or increased by 8.4%, respectively. After correcting for both soil and xylem water isotopes, the average contributions of shallow soil water increased by 7.4% each month, while those of deep soil water were not consistent. Our findings suggest that rooting depth and CVE have a greater impact on seasonal contribution ratios but a comparatively milder influence on seasonal patterns. This delineation is important for accurately quantifying plant water use strategies.

Combining organic and inorganic fertilizers is critical for increasing yield and improving soil fertility. However, the specific effects of this combination on greenhouse gas (GHG) emissions in hilly apple orchards remain unclear. Furthermore, studies on slope agriculture often overlook slope runoff, a significant factor to consider. Hence, we conducted a two-year field trial in a hilly apple orchard in north Shaanxi to investigate the impact of practical orchard measures on GHG emissions, runoff, apple yield, and fruit quality. Three management practices were implemented: (1) OCWS: combined organic and chemical fertilizers (substituting 60% chemical fertilizer with organic fertilizer) plus a water-saving system comprising a fish scale pit (FSP) and rainwater collection pit (RCP); (2) CWS: chemical fertilizer alone plus water-saving system; (3) CC: chemical fertilizer alone without water-saving system (the conventional practice based on local farmers’ practices), serving as the control treatment. The results revealed that the OCWS treatment had the lowest average surface temperature (22.5 ℃), which was 5.5% and 4.5% lower than the CWS and CC treatments, and the highest surface soil volumetric water content (21.7%), which was 8.4% and 10.4% higher than the CWS and CC treatments during apple growing season. Seasonal variation in N2O, CO2, and CH4 emissions followed similar trends across treatments, although the magnitude of change varied. Cumulative N2O, CO2, and CH4 emissions did not differ significantly among treatments. Furthermore, the OCWS treatment had a similar global warming potential (GWP) to the CC treatment but a 62.6% lower greenhouse gas intensity (GHGI) than the CC treatment. Averaged across two years, the OCWS and CWS treatments significantly reduced runoff by 49.2% and 43.9% and sediment yield by 72.1% and 68.7%, respectively, compared to the CC treatment. Moreover, precipitation positively correlated with runoff and erosive sediment. Averaged across two years, the OCWS treatment had the highest apple yield (37,550 kg hm–2), crop water production (69.4 kg hm–2 mm–1), transverse diameter (84.3 mm), single fruit weight (261.5 g), vitamin C (29.5 mg kg–1), soluble solids (14.3%), soluble sugars (10.7%), and sugar/acid ratio (55.0). Thus, the OCWS system is an effective management practice for improving apple yield and fruit quality and mitigating adverse environmental impacts on the Loess Plateau, with great potential in sustainable orchard management.

A sustainable and resilient crop production system is essential to meet the global food demands. Traditional chemical-based farming practices have become ineffective due to increased population pressures and extreme climate variations. Recently, nanobiotechnology is considered to be a promising approach for sustainable crop production by improving the targeted nutrient delivery, pest management efficacy, genome editing efficiency, and smart plant sensor implications. This review provides deeper mechanistic insights into the potential applications of engineered nanomaterials for improved crop stress resilience and productivity. We also have discussed the technology readiness level of nano-based strategies to provide a clear picture of our current perspectives of the field. Current challenges and implications in the way of upscaling nanobiotechnology in the crop production are discussed along with the regulatory requirements to mitigate associated risks and facilitate public acceptability in order to develop research objectives that facilitate a sustainable nano-enabled Agri-tech revolution. Conclusively, this review not only highlights the importance of nano-enabled approaches in improving crop health, but also demonstrated their roles to counter global food security concerns.

Rising temperatures impact different developmental stages of summer crops like mung bean, particularly during the crucial seed-filling stage. This study focused on two mung bean genotypes, categorized as heat-tolerant [HT] or heat-sensitive [HS]. These genotypes were grown in pots in an outdoor natural environment (average day/night temperature 36°C/24.3°C) until the onset of podding (40 days after sowing) and subsequently relocated to controlled-environment walk-in growth chambers for exposure to heat stress (42°C/30°C) or control conditions (35°C/25°C) until maturity. For all measured attributes, heat stress had a more pronounced effect on the HS genotype than on the HT genotype. Heat-stressed plants exhibited severe leaf damage, including membrane damage, reduced chlorophyll content, diminished chlorophyll fluorescence, and decreased leaf water content. Heat stress impeded the seed-filling rate and duration, decreasing starch, protein, fat, and mineral contents, with a notable decline in storage proteins. Heat stress disrupted the activities of several seed enzymes, inhibiting starch and sucrose accumulation and consequently decreasing individual seed weights and seed weight plant−1. This study revealed that heat stress during seed filling severely impaired mung bean seed yield and nutritional quality due to its impact on various stress-related traits in leaves and enzyme activities in seeds. Moreover, this research identified potential mechanisms related to heat tolerance in genotypes with contrasting heat sensitivity.

