Sustainable Crop Production Research Articles

Processing Tomato and Potato Response to Biostimulant Application in Open Field: An Overview

Biostimulants include a wide array of microorganisms and substances that can exert beneficial effects on plant development and growth, often enhancing nutrient uptake and improving tolerance against abiotic and biotic stress. Depending on their composition and time of application, these products can influence plant physiology directly as growth regulators or indirectly through environmental condition changes in the rhizosphere, such as nutrient and water availability. This review evaluated 48 case studies from 39 papers to summarize the effects of biostimulant application on fruit and tuber yields and on the quality of processing tomato and potato in open field conditions. For potato, PGPR bacteria were the main studied biostimulant, whereas the low number of studies on processing tomato did not permit us to delineate a trend. The yield and quality were greatly influenced by cultivars and biostimulant composition, application method, period, and dose. For processing tomato, a positive effect of the biostimulant application on the marketable yield was reported in 79% of the case studies, whereas for potato, the effect was reported in only 47%. Few studies, on processing tomato and potato, also reported data for quality parameters with contrasting results. The variability of crop response to biostimulant application in open field conditions highlights the need for more comprehensive studies. Such studies should focus on diverse cultivars, deeply understand the interaction of biostimulant application with agronomic management (e.g., irrigation and fertilization), and evaluate yield and quality parameters. This approach is crucial to fully understand the potential and limitations of biostimulant applications in agriculture, particularly regarding their role in sustainable crop production.

Bioengineering Bacillus spp. for Sustainable Crop Production: Recent Advances and Resources for Biotechnological Applications

AbstractThe goal of sustainable agriculture is to meet the rising need for food, while minimizing adverse impacts on the environment, protecting natural resources, and ensuring agricultural output over the long term. The pressing need to increase agricultural yield through sustainable agriculture is being emphasized. Several Bacillus species have been used as commercial biopesticides since they can act against plant pathogens by potentially suppressing them. At the same time, they can act as plant growth-promoting rhizobacteria and are known for their diverse characteristics and beneficial properties, making them potential candidates for use sustainable crop production programs. Knowledge of genetic information opens the door of possibility for understanding the way these microorganisms behave. By applying biotechnological tools to Bacillus, strategies can be adopted for the purpose of increasing the yield of crops and managing pests and pathogens that infect them. In this review, we identify the genes in the most significant Bacillus spp. that contribute to plant improvement. The most important biotechnological tools and advance computational approaches are described to provide an extended vision on this topic. However, increasing the crop production through application of beneficial microbial strains requires a multifaceted approach that considers ecological, economic, and social aspects. By implementing these strategies and practices, we can work towards a sustainable and resilient agricultural system that meets the growing food demand, while preserving the environment for future generations.

Effect of organic farming on root microbiota, seed production and pathogen resistance in winter wheat fields

Societal Impact StatementAgricultural intensification is a major driver of biodiversity decline in agrosystems. For instance, it has been shown that conventional farming leads to a decline in soil microbial diversity and triggers a strong selection process, altering the functioning of the whole ecosystem. The present study shows that organic farming increases diversity and affects composition of crop plant microbiota, mostly as a response to field management and soil characteristics. Furthermore, crop plant microbiota influences crop production and resistance to pathogens. Therefore, agricultural practices affect plant performance through microorganism‐mediated changes, which may be important pillars of future sustainable crop production.Summary Agricultural intensification threatens biodiversity, but the effects of intensification on microorganisms are still overlooked despite their role in ecosystem functioning. Microorganisms associated with plants provide many services that affect plant growth and health. Organic farming is expected to strongly affect species composition, richness, and their interactions. We analyzed the effect of the farming system on endophytic microbial assemblages associated with winter wheat plants and plant performance in the field. We collected environmental data through farmer interviews, soil analyses, and plant inventories and analyzed root microbiota at vegetative and flowering stages. Organic farming increased fungal and bacterial diversity associated to wheat plants and affected species composition in most phyla. This effect was mostly due to soil characteristics and field management and a little to plant diversity in the field. Microbial responses were more pronounced at the late developmental stage, likely as a result of accumulative effect of management actions during plant development. Seed production and resistance to pathogens were related to specific phyla that are important for seed production and/or wheat resistance to septoriose. This work advances our understanding of how agricultural practices affect plant performance through microorganism‐mediated changes and supports the use of microorganisms as pillars of sustainable crop production.

