Fertilizer Treatments Research Articles

Nitrogen fertilization and soil nitrogen cycling: Unraveling the links among multiple environmental factors, functional genes, and transformation rates

Anthropogenic nitrogen (N) inputs substantially influence the N cycle in agricultural ecosystems. However, the potential links among various environmental factors, nitrogen functional genes, and transformation rates under N fertilization remain poorly understood. Here, we conducted a five-year field experiment and collected 54 soil samples from three 0–4 m boreholes across different treatments: control, N-addition (nitrogen fertilizer) and NPK-addition (combined application of nitrogen, phosphorus and potassium fertilizers) treatments. Our results revealed pronounced variations in soil physiochemical parameters, metal concentrations and antibiotic levels under both N and NPK treatments. These alternations induced significant shifts in bacterial and fungal communities, altered NFG abundance and composition, and greatly enhanced rates of nitrate reduction processes. Notably, nutrients, antibiotics and bacteria exerted a more pronounced influence on NFGs and nitrate reduction under N treatment, whereas nutrients, metals, bacteria and fungi had a significant impact under NPK treatment. Furthermore, we established multidimensional correlations between nitrate reduction gene profiles and the activity rates under N and NPK treatments, contrasting with the absence of significant relationships in the control treatment. These findings shed light on the intricate relationships between microbial genetics and ecosystem functions in agricultural ecosystem, which is of significance for predicting and managing metabolic processes effectively.

Comparison of Organic and Inorganic Fertilization in Fenugreek Cultivation Using Nitrogen Indicators

Nitrogen indices could be used to evaluate organic and inorganic fertilization because they provide quantitative measures of nitrogen availability in the soil, allowing for a more accurate assessment of nutrient-management practices and optimization of crop yields. This study investigates the impact of different fertilization types and salinity on various soil parameters in fenugreek (Trigonella foenum-graecum L.) cultivation and nitrogen indices. A field experiment was established at the Agricultural University of Athens during the cropping period of 2018–2019 (CP I), 2019–2020 (CP II), and 2020–2021 (CP III) in a split-plot design with two main salinity treatments (high salinity, HS, and conventional salinity, CS) and five fertilization treatments (biocyclic–vegan humus soil (BHS), manure (FYM), compost (COMP), inorganic fertilization (11–15–15), and the control (C). The Nitrogen Balance Intensity (NBI) was statistically significantly affected by the factors of fertilization (p ≤ 0.01) and salinity (p ≤ 0.001) for CP I. The maximum NUEcrop value was recorded in the FYM treatment (0.83 ± 0.04) and the minimum in the COMP treatment (0.64 ± 0.04). Physiological efficiency (PE) was not significantly affected by any treatment for CP III. The fertilization factor significantly affected the NUEsoil index (p ≤ 0.001) for all three CPs. For CP I, the highest Nitrogen Uptake Efficiency (NUpE) value was recorded in the BHS treatment (27.08 ± 7.31) and the lowest in the C treatment (13.22 ± 7.31). There were no significant differences in CP I and CP II NUEbalance values among the NPK, BHS, and FYM treatments. These findings underscore the potential of organic fertilizers in addressing the global nitrogen challenge and promoting environmentally sustainable farming practices.

Weight Regain following Bariatric Surgery and in vitro Fertilization Outcomes

Introduction: The aim of this study was to estimate the time to pregnancy and live birth and evaluate the effect of weight regain in women with a history of bariatric surgery (BS) who underwent in vitro fertilization (IVF) treatments. Methods: This is a retrospective cohort study. All patients with previous BS who underwent IVF treatment in a tertiary university-affiliated hospital between 2013 and 2022 were included. Time to pregnancy and live birth were compared between patients who regained less than or greater than three points of body mass index (BMI) from the nadir weight after BS. Kaplan-Meier curves and log-rank tests were used to compare groups. Results: A total of 78 patients were included in this study. The positive β-hCG, clinical pregnancy, and live birth rates following BS were 89.4%, 78.9%, and 50.8%, respectively. The median time from the beginning of IVF treatments to a positive β-hCG test was 2.97 months (95% CI: 1.04–4.89 months), to a clinical pregnancy was 7.1 months (95% CI: 3.56–10.91), and to a live birth was 20.2 months. Women who maintained their nadir BMI following BS had nearly twice the chance of achieving a clinical pregnancy (HR 1.967, 95% CI: 1.026–3.771, p = 0.042) and were approximately three times more likely to achieve a live birth (2.864, 95% CI: 1.196–6.859, p = 0.018) than those who regained at least three points of BMI. Conclusion: Weight regain after BS is associated with a lower rate of live births and prolonged time to achieve clinical pregnancy and live birth.

