Chemical NPK Research Articles

EFFECT OF NANO AND CHEMICAL FERTILIZATION WITH NPK AND CHELATED ZINC ON VEGETATIVE GROWTH OF TAIFI AND KAMALI GRAPE CULTIVARS

This research was performed during the 2021 seasons in private orchard located in Bara-Bhar-Duhok governorate to study the effect of soil application of chemical and Nano-NPK, foliar spray with chelated Nano-Zinc and their interaction on vegetative growth of Taifi and Kamali grape cultivars (Vitis vinifera L.). NPK (20:20:20) was added to the soil at five levels (0, 216 g.vine-1, 324 g.vine-1 chemical NPK, 3.24 and 6.48 g.vine-1 Nano-NP (, chelated Nano-Zinc was added at three concentration (0, 100 and 200 mg.l-1). The results showed the superiority of the Taifi cultivar in traits of number of leaves per vine, Single leaf Area and leaves dry weight over the Kamali cultivar, while Kamali cultivar was superiority in traits of leaf area per cluster ratio and total chlorophyll over the Taifi cultivar. Soil application of chemical and Nano-NPK and foliar application of Nano-zinc fertilizer achieved significant increase in vegetative growth (number of leaves, Single leaf Area, and total leaves area per vine, total chlorophyll and leaves dry weight) compare to control. Furthermore, combination among high concentration of Nano-NPK, Nano-zinc for Taifi and Kamali cultivars improved all parameters in comparison with the control.

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.

Impacts of long-term chemical nitrogen fertilization on soil quality, crop yield, and greenhouse gas emissions: With insights into post-lime application responses

The improvement in the agricultural production through continuous and heavy nutrient input like nitrogen fertilizer under the upland red soil of south China deteriorates soil quality, and this practice in the future could threaten future food production and cause serious environmental problems in China. This research is initiated with the objectives of evaluating the impacts of long-term chemical nitrogen fertilization on soil quality, crop yield, and greenhouse gas emissions, with insights into post-lime application responses. Compared to sole application of chemical nitrogen fertilization, combined application with lime increased soil indicators (pH by 6.30 %–7.76 %, Ca2+ by 90.06 %–252.77 %, Mg2+ by 184.47 %–358.05 %, available P by 5.05 %–30.04 %, and soil alkali hydrolysable N by 23.49 %–41.55 %. Combined application of chemical nitrogen fertilization with lime (NPCa (0.59), NPKCa (0.61), and NKCa (0.27) significantly improved soil quality index compared to the sole application of chemical nitrogen fertilization (NP (0.31), NPK (0.36), and NK (0.16). Compared to sole application of chemical nitrogen fertilization, combined application with lime increased grain yield by 48.36 %–61.49 %. Structural equation modeling elucidated that combined application of chemical nitrogen fertilization and lime improved wheat grain yield by improving soil quality. Exchangeable Ca2+, exchangeable Mg2+, pH, and exchangeable Al3+ were the most influential factors of wheat grain yield. Overall, the combined application of chemical nitrogen fertilization and lime decreased global warming potential (calculated from N2O and CO2) by 16.92 % emissions compared to the sole application of chemical nitrogen fertilization. Therefore, liming acidic soil in upland red soil of South China is a promising management option for improved soil quality, wheat grain yield, and mitigation of greenhouse gas emissions.

Determining the potato samples processed manner with an electronic nose system supported by a machine-learning approach

Through several studies, electronic nose (E-nose) devices have been demonstrated to serve as useful measurement equipment for the fast and reliable analysis of complex odour profiles in a wide range of fields, including the area of ensuring food safety. In the same perspective, i.e. checking food safety comes this work, where potatoes are assessed using an E-nose principally made of five metal oxide gas sensors supported with a machine learning algorithm, said evaluation is based on their origin fields: naturally treated, treated with chemical NPK fertilizers, or treated with chicken manure. The technique of support vector machines has been exploited for the data obtained from the multi-sensor system in order to distinguish the potato types mentioned by following two methods: a direct method where all the data have been exploited with a rate of success of 91.7%, and a composed method where the classification was first between naturally treated samples and those treated differently with a success rate of 96.7%, then a classification between those treated differently had a 92.5% success rate. A microbiological analysis was also carried out and its results were compared with those obtained by the E-nose. As per the two methods’ results, the distinction of the potato types by the nature of the cultivated fields is possible with the recording of the multisensory system superiority due to response time, low cost, simplicity, and portability.