Sesame Stalk Compost in Soil Revitalization and Long-term Sustainable Crop Productivity in Organic Sesame (Sesamum indicum L.)

ABSTRACT Resource depletion is one of the primary concerns of modern agriculture farmers, which needs to be considered for long term sustainability. To assess the effect of sesame stalk compost on the growth, yield, and quality of sesame under organic cultivation, long-term (four years) field experiments were conducted for eight seasons consecutively from 2020 to 2023. The inoculated composts collected after 90 days of composting contain N (1.45–1.50%), P (0.22–25%), K (0.23–0.25%), Fe (510–514 ppm), Zn (150–154 ppm), Cu (286–288 ppm), and Mn (540–542 ppm), which was higher than the uninoculated sesame stalk. Similarly, the humic acid content (122 mg/g of compost), fulvic acid (23–24 mg/g of compost), total humic substances (145–146 mg/g of compost), and CO2–C evolution (186–188 mg/100 g of compost) were significantly higher with microbial inoculated composts than uninoculated compost. The results of the long-term field experiment indicated that application of sesame stalk compost @ 5 t/ha significantly increased the soil organic carbon (6.30 g/kg), soil organic carbon (SOC) stock (11.8 mg/ha), raised the pH to neutralize the acidic pH in red lateritic soil (6.8 to 7.2), reduced the soil bulk density (1.38 to 1.34), penetration resistance (720 kpa to 630 kpa), and available N, P, and K. As a result, the sesame grain yield obtained with application of sesame stalk compost @ 5 t/ha (778–782 kg/ha) was comparable with recommended doses of chemical fertilizers (794 kg/ha). Significant improvement in grain quality (24.2% of protein, 418–422 ppm of Ca, 12.4–12.6 ppm of Zn, 9.6 ppm of Fe and 2.6 ppm of Cu) and oil yield (364.1–367.5 kg/ha) was also observed due to the application of microbial inoculated sesame stalk compost.

Enhanced soil carbon storage and arbuscular mycorrhizal fungal biomass in a long-term nutrient management under soybean-based cropping system.

To ensure the sustainability of crop production and ecosystem functioning, a thorough understanding of the mechanisms governing soil carbon (C) sequestration and soil health is essential. This study examined the effects of three nutrient management practices (organic, inorganic, and integrated) and two cropping systems (soybean-wheat and soybean-chickpea), on arbuscular mycorrhizal fungi (AMF) and soil C-sequestration in a long-term (12 years) field experiment. We measured the stocks of soil organic carbon, total glomalin-related soil protein, pertinent soil quality parameters such as microbial biomass carbon, and β-glucosidase activity along with AMF biomass [microscopic parameters and 16:1ω5cis phospholipid fatty acid (AM PLFA) and neutral lipid fatty acid (AM NLFA)]. It was observed that the measures of AMF biomass were positively correlated with the soil organic carbon stocks, total glomalin-related soil protein stocks, and soil quality parameters. Organic practice recorded significantly higher AMF spores, mycorrhizal colonization percentage, AM PLFA (2.58 nmol g-1 soil), AM NLFA (7.95 nmol g-1 soil), soil organic carbon stocks (15.78 Mg ha-1), total glomalin-related soil protein stocks (2.10 Mg ha-1), and soil quality parameters such as microbial biomass carbon, and β-glucosidase activity than inorganic and integrated practices. In comparison to soybean-chickpea, C-sequestration was higher in soybean-wheat. Principal component analysis validated the said results and differentiated soybean-wheat under organic practice from the rest of the treatments. In conclusion, our results suggest that organic management in conjunction with soybean-wheat crop rotation enhances AMF and can be recommended for improving soil quality and C sequestration without compromising crop yield.