Effects of climate change and deep fertilization on the growth and yield of winter wheat in the Loess Plateau of China.

Global temperature is projected to rise continuously under climate change, negatively impacting the growth and yield of winter wheat. Optimizing traditional agricultural measures is necessary to mitigate potential winter wheat yield losses caused by future climate change. This study aims to explore the variations in winter wheat growth and yield on the Loess Plateau of China under future climate change, identify the key meteorological factors affecting winter wheat growth and yield, and analyze the differences in winter wheat yield and root characteristics under different fertilization depths. Meteorological data from 20 General Circulation Models were applied to drive the Decision Support System for Agrotechnology Transfer model, simulating the future growth characteristics of winter wheat under various fertilization depths. The Random Forest model was used to determine the relative importance of meteorological factors influencing winter wheat yield, root length density and leaf area index. The results showed that temperature and high emission concentration were primary factors influencing crop yield under future climate change. The temperature increase projected from 2021 to 2100 would be anticipated to shorten the phenology period of winter wheat by 2-16 days and reduce grain yield by 2.9-12.7% compared to the period from 1981 to 2020. Conversely, the root length density and root weight of winter wheat would increase by 1.2-10.9% and 0.2-24.1%, respectively, in the future, and excessive allocation of root system resources was identified as a key factor contributing to the reduction in winter wheat yield. Compared with the shallow fertilization treatment (N5), the deep fertilization treatments (N15 and N25) increased the proportion of roots in the deep soil layer (30-60 cm) by 2.7-10.2%. Because of the improvement in root structure, the decline in winter wheat yield under deep fertilization treatments in the future is expected to be reduced by 1.2% to 6.5%, whereas water use efficiency increases by 1.1% to 2.4% compared to the shallow fertilization treatment. The deep fertilization treatment can enhance the root structure of winter wheat and increase the proportion of roots in the deep soil layer, thereby effectively mitigating the decline in winter wheat yield under future climate change. Overall, optimizing fertilization depth effectively addresses the reduced winter wheat yield risks and agricultural production challenges under future climate change. © 2024 Society of Chemical Industry.

Effects of 40 Years of Fertilizer Application on the Characteristics of Soil Enzymatic Stoichiometry in Black Soil

Microorganisms produce extracellular enzymes to meet elemental requirements and cope with stoichiometric imbalances of resources. To gain insights into the cycling of C, N, and P, the activities of the C∶N∶P acquisition enzymes have been extensively investigated. To detect the effects of long-term fertilization practices on soil nutrient balance and characteristics of soil enzymatic stoichiometry in black soil, four different fertilization treatments were selected： no fertilization （CK）, nitrogen fertilizer （N）, phosphorus fertilizer （P）, and combination of nitrogen and phosphorus fertilizers （NP）. Soil samples were collected in both April 2021 and April 2022 to determine soil enzyme activities and their stoichiometric characteristics. The results showed that soil acid phosphatase and β-D-glucosidase activities were significantly higher in the N and NP treatments than in CK by 68%-158% and 26%-222%, respectively. Soil β-N-acetylaminoglucosidase activities were significantly higher in the P and NP treatments, with the highest around 75.48 nmol·（g·h）-1 and 106.81 nmol·（g·h）-1, respectively. Two-way ANOVA analysis showed that N and P inputs had a great impact on soil enzyme activities. Redundancy analysis showed that the main factors controlling enzyme activities were soil pH, microbial biomass phosphorus, and soil available P content. It was found that N inputs significantly increased enzyme vector length, which was ranged from 1.32 to 1.52, and the enzyme vector angles were all larger than 45°, suggesting C and P co-limited in the black soils. These findings suggest that 40 years of fertilization have had a great impact on soil enzymes and the related resource use strategy, which provides great implications for assessing soil nutrients balance and soil sustainability.