Combined Vinasse and Mineral NPK Fertilizer Affect Physio-Biochemical, Root, and Yield Characters of Faba Bean (vicia faba l.) Genotypes Grown on Saline Soil

The objective of this study is to assess the effects of combined applications of recommended traditional chemical fertilization NPK 100% without Vinasse and with 100, 75, 50 NPK + Vinasse on Physio-Biochemical, root, shoot traits, yield, and its attributes for four faba bean Giza-429, Giza-843, Misr-2 and Sakha-3 genotypes which are cultivated in the soil is salt affected of eastern Egypt. The experimental design was conducted using a strip-plot design with three replicates in 2020 and 2021. Treatments of different doses of chemical fertilization were 100% NPK without Vinasse and 100%, 75%, and 50% of NPK with Vinasse as supplementary organic fertilizer were arranged in vertical strips, while horizontal strips were devoted to faba bean genotypes (Vicia faba L.) i.e. Giza-429, Giza-843, Misr-2, and Sakha-3. Relative to the other fertilizer combinations, the 75% NPK + Vinasse did not contribute more than 5% more yield to Sakha 3 than it did with the 100% NPK + Vinasse. Both the fertilizer and cultivar main effects had the same positive linear trend, with relatively higher total seed yield in the case of the 75% NPK + Vinasse and of cv. Sakha 3. The harvest index (HI) was different only for fertilizer levels.The 75% NPK + Vinasse differed by a very negligible margin from the 100% NPK + Vinasse, but both differed from the other two levels. Along with seed yield, both straw and biological yields were significant for the interaction effects, as well as for the main effects. Within all fertilizer combinations, cultivars Giza 843 and Saka 3 consistently, as a subgroup, outyielded the other two cultivars, not only for total seed yield but also for all other yield component characters.

Effect of nitrogen reduction by chemical fertilization with green manure (Vicia sativa L.) on soil microbial community, nitrogen metabolism and and yield of Uncaria rhynchophylla by metagenomics.

Uncaria rhynchophylla is an important herbal medicine, and the predominant issues affecting its cultivation include a single method of fertilizer application and inappropriate chemical fertilizer application. To reduce the use of inorganic nitrogen fertilization and increase the yield of Uncaria rhynchophylla, field experiments in 2020-2021 were conducted. The experimental treatments included the following categories: S1, no fertilization; S2, application of chemical NPK fertilizer; and S3-S6, application of chemical fertilizers and green manures, featuring nitrogen fertilizers reductions of 0%, 15%, 30%, and 45%, respectively. The results showed that a moderate application of nitrogen fertilizer when combined with green manure, can help alleviate soil acidification and increase urease activity. Specifically, the treatment with green manure provided in a 14.71-66.67% increase in urease activity compared to S2. Metagenomics sequencing results showed a decrease in diversity in S3, S4, S5, and S6 compared to S2, but the application of chemical fertilizer with green manure promoted an increase in the relative abundance of Acidobacteria and Chloroflexi. In addition, the nitrification pathway displayed a progressive augmentation in tandem with the reduction in nitrogen fertilizer and application of green manure, reaching its zenith at S5. Conversely, other nitrogen metabolism pathways showed a decline in correlation with diminishing nitrogen fertilizer dosages. The rest of the treatments showed an increase in yield in comparison to S1, S5 showing significant differences (p < 0.05). In summary, although S2 demonstrate the ability to enhance soil microbial diversity, it is important to consider the long-term ecological impacts, and S5 may be a better choice.

Assessing the influence of diverse phosphorus sources on bacterial communities and the abundance of phosphorus cycle genes in acidic paddy soils.