The prevalence of electromagnetic fields (EMFs) caused by electromagnetic radiation is increasing in our daily lives, potentially bringing both adverse and beneficial effects. EMFs have garnered significant research attention in various disciplines, including agricultural science. However, our understanding of the impact of EMFs on the ecophysiological performance of plants under suboptimal conditions is limited. Despite this, there are indications that EMFs can improve crop productivity by enhancing seed germination, plant nutrition, precision farming, water use efficiency, root hydraulic conductance, plant water uptake, anti-oxidative defense, pest prevention, stress signaling, and hormonal pathways. This review highlights the practical application of EMFs for increasing plant biomass production by elucidating the underlying mechanisms involved in seed germination, plant growth, water relations, ion flux, photosynthesis, and antioxidant defense. We also highlight the prospects for using EMFs in sustainable agriculture and their potential to alleviate the conventional agricultural pressures related to food security issues.

Ephemeral gullies are widely distributed in the hilly and gully region of the Loess Plateau and play a unique role in the slope gully erosion system. Rapid and accurate identification of ephemeral gullies impacts the distribution law and development trend of soil erosion on the Loess Plateau. Deep learning algorithms can quickly and accurately process large data samples that recognize ephemeral gullies from remote sensing images. Here, we investigated ephemeral gullies in the Zhoutungou watershed in the hilly and gully region of the Loess Plateau in China using satellite and unmanned aerial vehicle images and combined a deep learning image semantic segmentation model to realize automatic recognition and feature extraction. Using Accuracy, Precision, Recall, F1value, and AUC, we compared the ephemeral gully recognition results and accuracy evaluation of U-Net, R2U-Net, and SegNet image semantic segmentation models. The SegNet model was ranked first, followed by the R2U-Net and U-Net models, for ephemeral gully recognition in the hilly and gully region of the Loess Plateau. The ephemeral gully length and width between predicted and measured values had RMSE values of 6.78 m and 0.50 m, respectively, indicating that the model has an excellent recognition effect. This study identified a fast and accurate method for ephemeral gully recognition in the hilly and gully region of the Loess Plateau based on remote sensing images to provide an academic reference and practical guidance for soil erosion monitoring and slope and gully management in the Loess Plateau region.

Study region: Xindiangou Watershed in Suide, the Loess Plateau, China Study focus: Deep soil water (DSW) is gradually depleted as vegetation stand age increases, resulting in dried soil layers (DSLs) in the Loess Plateau in China. However, it is unclear whether old-aged vegetation continues to use DSW under DSLs. This study monitored soil water five times (2001, 2005, 2006, 2007, 2020) in the deep profile for three common vegetation types [Pinus tabuliformis Carr. (P. tabuliformis), Caragana korshinskii Kom. (C. korshinskii), Platycladus orientalis L. Franco (P. orientalis)] planted in 1985. In 2020, we measured soil water content, root characteristics, and soil particle composition to investigate DSW status and the influencing factors. New hydrologic insights for the region: Soil water in the 2–10 m soil layer did not significantly differ from 17- to 36-year stand for the three vegetation types (p

Global climate variations induce extreme temperatures and significantly decrease crop production, leading to food insecurity worldwide. Temperature extremes (mainly cold stress (CS): chilling 0–15 °C and freezing