Sustainability of Organic Fertilizers Use in Dryland Mediterranean Agriculture

Organic fertilization is a key issue in European Union (EU) regulations, particularly in the context of promoting a circular nutrient economy, maintaining soil quality, and sequestering carbon to face climate change. In a rainfed system in Northeastern Spain, an experiment was set up (split-plot design). It included five pre-sowing N fertilization treatments: control, mineral, pig slurry, and composted sewage sludge (two rates). The average N rates were 0, 30, 141, 176, and 351 kg N ha−1, respectively. They were combined with mineral N topdressings (0, 50, and 100 kg N ha−1). Three crops were grown: barley (nine years), wheat (three years), and rapeseed (one year). In the driest years (c. 350 mm rainfall), the yields averaged 2.5, 2.0, and 1.9 Mg ha−1, respectively. The maximum yields were for barley (6.5 Mg ha−1) and wheat (5.5 Mg ha−1). The avoidance of a significant increase in soil residual NO3−-N, plus the control of soil build up of available P, micronutrients, and Cd, defines the fertilization strategies. (i) With a previous spring drought season, no fertilization is needed in the following year, if devoted to winter cereals. (ii) In rainier seasons, pig slurry or composted sewage sludge (lowest rate) applied at sowing is sufficient; however, 50 kg of mineral-N ha−1 at the topdressing can be applied. The study found that pig slurry favors K, Mg, Cu, and Zn availability, while composted sewage sludge enhances Fe availability. Although it is possible to reduce N inputs from organic fertilizers, organic C build-up will be constrained.

Effects of fertilization on soil ecological stoichiometry and fruit quality in Karst pitaya orchard

Pitaya (Hylocereus undulatus) is a significant cash crop in the karst region of Southwest China. Ecological stoichiometry is an essential method to research biogeochemical cycles and limiting elements. The purpose of this study was to explore the stoichiometric characteristics of C, N, and P in Karst pitaya orchards and fruit quality and to elucidate the mechanism and process of nutrient cycling. The results showed that: (1) Fruit quality was highest under the combination of chemical and organic fertilizers. Compared to the control, the contents of per-fruit weight, vitamin C, and soluble sugar increased significantly by 55.5%, 60.7%, and 23.0%, respectively, while the content of titratable acidity decreased significantly by 22.0%. (2) The content of soil nutrients under fertilization stress showed a downward trend in general, as did microbial biomass and extracellular enzyme activities. (3) Different fertilization treatments significantly affected the soil-microbial stoichiometry C:N ratio, C:P ratio, with research areas being significantly limited by C and P. (4) Spearman and PLS-SEM (partial least squares-structural equation model) analysis results showed that under the influence of fertilization, there was a significant positive effect between microorganisms and soil nutrients, but a significant negative effect between soil nutrients and quality. The results of this study offer an innovative perspective on pitaya quality research in Karst areas.

Phenological stages of wheat modulate effects of phosphorus fertilization in plant-soil microbial interactions

Abstract Aims Future phosphorus (P) fertilizer availability faces challenges due to limited phosphate rock mines and strict quality regulations regarding Cd contents in phosphate rock. In this study, conventional fertilization was partially substituted with meat bone meal (MBM), sludge (S), and the organo-mineral combination of S plus MBM (SMBM), in a wheat agroecosystem. Methods We investigated the impact of fertilization treatments and crop phenological stages on P availability, crop yield, and soil microbial responses. Analysis included enzyme activities, microbial biomass, and the composition of bacterial and fungal communities using metabarcoding. Additionally, we estimated functional genes related to the P cycle through qPCR. Crop yield and nutrient content in plants and soil were also determined. Results Replacing traditional fertilization with MBM and SMBM maintained crop yield at levels equivalent to conventional fertilization. S and SMBM produced 70% and 40% (respectively) more bioavailable P compared to conventional treatment (Trad). Significant differences between treatments in soil microbial biomass were observed in the flag leaf stage. S increased in 20% total soil microbial biomass compared to Trad. Crop phenology had a stronger impact on bacterial and fungal communities than fertilization treatments. The use of S enhanced microbial biomass and activity. Yield in both MBM and SMBM plots exhibited no statistically significant differences compared to traditional fertilization. Conclusion Organo-mineral fertilization emerges as a sustainable strategy for maintaining crop production while improving soil functionality. Our findings emphasize the primary influence of crop phenology on shaping soil microbial communities and influencing microbial biomass and functionality.

Single-cell exploration of active phosphate-solubilizing bacteria across diverse soil matrices for sustainable phosphorus management.

