Synthetic Fertilizers Research Articles

Augmenting the stability of soil aggregate carbon with nutrient management in worldwide croplands

Soil aggregates are the anticipated organic carbon repository, and the stability of aggregate is vital for the efficacy of carbon sequestration. The stability and carbon content of soil aggregates in croplands are affected by nutrient management; however, the changes of aggregate organic carbon stability (AOCS) remain elusive under nutrient management with nature-based solutions. A total of 2035 observations from 269 peer-reviewed articles was compiled to elucidate the changes of AOCS, including aggregate stability, physically protected organic carbon content (i.e., aggregate-associated carbon), and the decomposability of aggregate organic carbon under nutrient management with nature-based solution. The AOCS was significantly improved with nature-based nutrient addition (biochar, manure, straw, and soil conditioner) in contrast to merely synthetic fertilization. Aggregate stability and physically protected organic carbon increased by 18.8–23.3 % and 20.5–34.3 %, respectively, while the decomposability of aggregate organic carbon decreased. Furthermore, the changes of ACOS traits were strengthened with prolonged nutrient management with nature-based solution. Notably, AOCS decreased with the high levels of synthetic nitrogen, in which the contents of aggregate organic carbon and recalcitrant organic carbon were reduced. The findings indicate that nutrient management with nature-based solution can enhance AOCS, therefore, the viable nature-based nutrients are desirable for carbon sequestration in worldwide croplands.

Partial substitution of manure increases N2O emissions in the alkaline soil but not acidic soils

The fertilization regimes of combining manure with synthetic fertilizer are benefits for crop yields and soil fertility in cropping systems as compared to sole synthetic fertilization, but the responses of nitrous oxide (N2O) emissions to these practices are inconsistent in the literatures. We hypothesized that it is caused by different proportions of nitrogen (N) applied as manure and various soil properties. Here, we conducted a microcosm experiment, and measured the N2O emissions from control (no N) and five manure substitution treatments (supplied 100 mg N kg−1 using the combination of urea with manure) with a range of proportions of N applied as manure (0, 25%, 50%, 75%, and 100%) in three different soil types (fluvo-aquic soil, black soil, and latosol) under aerobic condition. The stimulated effect on N2O emissions was more pronounced after manure application in an alkaline soil with high nitrification rate, due to relatively rapid soil DOC depletion and N mineralization of manure. N2O emissions from partial substitution of urea with manure were significantly higher than manure-only addition under high soil pH due to abundant labile C from manure. However, there was no difference between manure substitution treatments under acid soils. Nitrification inhibitor substantially decreased N2O emissions with increasing soil pH, but it was less effective in mitigating N2O emissions with larger proportion of manure. This is likely due to the slow nitrification under low soil pH, and denitrification derived N2O increased with increasing manure application rate. Collectively, our study shows that the application of manure substitution to alkaline soils requires careful consideration, which might have rapid nitrification potential and hence trigger significant N2O emissions. The knowledge gained in this work will help the decision-makers in optimizing a sound N fertilization regime interacted with soil properties for sustainable crop production and N2O mitigation.

Feeding Our Food; Starving Our Environment

For thousands of years, farmers have utilized organic soil additives to enhance their crop yields and livelihoods. Today, modern agriculture largely relies on synthetic fertilizers to produce enough crops to supply our global population and its competitive markets. While these fertilizers successfully increase crop production, previous research has proven that they perpetuate long-term environmental and human health risks. My goal is to examine how human-environment relationships with fertilizers have changed over time and how capitalism influences the socio-environmental impact of synthetic fertilizers on our world today. Through the Institutions and Commons lens, I examine how fertilizer-related pollution and limited fertilizer regulations pose significant risks to the environmental commons of society and to the health of communities. Additionally, I utilize the Political Economy perspective to examine how capitalistic greed in the fertilizer industry has significantly contributed to global warming, overproduction of resources, and an altered human perception of nature as a whole. While there are advantages of synthetic soil-enhancement technologies, it is clear that more stringent agricultural regulations and responsibility measures are needed to minimize the negative long-term consequences of synthetic fertilizer use in modern farming practices.