Salinity is a major abiotic stress that causes substantial agricultural losses worldwide. Chickpea (Cicer arietinum L.) is an important legume crop but is salt-sensitive. Previous physiological and genetic studies revealed the contrasting response of two desi chickpea varieties, salt-sensitive Rupali and salt-tolerant Genesis836, to salt stress. To understand the complex molecular regulation of salt tolerance mechanisms in these two chickpea genotypes, we examined the leaf transcriptome repertoire of Rupali and Genesis836 in control and salt-stressed conditions. Using linear models, we identified categories of differentially expressed genes (DEGs) describing the genotypic differences: salt-responsive DEGs in Rupali (1,604) and Genesis836 (1,751) with 907 and 1,054 DEGs unique to Rupali and Genesis836, respectively, salt responsive DEGs (3,376), genotype-dependent DEGs (4,170), and genotype-dependent salt-responsive DEGs (122). Functional DEG annotation revealed that the salt treatment affected genes involved in ion transport, osmotic adjustment, photosynthesis, energy generation, stress and hormone signalling, and regulatory pathways. Our results showed that while Genesis836 and Rupali have similar primary salt response mechanisms (common salt-responsive DEGs), their contrasting salt response is attributed to the differential expression of genes primarily involved in ion transport and photosynthesis. Interestingly, variant calling between the two genotypes identified SNPs/InDels in 768 Genesis836 and 701 Rupali salt-responsive DEGs with 1,741 variants identified in Genesis836 and 1,449 variants identified in Rupali. In addition, the presence of premature stop codons was detected in 35 genes in Rupali. This study provides valuable insights into the molecular regulation underpinning the physiological basis of salt tolerance in two chickpea genotypes and offers potential candidate genes for the improvement of salt tolerance in chickpeas.

The interest in sustainable horticulture has recently increased, given anthropogenic climate change. The increasing global population will exacerbate the climate change situation induced by human activities. This will elevate global food demands and the vulnerability of horticultural systems, with severe concerns related to natural resource availability and usage. Sustainable horticulture involves adopting eco-friendly strategies to boost yields while maintaining environmental conservation. Biochar (BC), a carbon-rich material, is widely used in farming to improve soil physical and chemical properties and as an organic substitute for peat in growing media. BC amendments to soil or growing media improve seedling growth, increase photosynthetic pigments, and enhances photosynthesis, thus improving crop productivity. Soil BC incorporation improves abiotic and biotic stress tolerance, which are significant constraints in horticulture. BC application also improves disease control to an acceptable level or enhance plant resistance to pathogens. Moreover, BC amendments in contaminated soil decrease the uptake of potentially hazardous metals, thus minimizing their harmful effects on humans. This review summarizes the most recent knowledge related to BC use in sustainable horticulture. This includes the effect of BC on enhancing horticultural crop production and inducing resistance to major abiotic and biotic stresses. It also discuss major gaps and future directions for exploiting BC technology.

Growth stimulating bacteria help remediate dry arid soil and plant stress. Here, Pseudomonas sp. and Pantoea sp. we used to study the stress ecology of Hordeum vulgare and the environmental impact of water deficit on soil characteristics, growth, photosynthesis apparatus, mineral acquisition and antioxidiant defense. Plants inoculated with Pseudomonas or Pantoea had significantly higher (about 2 folds) soil carbon flux (soil respiration), chlorophyll levels (18%), net photosynthetic rate (33% in Pantoea and 54% in Pseudomonas), (44%) stomatal conductance than uninoculated plants in stressed conditions. Both bacterial strains improved leaf growth (23-29%) and root development under well-watered conditions but reduced around (25%) root biomass under drought. Plants inoculated with Pseudomonas or Pantoea under drought also increased of about 27% leaf respiration and transpiration (48%) but decreased water use efficiency, photoinhibition (91%), and the risk of oxidative stress (ETR/A) (49%). Drought stress increased most of the studied antioxidant enzymatic activities in the plants inoculated with Pseudomonas or Pantoea, which reduce the membrane damage and protect plants form oxidative defenses. Drought stress increased K+ acquisition around 50% in both shoots inoculated with Pseudomonas or Pantoea relative to non-stressed plants. Plants inoculated with Pseudomonas or Pantoea increased shoot Na+ while root Na+ only increased in plants inoculated with Pseudomonas in stressed conditions. Drought stress increased shoot Mg2+ in plants inoculated with Pseudomonas or Pantoea but did not affect Ca2+ relative to non-stressed plants. Drought stress increased about 70% K+/Na+ ratio only in plants inoculated with Pseudomonas relative to non-stressed plants. Our results indicate that inoculating barley with the studied bacterial strains increases plant biomass and can therefore play a role in the environmental remediation of drylands for food production.