Crop rotation and fungicides impact microbial biomass, diversity and enzyme activities in the wheat rhizosphere

Sustainable crop production systems should promote large and diverse soil microbial communities to enhance biological soil processes rather than depend solely on chemical interventions that include pesticide applications. Crop rotation increases above-ground temporal diversity which, relative to monoculture, usually increases soil microbial diversity. But comparisons between short and long crop rotations that also include pesticide effects are rare. A 5-yr (2013-2017) field study was conducted to investigate crop rotation and fungicide effects on the soil microbiome and activity. There were nine rotations, with or without fungicide applications, that included four 2-yr rotations (wheat preceded by canola, barley, pea, or flax), four 3-yr rotations where barley or canola were added to the 2-yr rotations, and one rotation where canola and wheat were stacked (canola-canola-wheat-wheat). In 2017, soil microbial biomass, composition, diversity and enzyme activities were measured in the rhizosphere of the final wheat crop in each rotation. Fungicides reduced fungal richness (the number of different fungal taxa) in the wheat rhizosphere (e.g., Chao1 indices of 64.0 vs. 79.9) especially in 2-yr rotations, but rotation length/type and the crops that preceded wheat had different effects on different taxa. Two of the three most predominant prokaryotic phyla, Proteobacteriota and Actinobacteriota, responded differently to rotation length: 3-yr rotations enriched the former (27.4% vs. 20.1% relative abundances), but 2-yr rotations enriched the latter (19.9% vs. 28.3% relative abundances). Relative to oilseed crops preceding the sampled wheat, a field pea preceding crop enriched Actinobacteriota (31.7% vs. 24.8% relative abundances) and the most abundant fungal class, Sordariomycetes (39.1% vs. 22.1% relative abundances), in addition to increasing microbial biomass carbon (MBC) and arylsulphatase activity by 33% and 57%, respectively. Correlations of the relative abundances of fungal or prokaryotic genera with β-glucosidase and arylsulphatase activities were similar (both positive or negative), but they were the opposite of correlations with acid phosphomonoesterase, suggesting a close link between C and S cycling. Besides the nutrient cycling implications of these soil microbial characteristics, there is need to study their biological disease control significance.

Effect of FYM and Inorganic Fertilizers on Growth, Yield of Wheat (Triticum aestivum L.) and Soil Properties of Red Alfisol

The soil multi-nutrient deficiency is not only a problem for soil quality, but also for crop productivity. In problematic soils, in particular acid soils, where low nutrient availability is a concern for general soil use, organic fertilizers are important. The importance of FYM is not limited to their role as accessibility, cost-effectiveness, soil nutrient reservoirs, moisture and ameliorating soil properties that determine soil fertility and productivity status. A pot experiment was conducted on wheat crop at Banaras Hindu University, India, to investigate the effect of FYM and inorganic fertilizers on growth, yield of wheat (Triticum aestivum L.) and soil properties of red Alfisol. The results revealed that maximum number of tiller pot-1 (17.0), plant height (78.0 cm), grain yield (27.4 g pot-1), straw yield (9.98 g pot-1), biological yield (67.5 g pot-1), harvest index (40.6%), were recorded in 1.5RF+FYM1applied pots. The correlation study revealed a significant positive correlation of soil organic carbon with biological yield, and soil available N, P and K. The integration of FYM along with 1.5 times RF significantly enhanced wheat productivity, quality, and soil nutrient availability, indicating the potential of this integrated approach for restoring soil fertility in degraded soils to sustainable crop production in red Alfisol.

Response of Onion to Deficit Irrigation Levels at Different Growth Stages on Yield and Water Productivity

The Ethiopian vegetable sub-sector, particularly onion, is crucial for the economy due to its high productivity and ease of cultivation. However, water scarcity in arid and semi-arid regions hinders its expansion. This study conducted at Wondo Genet Agricultural Research Center aimed to investigate the impact of deficit irrigation levels at various growth stages on onion yield and water productivity. The experiment employed a split plot design with four crop growing stages and three deficit irrigation levels. Results revealed that deficit irrigation significantly affected onion growth parameters and yield components. Bulb diameter, number of leaves per plant, and total bulb yield 5.84 cm, 6.85, 23.26 t/ha, respectively, were notably influenced by deficit irrigation levels, with the highest yields observed under full irrigation. Additionally, water use efficiency varied with deficit irrigation application timing, with the highest efficiency recorded during the maturation stage. Overall, deficit irrigation during initial and maturation stages at 55% ETc application level emerged as the most viable option, ensuring sustainable crop production in water-scarce areas. These findings underscore the importance of adopting deficit irrigation strategies to optimize water use efficiency and enhance onion yield in Ethiopia's vegetable sub-sector.