PENYULUHAN DAN PENDAMPINGAN PENGOLAHAN KOTORAN TERNAK SAPI DI DUSUN MONGGE-2 MENJADI PUPUK ORGANIK PADAT

Mongge-2 Hamlet, one of the hamlets in the Penyangga Village area. Services activity accompanied by assistance in processing livestock manure to produce organic fertilizer to support sustainable integrated farming system in this hamlet. The aim is to empower the community with productive activities through optimizing the potential of natural resources and human resources by involving relevant stakeholders. This service activity will be carried out in 2023, starting with a location survey activity. The next activity is coordinated to determine target communities to be given regular counseling and assistance to produce solid organic fertilizer and how to apply it in the field. After the outreach and mentoring activities are carried out, monitoring, reporting and publication are carried out. The organic fertilizer produced is applied to garden and agricultural cultivation around Mongge-2 Hamlet. This organic fertilizer is expected to play a role in improving the soil and is expected to reduce the use of synthetic fertilizers and increase the fertility of the media used. so that agricultural products are healthier for consumption. Further research needs to be carried out to determine the content of the organic fertilizer produced and its effect on the growth of agricultural cultivation of certain commodities.

Synthetic consortia of four strains promote Schisandra chinensis growth by regulating soil microbial community and improving soil fertility.

Synthetic consortia performed better in promoting Schisandra chinensis growth than individual strains, and this result provides valuable information for the development of synthetic microbial fertilizers. Schisandra chinensis is an herbal medicine that can treat numerous diseases. However, the excessive reliance on chemical fertilizers during the plantation of S. chinensis has severely restricted the development of the S. chinensis planting industry. Plant growth-promoting rhizobacteria (PGPR) can promote the growth of a wide range of crops, and synthetic consortia of them are frequently superior to those of a single strain. In this study, we compared the effects of four PGPR and their synthetic consortia on S. chinensis growth. The pot experiment showed that compared with the control, synthetic consortia significantly increased the plant height, biomass, and total chlorophyll contents of S. chinensis, and their combined effects were better than those of individual strains. In addition, they improved the rhizosphere soil fertility (e.g., TC and TN contents) and enzyme activities (e.g., soil urease activity) and affected the composition and structure of soil microbial community significantly, including promoting the enrichment of beneficial microorganisms (e.g., Actinobacteria and Verrucomicrobiota) and increasing the relative abundance of Proteobacteria, a dominant bacterial phylum. They also enhanced the synergistic effect between the soil microorganisms. The correlation analysis between soil physicochemical properties and microbiome revealed that soil microorganisms participated in regulating soil fertility and promoting S. chinensis growth. This study may provide a theoretical basis for the development of synthetic microbial fertilizers for S. chinensis.

Biochar Loaded with a Bacterial Strain N33 Facilitates Pecan Seedling Growth and Shapes Rhizosphere Microbial Community.

Biochar and beneficial microorganisms have been widely used in ecological agriculture. However, the impact of biochar loaded with microbes (BM) on plant growth remains to be understood. In this study, BM was produced by incubating pecan biochar with the bacterial strain N33, and the effects of BM on pecan growth and the microbial community in the rhizosphere were explored. BM application significantly enhanced the biomass and height of pecan plants. Meanwhile, BM treatment improved nutrient uptake in plants and significantly increased the chlorophyll, soluble sugars, and soluble proteins of plants. Furthermore, BM treatment improved the soil texture and environment. Finally, BM application substantially enhanced the diversity of soil fungi and bacteria as well as the relative abundances of the phyla Firmicutes and Chloroflexi, and families Bacillaceae and Paenibacillaceae, as shown by high-throughput sequencing. Together, this study clarified the growth-promotive effects of BM on pecan plants and suggested an alternative to synthetic fertilizers in their production.

Microbial consortium with multifunctional attributes for the plant growth of eggplant (Solanum melongena L.).

