Fertilization Strategies Research Articles

PRELIMINARY RESULTS REGARDING THE EFFECTS OF GREEN MANURES ON WHEAT CULTIVATION ON THE ACIDIC SOILS OF THE NORTH-WEST REGION OF ROMANIA

This study addressed the burgeoning interest in ecological agriculture, emphasizing sustainable and regenerative practices. Among these, the utilization of green manures emerged as pivotal for enhancing soil health and augmenting the yield of nutritionally dense crops. Five plant species (triticale, peas, soybeans, sunflower, and rapeseed) were selected for incorporation, sown during the summer, and subsequently integrated into the soil while still in their vegetative phase, preceding the optimal sowing window for wheat. The experiment encompassed three repetitions for the principal crop, of wheat implemented through split-plot design. Each repetition comprised both a fertilized and an unfertilized plot, further sub-divided, with certain segments receiving fungicidal treatment and others left untreated. The experimental setup was situated on an albic luvisol, exhibiting humus content ranging from 1% to 1.8% in the plow layer, coupled with an acidic pH range of 4.2 to 5.3. The trial site was located within the experimental fields of the Plant Protection Laboratory at the Livada Agricultural Research and Development Station, Satu Mare County. The primary aim of this experiment was to evaluate the influence of green manures, including their synergistic interplay with chemical fertilizers (calcium ammonium nitrate 27% N), on wheat. Evaluative parameters encompassed yield metrics, weed infestation levels, disease and pest resistance, along with the quality attributes of the principal crops. Ultimately, the study sought to furnish a encompassing comprehension of the advantages conferred by this regenerative agricultural practice, within the contemporary framework of ecological and agronomic imperatives. In conclusion, the inaugural year of experimenting with green manures did not yield an immediate augmentation in crop yield. However, it became evident that additional fertilization was required to fully harness the benefits of green manures. Encouragingly, the data spotlighted a propitious finding—green manures bolstered the disease resistance of wheat, implying enduring advantages for crop health. Furthermore, the adoption of rapeseed and peas as green manure crops, demonstrated a noteworthy reduction in weeding, affording an economical and pragmatic edge for sustainable agricultural practices. Additionally, when amalgamated with chemical fertilizers, the interaction with green manures evinced an augmented production capacity, underscoring the potential for a synergistic strategy in maximizing crop output. These revelations highlight the significance of a holistic and integrated approach to agricultural methodologies, underscoring the value of amalgamating green manures with judicious fertilization strategies. As we persist in our exploration and refinement of these techniques, the potential for enhancing both productivity and sustainability in our agricultural systems remains considerable, ultimately contributing to a more resilient and efficient food production process.

Biomass Ash as a Substitute for Lime and Its Impact on Grassland Soil, Forage, and Soil Microbiota

In this eight-year grassland field trial, we compared the fertilization effects of biomass ashes (BMAs) and carbonated lime (CaCO3) in combined application with cattle slurry (CS). Our study focused on plant coverage, forage yield, and quality, as well as soil physicochemical and microbiological properties. The fertilization strategies included CS mixed with BMA or CaCO3 applied three times a year and a separate annual application of ash or CaCO3, independent of CS. Samplings were performed in 2010, 2014, and 2018. Despite an absence of observable effects on soil, microbial properties, and forage quality, CS application, with or without BMA/CaCO3, resulted in higher forage yields compared to the unfertilized control and plots receiving only ash or CaCO3. Forage properties remained consistent across treatments. However, the combined application of CS with both ash and CaCO3 led to a reduction in volatile organic compounds, total carbon, total nitrogen, nitrate, and electrical conductivity in the soil from 2010 to 2018. Additionally, the relative abundance of specific microbial families (Nitrosomonadaceae, Acidothermaceae, Bacillaceae, and Peptostreptococcaceae) varied based on whether soils received a single amendment or a combination thereof. Our findings suggest that BMA is a valuable substitute for traditional liming agents, regardless of the application mode.

Additional organic and bacterium fertilizer input regulated soybean root architecture and dry matter distribution for a sustainable yield in the semi-arid Region of China.