The impact of chemical fertilizers on soil microbial communities is well acknowledged. This study assesses the influence of various phosphorus sources on soil bacterial composition, abundance, and Phosphorus Cycle Gene Abundance. Three phosphorus sources (natural phosphate rock, triple super phosphate (TSP), and chemical fertilizer NPK) were field tested following two rice cultivation cycles. Soil samples were subsequently collected and analyzed for bacterial groups and phosphorus cycle genes. Results indicated that the bacterial community composition remained consistent, comprising five main phyla: Firmicutes, Actinobacteria, Proteobacteria, Halobacterota, and Chloroflexia, regardless of fertilizer type. NPK fertilizer significantly reduced the relative abundance of Chloroflexia by 19% and Firmicutes by 16.4%, while increasing Actinobacteria and Proteobacteria by 27.5 and 58.8%, respectively. TSP fertilizer increased Actinobacteria by 27.1% and Halobacterota by 24.8%, but reduced Chloroflexia by 8.6%, Firmicutes by 12.6%, and Proteobacteria by 0.6%. Phosphate rock application resulted in reductions of Chloroflexia by 27.1%, Halobacterota by 22.9%, and Firmicutes by 6.2%, alongside increases in Actinobacteria by 46.6% and Proteobacteria by 23.8%. Combined application of TSP, NPK, and phosphate rock led to increases in Proteobacteria (24-40%) and Actinobacteria (13-39%), and decreases in Chloroflexia (5.2-22%) and Firmicutes (6-12.3%) compared to the control (T0). While the different phosphorus sources did not alter the composition of phosphorus cycle genes, they did modulate their abundance. NPK fertilizer did not significantly affect ppK genes (57-59%) but reduced gcd (100 to 69%), 3-phytase (74 to 34%), appA (91 to 63%), and phoD (83 to 67%). Phosphate rock reduced appA and gcd by 27 and 15%, respectively, while increasing 3-phytase by 19%. TSP decreased ppK and phoD by 42 and 40%, respectively, and gcd and appA by 34 and 56%, respectively. Combined fertilizers reduced appA (49 to 34%), 3-phytase (10 to 0%), and gcd (27 to 6%), while increasing ppK (72 to 100%). Among tested phosphorus sources, natural phosphate rock was best, causing moderate changes in bacterial composition and phosphorus genes, supporting balanced soil microbial activity. These findings highlight the complex interactions between fertilizers and soil microbial communities, underscoring the need for tailored fertilization strategies to maintain soil health and optimize agricultural productivity.

Assaying the Use of a Leonardite-Suspension Concentrate-Based Product as a Potential Biostimulant to Enhance Growth, NPK Use Efficiency, and Antioxidant Capacity in Lactuca sativa L.

Biostimulants are presented as a potential tool to achieve the main objectives of modern agriculture: increase crop yield and nutritional quality while reducing chemical fertilizer use. Here, we investigated the use of a HS-based product (BLACKJAK®, from Sofbey S.A., Mendrisio, Switzerland) as a biostimulant to enhance plant growth, nitrogen (N), phosphorus (P), and potassium (K) use efficiency, as well as antioxidant capacity. For this purpose, BLACKJAK® was applied to lettuce (Lactuca sativa L.) as radicular (‘R’) and foliar (‘F’) at doses: 0.20 mL/L (R1), 0.40 mL/L (R2), 0.60 mL/L (R3), and 0.80 mL/L (R4), 5.00 mL/L (F1), 7.50 mL/L (F2), 10.00 mL/L (F3), and 12.50 mL/L (F4), along with a control. Shoot fresh weight (FW) and dry weight (DW), leaf area, NPK use efficiency parameters, and antioxidant capacity were evaluated. Our results showed that R1, R2, R3, F2, and F3 enhanced shoot FW and leaf area, while only R3 increased shoot DW. Furthermore, in general, most of the doses employed enhanced NPK use efficiency parameters such as apparent crop recovery, nutrient export, physiological efficiency, and internal utilization of applied nutrients. Similarly, HS also increased ascorbate, glutathione, and phenol concentrations, showing an improvement in antioxidant capacity measured through FRAP (Ferric Reducing Antioxidant Power) and TEAC (Trolox Equivalent Antioxidant Capacity) assays. Overall, root-HS offered better results than foliar-HS, especially at R3. Hence, our results indicate that BLACKJAK® could be a good candidate to enhance crop productivity and nutritional quality while reducing the use of chemical NPK fertilizers.

Effect of Combinations of Chemical, Nano-Fertilizer and Bio-Fertilizer NPK on Yield and Quality Traits of some Bread Wheat Cultivars Triticum aestivum L.