Numerous studies have highlighted the BR (brassinosteroid) induced stress tolerance to different environmental cues. Increased free radicals and other oxidative species are produced in plant system by various environmental stresses such as high, low temperature, drought stress, light stress, pathogen infection and nutrient deficiency. The main approach followed by a plant system to overcome this stress is, either use primary metabolites and/or engaging secondary metabolites. The ROS (reactive oxygen species) neutralization is achieved by intricate antioxidant system developed by the plant cell. The primary metabolite stress tolerance is achieved mostly through classical antioxidant system viz ascorbate peroxidase, superoxide dismutase, catalase, glutathione reductase and monodehydroascorbate reductase, the low molecular weight antioxidants ascorbate and glutathione. On the other hand, the second level of defence is achieved by employing diverse secondary metabolites like lignins, tannins, flavonoids, stilbenes, hydroxycinnamate esters, phenolics synthesized in plants, thereby, playing great role in ROS scavenging. In this review we analyze the multifaceted role of BR signaling in various abiotic stresses and its potential crosstalk with other ROS signaling and phenylpropanoid pathway.

Antimony (Sb) is introduced into soils, sediments, and aquatic environments from various sources such as weathering of sulfide ores, leaching of mining wastes, and anthropogenic activities. High Sb concentrations are toxic to ecosystems and potentially to public health via the accumulation in food chain. Although Sb is poisonous and carcinogenic to humans, the exact mechanisms causing toxicity still remain unclear. Most studies concerning the remediation of soils and aquatic environments contaminated with Sb have evaluated various amendments that reduce Sb bioavailability and toxicity. However, there is no comprehensive review on the biogeochemistry and transformation of Sb related to its remediation. Therefore, the present review summarizes: (1) the sources of Sb and its geochemical distribution and speciation in soils and aquatic environments, (2) the biogeochemical processes that govern Sb mobilization, bioavailability, toxicity in soils and aquatic environments, and possible threats to human and ecosystem health, and (3) the approaches used to remediate Sb-contaminated soils and water and mitigate potential environmental and health risks. Knowledge gaps and future research needs also are discussed. The review presents up-to-date knowledge about the fate of Sb in soils and aquatic environments and contributes to an important insight into the environmental hazards of Sb. The findings from the review should help to develop innovative and appropriate technologies for controlling Sb bioavailability and toxicity and sustainably managing Sb-polluted soils and water, subsequently minimizing its environmental and human health risks.

Potassium (K) levels are decreasing worldwide in agricultural soils, and K deficiency is becoming a major issue. Study on damask rose response to K application is scarce. Furthermore, despite its importance in the cell division, photosynthesis and protein synthesis, there is a lack of published reports on plant responses to zinc (Zn) application. Further research is required to understand the damask rose's response to both elements. This study investigated the effects of K and Zn foliar application on the vegetative growth, flower yield, and volatile oil content and composition of damask rose. K and Zn nutrition was applied either individually or combined as K2SO4 and ZnSO4 at 0.5 or 1.0%. Foliar application of K2SO4 and ZnSO4 was applied with a manual pump four times in each growing season, the first at the beginning of stem elongation and leaf formation, and then at two-weekly intervals. Results showed that K and/or Zn treatments significantly improved the growth characters, flower yield, relative water content (RWC), stomatal conductance, and essential oil content and composition such as linalool, nerol, citronellol, geraniol, and nonadecane. The chlorophyll content, total soluble sugars (TSS), and protein content also increased, but free amino acid content decreased, suggesting that the distribution of nitrogenous compounds (between amino acids and proteins) and their transformation were influenced by K and Zn supply. Individual applications of K or Zn increased the N, P, K, and Zn contents in damask rose leaves, relative to the control, which increased further with combined applications of K and Zn. Results suggest that foliar application of K and/or Zn could be part of the damask rose fertilization program to provide plants with the optimum level of nutrition for improving the quantity and quality of flowers and essential oil yields.