In the dryland area of the Loess Plateau in northwest China, long-term excessive fertilization has led to soil compaction and nutrient loss, which in turn limits crop yield and soil productivity. To address this issue, we conducted experiments using environmentally friendly organic fertilizer and bacterium fertilizer. Our goal was to investigate the effects of additional organic and bacterium fertilizer inputs on soil water migration, crop root architecture, and yield formation. We implemented six different fertilizer strategies, namely: Nm (mulching, N 30 kg/ha), NPK1m (mulching, N 60 kg/ha; P 30 kg/ha; K 30 kg/ha), NPK2m (mulching, N 90 kg/ha; P 45 kg/ha; K 30 kg/ha), NPKOm (mulching, N 90 kg/ha; P 45 kg/ha; K 30 kg/ha; organic fertilizer 2 t/ha), NPKBm (mulching, N 60 kg/ha; P 30 kg/ha; K 30 kg/ha; bacterium fertilizer 10 kg/ha), and N (N 30 kg/ha; no mulching). The results revealed that the addition of bacterium fertilizer (NPKBm) had a positive impact on soybean root system development. Compared with the other treatments, it significantly increased the total root length, total root surface area, and total root length density by 25.96% ~ 94.89%, -19.63% ~ 36.28%, and 9.36% ~ 28.84%, respectively. Furthermore, NPKBm enhanced soil water consumption. In 2018, water storage during the flowering and podding periods decreased by 12.63% and 19.65%, respectively, while water consumption increased by 0.97% compared to Nm. In 2019, the flowering and harvest periods decreased by 23.49% and 11.51%, respectively, while water consumption increased by 0.65%. Ultimately, NPKBm achieved high grain yield and significantly increased water use efficiency (WUE), surpassing other treatments by 76.79% ~ 78.97% and 71.22% ~ 73.76%, respectively. Subsequently, NPK1m also exhibited significant increases in yield and WUE, with improvements of 35.58% ~ 39.27% and 35.26% ~ 38.16%, respectively. The use of bacterium fertilizer has a profound impact on soybean root architecture, leading to stable and sustainable grain yield production.

Assessing the Alteration of Soil Quality under Long-Term Fertilization Management in Farmland Soil: Integrating a Minimum Data Set and Developing New Biological Indicators

The key role of soil quality improvement in achieving sustainable agricultural development based on highly intensive use of farmland is increasingly being recognized, as is the ponderance of suitable evaluation of the soil quality. The overarching goal of this study was to determine an accurate assessment framework by the comparison of the scoring function (linear and non-linear) and integration method (area and weighted additive), which integrally evaluates the soil quality of an eleven-year field fertilization experiment (including CK, no fertilizer; CF, conventional fertilization; SF, formulated fertilization; SFO, SF with organic fertilizer). Thirty-three properties, including eighteen physiochemical-related and fifteen biological-related properties, associated with soil functions were measured as potential soil quality indicators, and the soil multifunctionality (SMF) was applied to validate the soil quality indices (SQIs). Principal component analysis and relationship analysis were used with indicators sensitive to management to determine a minimum data set (MDS). The results showed that the electrical conductivity, large macroaggregate-associated total nitrogen, small macroaggregate-associated organic carbon, carbon fixation, and enzyme activities of phenol oxidase and cellulase were chosen as the MDS. All the SQIs were significantly correlated with the SMF (p < 0.05). The fertilization strategies affected most indicators in different ways, and the index developed using the non-linear function and weighted additive integration method (SQI-NL) had the best sensibility and discriminability. The SQI value with the SQI-NL-MDS method was higher following the fertilization treatments than that of no fertilizer (p < 0.05), and the treatment of the organic fertilizer had the highest SQI value (0.66). Soil quality evaluation in long-term fertilized farmland suggested that the soil quality constraints between treatments of synthetic and organic fertilizer are related to the soil functions of nutrient cycling and sustain biological activity due to their higher contribution rates to the SQI in the organic fertilizer treatment, which provides insights into ways to reduce the gap in soil quality. The framework method can provide an accurate quantitative tool for the evaluation of soil quality from the target indicators by bridging management objectives and field-level actions.

Microbial Organic Fertilizer Combined with Magnetically Treated Water Drip Irrigation Promoted the Stability of Desert Soil Aggregates and Improved the Yield and Quality of Jujubes.