Phosphate-solubilizing bacteria (PSB) are crucial for enhancing phosphorus bioavailability and regulating phosphorus transformation processes. However, the in situ phosphorus-solubilizing activity and the link between phenotypes and genotypes for PSB remain unidentified. Here we employed single-cell Raman spectroscopy combined with heavy water to discern and quantify soil active PSB. Our results reveal that PSB abundance and in situ activity differed significantly between soil types and fertilization treatments. Inorganic fertilizer input was the key driver for active PSB distribution. Targeted single-cell sorting and metagenomic sequencing of active PSB uncovered several low-abundance genera that are easily overlooked within bulk soil microbiota. We elucidate the underlying functional genes and metabolic pathway, and the interplay between phosphorus and carbon cycling involved in high phosphorus solubilization activity. Our study provides a single-cell approach to exploring PSB from native environments, enabling the development of a microbial solution for the efficient agronomic use of phosphorus and mitigating the phosphorus crisis.

Organic substitution contrasting direct fertilizer reduction increases wheat productivity, soil quality, microbial diversity and network complexity

Excessive use of chemical fertilizers negatively impacts crop productivity and farmland ecosystem, impeding sustainable agricultural progress. Consequently, there is an immediate need for a chemical fertilizer reduction strategy that ensures crop productivity and improves soil quality and the ecological environment of farmland. This study implemented a three-year (2018–2020) field experiment with two chemical fertilizer reduction methods (direct fertilizer reduction and organic substitution) to investigate their effects on wheat productivity, soil quality, heavy metal pollution risk and microbial characteristics. The results showed that organic substitution treatments (OF1, OF2 and OF3) improved most wheat plant (nutrient uptake and yield and its components) and soil properties (soil nutrients and carbon and nitrogen fractions), leading to increased crop productivity index (CPI, by 9.18 %-16.39 % and 14.14 %-23.36 %) and soil quality index (SQI, by 84.67 %-138.86 % and 104.11 %-175.91 %) compared to conventional fertilization (CF) and direct fertilizer reduction treatments (RF1, RF2 and RF3) in 2019 and 2020. Additionally, organic substitution enhanced the diversity and network complexity of bacterial community, while raising the soil pollution index (SPI, by 9.30 %-12.84 % and 12.20 %-18.49 %) without causing soil heavy metal pollution. Thus, it is recommended to adopt organic fertilizer substitution as the primary chemical fertilizer reduction strategy for wheat production. This approach will ensure crop yield, and improve soil quality and microbial characteristics, but its long-term application requires monitoring changes in soil heavy metals. Overall, this study provides guidelines for implementing scientific fertilization in agricultural practices, thus contributing to the health and sustainability of farmland ecosystems.

Assessing the Fates of Water and Nitrogen on an Open-Field Intensive Vegetable System under an Expert-N System with EU-Rotate_N Model in North China Plain.

Nitrate leaching, greenhouse gas emissions, and water loss are caused by conventional water and fertilizer management in vegetable fields. The Expert-N system is a useful tool for recommending the optimal nitrogen (N) fertilizer for vegetable cultivation. To clarify the fates of water and N in vegetable fields, an open-field vegetable cultivation experiment was conducted in Dongbeiwang, Beijing. This experiment tested two irrigation treatments (W1: conventional and W2: optimal) and three fertilizer treatments (N1: conventional, N2: optimal N rate by Expert-N system, and N3: 80% optimal N rate) on cauliflower (Brassica oleracea L.), amaranth (Amaranthus tricolor L.), and spinach (Spinacia oleracea L.). The EU-Rotate_N model was used to simulate the fates of water and N in the soil. The results indicated that the yields of amaranth and spinach showed no significant differences among all the treatments in 2000 and 2001. However, cauliflower yield under the W1N2 and W1N3 treatments obviously reduced in 2001. Compared with the W1 treatment, W2 reduced irrigation amount by 27.9-29.8%, water drainage by over 76%, increased water use efficiency by 5-17%, and irrigation water use efficiency by 29-45%. Nitrate leaching was one of the main pathways in this study, accounting for 8.4% of the total N input; compared to N1, the input of fertilizer N under the N2 and N3 treatments decreased by over 66.5%, consequently reducing gaseous N by 48-72% and increasing nitrogen use efficiency (NUE) by 17-37%. Additionally, compared with the W1 treatments, gaseous N loss under the W2 treatments was reduced by 18-26% and annual average NUEs increased by 22-29%. The highest annual average NUEs were under W2N3 (169.6 kg kg-1) in 2000 and W2N2 (188.0 kg kg-1) in 2001, respectively. We found that optimizing fertilizer management allowed subsequent crops to utilize residual N in the soil. Therefore, we suggest that the W2N3 management should be recommended to farmers to reduce water and N loss in vegetable production systems.