A field experiment was conducted during the agricultural season 2022-2023 in the fields of the College of Agriculture - Al-Qasim Green University, located at latitude 32.33 north and longitude 42.45 east, in soil with a mixture of clay textures in order to study the effect of chemical and nano fertilizer NPK and bio-fertilizer on yield and quality traits of wheat cultivars. the bread. The experiment was applied according to split-plots arrangement using randomized complete block design (RCBD) with three replicates. Three cultivars of bread wheat occupied IPA-99, Bahouth-22 and Baghdad, and were given the symbols V1, V2, and V3 on the main plots, while fertilizer combinations occupied the sub plots, which are fully recommended compound fertilizer and fully recommended compound fertilizer + biofertilizer and compost. Full compound recommendation + nano fertilizer and 50% compound fertilizer only and 50% compound fertilizer + 50% biofertilizer and 50% compound fertilizer + 50% nanofertilizer and 50% complex fertilizer + 50% biofertilizer + 50% nanofertilizer and the codes were given F1 and F2 and F3, F4, F5, F6, and F7, respectively. The results of the study showed the superiority of cultivar IBA-99 over the other two cultivars by giving the highest average percentage of protein in grains and the ratio of wet and dry gluten, which amounted to 12.73%, 36.13% and 13.54%, respectively. Baghdad cultivar achieved a significantly excelled by giving the highest average of grain yield, biological yield and harvest index, which amounted to 4.60 tons ha-1 and 13.55 tons ha-1 and 33.04%, respectively. The plants treated with the fertilizer combination 50% compound fertilizer + 50% bio-fertilizer + 50% nano-fertilizer excelled in most of the studied traits (grain yield, biological yield, harvest index, protein percentage in grains, carbohydrates in grains, and the ratio of wet and dry gluten), which amounted to 5.15 tons ha-1 and 15.89 ton ha-1, 35.70%, 13.87%, 60.46%, 38.24%, and 14.71%, respectively.

Cropping rotation improved the bacterial diversity and N-cycling genes in tobacco fields through a 19-year long-term experiment

Soil microorganisms play crucial roles in various processes within the soil ecosystem, such as nutrient cycling, organic matter decomposition, and maintenance of soil structure. However, their responses to fertilization and different cropping systems in tobacco soils remain poorly understood. In this study, we conducted a 19-year-long field experiment on rice-tobacco rotation cropping (R) and continuous tobacco cropping (C), with three fertilization treatments: no fertilizer (NF), chemical NPK fertilizer (NPK), and composted pig manure (OM). The composition, co-occurrence patterns, N-cycling genes (nifH, AOA-amoA, AOB-amoA, nirS, nirK, and nosZ) of the bacterial communities as well as the soil properties were analyzed in the soils after tobacco was harvested. The pH and available potassium (AK) in the rotation cropping soil were significantly lower than those in continuous cropping soil, while the α-diversity index, and the abundance of nifH, nirS, nirK, and nosZ genes were opposite. The phyla Chloroflexi, Desulfobacterota, MBNT15, and Nitrospinota, as well as number of low-abundance genera, were significantly enriched in rice-tobacco rotation cropping. Partial least squares path model (PLSPM) indicated that cropping systems had a greater influence on the variations in bacterial communities compared to fertilization practices. These findings enhance our understanding of the significance of land management and fertilization in shaping the soil bacteria of tobacco. The rice-tobacco rotation cropping system demonstrated greater benefits to soil microorganisms and N-cycling genes compared to continuous cropping system.

Enhancing onion growth and yield through agroecological practices: Organic fertilization and intercropping

The harmonious integration of two agroecological methods, namely intercropping and organic fertilization, illustrates a sustainable approach that not only boosts crop productivity but also minimizes the environmental impact, demonstrating a commitment to both higher yields and responsible environmental stewardship. This research aims to explore the effects of organic fertilization on onions intercropped with pepper, fennel, and carrots within an agroecological context. The study was conducted over two seasons using a randomized complete block design with 12 treatments. Notably, organic fertilization yielded results similar to mineral fertilization (NPK). Among intercropping combinations, onion-carrot displayed the highest yield and growth characteristics. Onion-pepper intercropping didn't significantly impact onion growth, while onion-fennel intercropping negatively affected agronomic parameters. Carrot intercropping led to increased plant height, with inorganic fertilization demonstrating stronger effects than organic fertilization. NPK fertilizer notably enhanced stem diameter, particularly in onion-carrot intercropping. Intercropping, especially with NPK, positively influenced the number of leaves per plant. NPK fertilizer excelled in enhancing plant fresh weight, with onion-pepper and onion-carrot intercropping enhancing second-season yields. NPK fertilizer also stood out in plant dry weight, and onion-carrot intercropping excelled in bulb weight. Yield was significantly impacted by intercropping and fertilization, with NPK significantly enhancing yield and onion-carrot intercropping demonstrating promising results. Principal component analysis revealed that onion-carrot intercropping with organic fertilizer nearly matched chemical NPK yield levels. The study provides valuable insights into optimizing onion cultivation and recommends adopting onion-carrot intercropping in the Fes-Meknes region. Overall, this research advances understanding of the intricate interplay between organic fertilization and intercropping, offering strategies for improved yield and sustainability in agroecological systems.