In the southern Xinjiang region of China, developing efficient irrigation and fertilization strategies to enhance resource utilization and prevent desertification is of critical importance. This study focuses on jujubes in Xinjiang, China, and involves a three-year field experiment aimed at exploring the optimal application strategy of magnetically treated water combined with microbial organic fertilizer to provide scientific support for high-quality jujube production. The experiment included a control group (using only fresh water, denoted as CK) and combinations of magnetically treated water drip irrigation with varying amounts of microbial organic fertilizer: in 2021, treatments included M0 (only irrigating with magnetically treated water), M6 (0.6 t/ha), M12 (1.2 t/ha), M18 (1.8 t/ha), and M24 (2.4 t/ha); in 2022 and 2023, treatments included M0, M6 (0.6 t/ha), M12 (1.2 t/ha), M24 (2.4 t/ha), and M48 (4.8 t/ha). This study investigated the effects of magnetically treated water drip irrigation combined with microbial organic fertilizer on soil physical properties, hydraulic parameters, enzyme activity, aggregate stability, and jujube yield and quality. The application of microbial organic fertilizer significantly reduced the soil bulk density by 3.07% to 11.04% and increased soil porosity by 1.97% to 14.75%. Soil saturated hydraulic conductivity gradually decreased with the increasing amount of microbial organic fertilizer, with a reduction range of 5.95% to 13.69%, while the water-holding capacity significantly improved (from 0.217 cm3/cm3 to 0.264 cm3/cm3). Additionally, microbial organic fertilizer significantly enhanced the activities of urease, catalase, and sucrase in the soil and significantly increased the proportion of large soil aggregates. Jujube yield increased by 3.66% to 21.38%, and the quality significantly improved, as evidenced by the increase in soluble sugar and flavonoid content. The Gauss model calculation results recommended 3.09 t·hm2 as the optimal amount of microbial organic fertilizer for comprehensively improving jujube yield and quality. These findings indicate that magnetically treated water drip irrigation combined with high amounts of microbial organic fertilizer significantly improved soil physical properties, hydraulic parameters, enzyme activity, aggregate stability, and jujube yield and quality, providing scientific evidence for desert soil improvement and agricultural production.

Mechanism of Iron Transport in the Triticum aestivum L.–Soil System: Perception from a Pot Experiment

Iron is one of the necessary trace elements for plant growth and the human body. The ‘hidden hunger’ phenomenon in the human body caused by an imbalance of iron in soil is increasingly prominent. Addressing this issue and optimizing soil through regulatory measures to improve the absorption and utilization of iron by crops has become an urgent priority in agricultural development. This study carries out pot experiments to observe the growth process of Triticum aestivum L. under various soil iron environments. Combined with previous research results, the transport mechanism of iron in the soil—Triticum aestivum L. system was systematically explored. The results indicate that during the jointing and maturity stages of Triticum aestivum L., iron was preferentially enriched in the underground parts; at the maturity stage, the iron content in various organs of Triticum aestivum L. shows a trend of increase followed by a decrease with the soil iron content varying in the following sequence: deficient, moderately deficient, medium, moderately adequate, and adequate. The iron-deficient stress environment causes an increase in the effectiveness of rhizosphere iron, resulting in a higher level of iron in the plant stems, leaves, and seeds. Conversely, when the soil iron content is medium or adequate, the effectiveness of rhizosphere iron decreases, leading to a reduction in the iron content in each part of the plant. A concentration gradient of 7.2 mg/kg in the experimental setup is found to be the most favorable to the enrichment of iron in the shoots of Triticum aestivum L. plants. The findings of this experiment provide guidance for the fertilization strategy to mitigate iron deficiency symptoms in plants under similar acidic-alkaline conditions of soil, as well as a systematic mechanism reference and basis for studying the soil-plant-human health relationship.

Crop Diversification and Fertilization Strategies in a Rainfed System with Drought Periods

Crop diversification and the reduction of nitrogen (N) inputs are key issues in the EU for more sustainable agriculture. An experiment was set up in a semiarid rainfed Mediterranean system. Our hypothesis was that these challenges could be addressed by introducing new crops and using pig slurries (PSs). The experimental factors were N fertilization at sowing (with or without PS) combined (according to a split-block design) with N fertilization as topdressing (the control, two N mineral rates, and two N rates from PS). Barley, rapeseed, and pea performances were evaluated in two different crop sequences: (i) barley–rapeseed or rapeseed–barley after a fallow season, and (ii) barley–pea or pea–barley after a fallow season followed by a non-fertilized barley crop. The results of the four-year study demonstrated that under a spring drought risk, barley performed better than peas in terms of relative crop yield maintenance. After fallow, N can be saved while maintaining the yields and total biomass of barley and rapeseed. In the second crop sequence, maximum pea and barley yields were associated with a minimum topdressing of 60 or 120 kg mineral N ha−1, respectively. However, slurry fertilization at sowing also allowed the highest yields for barley. Rapeseed and peas can be introduced to reduce N fertilization inputs. However, the obtained yield plateau for pea and rapeseed (3 and 4 Mg ha−1, respectively) and the effect of a yield spring drought on pea yields (50% reduction) might be a constraint for the success of EU policies on crop diversification.