Soil organic carbon regulation by pH in acidic red soil subjected to long-term liming and straw incorporation

The manipulation of soil pH through liming and straw incorporation plays a pivotal role in influencing soil organic carbon (SOC) dynamics in acidic red soil. This study aimed to assess the impact of these practices on SOC and elucidate the relationship between SOC and pH. Over a 31-year field experiment, seven different fertilization treatments were implemented: unfertilized (CK), nitrogen and potassium fertilizers (NK), NK with lime (NKCa), nitrogen, phosphorous, and potassium fertilizers (NPK), NPK with lime (NPKCa), NPK with straw (NPKS), and NPKS with lime (NPKSCa). Results revealed that liming and straw incorporation significantly elevated soil pH by 0.13–0.73 units. Lime application boosted SOC and mineral-associated organic carbon (MAOC) by 20.2% and 28.7%, respectively, in NK treatment, whereas its impact on SOC in NPK and NPKS treatments were negligible. SOC witnessed a 17.1% increase with NPKS and a 15.2% increase with NPKSCa compared to NPK alone. Notably, NPKS and NPKSCa led to a significant surge in particulate organic carbon (POC) by 19.7% and 37.7%, respectively, albeit NPKSCa reduced MAOC by 14.9% relative to NPK. Linear regression analysis unveiled a positive correlation between POC and soil pH, while SOC and MAOC exhibited an initial rise at lower pH levels followed by stabilization as pH continuously increasing. A partial least squares path model showed two pathways through which pH influenced SOC: firstly, by positively affecting SOC through increasing Fe and Al oxides contents and enhanced aggregate stability, and secondly, by negatively influencing SOC through altered ratios of fungi/bacteria and Gram-positive bacteria/Gram-negative bacteria. In conclusion, the long-term effects of lime and straw application on SOC and MAOC were contingent upon soil pH, with more pronounced positive effects observed at lower pH levels. These findings underscore the importance of considering soil pH when implementing lime and straw strategies to mitigate acidification and regulate SOC in acidic red soil.

Reduced Chemical Fertilizer Combined with Vermicompost Application Affects the Growth, Yield, and Quality of Watermelon

Continuous application of chemical fertilizers in plant cultivation can lead to the deterioration of the soil environment, resulting in reduced crop yield and quality. Currently, organic fertilizers, such as vermicompost, can partially replace chemical fertilizers and maximize yields while maintaining soil fertility. However, the effects of chemical fertilizers combined with vermicompost on watermelon (Citrullus lanatus) yield and quality are unclear. A field experiment was carried out on the watermelon cultivar Lihua No. 6. Six treatments were applied: no fertilizer (CK, control, 0N–0P–0K), 100% chemical fertilizer [CF, 5.4N–1P–5.4K (256, 47, and 255 kg·ha−1)], 75% chemical fertilizer + 25% organic fertilizer [A1, 5.4N–1P–5.4K (192, 35, and 191 kg·ha−1) + 2250 kg·ha−1 vermicompost], 50% chemical fertilizer + 50% organic fertilizer [A2, 5.4N–1P–5.4K (128, 24, and 127 kg·ha−1) + 4500 kg·ha−1 vermicompost], 25% chemical fertilizer + 75% organic fertilizer [A3, 5.4N–1P–5.4K (64, 12, and 64 kg·ha−1) + 6750 kg·ha−1 vermicompost], and 100% organic fertilizer (A4, 9000 kg·ha−1 vermicompost). Indices related to the growth, yield, and quality of watermelons were determined. Compared with CK, chemical fertilizer alone or in combination with organic fertilizers significantly increased growth parameters (plant height and leaf area) and chlorophyll content. The five fertilizer treatments enhanced the single fruit weight, yield, and biomass. In addition, the yield of reduced chemical fertilizer plus organic fertilizer was comparable to that of watermelons treated with CF. Compared with CF, the fertilizer treatments, especially the 1:1 mixture of chemical and organic fertilizer (A2) group, had elevated fruit-soluble solids and soluble sugar content, and reduced organic acid levels. Therefore, a combination of 50% chemical fertilizer and 50% organic fertilizer can effectively enhance the yield and quality of watermelons. These findings have important implications for guiding the management of watermelon fertilization and development of sustainable agriculture.

Integration of the landscape of fear concept in grassland management: An experimental study on subtropical monsoon grasslands in Bardia National Park, Nepal.