Influence of Organic Manure and Chemical Fertilization on Flowering and Yield Bulbs of Tulip Frenged, Tulipa gesneriana L.

The experiment was designed to evaluate the effect of levels of two types of fertilizers: organic (farmyard) manure (O0= 0, O1= 200, O2= 400 g/m2) and NPK fertilizer (15:15:15) (F0= 0, F1= 80, F2= 120 g/m2) on decorative features of Tulip Frenged, Tulipa gesneriana. All the flowering and bulb quality attributes were significantly influenced by the addition of farmyard manure and NPK to the soil. The results indicated that the farmyard manure FYM added to the soil increased the spike and flower diameter and reduced the number of days of flower color show, in comparison, the plants grown without farmyard manure and chemical fertilizer NPK. the highest flower diameter was recorded when the FYM2 with chemical fertilizer NPK F1 and F2 were mixed and added to the soil together. The results showed that the bulbs, which were planted in soil containing farmyard manure and NPK chemical fertilizer, shortened the flower days to show color and open. NPK applications increased the weight and diameter of bulbs.

Partially substituting chemical NPK fertilizers and their impact on Eureka lemon trees (Citrus limon L. Burm) productivity and fruit quality

The main aim of this study is to improve productivity, physical and chemical properties of the fruits and fruit quality of Eureka Lemon trees while lowering production costs by investigating the use of different NPK alternative sources (slow release, and bio) to reduce the use of chemical NPK fertilizers. Ten treatments of NPK fertilizers were applied. The results indicate that the highest values of yield (111.0 and 114.0 kg/tree) were found with 100% chemical NPK (control) for both first and second seasons, respectively. The lemon fruit weight ranged from 131.3 to 152.4 and 131.4 to 153.5 g for first and second seasons, respectively, for all treatments under study. The highest values of fruit length and fruit diameter were found with 100% chemical NPK (control) for both two seasons. The highest values of juice quality parameters (TSS, juice acidity, TSS/acid ratio and vitamin C concentration) responded favorably to higher chemical NPK treatment rates. The highest values of TSS, juice acidity, TSS/Acid ratio, and vitamin C concentration were 9.45%, 6.25%, 1.524 and 4.27 mg/100 g, respectively, were found with 100% chemical NPK (control) for both two seasons. Meanwhile, the lowest value of total sugar was found with 100% chemical NPK (control) for both two seasons.

Effects of Different Kinds of Fertilizers on the Vegetative Growth, Antioxidative Defense System and Mineral Properties of Sunflower Plants

Long-term use of inorganic fertilizers can increase soil acidity, be harmful to the environment, and leaving bad effects on human health. Organic fertilizer application is one of the safer alternatives with numerous benefits, such as supplying nutrients for plant growth. Sunflower is one of the most important grown oilseed crops in the world. Sunflower plants need a supply of essential nutrients for their optimal growth. As a result, the aim of this research is to explore the effect and mechanism of two organic fertilizers from different sources (sugarcane bagasse ash (SBA), compost coupled with biofertilizer (CCB)) and NPK inorganic fertilizer as a control on enzyme activity, physiological traits, and the uptake of mineral contents and heavy metals in sunflower plant (Helianthus annuus L.). Fresh or dry mass (FM, DM), osmolytes and secondary metabolites, photosynthesis pigments, and enzymatic and non-enzymatic antioxidant molecules were all determined. Both sugarcane bagasse ash and compost coupled with biofertilizer resulted in a high value of fresh and dry mass, plant height, and chlorophyll content. The results revealed that the use of sugarcane bagasse ash (SBA) and compost coupled with biofertilizer increased osmolyte contents (soluble proteins and soluble sugars), antioxidants system enzyme/molecule (catalase, superoxide dismutase, peroxidase, and TGS) and secondary metabolites. However, the highest value of proline, total free amino acids, and phenolic compounds in sunflower plants was determined after NPK fertilizer application. On the contrary, it lowered Na, Na/K ratio, and Cd content. Data showed that organic fertilizers enhanced the accumulation of Cl, PO4, and SO4 content in sunflower plants. Generally, CCB and SBA treatments increased Cu, Zn, and Pb accumulation in sunflower plants. Using organic fertilizers with chemical NPK fertilizer can improve the chemical, physical, and biological soil properties.