Assessment of Endogenous Soil Fertility to Update Fertilization of Maize (Zea mays L) Crops in the Savannah Region of Togo

The diagnosis of soil fertility is a prerequisite for the formulation of balanced and site-specific fertilizer recommendations. Macro elements (nitrogen – N, phosphorous – P and potassium – K) based nutrient omission trials were conducted in the districts of Oti, Tandjoare, Tone and Kpendjal of the Savannah region. The objective was to assess endogenous soil fertility under maize cropping to further develop updated site-specifique fertilization schemes for the crop. A total of twenty-five producers were selected in the region (eight in Tandjoare, seven in Tone, five in Oti and five in Kpendjal) for the study in a paticipatory approach. The approach was participatory in order to involve the end user in the exercise. A randomized complete block design was adopted with five fertilization treatments including N0P0K0 (T1), N0P60K70 (T2), N120P0K70 (T3), N120P60K0 (T4) and N120P60K70 (T5) kg ha-1 for the trial. The unit plot size was 100 m2 (10 m x10 m). Grain yield, yield response to nutrients and Agronomic Efficiency (AE) were determined. Genstat Edition 12th was used to discriminate means.The average yields were 0.56, 0.83, 3.18, 3.44 and 4.57 Mg ha-1 respectively for T1, T2, T3, T4 and T5 in Tandjoare, 0.32, 0.52, 1.06, 2.39 and 3.02 Mg ha-1 respectively for T1, T2, T3, T4 and T5 in Tône, 1.01, 1.35, 2.56, 3.16 and 4.39 Mg ha-1 respectively for T1, T2, T3, T4 and T5 in Oti and 0.39, 0.75, 1.54, 2.33 and 3.31 Mg ha-1 respectively for T1, T2, T3, T4 and T5 in Kpendjal. The ranking of yield data by fertilizer treatment indicates that all three macronutrients (N, P and K) are required for maize production in the Savannah region, with a priority ranking of N>P>K. The results also showed that the best Agronomic Efficiency is obtained when all macronutrients are supplied in all four districts. The results of this diagnostic will be used as a basis for formulating balanced, site-specific fertilizer recommendations for intelligent, environmentally-friendly agriculture.

Combined use of digestate and inorganic fertilizer alleviates the burden of class 1 integrons in perennial ryegrass rhizosphere without compromising aerial biomass production.

Antimicrobial resistance (AMR) is one of the main global health challenges. Anaerobic digestion (AD) can significantly reduce the burden of antibiotic resistance genes (ARGs) in animal manures. However, the reduction is often incomplete. The agronomic use of digestates requires assessments of their effects on soil ARGs. The objective of this study was to assess the effect of digestate on the abundance of ARGs and mobile genetic elements (MGEs) in the rhizosphere of ryegrass (Lolium perenne L.) and to determine whether half-dose replacement of digestate with urea (combined fertilizer) can be implemented as a safer approach while maintaining a similar biomass production. A greenhouse assay was conducted during 190days under a completely randomized design with two experimental factors: fertilizer type (unfertilized control and fertilized treatments with equal N dose: digestate, urea and combined fertilizer) and sampling date (16 and 148days after the last application). The results indicated that the digestate significantly increased the abundance of clinical class 1 integrons (intI1 gene) relative to the unfertilized control at both sampling dates (P < 0.05), while the combined fertilizer only increased them at the first sampling. Sixteen days after completing the fertilization scheme only the combined fertilizer and urea significantly increased the biomass production relative to the control (P < 0.05). Additionally, by the end of the assay, the combined fertilizer showed significantly lower levels of the macrolide-resistance gene ermB than digestate and a cumulative biomass similar to urea or digestate. Overall, the combined fertilizer can alleviate the burden of integrons and ermB while simultaneously improving biomass production.

Multimedia Nitrogen and Phosphorus Migration and Source Control Using Multivariate Analysis and XGBoost: The Case Study in a Typical Agricultural Basin, Danjiangkou Reservoir

Preventing eutrophication requires a deep understanding of nutrient sources and migration processes. The Guanshan River in the Danjiangkou Reservoir was selected as a typical agricultural basin. River water, sediment, and soil samples were collected to determine nitrogen (N) and phosphorus (P) contents and forms. Multivariate statistical analysis, buffer analysis, and extreme gradient boosting regression (XGBoost) were used to investigate the nutrient sources, the sources’ scale effects, and migration. The results showed that the exogenous sources of river nutrients were fertilizer (provided phosphate (PO4-P) and ammonium (NH4-N)), domestic wastewater (provided nitrate (NO3-N) and organic nitrogen), and natural soil and rock leaching (provided PO4-P and organic phosphorus). Fertilization within 300–1200 m and domestic wastewater discharge within 150 m of the river affected the contents of the river nutrients significantly (with R ranging between 0.40 and 0.73, p ≤ 0.01). The sediment was the N source and P sink of the overlying water. With NH4-N/PO4-P compound fertilization, the NO3-N and calcium-bound phosphorus (Ca-P) exhibited co-enrichment. Appropriately increasing NH4-N application could stimulate P biological uptake, thus inhibiting P emigration from agricultural soil under N-limited states. In conclusion, this study effectively recognized river nutrient sources and their scale impacts and also explored more effective fertilization strategies, which are beneficial for the optimized management of agricultural activities.