The 'landscape of fear' concept offers valuable insights into wildlife behaviour, yet its practical integration into habitat management for conservation remains underexplored. In this study, conducted in the subtropical monsoon grasslands of Bardia National Park, Nepal, we aimed to bridge this gap through a multi-year, landscape-scale experimental investigation in Bardia National Park, Nepal. The park has the highest density of tigers (with an estimated density of ~7 individuals per 100 km2) in Nepal, allowing us to understand the effect of habitat management on predation risk and resource availability especially for three cervid species: chital (Axis axis), swamp deer (Rucervus duvaucelii) and hog deer (Axis porcinus). We used plots with varying mowing frequency (0-4 times per year), size (ranging from small: 49 m2 to large: 3600 m2) and artificial fertilisation type (none, phosphorus, nitrogen) to assess the trade-offs between probable predation risk and resources for these cervid species, which constitute primary prey for tigers in Nepal. Our results showed distinct responses of these deer to perceived predation risk within grassland habitats. Notably, these deer exhibited heightened use of larger plots, indicative of a perceived sense of safety, as evidenced by the higher occurrence of pellet groups in the larger plots (mean = 0.1 pellet groups m-2 in 3600 m2 plots vs. 0.07 in 400 m2 and 0.05 in 49 m2 plots). Furthermore, the level of use by the deer was significantly higher in larger plots that received mowing and fertilisation treatments compared to smaller plots subjected to similar treatments. Of particular interest is the observation that chital and swamp deer exhibited greater utilisation of the centre (core) areas within the larger plots (mean = 0.21 pellet groups m-2 at the centre vs. 0.13 at the edge) despite the edge (periphery) also provided attractive resources to these deer. In contrast, hog deer did not display any discernible reaction to the experimental treatments, suggesting potential species-specific variations in response to perceived predation risk arising from management interventions. Our findings emphasise the importance of a sense of security as a primary determinant of habitat selection for medium-sized deer within managed grassland environments. These insights carry practical implications for park managers, providing a nuanced understanding of integrating the 'landscape of fear' into habitat management strategies. This study emphasises that the 'landscape of fear' conceptcan and should be integrated into habitat management to maintain delicate predator-prey dynamics within ecosystems.

Manure application enriches phage-associated antimicrobial resistance and reconstructs ecological network of phage-bacteria in paddy soil

Antimicrobial resistance is an urgent threat to global health, causing serious antibiotic-resistant infections and deaths. The phages can serve as genetic reservoirs for bacterial adaptation, facilitating the horizontal transfer of antibiotic resistance genes (ARGs). However, how environmental perturbations impact the variation in viral ARGs via the phage-bacterial ecological network remains obscure. This study applied combined metagenomic and viromic sequencing without amplification bias to investigate the variations in the viral resistome and the ecological phage-bacterial networks in the paddy soils with different fertilizers. Results showed that manure application significantly changed the microbial community composition and increased the abundance of bacterial ARGs. The numbers of shared ARGs between paired virome and metagenome, as well as the diversity of host bacteria for phage-associated ARGs distinctly increased with manure amendment compared to chemical fertilizer treatment and non-fertilizer control. Elevated abundance of genes encoding stress and gene transfer-associated functions was observed in the manured soil viromes. Manure fertilization restructured the phage-bacteria ecological network with increased interactions potentially facilitating the dissemination of ARGs in the manure amended soils.

Mycorrhizal symbiosis and natural dye waste organic fertilizer: Enhancing growth and yield in indigofera tinctoria

Background: Indigofera tinctoria, commonly known as true indigo, is a plant widely used in the textile industry for its natural indigo dye, which produces a rich blue color for fabrics. Indigofera tinctoria, known for its natural bluish-purple dye, generates 10% dye and 90% waste during extraction, requiring effective waste management. This study aimed to optimize organic fertilizer and mycorrhiza doses from I. tinctoria waste for enhancing soil fertility in arid regions. Methods: The study was conducted from May to December 2020 in Puron Village, Bulu District, Sukoharjo Regency. A factorial Completely Randomized Block Design (CRBD) with 2 factors was employed. The first factor consisted of 5 levels of I. tinctoria organic fertilizer treatments: 0, 100, 200, 300, and 400 g per plant. The second factor included 3 levels of mycorrhiza treatments: 0, 10, and 20 g per plant. Variables observed included mycorrhizal infection on roots, plant growth rate, and yield (fresh leaf and shoot weight of I. tinctoria). Data analysis utilized ANOVA at a 5% significance level followed by Duncan Multiple Range Test (DMRT). Results: The results indicated that organic fertilizer from natural dye waste at a dosage of 200 g per plant increased the percentage of mycorrhizal-infected roots and boosted shoot weight by 63.27% at 8 weeks after planting (WAP). Mycorrhiza at 10 g per plant increased mycorrhizal infection percentage and enhanced shoot weight by 45.98% at 4 WAP. The combination of I. tinctoria extraction waste organic fertilizer at 200 g per plant and mycorrhiza at 10 g per plantshowed interaction, significantly increasing the growth of root nodules of Indigofera tinctoria by 84.04% at 12 WAP. Conclusion: The integration of organic fertilizer derived from indigo dye waste and mycorrhiza presents a promising strategy for enhancing I. tinctoria growth and productivity. Novelty/Originality of this Study: This study is distinctive in its demonstration of the effective use of I. tinctoria extraction waste as an organic fertilizer, aligning with zero-waste principles and contributing to improvements in plant growth and soil fertility. Furthermore, it investigates the synergistic effects of mycorrhizal associations on enhancing nutrient absorption and overall productivity of I. tinctoria, an aspect that has not been thoroughly explored in prior research.