Anthropogenic interventions play a key role in promoting positive feedback of soil–plant–environment interactions, but systematic reports on how anthropogenic activities influence soil physiochemical, microorganism-induced properties and soil health are still limited. Here, we assessed the impact of anthropogenic interventions, including crop diversification in rotations, soil physical disturbance, synthetic chemical inputs, and biofertilizer use on soil microbial community structure and function, and the consequential effects on agroecosystem productivity and environmental sustainability. Summarizing the results of over 160 medium- to long‐term experiments from various soil-climatic zones across the globe in this review illustrated that (1) increasing crop diversification in rotations could bring positive impacts on soil microorganisms and soil health, especially including legume crops in rotations. (2) However, monocultures such as continuous wheat cropping could negatively impact soil health by enhancing activities of host specific pathogens. (3) Physical agronomic practices such as tillage can alter soil microbial communities by shifting microclimate conditions. (4) Mineral nitrogen fertilizer use, a leading nutrient input, may have exceeded the planetary boundary of N cycling, and is causing soil acidification and decreasing microbial biomass. (5) Synthetic chemicals, essential for disease management (pesticides) and yield sustainability (fertilization) in conventional agroecosystems are often toxic to non-target soil microorganisms, while bio-fungicides and biofertilizers—a more sustainable approach—carry significant risks to trigger succession of the native soil microbial community, thus impacting soil health. The key is to establish a rational balance between anthropogenic activities for agroecosystem productivity and potential negative influences on the soil microbial community and long-term soil health.

Fiber length of cotton (Gossypium hirsutum L.) decreases under drought stress, potassium (K) could diminish the decreased caused by drought, but the mechanism associated with this alleviation effect is not clear. We evaluated the effect of K on fiber elongation using two cotton cultivars, Simian 3 and Siza 3, grown in well-watered and drought-stressed conditions. Potassium fertilizer (K2O) was applied 0, 150, or 300 kg ha−1 in each growing condition. Drought stress reduced the final fiber length due to a decline in the maximum rate of rapid elongation (Vmax, mm day−1). The application of K alleviated the drought-induced fiber length reduction by increasing Vmax. At 10 and 15 days post-anthesis (DPA), drought significantly reduced osmotic potential (OP) and increased K+ and malate contents at all K rates, relative to well-watered conditions, which was associated with increased activities of phosphoenolpyruvate carboxylase (PEPC), V-ATPase, PPase, and PM H+-ATPase in cotton fiber. However, the relative contribution of K+ and malate to OP declined under drought in comparison with well-watered condition. Compared with control without K, K application decreased OP and increased the accumulation of osmolytes (K+, malate and soluble sugar) as well as the activities of related enzymes in fiber irrespective of water treatments. Moreover, K application increased osmotic adjustment during drought, and improved the contribution of K+ and malate to OP, especially under drought stress. This study showed that drought decreased fiber length by reducing Vmax, and K application ameliorates the decline in fiber elongation due to drought by enhancing osmolytes accumulation and their contribution to OP in fiber cells. Keywords: Cotton (Gossypium hirsutum), Fiber length, Drought stress, Potassium application, Osmolyte

The effect of biochar application on photosynthetic traits and yield in peanut (Arachis hypogaea L.) is not well understood. A 2-year field experiment was conducted in Northwest Liaoning, China to evaluate the effect of biochar application [0, 10, 20, and 40 t ha−1 (B0, B10, B20, and B40)] on leaf gas exchange parameters, chlorophyll fluorescence parameters, and yield of peanut. B10 improved photochemical quenching at flowering and pod set and reduced non-photochemical quenching at pod set, relative to B0. B10 and B20 increased actual photochemical efficiency and decreased regulated energy dissipated at pod set, relative to B0. B10 significantly increased net photosynthetic rate, transpiration rate, stomatal conductance, and water use efficiency at flowering and pod set, relative to B0. Compared with B0, B10 significantly improved peanut yield (14.6 and 13.7%) and kernel yield (20.2 and 14.4%). Biochar application increased leaf nitrogen content. B10 and B20 significantly increased plant nitrogen accumulation, as compared to B0. The net photosynthetic rate of peanut leaves had a linear correlation with plant nitrogen accumulation and peanut yield. The application of 10 t ha−1 biochar produced the highest peanut yield by enhancing leaf photosynthetic capacity, and is thus a promising strategy for peanut production in Northwest Liaoning, China.