Nitrous oxide (N2O) emission characteristics of farmland (rice, wheat, and maize) based on different fertilization strategies.

Fertilizer application is the basis for ensuring high yield, high quality and high efficiency of farmland. In order to meet the demand for food with the increasing of population, the application of nitrogen fertilizer will be further increased, which will lead to problems such as N2O emission and nitrogen loss from farmland, it will easily deteriorate the soil and water environment of farmland, and will not conducive to the sustainable development of modern agriculture. However, optimizing fertilizer management is an important way to solve this problem. While, due to the differences in the study conditions (geographical location, environmental conditions, experimental design, etc.), leading to the results obtained in the literatures about the N2O emission with different nitrogen fertilizer application strategies have significant differences, which requiring further comprehensive quantitative analysis. Therefore, we analyzed the effects of nitrogen fertilizer application strategies (different fertilizer types and fertilizer application rates) on N2O emissions from the fields (rice, wheat and maize) based on the Meta-analysis using 67 published studies (including 1289 comparisons). For the three crops, inorganic fertilizer application significantly increased on-farm N2O emissions by 19.7-101.05% for all three; and organic fertilizer increased N2O emissions by 28.16% and 69.44% in wheat and maize fields, respectively, but the application of organic fertilizer in rice field significantly reduced N2O emissions by 58.1%. The results showed that overall, the application of inorganic fertilizers resulted in higher N2O emissions from farmland compared to the application of organic fertilizers. In addition, in this study, the average annual temperature, annual precipitation, soil type, pH, soil total nitrogen content, soil organic carbon content, and soil bulk weight were used as the main influencing factors of N2O emission under nitrogen fertilizer strategies, and the results of the study can provide a reference for the development of integrated management measures to control greenhouse gas emissions from agricultural soils.

Exploring adaptation strategies for smallholder farmers in dryland farming systems and impact on pearl millet production under climate change in West Africa

Understanding and identifying appropriate adaptation optons for cropping systems and management practices at spatial and temporal scales is an important prerequisite for scaling. Pearl millet (Pennisetum glaucum (L) R. Br.) could be regarded as a risk-reducing measure crop under climate change when coupled with tactical agronomic management practices. In this study, we assess the impacts of adaptation strategies such as cultivar type, planting windows, and fertilizer strategies on pearl millet production under rainfed farming systems over Nigeria and Senegal using the Agricultural Production Systems Simulator (APSIM) model. The impact of climate change on millet yield was evaluated using a validated APSIM-millet module that utilized yield data collected through participatory research and extension approach (PREA) in contrasting environments. The climate model projections for the mid-century period (2040–2069) were compared against a baseline period of 1980–2009 for both locations. During the simulation, two millet varieties (improved local and dual-purpose) with two sowing regimes were considered comparing traditional farmers’ sowing window (dry sowing) and agronomic sowing window (planting based on the onset of the rainfall) at three different fertilizer levels [low (23 kg N ha−1), medium (40.5 kg N ha−1), and high (68.5 kg N ha−1) respectively]. The performance of the APSIM-millet module was found to be satisfactory as indicated by the low Root Means Square Error (RMSE) and Normalized Root Mean Square Error (NRMSE) values. The range for grain yield was between 17.7% and 25.8%, while for AGB it was between 18.6% and 21.4%. The results showed that farmers’ sowing window simulated slightly higher grain yield than the agronomic sowing window for improved local millet cultivar indicating yield increased by 8–12%. However, the projected changes in the mid-century (2040–2069) resulted in a decline in yield against baseline climate for both varieties and sowing windows, indicating the negative impact of climate change (CC) on yield productivity. The comparison between dual-purpose millet and improved local millet indicates that disseminating the improved millet variety and implementing early sowing could be an effective adaptation strategy in reducing risks and losses caused by climate change. Similarly, low magnitude impacts simulated on grain yield (&amp;lt; −8% in Nigeria compared to &amp;gt; −8% in Senegal) even though both locations are in the same agroecological zone.