Vali@mPEG‐TK‐COS: A Dual‐Function Nano‐Pesticide for Fungicidal Action and Plant Immune Modulation

ABSTRACTPesticides play a crucial role in safeguarding crops against pathogens and pests, yet the limited bioavailability of conventional formulations leads to excessive usage, causing environmental and health concerns. In this study, we developed a novel intelligent response‐controlled release nano‐pesticide, Vali@mPEG‐TK‐COS, by coupling chitosan oligosaccharide (COS), a plant immunity regulator, and methoxy polyethylene glycols (mPEG) at either end of thioketal (TK), a material responsive to reactive oxygen species (ROS), and incorporating validamycin (Vali) for controlled release. Vali@mPEG‐TK‐COS exhibits ROS‐responsive behaviour, releasing Vali and COS in response to plant ROS bursts, exhibiting dual capabilities in pathogen control and plant immunity induction during pathogenic attacks. Plant disease experiments confirmed the superior efficacy of Vali@mPEG‐TK‐COS against Rhizoctonia solani, surpassing the control effects of Vali or COS alone. This study presents a sophisticated ROS‐responsive controlled‐release nano‐pesticide with dual fungicidal and plant immunomodulatory properties, offering an advanced strategy to enhance the efficiency of existing pesticides and promote sustainable crop production by reducing overall pesticide usage.

Influence of Crop Residue Management on Maize Production Potential

Residue management at the farm level is essential for ensuring sustainable agricultural productivity. This field experiment, initiated in 2005, provides maize data from 2016 to 2018. This study evaluates the impact of crop residue management and fertilization on maize yield and yield components. Maize was grown in a crop rotation sequence consisting of field pea (Pisum sativum L.), durum wheat (Triticum durum Desf.), milk thistle (Silybum marianum (L.) Gaertn.), and maize (Zea mays L.). The measures studied include aboveground biomass removal (K), aboveground biomass incorporation (R), mineral fertilizer application (F), and their combination (RF). The results indicate that R and RF significantly improve yield parameters, such as kernel number per ear (KNE), thousand seed weight (TSW), stalk yield, and harvest index (HI), compared to control (K) or aboveground biomass incorporation alone (R). Grain yield varied across the years, with significant increases being observed for the fertilizer treatments, particularly when combined with straw or stalk incorporation. A nominal increase in grain yield of 1.43 t ha−1 for the F treatment and 1.86 t ha−1 for the RF treatment represents an increase of 39% to 51% compared to K and R. Strong positive correlations were observed between grain yield and several factors, including ears per hectare (0.61), KNE (0.94), TSW (0.61), and HI (0.85). These findings underscore the role of crop residue management and promoting sustainable crop production.

Land Suitability Assessment and Crop Water Requirements for Twenty Selected Crops in an Arid Land Environment

Expanding projects to reclaim marginal land is the most effective way to reduce land use pressures in densely populated areas, such as Egypt’s Nile Valley and Delta; however, this requires careful, sustainable land use planning. This study assessed the agricultural potential of the El-Dabaa area in the northern region of the Western Desert, Egypt. It focused on assessing land capability, evaluating crop suitability, mapping soil variability, and calculating crop water requirements for twenty different crops. In this work, we evaluated land capability using the modified Storie index model and assessed soil suitability using the land use suitability evaluation tool (LUSET). We also calculated crop water requirements (CWRs) utilizing the FAO-CROPWAT 8.0 model. Additionally, we employed ArcGIS 10.8 to create spatial variability maps of soil properties, land capability classes, and suitability classes. Using a systematic sampling grid, 100 soil profiles were excavated to represent the spatial variability of the soil in the study area, and the physicochemical parameters of the soil samples were analyzed. The results indicated that the study area is primarily characterized by flat to gently sloping surfaces with deep soils. Furthermore, there are no restrictions on soil salinity or alkalinity, no sodicity hazards, and low CaCO3 levels. On the other hand, the soils in the study area are coarse textured and have low levels of CEC and organic matter (OM), which are the major soil limiting factors. As a result, the land with fair capability (Grade 3) accounted for the vast majority of the study area (87.3%), covering 30599.4 ha. Land with poor capability (Grade 4) accounted for 6.5% of the total area, while non-agricultural land (Grade 5) accounted for less than 1%. These findings revealed that S2 and S3 are the dominant soil suitability classes for all the studied crops, indicating moderate and marginal soil suitabilities. Furthermore, there were only a few soil proportions classified as unsuitable (N class) for fruit crops, maize, and groundnuts. Among the crops studied, barley, wheat, sorghum, alfalfa, olives, citrus, potatoes, onions, tomatoes, sunflowers, safflowers, and soybeans are the most suitable for cultivation in the study area. The reference evapotranspiration (ETo) varied between 2.6 and 5.9 mm day−1, with higher rates observed in the summer months and lower rates in the winter months. Therefore, the increase in summer ETo rates and the decrease in winter ones result in higher CWRs during the summer season and lower ones during the winter season. The CWRs for the crops we studied ranged from 183.9 to 1644.8 mm season−1. These research findings suggest that the study area is suitable for cultivating a variety of crops. Crop production in the study area can be improved by adding organic matter to the soil, choosing drought-resistant crop varieties, employing effective irrigation systems, and implementing proper management practices. This study also provides valuable information for land managers to identify physical constraints and management needs for sustainable crop production. Furthermore, it offers valuable insights to aid investors, farmers, and governments in making informed decisions for agricultural development in the study region and similar arid and semiarid regions worldwide.