Long-term chemical fertilization results in a loss of temporal dynamics of diazotrophic communities in the wheat rhizosphere

Diazotrophs are potential bacterial biofertilizers with efficacy for plant nutrition, which convert atmospheric N2 into plant available nitrogen. Although they are known to respond strongly to fertilization, little is known about the temporal dynamics of diazotrophic communities throughout plant developmental under different fertilization regimes. In this study, we investigated diazotrophic communities in the wheat rhizosphere at four developmental stages under three long-term fertilization regimes: no fertilizer (Control), chemical NPK fertilizer only (NPK), and NPK fertilizer plus cow manure (NPKM). Fertilization regime had greater effect (explained of 54.9 %) on diazotrophic community structure than developmental stage (explained of 4.8 %). NPK fertilization decreased the diazotrophic diversity and abundance to one-third of the Control, although this was largely recovered by the addition of manure. Meanwhile, Control treatment resulted in significant variation in diazotrophic abundance, diversity, and community structure (P = 0.001) depending on the developmental stage, while the NPK fertilization resulted in the loss of temporal dynamics of the diazotrophic community (P = 0.330), which could be largely recovered by the addition of manure (P = 0.011). Keystone species identified in this study were quite different among the four developmental stages under Control and NPKM treatment but were similar among stages under NPK treatment. These findings suggest that long-term chemical fertilization not only reduces diazotrophic diversity and abundance, but also results in a loss of temporal dynamics of rhizosphere diazotrophic communities.

The Inorganic Carbon Fixation Improved by Long-Term Manure Fertilization in Kastanozems under Rotation System of North China

In China, manure is the most abundant organic fertilizer product. Understanding the changes in soil inorganic carbon (SIC) resulting from long-term manure fertilization is vital for accurately evaluating agricultural soil carbon stocks and predicting global change. However, a comprehensive and quantitative understanding of the impacts of long-term fertilization on SIC is lacking. This study was conducted to assess the effects of SIC changes in topsoil (0–20 cm), aggregates of kastanozems and influencing factors under the potato-rape-naked oats cultivation system after 16 years of long-term different fertilization in Wuchuan station. The results showed that 16 years of application of manure promoted the fixation of SIC by 2.25 t ha−1–3.25 t ha−1. As soil organic carbon (SOC) content, exchangeable calcium and magnesium concentrations in free coarse particulate organic matter (cfPOM) increased, the crystallization of carbonate was promoted at the aggregate level. The distribution proportion of free-coarse particulate organic matter (cfPOM) and microaggregates in mineral-related organic matter (iMOM) were also increased which affected the content of SIC. However, the pH value of NPKM treatment was lower than that of M treatment, which reduced the amount of carbonate crystallization. Thus, the application of manure alone was the best way to promote the fixation of SIC in topsoil rather than manure combined with chemical NPK fertilize. This work provides a new insight into the conversion of inorganic carbon, which is beneficial to promote the sequestration of inorganic carbon.