Interactive effects of soil salinity and nitrogen fertilizer types on nitrous oxide and ammonia fluxes

Soil salinization, impaired by climate change and poor management practices, poses a global threat, particularly in arid and semi-arid regions, leading to significant land degradation. This study aims to investigate the effects of different nitrogen (N) fertilizer sources (urea, ammonium-sulfate, and biogas waste) on CO2, N2O, and NH3 emissions and soil enzyme activities in two soil types varying in salinity level (non-saline: EC = 1.15 dS m−1, and saline: EC = 35.80 dS m−1) in a robotized continuous-flow soil incubation system. Our results showed a sharp increase in N2O and CO2 emissions (up to 0.51 ± 0.02 g N2O-N ha−1 day−1, 28.1 ± 3.9 kg CO2-C ha−1 day−1) in non-saline soils following soil rewetting, attributed to bacterial denitrification. However, this pattern was not observed in saline soils, suggesting that salinity causes partial inhibition to the regeneration of soil organic matter mineralization and denitrification processes after rewetting. Although salinity did not alter the overall cumulative N2O losses in any fertilizer treatment, it significantly delayed the evolution of N2O peak during the incubation period. On the other hand, NH3 volatilization was significantly higher in N-fertilized saline soils compared to non-saline soils (241% and 157% in ammonium-sulfate and biogas waste treatments, respectively), except for urea treatment, likely due to the decrease in nitrification rates. Furthermore, the study clearly showed lower soil enzyme activity levels for both nitrate reductase and urease activity. Interestingly, the lowest NH3 emissions were measured in urea treatment in both soils. Overall, our findings highlight the complex interplay between soil salinity, nitrogen fertilizer sources, and microbial processes, significantly influencing gaseous nitrogen emissions and N cycling in agricultural soils. Identifying the specific fertilizer treatments that minimize or maximize gaseous nitrogen losses in varying soil salinity, may guide the selection of appropriate fertilization strategies for farmers and policymakers to mitigate environmental impacts of fertilizer use during agricultural production.

Response of Soil Fungal Community in Coastal Saline Soil to Short-Term Water Management Combined with Bio-Organic Fertilizer

This study aimed to elucidate the response of soil microbial communities to saline soil amelioration via biological organic fertilizer. A year-long experiment was conducted on coastal saline soil, employing water and fertilizer strategies. Three treatments were compared: dry field (control, CK), paddy field (W), and combined dry and irrigated fields with biological organic fertilizer (BW). Soil DNA was extracted and sequenced using high-throughput methods, revealing significant reductions in soil electrical conductivity (EC) and pH with W and BW treatments. Moreover, the BW treatment notably increased soil organic carbon content by 17.2%, as well as soil urease and alkaline phosphatase activity. Fungal community richness increased, with the BW treatment showing a 36% rise in the ACE index and a 24% increase in the Shannon index, while the Simpson index decreased by 59%. Dominant fungal phyla were Ascomycota, Mortierellomycota, and Basidiomycota, with Basidiomycota prevailing at the genus level. Redundancy analysis (RDA) indicated that soil pH, EC, and organic carbon were key determinants of fungal community distribution, with the BW treatment correlating negatively with pH and salt and positively with soil organic carbon (SOC). Fungal functional groups varied among treatments, with saprophytic fungi predominating, but the BW treatment showed a higher relative abundance of animal pathogenic fungi. In summary, the integration of biological organic fertilizer with flooding ameliorates soil properties and influences the changes in soil fungal community structure and function in the short term. These results could enhance the scientific basis for the efficient utilization and development of saline soil resources in coastal areas.

Zinc biofortification of wheat through fertilizer and genotype management

This study investigated the responses of two wheat varieties, Alvand (Zn-inefficient) and Pishtaz (Zn-efficient), to various zinc (Zn) fertilization methods to determine optimal strategies for enhancing wheat growth and grain quality. The primary aim of this research was to evaluate the effects of various Zn fertilization strategies, including foliar applications of Zn sulfate and Zn-EDTA with and without urea, as well as synthetic Zn amino acid complexes, along with soil applications of Zn sulfate, on the yield and nutritional quality of grains in these two contrasting wheat varieties. The results revealed that wheat varieties responded differently to Zn treatments. While Alvand showed a promising trend of elevated grain yield with foliar zinc sulfate application, Pishtaz exhibited a stronger response to foliar treatments like Zn-Met and Zn-EDTA + urea. Yield components as 1000-grain weight and spike weight, were significantly influenced by Zn fertilization. Foliar application of zinc sulfate + urea enhanced 1000-grain weight in Alvand, whereas Zn-EDTA + urea substantially increased spike weight in Pishtaz. Soil application of zinc sulfate was found to be as an effective method to enhance grain Zn content. Furthermore, the Zn concentrations in flour, straw, bran, and roots elucidated the complex patterns of Zn distribution among various plant tissues. Soil applications were particularly effective in increasing Zn levels in flour and bran, while foliar treatments influenced Zn content in straw and roots. Overall, this research highlights the importance of Zn fertilization strategies for different wheat varieties biofortification. These findings can provide practical implications for sustainable wheat production, addressing Zn deficiency challenges, and advancing food security worldwide. Further exploration into the underlying mechanisms of these responses is encouraged to refine Zn management practices for wheat cultivation.