Identifying hidden factors influencing soil Olsen-P in an alkaline calcareous soil using machine learning and geostatistical techniques

Phosphorus (P) deficiency is one of the major constraints for sustainable crop production in calcareous soils. This study aimed to elucidate the key soil characteristics modulating the variability of soil Olsen P in these typical soils. A comprehensive soil sampling initiative (1.5 samples per hectare) was conducted on a 100-hectare farm, considering 31 attributes that included soil physical and chemical properties, and geographic attributes. Three machine learning algorithms—partial least square regression (PLSR), random forest (RF), and cubist regression (CR)—were employed to understand key variables controlling soil Olsen P. Furthermore, the same data set was used to spatially map the variations in Olsen P levels using ordinary kriging. The results revealed that soil chemical factors, specifically exchangeable manganese and zinc, cation exchange capacity, and carbonate, played a crucial role in controlling P levels. Among the machine learning models, the best performing model was RF (R2= 0.95, RMSE= 1.30 mg kg-1) followed by CR (R2= 0.92 and RMSE= 1.43 mg kg-1). Additionally, the analysis using a Gaussian semi-variogram model showed a good performance (R2= 0.78, RMSE = 2.05 m) in visualizing the spatial distribution of Olsen P, revealing its heterogeneity. The resulting pattern of Olsen P distribution may be attributed not only to soil properties but also to external factors, such as sediment transport through watercourses across the study area and atmospheric deposition from a nearby P mining. Overall, the combination of geostatistical methods and machine learning approach demonstrates a significant potential in understanding the complexity of soil available P (Olsen-P)that could help to develop sustainable and precise P management.

Microbe-Friendly Plants Enable Beneficial Interactions with Soil Rhizosphere Bacteria by Lowering Their Defense Responses.

The use of plant growth-promoting rhizobacteria presents a promising addition to conventional mineral fertilizer use and an alternative strategy for sustainable agricultural crop production. However, genotypic variations in the plant host may result in variability of the beneficial effects from these plant-microbe interactions. This study examined growth promotion effects of commercial vegetable crop cultivars of tomato, cucumber and broccoli following application with five rhizosphere bacteria. Biochemical assays revealed that the bacterial strains used possess several nutrient acquisition traits that benefit plants, including nitrogen fixation, phosphate solubilization, biofilm formation, and indole-3-acetic acid (IAA) production. However, different host cultivars displayed genotype-specific responses from the inoculations, resulting in significant (p < 0.05) plant growth promotion in some cultivars but insignificant (p > 0.05) or no growth promotion in others. Gene expression profiling in tomato cultivars revealed that these cultivar-specific phenotypes are reflected in differential expressions of defense and nutrient acquisition genes, suggesting that plants can be categorized into "microbe-friendly" cultivars (with little or no defense responses against beneficial microbes) and "microbe-hostile" cultivars (with strong defense responses). These results validate the notion that "microbe-friendly" (positive interaction with rhizosphere microbes) should be considered an important trait in breeding programs when developing new cultivars which could result in improved crop yields.