In the past few decades, the pressure of higher food production to satisfy the demand of ever rising population has inevitably increased the use synthetic agrochemicals which have deterioration effects. Biostimulants containing beneficial microbes (single inoculants and microbial consortium) were found as an ideal substitute of synthetic chemical fertilizers. In recent years, microbial consortium is known as a better bioinoculant in comparison to single inoculant bioformulation because of multifarious plant growth-promoting advantages. Looking at the advantageous effect of consortium, in present investigation, different bacteria were isolated from rhizospheric soil and plant samples collected from the Himalayan mountains on the green slopes of the Shivaliks, Himachal Pradesh. The isolated bacteria were screened for nitrogen (N) fixation, phosphorus (P)solubilization and potassium (K) solubilization plant growth promotingattributes, and efficient strains were identified through 16S rRNA gene sequencingand BLASTn analysis. The bacteria showing a positive effect in NPK uptake were developed as bacterial consortium for the growth promotion of eggplant crop. A total of 188 rhizospheric and endophytic bacteria were sorted out, among which 13 were exhibiting nitrogenase activity, whereas 43 and 31 were exhibiting P and K solubilization traits, respectively. The selected three efficient and potential bacterial strains were identified using 16S rRNA gene sequencing as Enterobacter ludwigii EU-BEN-22 (N-fixer; 35.68 ± 00.9 nmol C2H4 per mg protein per h), Micrococcus indicus EU-BRP-6 (P-solubilizer; 201 ± 0.004 mg/L), and Pseudomonas gessardii EU-BRK-55 (K-solubilizer; 51.3 ± 1.7 mg/mL), and they were used to develop a bacterial consortium. The bacterial consortium evaluation on eggplant resulted in the improvement of growth (root/shoot length and biomass) and physiological parameters (chlorophyll, carotenoids, total soluble sugar, and phenolic content) of the plants with respect to single culture inoculation, chemical fertilizer, and untreated control. A bacterial consortium having potential to promote plant growth could be used as bioinoculant for horticulture crops growing in hilly regions.

Organic Fertilizers and Bio-Waste for Sustainable Soil Management to Support Crops and Control Greenhouse Gas Emissions in Mediterranean Agroecosystems: A Review

Agriculture is facing several challenges related to its sustainability. In this regard, the need to reduce its environmental impact related to the use of synthetic inputs and its potential role in mitigating global warming and climate change call for a review of crop management. In this context, and in the framework of achieving sustainable development goals, the use of organic fertilizers and bio-waste represents a valuable contribution to the agricultural transition towards a bioeconomy model by reducing the negative impacts of waste disposal. Farmyard manure, composts, digestate from agrifood processes, and biochar are, among organic fertilizers, commonly used to manage soils and support crop growth. These fertilizers can provide essential nutrients, improve structure, and enhance microbial activity, thus increasing soil fertility and agriculture sustainability. While organic fertilizers offer the benefits of soil fertility and plant nutrition, their impact on greenhouse gas (GHG) emissions is complex and varies depending on factors such as fertilizer type, soil conditions, and management practices. Although organic fertilizers may initially increase GHG emissions, they often lead to carbon sequestration in soils highlighting a negative C balance. Additionally, organic fertilizers promote a reduction in fossil fuel consumption used for synthetic fertilizer production, further contributing to GHG emissions’ reduction. Therefore, while organic fertilizers pose challenges in managing GHG emissions, their various benefits warrant careful consideration and strategic implementation in agricultural systems.

Manure replacing synthetic fertilizer improves crop yield sustainability and reduces carbon footprint under winter wheat–summer maize cropping system

Manure replacing synthetic fertilizer is a viable practice to ensure crop yield and increase soil organic carbon (SOC), but its impact on greenhouse gas (GHG) emissions is inconsistent, thus remains its effect on CF unclear. In this study, a 7-year field experiment was conducted to assess the impact of replacing synthetic fertilizer with manure on crop productivity, SOC sequestration, GHG emissions and crop CF under winter wheat–summer maize cropping system. Five treatments were involved: synthetic nitrogen, phosphorus, and potassium fertilizer (NPK) and 25%, 50%, 75%, and 100% of manure replacing synthetic N (25%M, 50%M, 75%M, and 100%M). Compared with NPK treatment, 25%M and 50%M treatments maintained annual yield (winter wheat plus summer maize) and sustainable yield index (SYI), but 75%M and 100%M treatments significantly decreased annual yield, and 100%M treatment also significantly reduced annual SYI. The SOC content exhibited a significant increasing trend over years in all treatments. After 7 years, SOC storage in manure treatments increased by 3.06–11.82 Mg ha−1 relative to NPK treatment. Manure treatments reduced annual GHG emissions by 14%–60% over NPK treatment. The CF of the cropping system ranged from 0.16 to 0.39 kg CO2 eq kg−1 of grain without considering SOC sequestration, in which the CF of manure treatments lowered by 18%–58% relative to NPK treatment. When SOC sequestration was involved in, the CF varied from −0.39 to 0.37 kg CO2 eq kg−1 of grain, manure treatments significantly reduced the CF by 22%–208% over NPK treatment. It was concluded that replacing 50% of synthetic fertilizer with manure was a sound option for achieving high crop yield and SYI but low CF under the tested cropping system.