Ten years of urea fertilization alter the pqqC‐harbouring community and increase soil inorganic phosphorus mobilization

AbstractThe bacterial communities that harbour the pyrroloquinoline quinone gene (pqqC‐harbouring bacteria communities) play a pivotal role in the mobilization of inorganic phosphorus (Pi). However, there is limited knowledge regarding the connection between soil pqqC‐harbouring bacterial communities and Pi fractions, as well as the factors that can regulate them, particularly under different fertilization strategies in the agricultural soil. High‐throughput sequencing was used to investigate the pqqC‐harbouring communities from the wheat (Triticum aestivum L.)–sweet potato (Ipomoea batatas L.) season in a 9‐year field experiment, including without fertilization (control), nitrogen (N) and potassium (K) fertilization (NK), NPK fertilization (NPK) and the combined application of chemical NPK and organic fertilizer (NPKM), and to explore their relationships with Pi fractions and their regulatory factors. Long‐term N fertilization and crop type substantially changed the community composition of pqqC‐harbouring bacteria but had no effect on their diversity. In two crop seasons, long‐term N fertilization significantly increased the content and proportion of moderately labile Pi (aluminium‐ and iron‐bound P) and available P (AP) and significantly decreased the proportion of recalcitrant Pi (calcium‐bound P) compared with the control. Specifically, AP increased by 79%–778%, Fe‐P by 64%–88%, and Al‐P by 71%–308%, while Ca‐P decreased by 10%–59%. N fertilization increased the relative abundance of Micromonospora, which was significantly positively correlated with moderately labile Pi and AP. Moreover, the relative abundance of some Streptomyces increased by 391% in the sweet potato season, and they were positively correlated with AP. Structural equation modelling revealed that the interplay between the pqqC‐harbouring community composition and Pi mobilization was mainly governed by pH, underscoring the role of pH in shaping the communities of Pi‐mobilizing microbes and their effect on Pi mobilization processes. This study emphasized how N fertilization and crops reshape Pi‐mobilizing microbial communities, which in turn affects Pi mobilization and P availability. Overall, these findings offer valuable insights into optimizing P cycles and availability through N fertilization strategies.

Assessing the global warming potential impact of organic fertilizer strategies in rice cultivation in Sri Lanka.

Rice is the staple food in Sri Lanka, and over 15% of the national land is allocated for rice cultivation. Greenhouse gas (GHG) emissions from rice fields account for 10% of national GHG emissions. The country has committed to reducing its emissions by 14.5% between 2010 and 2030 and achieving net zero emissions by 2060. In 2021, the country banned agro-fertilizer imports and opted for organic fertilizers, leading to a notable decrease in production and posing challenges to food security. However, the impact of adopting compost fertilizers alone remains unexplored. This study evaluated the global warming impact of two organic fertilizer strategies: switching to compost fertilizer instead of urea and applying rice straw compost instead of retaining crop residue. We applied the Denitrification and Decomposition model (DNDC 95) to rice field management data from Sri Lanka's Mahaweli H agricultural region. Simulations suggest that both strategies would increase the global warming potential of rice fields, mainly owing to elevated N2O emissions. This outweighs the mitigation benefits of avoiding crop residue retention and adding organic carbon through compost. Overall, our results point to the potential risk of shifting exclusively to compost-based fertilizers.

Research on Enhancing the Yield and Quality of Oat Forage: Optimization of Nitrogen and Organic Fertilizer Management Strategies

In the context of the increasingly serious issues of resource waste, soil degradation, and environmental pollution caused by excessive nitrogen fertilizer application worldwide, this study conducted a two-year field experiment in Qinghai Province to explore suitable nitrogen fertilizer management strategies for the region. Ten fertilization levels were set, incorporating varying ratios of conventional nitrogen fertilizer and organic fertilizer, as well as the proportion of base fertilizer and topdressing. The focus was on monitoring the forage yield, quality, and related physiological indicators of oats during the flowering and milk stages. The use of correlation analysis and the multi-criteria decision-making model TOPSIS was applied for comprehensive data evaluation to determine the optimal fertilization strategy. After systematic data collection and analysis, the results showed that when 75% conventional nitrogen fertilizer was combined with 4500 kg·hm−2 of organic fertilizer (F4), the oat yield during the milking stage reached its peak at 14,722.48 kg·hm−2. Additionally, the yield effect was optimal (13,677.34 kg·hm−2) when using 30% base fertilizer and 70% jointing fertilizer (D2). Regarding nutritional quality, the fertilization strategy combining 75% conventional nitrogen fertilizer with 4500 kg·hm−2 of organic fertilizer, along with 30% base fertilizer and 70% jointing fertilizer (F4D2), significantly reduced the content of acid detergent fiber (ADF), neutral detergent fiber (NDF), and coarse fiber (CF) in oats, while increasing the content of EE (crude fat) and CP (crude protein). This significantly improved the nutritional value of oats. Correlation analysis further revealed the positive effect of fertilization amount and fertilization period on oat yield, as well as a negative correlation with fiber content. Finally, through comprehensive evaluation using the multi-criteria decision-making model TOPSIS, we verified the superiority of the fertilization strategy.