Fruit growth and water use of two pear cultivars grown in South Africa: implications for precision irrigation scheduling

In South Africa, as in other semi-arid countries, sustainable production of high-value crops requires precise management of limited water resources. We investigated daily and seasonal changes in stem and fruit growth as indicators of water stress in pear (Pyrus communis L.) trees, in the Western Cape Province. Stem and fruit growth data were collected hourly throughout the 2022–2023 growing season on 2 cultivars commonly planted in South Africa – Packham’s Triumph and Forelle. Soil water content, tree sap flow, and orchard microclimate were also monitored. Fruit maximum daily shrinkage (MDS) was highly sensitive to soil water deficit and more sensitive than stem size changes. However, the patterns of fruit MDS for both cultivars changed as the season progressed. Early in the season (October–December), there was a strong correlation between fruit MDS and soil water deficit (R2 ~ 0.72). The fruit shrunk with increasing soil water deficit as water loss through transpiration exceeded gains through xylem and phloem inflows. In contrast, daytime fruit size swelled from late December until harvest (February/March), likely because of the dominance of phloem inflows and decreased peel transpiration as the fruit matured. Correlation between fruit expansion and soil water deficit was weaker (R2 ~ 0.32) during the later stage even though fruit growth continued until harvest. Stem MDS consistently showed midday shrinkage throughout the season in response to soil water deficit, but with more scatter (R2~ 0.37). Seasonal total transpiration was greater for Forelle (733 mm) than Packham’s Triumph (539 mm) because of the higher leaf area index of the Forelle and the longer growing season. This study suggests that pear fruit growth data can provide accurate estimates of tree water status, but only during the early stages of growth. Towards maturity, fruit size changes respond indirectly to water deficit, possibly through reductions in photosynthesis.

Genome-wide analysis of calmodulin binding Protein60 candidates in the important crop plants.

Efficient management of environmental stresses is essential for sustainable crop production. Calcium (Ca²⁺) signaling plays a crucial role in regulating responses to both biotic and abiotic stresses, particularly during host-pathogen interactions. In Arabidopsis thaliana, calmodulin-binding protein 60 (CBP60) family members, such as AtCBP60g, AtCBP60a, and AtSARD1, have been well characterized for their involvement in immune regulation. However, a comprehensive understanding of CBP60 genes in major crops remains limited. In this study, we utilized the Phytozome v12.1 database to identify and analyze CBP60 genes in agriculturally important crops. Expression patterns of a Oryza sativa (rice) CBP60 gene, OsCBP60bcd-1, were assessed in resistant and susceptible rice genotypes in response to infection by the bacterial pathogen Xanthomonas oryzae. Localization of CBP60 proteins was analyzed to predict their functional roles, and computational promoter analysis was performed to identify stress-responsive cis-regulatory elements. Phylogenetic analysis revealed that most CBP60 genes in crops belong to the immune-related clade. Expression analysis showed that OsCBP60bcd-1 was significantly upregulated in the resistant rice genotype upon pathogen infection. Subcellular localization studies suggested that the majority of CBP60 proteins are nuclear-localized, indicating a potential role as transcription factors. Promoter analysis identified diverse stress-responsive cis-regulatory elements in the promoters of CBP60 genes, highlighting their regulatory potential under stress conditions. The upregulation of OsCBP60bcd-1 in response to Xanthomonas oryzae and the presence of stress-responsive elements in its promoter underscore the importance of CBP60 genes in pathogen defense. These findings provide a basis for further investigation into the functional roles of CBP60 genes in crop disease resistance, with implications for enhancing stress resilience in agricultural species.