Arachis hypogaea (peanut) is a globally important oilseed crop with high nutritional value. However, upon exposure to overnight chilling stress, it shows poor growth and seedling necrosis in many cultivation areas worldwide. Calcium (Ca2+) enhances chilling resistance in various plant species. We undertook a pot experiment to investigate the effects of exogenous Ca2+ and a calmodulin (CaM) inhibitor on growth and photosynthetic characteristics of peanut exposed to low night temperature (LNT) stress following warm sunny days. The LNT stress reduced growth, leaf extension, biomass accumulation, gas exchange rates, and photosynthetic electron transport rates. Following LNT stress, we observed larger starch grains and a concomitant increase in nonstructural carbohydrates and hydrogen peroxide (H2O2) concentrations. The LNT stress further induced photoinhibition and caused structural damage to the chloroplast grana. Exogenous Ca2+ enhanced plant growth following LNT stress, possibly by allowing continued export of carbohydrates from leaves. Foliar Ca2+ likely alleviated the nocturnal chilling-dependent feedback limitation on photosynthesis in the daytime by increasing sink demand. The foliar Ca2+ pretreatment protected the photosystems from photoinhibition by facilitating cyclic electron flow (CEF) and decreasing the proton gradient (ΔpH) across thylakoid membranes during LNT stress. Foliar application of a CaM inhibitor increased the negative impact of LNT stress on photosynthetic processes, confirming that Ca2+–CaM played an important role in alleviating photosynthetic inhibition due to the overnight chilling-dependent feedback.

Soil health is defined as the capacity of soil to function, within ecosystem boundaries, to sustain crop and animal productivities, maintain or enhance environmental sustainability, and improve human health worldwide. In agro-ecosystems, the soil health can change due to anthropogenic activities, such as preferred cropping practices and intensive land-use management, which can further impact soil functions. Previous assessment of soil health in agriculture mostly relates to soil eco-functions that are integrated with non-biological properties such as soil nutrients and soil structures. In recent years, biological properties such as soil microorganisms were considered as an essential composition in soil health as well. However, systematic reviews of soil health and its potential feedback to human society under different cropping practices are still limited. In this review, we discussed 1) the impact of common and novel cropping practices in agro-systems on soil health, 2) the evolution of plant–microbe–soil complex and the biochemical mechanisms under the pressure of agriculture that responsible for soil health, 3) changes in the concept of soil quality and health over recent decades in agro-systems and the key indicators currently used for evaluating soil health, and 4) issues in agroecosystems that affect soil health the most, particularly how various cropping practices have developed over time with human activities in agroecosystem. This knowledge, along with necessary policies, will help to ensure healthy soil—a crucial component for sustainable ecosystem development.

The development of functional food ingredients using legume seed proteins has potential for nutraceutical use. We purified recombinant β-conglutin proteins (rβ1 to rβ4, and rβ6) from narrow-leafed lupin using affinity–chromatography, and evaluated their anti-inflammatory activity using ex vivo and in vitro systems. rβ1, rβ3, and rβ6 produced lower levels of pro-inflammatory mediators such as nitric oxide (about –34.0–fold in all cases), iNOS mRNA (−7.15, −7.97, −7.41–fold), interleukin 1β (−12.05, −11.64, −12.16–fold), chemokine CCL5 (−16.0, −18.0, −19.0–fold), and cytokines including TNF-α, INF-γ, IL-1β, IL-2, IL-6, IL-8, and IL-12 (β1: −28, −100, −8, −2, −49, −45, −127–fold; β3: −22, −400, −9, −3, −33, −10, −2.54–fold; β6: −72, −122, −11, −3, −2000, −13, −338–fold).These results suggest that the β1, β3, and β6 conglutins have potential as functional food components in nutraceuticals and that can provide alternative therapies for the prevention and treatment of inflammatory-related diseases.