Utilizing Insect Frass (Faecal Matter): A Sustainable Approach to Organic Fertilization in Agriculture

Insect frass, commonly known as insect fecal matter, is emerging as a sustainable solution for organic fertilization in agriculture. This paper explores the potential benefits and applications of utilizing insect frass as an organic fertilizer, highlighting its role in promoting sustainable agricultural practices. Through a comprehensive review of literature, this study examines the nutrient composition of insect frass and its impact on soil fertility and plant growth. Furthermore, the paper discusses the ecological advantages of incorporating insect frass into agricultural systems, including its ability to reduce reliance on chemical fertilizers and minimize environmental pollution. Additionally, the study delves into various methods of utilizing insect frass in different agricultural settings, ranging from soil incorporation to foliar applications. Moreover, the paper addresses the economic feasibility of insect frass as a viable alternative to conventional fertilizers, considering factors such as production costs and market demand. By synthesizing existing research and providing insights into practical applications, this paper underscores the potential of insect frass as a sustainable approach to organic fertilization in agriculture. Ultimately, this study aims to promote further exploration and adoption of insect frass as a valuable resource for enhancing soil health, increasing crop yields, and fostering ecological sustainability in agricultural practices. As agricultural sustainability becomes increasingly imperative, innovative solutions are sought to reduce reliance on synthetic fertilizers and mitigate environmental impacts. In this pursuit, the utilization of insect frass as an organic fertilizer presents a promising avenue for sustainable agriculture. With the rapid expansion of the human population, the mass breeding of insects for feed and food has emerged as a highly efficient means of protein production. A notable byproduct of this process is insect feces, or frass, which exhibits remarkable nutrient content and abundance, surpassing animal biomass production by up to 40 times. Harnessing insect frass as an organic fertilizer offers numerous advantages, including enhanced soil fertility, improved crop yield, and reduced dependency on agrochemicals.

A novel smart fertigation system for irrigation with treated wastewater: Effects on nutrient recovery, crop and soil

Both southern and northern regions of Italy are experiencing reduced precipitation and increased heat waves due to climate change, negatively affecting agricultural sector. Urban wastewater could be a solution to this problem, providing a constant source for irrigation and reducing synthetic fertilizer use. This research presents a two-year field study on using tertiary treated wastewater for processing tomato crop irrigation through an innovative smart fertigation system, designed to supply the exact doses of NPK nutrients considering those already delivered to the plants via the irrigation water. With the aim of studying the effects of irrigation with treated wastewater, three water sources were compared: fresh water added with chemical fertilizer, tertiary treated wastewater added with chemical fertilizer and tertiary treated wastewater without addition of fertilizer. The proposed system was efficient and consistent with the design, it saved considerable amounts of fertilizers, handling nutrient fluctuations in wastewater. Of the three irrigation water types that have been tested, only the one that used tertiary treated wastewater alone without additional fertilizers was not capable of meeting tomato nutritional needs, despite the fact that significant macronutrient savings were achieved. No negative effects on soil or plant physiological performances were observed. Plants irrigated with wastewater showed similar growth and productivity to those irrigated with fresh water and no significant differences in fruit quality were found, highlighting the benefits of wastewater reuse for crop irrigation.

Enhancing phosphorus use efficiency and soil quality indicators in lowland paddy ecosystem through Azolla, rice straw, and NPKS fertilizers