Household food security contextualised: A comparison of Ambros and Maramanzhi villages, South Africa

Smallholder agriculture plays a crucial role in achieving food security, particularly at the household level. However, fallow fields are progressively increasing in former homelands of South Africa. While substantial efforts have been devoted towards addressing food insecurity, access to arable land has not translated to sustainable crop production for smallholder farmers in former homelands of the country. This paper analyses household food security in the context of deagrarianization in two villages, Ambros (Eastern Cape) and Maramanzhi (Limpopo). Using a mixed-method approach, a total of 106 semi-structured questionnaires were administered through face-to-face interviews with household heads. Descriptive statistics were analysed using the IBM SPSS Statistics 27.0 computer program. Meanwhile, qualitative data was coded and content analysis was conducted on NVivo 12 software. The key findings revealed that the primary household income in the study area was earned from social grants. Furthermore, home gardens, with an average size of 4100m2 in Ambros and 4400m2 in Maramanzhi village, played a crucial role in supporting household crop production. However, food insecurity threatened the sustainability of rural livelihoods because the Household Food Insecurity Access Scale (HFIAS) indicator highlighted that a majority of 54% of households in Ambros and 69% in Maramanzhi were mildly food insecure. Food insecurity challenges varied between the two villages but these were mainly perpetuated by food shortages caused by insufficient monthly income and waning household crop production. Although acquiring food was rated as a very important reason for cultivating in both villages, deagrarianization eroded opportunities for increased crop production. Among other solutions, this study recommends that the government improve the delivery of basic services such as water to promote household crop production and the revitalization of fallow fields. These transformations can potentially enhance food security, income and employment opportunities for rural households, contributing to the sustainability of rural livelihoods.

Optimization of Amaranthus production under irrigation and poultry manure application using grey relational analysis

This study was carried out to optimize Amaranthus production under varying irrigation levels and poultry manure applications using Grey Relational Analysis. The experimental design was split-plot, where irrigation treatment was the main plot, while poultry manure was the subplot treatment. The irrigation levels are FIT50, FIT75, FIT100 and FIT135 which correspond to 50% Full irrigation, 75% full irrigation, 100% full irrigation and 135% full irrigation treatments, in combination with the poultry manure application rates M0t/ha, M5t/ha, M10t/ha and M20t/ha. Sixteen experimental treatments were arranged in a 4 x 4 factorial experimental design and replicated 3 times. Sprinkler irrigation system was adopted for the study. Results showed that there was corresponding increase in the response of Amaranthus growth characteristics and yield to the combination of irrigation and poultry manure treatments. The Crop Water-use efficiency initially showed a linear corresponding increase to an average value of 473kg/ha/mm but later exhibits a diminishing return beyond FIT100 irrigation. While production cost showed continual increase to average value of $377/ha as the inputs treatment level also increased to FIT135 irrigation combined with the poultry manure M20t/ha. Grey Relational Grades (GRG) calculated were 0.854, 0.790, 0.787, 0.765, 0.740, 0.629, 0.621, 0.620, 0.546, 0.543, 0.515, 0.475, 0.458, 0.443, 0.417 and 0.403 respectively. Amaranthus cultivated under FIT100_M20t/ha treatment matched with the highest GRG value 0.854, making FIT100_M20t/ha treatment the optimum. Analysis of variance for the GRG showed that irrigation and poultry manure are highly significant input variables for Amaranthus production. The findings from this study guide farmers on the optimal combination of water and organic fertilizer to maximize Amaranthus yield and minimize resource waste, thereby enhancing sustainability in crop production.

Protective role of reactive aluminum phases to stabilize soil organic matter against long-term cultivation in the humid tropics under volcanic influence

ABSTRACT Cultivation can cause rapid depletion of soil organic matter (SOM), particularly in the humid tropics. Understanding the factors controlling SOM storage is a key step toward effective soil management for sustainable crop production. While clay + silt content is known to be an important factor for soil organic carbon (SOC) storage, recent studies have shown greater importance of oxalate-extracted Al (Alo; roughly corresponds to short-range-order aluminosilicate minerals and organo-Al complexes) and Fe (Feo). However, the extent to which these mineralogical factors control the response of SOM pool to land-use changes remains unclear, especially in the tropics. This study aimed to clarify the factors regulating SOM content in croplands compared to secondary forests or home gardens in Negros Occidental, Philippines. Along two line transects having a wide range of Alo contents, soil samples were collected at a depth of 0 − 10 cm from sugarcane sites (n = 33; long-term continuous cultivation of >70 years) that were paired with either secondary forests (n = 10) or home gardens (n = 20). Sugarcane sites had significantly lower SOC and total nitrogen (N) contents than secondary forest and home garden sites, whereas there was no clear difference between the latter two land uses. Both SOC and total N contents showed significant positive correlations with Alo content and, to a much less extent, with Feo content, but not with clay + silt content. The slope of the regression line between SOC and Alo was indifferent between sugarcane and the other two land uses, while the intercept was significantly lower in the sugarcane sites. These results suggest the protective role of Alo phases in both agricultural and forest soils and the presence of unprotected SOM (e.g. plant litter) in the latter sites. Furthermore, δ13C analysis suggested that the proportion of forest (C3 plant) derived carbon remaining in the sugarcane soils ranged between 10% and 50% and increased with Alo content. Together, our study showed indirect evidence of Alo-induced stabilization of SOM against long-term cultivation under the humid tropical environment.