Salt stress inhibits photosynthetic process and triggers excessive formation of reactive oxygen species (ROS). This study examined the role of arbuscular mycorrhizal (AM) association in regulating photosynthetic capacity and antioxidant activity in leaves of two maize genotypes (salt-tolerant JD52 and salt-sensitive FSY1) exposed to salt stress (100 mM NaCl) in soils for 21 days. The leaf water content, chlorophyll content, and photosynthetic capacity in non-mycorrhizal (NM) plants were decreased by salt stress, especially in FSY1, with less reduction in AM plants than NM plants. Salinity increased the activities of antioxidant enzymes (superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), and glutathione reductase (GR)) in both genotypes regardless of AM inoculation, but decreased the contents of non-enzymatic antioxidants (reduced glutathione (GSH) and ascorbate (AsA)), especially in FSY1, with less decrease in AM plants than NM plants. The AM plants, especially JD52, maintained higher photosynthetic capacity, CO2 fixation efficiency, and ability to preserve membrane integrity than NM plants under salt stress, as also indicated by the higher antioxidant contents and lower malondialdehyde (MDA)/electrolyte leakage in leaves. To conclude, the higher salt tolerance in AM plants correlates with the alleviation of salinity-induced oxidative stress and membrane damage, and the better performance of photosynthesis could have also contributed to this effect through reduced ROS formation. The greater improvements in photosynthetic processes and antioxidant defense systems by AM fungi in FSY1 than JD52 under salinity demonstrate genotypic variation in antioxidant defenses for mycorrhizal amelioration of salt stress.

Film mulch increases the crop grain yield via topsoil moisture and temperature improvement in cool, semi-arid areas, but little is known about the role of the hydrological and thermic relationship between early and later crop growth seasons in the improving grain yield. We conducted a field experiment to compare polyethylene film mulching (PM) with no mulching (CK) in 2014 and 2015 on the semi-arid Loess Plateau of China. Compared to CK, PM decreased evapotranspiration before the twelve-leaf stage (V12), but increased evapotranspiration after the V12 stage, and significantly increased the topsoil temperature before the six-leaf stage (V6) and the accumulation of soil growing degree days. Corn plants with PM treatment reached the V6 stage earlier, significantly enhancing the contemporary dry matter accumulation. The harvest index, 100-grain weight, and grain yield significantly increased in PM relative to CK in both years. The growing period to the whole growing season evapotranspiration ratio had a negative correlation with the grain yield before the V12 stage, but a positive correlation after the V12 stage. The grain yield had a negative correlation with the air growing degree days (GDDair) before the V6 stage, but positive correlation from silking to harvest. Conclusively, film mulch promoted the early development of maize via an increased soil temperature before the V6 stage, saved soil water before the V12 stage, resulted in a longer grain-filling period, and increased the GDDair and evapotranspiration during the grain-filling period, which is key to increasing the maize yield.

Globally, chickpea production is severely affected by salinity stress. Understanding the genetic basis for salinity tolerance is important to develop salinity tolerant chickpeas. A recombinant inbred line (RIL) population developed using parental lines ICCV 10 (salt-tolerant) and DCP 92-3 (salt-sensitive) was screened under field conditions to collect information on agronomy, yield components, and stress tolerance indices. Genotyping data generated using Axiom®CicerSNP array was used to construct a linkage map comprising 1856 SNP markers spanning a distance of 1106.3 cM across eight chickpea chromosomes. Extensive analysis of the phenotyping and genotyping data identified 28 quantitative trait loci (QTLs) explaining up to 28.40% of the phenotypic variance in the population. We identified QTL clusters on CaLG03 and CaLG06, each harboring major QTLs for yield and yield component traits under salinity stress. The main-effect QTLs identified in these two clusters were associated with key genes such as calcium-dependent protein kinases, histidine kinases, cation proton antiporter, and WRKY and MYB transcription factors, which are known to impart salinity stress tolerance in crop plants. Molecular markers/genes associated with these major QTLs, after validation, will be useful to undertake marker-assisted breeding for developing better varieties with salinity tolerance.

Common bean (Phaseolus vulgaris L.) is a major component of agricultural systems and diets of the urban and rural populations of East and Central Africa, providing Fe and Zn essential to the health and well-being of African women and children, and protein essential for the entire household. However, bean consumption is limited by constraints such as long cooking time (CT). Cooking demands large amounts of water, fuel and time. It has negative effects on the environment, livelihoods, security and health. Genetic variability in cooking time is documented. Recent development of new breeding methods based on pedigree and genomic selection together with optimal contribution selection (OCS) offers an opportunity to accelerate breeding for rapid CT and higher Fe and Zn grain content. Genotypic and phenotypic data of an African diversity pool, representing key bean market classes, were used to generate genomic estimated breeding values (GEBVs) for grain yield, CT, Fe and Zn. GEBV’s were weighted to maximise the desired outcome in an economic index. From 161 candidate bean genotypes with GEBVs, 67 were chosen for 80 matings within six major grain market classes. An additional 22 breeder nominated matings were included. The predicted outcomes in the first cycle showed a major improvement in population mean for index (+286.77 US$/ha), 6.2% increase in GY and 7.3% reduction in CT, with an achieved increase in population co-ancestry of 0.0753. A 30% reduction in the mean population CT and improved Fe (15%) and Zn (10%), is expected after 5 cycles of annual recurrent selection.