Differential Effects of Nitrogen and Phosphorus Fertilization Rates and Fertilizer Placement Methods on P Accumulations in Maize.

Crop production in Afghanistan suffers from limited phosphorus (P) availability, which severely hinders national agriculture sustainability. This study hypothesized that deep fertilizer placement could significantly enhance the uptake of immobile P and, thus, tissue P accumulation and crop yield. A two-year pot experiment growing two maize (Zea mays) hybrid cultivars (Xida-789 and Xida-211) was, therefore, conducted to test these hypotheses under three contrasting fertilizer placement methods (broadcast, side band, and deep band). In doing so, P concentrations in both maize tissues and soils were compared at 45, 60, and 115 days after sowing (DAS) under nine combinations of nitrogen (N) and P fertilizer rates (kg ha-1: N112P45, N112P60, N112P75, N150P45, N150P60, N150P75, N187P45, N187P60, N187P75). Results have shown that deep band placement significantly increased P uptake efficiency, leading to greater P concentration and accumulation in maize tissues compared to the other two fertilization methods. This improved P uptake was attributed to several factors associated with deep placement, including reduced P fixation, enhanced root access to P, and moisture availability for P uptake. Additionally, deep band placement combined with higher N application rates (N187 and N150) further enhanced plant P uptake by promoting P availability and utilization mechanisms. Deep band placement also resulted in significantly higher total soil P, Olsen-P, and P use efficiency than broadcast and side band methods, indicating a more efficient P fertilization strategy for maize that can improve growth and yield. This study also found positive correlations between P concentration in plant organs and soil Olsen-P, highlighting the importance of adequate soil P levels for optimal plant growth. Overall, our results have shown that deep band fertilizer placement emerged as a superior strategy for enhancing P uptake efficiency, utilization, and maize productivity compared to broadcast and side band placement. The outcome generated from the deep band fertilization by this greenhouse study can be recommended for field practices to optimize P fertilizer use and improve maize production while minimizing potential environmental P losses associated with broadcast fertilization.

Comprehensive assessment of combined inorganic and organic fertilization strategies on cotton cultivation: implications for sustainable agriculture.

The integration of inorganic and organic fertilizers is increasingly being recommended to address the demand for sustainable cotton cultivation and to mitigate the ecological impacts of reliance on inorganic fertilizers. However, the nuanced effects of this combined fertilization approach on soil quality, cotton growth, yield, and their interaction mechanisms, remain unclear. To elucidate this, a 2-year field trial (2022-2023) was conducted, incorporating five fertilization treatments: low inorganic fertilizer (BI1), high inorganic fertilizer (BI2), organic fertilizer (BO), combined low inorganic and organic fertilizer (BIO1), and combined high inorganic and organic fertilizer (BIO2). This study aimed to evaluate the influence of these treatments on soil quality, cotton growth, and yield. The results indicate that the BO treatment significantly enhanced plant height growth rate, and BIO1 treatment increased leaf area index and dry matter accumulation growth rate. Critical soil parameters such as alkali-hydrolyzed nitrogen and available potassium emerged as pivotal determinants of soil quality over the trial period, corresponding to soil quality index (SQI) values of 0.482 and 0.478, and yields of 7506.19 kg ha-1 and 6788.02 kg ha-1, respectively. Water productivity reached optimum levels at SQI values of 0.461 and 0.462, with corresponding efficiencies of 13.31 kg (ha mm)-1 and 12.16 kg (ha mm)-1. Partial least squares path modeling revealed that integrating organic fertilizer with reduced inorganic fertilizer usage significantly boosts cotton yield by enhancing soil quality (path coefficient: 0.842). In conclusion, this integrated fertilization strategy not only improves soil health but also increases agricultural productivity. It presents a promising approach for optimizing crop yields while fostering sustainable agricultural practices. © 2024 Society of Chemical Industry.