A Review on Plant-microbe Interactions and its Defence Mechanism

Plant-microbe interactions are fundamental to plant health, growth, and defense, influencing agricultural productivity and ecosystem dynamics. These interactions range from symbiotic relationships, such as those with mycorrhizal fungi and nitrogen-fixing bacteria, to pathogenic encounters that trigger complex plant immune responses. Beneficial microbes, including rhizobacteria, mycorrhizae, and endophytes, play a crucial role in enhancing plant defenses through mechanisms like induced systemic resistance (ISR) and production of antimicrobial compounds. Advances in our understanding of these interactions have enabled the development of innovative strategies for crop protection, such as the use of biocontrol agents and microbial inoculants. Additionally, plant breeding and genetic engineering have been employed to introduce resistance genes and modify plant immune responses, resulting in disease-resistant varieties. However, harnessing plant-microbe interactions for sustainable agriculture faces challenges due to the complexity of these interactions in natural environments and the influence of abiotic factors. Limitations in research methodologies, such as difficulties in isolating and studying unculturable microbes, further complicate the translation of findings into practical applications. To overcome these barriers, future research should focus on integrating multi-omics approaches, employing synthetic microbial communities (SynComs), and leveraging CRISPR/Cas technologies for precise manipulation of plant and microbial genes. Microbiome engineering holds promise for promoting beneficial microbial communities, improving plant resilience, and reducing chemical inputs in agriculture. Addressing these challenges will be critical for realizing the full potential of plant-microbe interactions, ultimately contributing to sustainable crop production, improved food security, and ecosystem health. This review highlights current advances, applications, and future directions in the study of plant-microbe interactions, emphasizing their significance for modern agriculture.

Isolation and Identification of Multi-Traits PGPR for Sustainable Crop Productivity Under Salinity Stress

High salinity poses a significant threat to arable land globally and contributes to desertification. Growth-promoting rhizobacteria assist plants in mitigating abiotic stresses and enhancing crop productivity through the production of siderophores, exopolysaccharides (EPS), solubilisation of phosphate, indole-3-acetic acid (IAA), and other secondary metabolites. This study aimed to isolate, identify, and characterise bacteria that exhibit robust growth-promoting properties. A total of 64 bacterial isolates from the rhizosphere of Miscanthus sinensis were evaluated for plant growth-promoting (PGP) traits, including IAA, EPS, siderophores, and solubilisation of phosphate. Among them, five isolates were selected as plant growth-promoting rhizobacteria (PGPR) based on their PGP features and identified via 16S rRNA sequencing: Enterococcus mundtii strain INJ1 (OR122486), Lysinibacillus fusiformis strain INJ2 (OR122488), Lysinibacillus sphaericus strain MIIA20 (OR122490), Pseudomonas qingdaonensis strain BD1 (OR122487), and Pseudomonas qingdaonensis strain MIA20 (OR122489), all documented in NCBI GenBank. BD1 demonstrated a higher production of superoxide dismutase (SOD) (17.93 U/mg mL), catalase (CAT) (91.17 U/mg mL), and glutathione (GSH) (0.18 U/mg mL), along with higher concentrations of IAA (31.69 µg/mL) and salicylic acid (SA) (14.08 ng/mL). These isolates also produced significant quantities of amino and organic acids. BD1 exhibited superior PGP traits compared to other isolates. Furthermore, the NaCl tolerance of these bacterial isolates was assessed by measuring their growth at concentrations ranging from 0 to 200 mM at 8-h intervals. Optical density (OD) measurements indicated that BD1 and INJ2 displayed significant tolerance to salt stress. The utilisation of these isolates, which enhances plant growth and PGP traits under salt stress, may improve plant development under saline conditions.