Life cycle assessment of a high-tech vertical decoupled aquaponic system for sustainable greenhouse production

IntroductionAquaponics provide multiple benefits due to the simultaneous yield of vegetables and fish, however they are characterized by increased greenhouse gas emissions owing to intensive production system. The most appropriate method for quantifying the environmental effects of these systems is Life Cycle Assessment with which the identification of hotspots and the suggestion of improved production plans can be achieved. The purpose of the present study was to evaluate the environmental impact of a pilot high-tech aquaponic system utilized for the simultaneous production of baby lettuce and rocket as well as rainbow trout, in indicators such as Global Warming Potential.Materials and methodsTo achieve this goal, data on inputs and outputs were collected from 12 case studies that were implemented, combining different fertilizer treatments, substrate choices, plant species cultivated and water source provision. Life Cycle Assessment was performed using SimaPro v.9.4.0.2 software.ResultsThe results showcase that the optimal case studies include the cultivation of baby lettuce and rocket in perlite substrate using wastewater from fish and partial use of synthetic fertilizers. Indicatively, Global Warming Potential of these cases was calculated at 21.18 and 40.59 kg CO2-eq/kg of vegetable respectively. The parameter with the greatest impact on most of the environmental indicators was electricity consumption for the operation of the oxygen supply pump for the fish tanks, while greenhouse infrastructure had the greatest impact in Abiotic Depletion and Human Toxicity impact categories. In an alternative production scenario tested where renewable energy sources were used, system impacts were reduced by up to 50% for Global Warming Potential and 86% for Eutrophication impact. The results of this study aspire to constitute a significant milestone in environmental impact assessments of aquaponic production systems and the adoption of more sustainable farming practices.

Soil chemical responses to fertilization, with or without a cover crop, in an olive orchard in southwestern Buenos Aires (Argentina)

Our objective was to study the effect of fertilization on soil chemical traits on an olive orchard (artificially irrigated), considering areas with or without a cover crop, in southwestern Buenos Aires, Argentina, during the period 2020/2021. Fertilization treatments were (1) organic manure applied to the soil near the tree trunk; inorganic fertilization applied to the (2) soil or (3) to the leaves of Olea europaea L. trees; and (4) unfertilized control. Seeding of Vicia benghalensis L. and Avena sativa L. around subplots (one per each of the four studied treatments) constituted the areas with a cover crop. Subplots which were not seeded corresponded to the control areas. Soil pH was lower (p<0.05) under organic and inorganic soil fertilization. In areas without a cover crop in April 2021, soil nitrate concentrations were greater (p<0.05) under organic soil fertilization than in the control. At 0-20 cm soil depth, P concentrations were greater (p<0.05) under organic and inorganic soil fertilizations than in the other treatments. The greatest (p<0.05) K concentrations were found in the organic fertilization treatment. Organic soil fertilization on areas without a cover crop showed greater values for the soil chemical studied traits.