PurposeThis study investigates the influence of incorporating Azolla, rice straw, and NPKS fertilizers on phosphorus use efficiency (PUE) and rice productivity in lowland paddy fields. Despite Azolla’s well-known role as a nitrogen-fixing aquatic fern in rice production, its specific impact on PUE remains unclear. The primary objective is to explore diverse treatment combinations to identify synergies that enhance both PUE and overall rice productivity.MethodsThe study was conducted at Mkula Irrigation Scheme in the Kilombero Valley, Tanzania; the field experiment employed a randomized complete block design with 13 treatments and three replications. Treatments comprised various combinations of Azolla, rice straw, and chemical fertilizers, incorporating 50% and 100% rates of nitrogen (N) applied with phosphorus (P), potassium (K), and sulfur (S).ResultsThe study reveals the substantial impact of Azolla application on total nitrogen, available phosphorus, and exchangeable potassium levels in the soil. Particularly noteworthy were treatment combinations involving Azolla, rice straw, and reduced rates of synthetic nitrogen, along with specific P, K, and S applications, which exhibited the highest phosphorus uptake and PUE. Specifically, combining rice straw and Azolla with reduced N rates, alongside 30 kg P ha−1 + 30 kg K ha−1 + 20 kg S ha−1, resulted in the highest phosphorus uptake (73.57 kg/ha) and PUE (46.24%).ConclusionIntegrated nutrient management, incorporating rice straw and Azolla alongside synthetic fertilizers, demonstrates synergistic effects on phosphorus uptake and efficiency while maintaining soil quality. The study underscores the potential of such integrated strategies to optimize PUE and contribute to sustainable rice production in lowland paddy fields.

Nano Fertilizers: New Vistas towards Sustainable Agriculture and Climate Change Mitigation: A Review

To ensure the food and nutritional security of the burgeoning global population, food production needs to be doubled in developing countries by 2050. Currently, 30-40% of agriculture production predominantly relies on chemical fertilizers. Precise crop nutrition, low nutrient efficiency, maintaining soil fertility, less damage to soil flora and minimal environmental footprint are the major challenges in modern agriculture. Recent developments in the application of nanotechnology to produce agriculture inputs emerged as a sustainable solution for addressing the challenges in modern intensive agriculture by replacing synthetic bulk fertilizers with their nanoparticle size ( less than 100 nm), superior properties and smart delivery system. Nano fertilizers had the potential to fulfill the requirements of plant nutrition along with imparting sustainability in crop production without compromising the yield of the crops. Some of the current research studies have been reviewed in this paper with citation and these results showed that nano fertilizers have a substantial effect on plant growth, development and physiological parameters including chlorophyll content and photosynthetic activity, it depends on their composition, method and time of application. Their enhanced nutrient use efficiency, correlated with mitigating greenhouse gas emissions. Hence evolving as a cutting-edge approach for sustainable agriculture in climate change is enlightened in this review.

Investigating the Impacts of Wastewaters on Lettuce (Lactuca sativa) Seed Germination and Growth

There is an opportunity for agriculture to utilize the many different waste streams in our world and capitalize on what would otherwise be viewed as waste products. Hydrothermal liquefaction (HTL) is an emerging technology for converting wet biomass to bio-crude oil, while aquaponics is a practice tracing back to indigenous communities around the world; both technologies have the potential to sustainably provide the necessary nutrients for crop growth. Food systems worldwide are actively transitioning to address the many challenges of climate change in a sustainable and efficient manner. Urban agriculture (UA) has the potential to generate localized crops in densely populated areas year-round, but has its challenges, involving high capital requirements, especially for vertical farming and controlled-environment agriculture, and being energy intensive due to artificial lighting and fossil fuel-based synthetic fertilizers. This study investigated the potential for aquaponic and HTL effluents to be used in hydroponic systems through a seed germination screening experiment. Buttercrunch lettuce (Lactuca sativa L.) seeds were placed in Ziploc plastic bags on paper towels saturated with the wastewater treatments for 10 days while their total length of growth was routinely measured from the tip of the root to the tip of the cotyledons. The Chicago High School for Agricultural Sciences (CHSAS) aquaponic effluent with a 5.8× times higher nitrate concentration and 4.25× higher ammonia concentration outperformed the Bevier aquaponic effluent and improved any other source water it was combined with. Results also showed that seed germination was not inhibited in the presence of 2–8% solutions of hydrothermal liquefaction aqueous phase (HTL-AP), which performed on par with standard hydroponic fertilizer; solutions of a higher percentage, though, may lead to inhibitory effects in plants, and those of a lower percentage may not provide enough nutrients in the proper forms to sustain plant growth. However, the nutrient analyses revealed that there is still much to investigate regarding the combination of wastewaters to provide a complete, well-rounded, and sustainable source for hydroponic crop production.