The rising temperatures are resulting in heat stress for various agricultural crops to limit their growth, metabolism, and leading to significant loss of yield potential worldwide. Heat stress adversely affects normal plant growth and development depending on the sensitivity of each crop species. Each crop species has its own range of temperature maxima and minima at different developmental stages beyond which all these processes get inhibited. The reproductive stage is on the whole more sensitive to heat stress, resulting in impaired fertilization to cause abortion of flowers. During seed filling, heat stress retards seed growth by affecting all the biochemical events to reduce seed size. Unfavorable temperature may significantly affect photosynthesis, respiration, water balance, and membrane stability of leaves. To combat heat stress, plants acquire various defense mechanisms for their survival such as maintaining membrane stability, and scavenging reactive oxygen species by generating antioxidants and stress proteins. Thermo-tolerance can be improved by the accumulation of various compounds of low molecular mass known as thermo-protectants as well as phyto-hormones. Exogenous application of these molecules has benefited plants growing under heat stress. Alternatively, transgenic plants over-expressing the enzymes catalyzing the synthesis of these molecules may be raised to increase their endogenous levels to improve heat tolerance. In recent times, various transgenics have been developed with improved thermo-tolerance having potential benefits for inducing heat tolerance in food crops. Updated information about of the effects of heat stress on various food crops and their responses as well as adaptive mechanisms is reviewed here.

In the Australian grainbelt, early winter rainfall has declined during the last 30 years, and farmers sow their crops dry, increasing the risk of early season drought. This study aimed to examine whether differences in the root systems were associated with tolerance to early season drought. Three wheat cultivars with different root systems were grown in 1 m columns in a glasshouse. Immediately after sowing in dry soil, 440 mL water (equivalent to 25 mm rainfall) was supplied to each column, and no water was added to induce the early-season drought for the next 30 days. Shoot and root traits were measured at the end of the early season drought, anthesis and at maturity, respectively. The restricted water supply reduced Ψleaf, stomatal conductance, leaf photosynthetic rate, shoot and root biomass. Early season drought delayed phenology in all cultivars, but there was recovery of root and shoot biomass at anthesis in all three cultivars. Leaf area and shoot biomass at anthesis in Bahatans-87 (large root system) recovered better than Tincurrin (small root system). At maturity, early season drought reduced grain yield more in Tincurrin than Bahatans-87. The slow phenology of Bahatans-87 allowed greater recovery after the drought in leaf area and shoot biomass, which may explain the smaller reduction in grain yield after early season drought.

Root system size is a key trait for improving water and nitrogen uptake efficiency in wheat (Triticum aestivum L.). This study aimed (i) to characterize the root system and shoot traits of five wheat cultivars with apparent differences in root system size; (ii) to evaluate whether the apparent differences in root system size observed at early vegetative stages in a previous semi-hydroponic phenotyping experiment are reflected at later phenological stages in plants grown in soil using large rhizoboxes. The five wheat cultivars were grown in a glasshouse in rhizoboxes filled to 1.0 m with field soil. Phenology and shoot traits were measured and root growth and proliferation were mapped to quantify root length density (RLD), root length per plant, root biomass and specific root length (SRL). Wheat cultivars with large root systems had greater root length, more root biomass and thicker roots, particularly in the top 40 cm, than those with small root systems. Cultivars that reached anthesis later had larger root system sizes than those that reached anthesis earlier. Later anthesis allowed more time for root growth and proliferation. Cultivars with large root systems had 25% more leaf area and biomass than those with small root systems, which presumably reflects high canopy photosynthesis to supply the demand for carbon assimilates to roots. Wheat cultivars with contrasting root system sizes at the onset of tillering (Z2.1) in a semi-hydroponic phenotyping system maintained their size ranking at booting (Z4.5) when grown in soil. Phenology, particularly time to anthesis, was associated with root system size.