Castor Bean Meal Fertilizer Improves Peanut Yield and Quality by Regulating the Soil Physicochemical Environment and Soil Enzyme Activities

PurposeFertilization is important for improving crop yield and soil quality. Elucidation of the effects of castor bean meal (CBM) fertilizer on peanut yield and quality and soil fertility can lead to additional fertilization options for peanut and provide a theoretical reference for achieving a high-quality, high-yielding peanut.MethodsDuring 2022–2023, a two-year long-term field experiment was conducted in Tongliao city, Inner Mongolia, China. No fertilizer (CK) was used as the control, and the effects of different treatments, i.e., CBM fertilizer (B1: 2520 kg ha-1, B2: 5040 kg ha-1, and B3: 10,080 kg ha-1), chemical fertilizer alone (F1: 175 kg ha-1, F2: 350 kg ha-1, and F3: 700 kg ha-1), and cow manure alone (N1: 3724 kg ha-1, N2: 7448 kg ha-1, and N3: 14,896 kg ha-1) on peanut yield and quality and soil fertility were investigated.ResultsThe results showed that CBM fertilizer application improved soil ecology. Compared with other fertilization treatments, the soil pH of B3 treatment decreased by 8.5%, but significantly increased the contents of organic carbon (SOC), total nitrogen (TN), total phosphorus (TP), total potassium (TK), alkali-hydrolyzed nitrogen (AN), basic phosphorus (AP) and rapidly available potassium (AK) in the soil, which increased by 86.4%, 64.6%, 70.5%, 11.3%, 75.8%, 150.1%, and 116.2%, respectively, compared with CK. Meanwhile, B1, B2, N1 and N2 treatments also led to the elevation of the above indexes. In addition, the activities of urease (URE), sucrase (SUC), phosphatase (PPL), catalase (CAT), amylase (AMY) and protease (PRO) in the B3 treatment were significantly greater than those in the other fertilization treatments, with increases of 256.4%, 248.4%, 68.2%, 96.8%, 267.3%, and 155.7%, respectively, compared with CK. The B3 treatment also significantly increased the rootlet length(PRL), number of branches(BN), plant height(PLH) and lateral branch length(LBL) of the peanut plants. Compared with the other treatments, the B3 treatment had a greater peanut yields, reaching 8059.5 kg ha-1 and 9935.7 kg ha-1 in 2022 and 2023, respectively. Compared with the other treatments, the B1 treatment significantly increased the contents of protein (Pro), fat (FAT), unsaturated fatty acid (UFA) and vitamin E (VE), which increased by 23.3%, 6.1%, 1.0%, 29.1%, respectively, compared with CK, but the total sugar (TS) content was reduced by 9.1%. Correlation analysis further confirmed that peanut yield and quality were significantly correlated with soil nutrients and enzyme activities.ConclusionsThis study showed that the application of CBM fertilizer has certain positive effects. For example, the B3 treatment has certain potential for increasing peanut yield, and the B1 treatment can be used for peanut quality improvement. Therefore, CBM fertilizer is recommended as a new type of organic fertilizer for improving the peanut quality and yield.

Subsurface Drainage and Nitrogen Fertilizer Management Affect Fertilizer Fate in Claypan Soils

Sustainable nitrogen (N) fertilizer management practices in the Midwest U.S. strive to optimize crop production while minimizing N gas emission losses and nitrate-N (NO3-N) losses in subsurface drainage water. A replicated site in upstate Missouri from 2018 to 2020 investigated the influence of different N fertilizer management practices on nutrient concentrations in drainage water, nitrous oxide (N2O) emissions, and ammonia (NH3) volatilization losses in a corn (Zea mays, 2018, 2020)–soybean (Glyince max, 2019) rotation. Four N treatments applied to corn included fall anhydrous ammonia with nitrapyrin (fall AA + NI), spring anhydrous ammonia (spring AA), top dressed SuperU and ESN as a 25:75% granular blend (TD urea), and non-treated control (NTC). All treatments were applied to subsurface-drained (SD) and non-drained (ND) replicated plots, except TD urea, which was only applied with SD. Across the years, NO3-N concentration in subsurface drainage water was similar for fall AA + NI and spring AA treatments. The NO3-N concentration in subsurface drainage water was statistically (p < 0.0001) lower with TD urea (9.1 mg L−1) and NTC (8.9 mg L−1) compared to fall AA + NI (14.6 mg L−1) and spring AA (13.8 mg L−1) in corn growing years. During corn years (2018 and 2020), cumulative N2O emissions were significantly (p < 0.05) higher with spring AA compared to other fertilizer treatments with SD and ND. Reduced corn growth and plant N uptake in 2018 caused greater N2O loss with TD urea and spring AA compared to the NTC and fall AA + NI in 2019. Cumulative NH3 volatilization was ranked as TD urea > spring AA > fall AA + NI. Due to seasonal variability in soil moisture and temperature, gas losses were higher in 2018 compared to 2020. There were no environmental benefits to applying AA in the spring compared to AA + NI in the fall on claypan soils. Fall AA with a nitrification inhibitor is a viable alternative to spring AA, which maintains flexible N application timings for farmers.