The effect of farming techniques on degradation of DDT in historical cotton farms

DDT was used in the mid 20th century for crop and livestock production. After use, DDT and its degradates DDE and DDD (collectively DDX) remain in the environment for decades. A few studies have reported that the rate of degradation of DDT into its metabolites is affected by various farming techniques like tillage, irrigation, and use of fertilizers. However, most of these studies did not evaluate active farms, and none of them focused on the Southeast US or historical cotton farms. Therefore, in this study, we aimed to determine if different farming techniques affect the decomposition of DDT in Walton County, Georgia, where farms historically grew cotton. Five Walton County farms were sampled for soil, and churches were sampled as control sites. The extensive land history of the farms was recorded, and the soil levels of p,p’-DDT, p,p’-DDE, p,p’-DDD, o,p’-DDT, and o,p’-DDE were measured using gas chromatography-tandem mass spectrometry. All farm sites had detectable levels of p,p’-DDT, p,p’-DDE, and p,p’-DDD, while few sites had detectable levels of o,p’-DDT and o,p’-DDE. Tillage was found to speed up p,p’-DDE degradation, but there was no effect on p,p’-DDT degradation. Plowing was associated with an increase in decomposition of p,p’-DDT, but p,p’-DDE and p,p’-DDD were not significantly increased. The largest difference in the degradation of DDT was based on the fertilizer type. Natural fertilizer sped up degradation of p,p’-DDT and p,p’-DDE; synthetic fertilizer increased p,p’-DDE degradation, but not p,p’-DDT degradation.

Combined interaction between the diazotrophic Niallia circulans strain YRNF1 and arbuscular mycorrhizal fungi in promoting growth of eggplant and mitigating root rot stress caused by Rhizoctonia solani

Rhizoctonia root rot of eggplant, caused by Rhizoctonia solani, is an economically important disease. Niallia circulans YRNF1 and arbuscular mycorrhizal fungi (AMF) were assessed for their biocontrol and biofertilizing effects against R. solani, as potential replacements for synthetic fungicides and fertilizers. The diazotrophic N. circulans YRNF1, isolated from soil, reduced in vitro growth of R. solani by 42%. GC-MS analysis of culture filtrate of N. circulans YRNF1 detected bioactive compounds, including butyric acid (85%) and ethylene glycol (8%). In greenhouse experiments, combined application of N. circulans YRNF1 and AMF reduced the severity of eggplant root rot by 26%. This combined treatment triggered the transcriptional expression of five resistance genes (JERF3, PAL1, C3H, CHI2, and HQT) in the treated eggplants. Biochemical analyses of the infected eggplant roots treated with the combined bio-inoculants showed enhancement of the phenol content (+188%), and increased antioxidant enzyme activity, mainly of POD (+104%) and PPO (+72%). Combined application of N. circulans YRNF1 and AMF also promoted eggplant growth and improved the total NPK concentrations in treated plant leaves. Inoculation of eggplant with N. circulans YRNF1 in the presence of AMR increased the mycorrhization level. This is the first report of N. circulans and AMF as potential agents for biological control of Rhizoctonia root rot and growth promotion of eggplant.

The Role of Organic Farming in Sustainable Agriculture

Organic farming, as a sustainable alternative to conventional high-input practices reliant on synthetic fertilizers, fungicides, and pesticides, prioritizes the vitality of soil as a living ecosystem. Embracing practices such as crop rotation, animal manures, crop residues, green manures, and biological pest and disease control, organic agriculture aims to uphold soil health and productivity. By meeting present food demands in an environmentally conscientious manner, organic farming also safeguards the needs of future generations, thereby preserving and nurturing our ecosystem. Modern agriculture has detrimentally impacted the environment, leading to issues such as decreased soil fertility, elevated water hardness, insect resistance development, reduced genetic diversity in plants, heightened levels of toxic residues in the food chain and animal feed, contributing to health problems and environmental degradation. In contrast, organic farming nurtures plants with essential macronutrients and micronutrients while simultaneously enhancing soil physical, chemical, and biological characteristics. Guided by the ethos of sustainability, organic farming prioritizes mitigating health risks linked to synthetic inputs and cultivating a healthier ecosystem. The minimal environmental footprint of organic farming positions it as a practical solution for tackling urgent concerns like soil degradation, water pollution, and global ecological well-being. Essentially, organic farming stands out as a beacon of sustainable agriculture, paving the way to reconcile food production with environmental conservation. Moreover, organic farming's low environmental impact presents an opportunity to rehabilitate and enhance degraded agricultural lands.

Exploring the best nutrient management options for improving the maize yield for future climate change scenario with DSSAT crop simulation model in century old Permanent Manurial Experiment

Increasing the C sequestration potential and higher soil organic carbon stocks with the application of organic manures will reflect in the improvement of crop productivity. Long-term monitoring approach is essential to evaluate these impacts, especially given the escalating effects of climate change on agriculture. Recognizing this, a 112-year-long Permanent Manurial Experiment (PME) at Tamil Nadu Agricultural University, Coimbatore, India, investigates the influence of application of organic manures. Utilizing the DSSAT crop simulation model, the study assessed the impact of organic manure, specifically NPK + FYM (Farm Yard Manure), on maize yield over 25 years on a sandy-loam Alfisol. Data collected from the field experiment including crop growth parameters, management options, weather, and soil data were used for simulations. Results showed a 93.8% agreement between simulated and observed yields, endorsing NPK + FYM treatment with a 20% increase in grain yield by 2032 compared to using 100% NPK alone. Furthermore, the study explored future climate change scenarios’ impact on maize yield. It highlighted that NPK + FYM consistently outperformed other treatments, emphasizing its efficacy in increasing the yields under changing climatic conditions. This approach emerges as promising for enhancing carbon sequestration, elevating soil organic carbon stocks, and significantly improving crop productivity. In conclusion, adopting the NPK + FYM treatment is recommended to achieve optimal maize yield outcomes, surpassing the effects of using NPK or FYM independently. This research signifies the potential of combining organic manures with synthetic fertilizers in sustainable agriculture amid evolving climate challenges.

Identifying functional multi-host shuttle plasmids to advance synthetic biology applications in Mesorhizobium and Bradyrhizobium.

Ammonia availability has a crucial role in agriculture as it ensures healthy plant growth and increased crop yields. Since diazotrophs are the only organisms capable of reducing dinitrogen to ammonia, they have great ecological importance and potential to mitigate the environmental and economic costs of synthetic fertilizer use. Rhizobia are especially valuable being that they can engage in nitrogen-fixing symbiotic relationships with legumes, and they demonstrate great diversity and plasticity in genomic and phenotypic traits. However, few rhizobial species have sufficient genetic tractability for synthetic biology applications. This study established a basic genetic toolbox with antibiotic resistance markers, multi-host shuttle plasmids and a streamlined protocol for biparental conjugation with Mesorhizobium and Bradyrhizobium species. We identified two repABC origins of replication from Sinorhizobium meliloti (pSymB) and Rhizobium etli (p42d) that were stable across all three strains of interest. Furthermore, the NZP2235 genome was sequenced and phylogenetic analysis determined its reclassification to Mesorhizobium huakuii. These tools will enable the use of plasmid-based strategies for more advanced genetic engineering projects and ultimately contribute towards the development of more sustainable agriculture practices by means of novel nitrogen-fixing organelles, elite bioinoculants, or symbiotic association with nonlegumes.

Linking the humification of organic amendments with size aggregate distribution: Insights into molecular composition using FT-ICR-MS

Soil organic matter (SOM) plays a pivotal role in enhancing physical and biological characteristics of soil. Humic substances constitute a substantial proportion of SOM and their increase can improve crop yields and promote agricultural sustainability. While previous research has primarily assessed the influence that humic acids (HAs) derived from natural water have on soil structure, our study focuses on the impact of HAs on soil aggregation under different fertilizer regimes. During the summer cropping season, maize was cultivated under organic and synthetic fertilizer treatments. The organic fertilizer treatment utilized barley (Hordeum vulgare L.) and hairy vetch (Vicia villosa R.) as an organic amendment five days prior to maize planting. The synthetic treatment included a synthetic fertilizer (NPK) applied at South Korea's recommended rates. The organic treatment resulted in significant improvements in the soil aggregates and stability (mean weight diameter, MWD; p < 0.05) compared to the synthetic fertilizer application. These improvements could be primarily attributed to the increased quantity and quality of HAs in the soil derived from the organic amendment. The amount of extracted HAs in the organic treatment was nearly twice that of the synthetic treatment. Additionally, the organic treatment had a 140 % larger MWD and a 40 % increase in total phenolic content compared to the synthetic treatment. The organic treatment also had an increased macronutrient uptake (p < 0.001), an 11 % increase in aboveground maize biomass, and a 21 % increase in grain yield relative to the synthetic treatment. Thus, the enhancement of HA properties through the incorporation of fresh organic manure can both directly and indirectly increase crop productivity.