Impact of long-term fertilization on phosphorus fractions and manganese oxide with their interactions in paddy soil aggregates

One under-studied microelement, manganese (Mn), due to its potential to considerably interact, and limit labile, and moderately-labile soil phosphorus (P) pools, was studied in Nanchang (NC), and Qiyang (QY) under paddy conditions. The Hedley's P sequential fractionation procedure was utilized to extract, and quantify various P fractions at both surface (0–20 cm) and subsurface (20–40 cm) layers. Unfertilized control (CK), nitrogen, phosphorus, and potassium (NPK), and NPK amended with animal manure (NPKM) were used as treatments. From both sites, the manure amended fertilizer (NPKM) compared to chemical NPK formed higher proportions of macro-aggregates (>2 and 2–0.25 mm) in both layers. Total P (TP) values of 842.1 (>2 mm), and 744.4 mg kg−1 (2–0.25 mm) from NC, and QY, respectively were accumulated by NPKM compared to NPK, and CK. Total P values of 806.4, and 350.4 mg kg−1 in the >2 mm aggregate size, respectively for NC, and QY were observed in the subsurface layer. Inorganic moderately labile P (NaOH-Pi) was the dominant fraction under all fertilizer treatments. Concentrations of 232.3 (<0.053 mm), and 202.1 mg kg−1 (0.25–0.053 mm) of NaOH-Pi were accumulated by NPKM, respectively for NC, and QY in the surface layer. In the subsurface layer, concentrations of NaOH-Pi (217.5 mg kg−1; <0.053 mm) from NC, and residual-P (57.3 mg kg−1; >2 mm) from QY were accumulated by NPKM. Similarly, NPKM in contrast to NPK contributed higher Mehlich-3 manganese (M3-Mn) oxide in all aggregate sizes from both sites. Generally, macro-aggregates contributed higher TP, fractions of P, and M3-Mn oxide than micro-aggregates. There was a positive relationship between P pools and M3-Mn oxide at both sites. Additions of animal manure were associated with increased P fractions, and Mn oxides in the paddy soil aggregates, which raises environmental concern.

Long-term returning agricultural residues increases soil microbe-nematode network complexity and ecosystem multifunctionality

The negative environmental impacts of chemical fertilizers have been recognized for a long time, and the returning of agricultural residues to the soil is considered a sustainable agricultural practice. However, few studies have focused on the ecological and economic benefits of returning agricultural residues to the soil simultaneously. Using a 16-year field experiment, we integrally evaluated and compared the ecological and economic benefits of six fertilization practices. The treatments included a no-fertilizer control, conventional chemical NPK fertilization, and partial substitutions of the NPK in chemical fertilizers with a low (30%) or high (60%) level of agricultural residues (straw or cattle manure). The amount of N, P and K inputs remained constant across all fertilization treatments, but the source of N, P and K differed. Ecological benefits were assessed through a study of ecosystem multifunctionality and through a co-occurrence network analysis of the soil micro-food web. Our results showed that applications of agricultural residues increased soil microbial biomass and diversity, soil co-occurrence network complexity, and ecosystem multifunctionality compared with the chemical fertilization alone. The high-level straw substitution treatment supported the greatest ecosystem multifunctionality and soil network complexity. Random Forest regression analysis revealed that soil microbial biomass and fungal diversity were important biological traits associated with ecosystem multifunctionality. The economic benefit was highest when cattle manure was returned to the soil, lowest when crop straw was returned to the soil, and intermediate with chemical fertilization alone. Therefore, the return of cattle manure to the soil provided comprehensive ecosystem services. Our findings increase the understanding of the relationships between economic and ecological effects of returning agricultural residues to the soil.

Combined application of organic manure and chemical fertilizers stabilizes soil N-cycling microflora

• The abundance of N-cycling genes differently responded to NPK application.• Chemical NPK application greatly altered the N-cycling microbial community structure.• Soil acidification was the main driver for the variation in the N-cycling microbial community.• Manure addition was beneficial for stabilizing the N-cycling microbial community.Straw and manure are widely applied to agricultural systems, and greatly shape soil N-cycling microflora. However, we still lack a comprehensive understanding of how these organic materials structure soil N-cycling microbial communities. In this study, metagenomic analysis was performed to investigate the compositional variation in N-cycling microbial communities in a 30-year long-term experiment under five fertilization regimes: no fertilization (Control), chemical fertilization only (NPK), and NPK with wheat straw (NPK + HS), pig manure (NPK + PM), and cow manure (NPK + CM). Long-term NPK application differentially changed N-cycling gene abundance and greatly altered N-cycling microbial community structure. NPK + HS resulted in a similar pattern to NPK in terms of gene abundance and community structure. However, NPK + PM and NPK + CM significantly increased most genes and resulted in a community similar to that of the Control. Further analysis revealed that serious soil acidification caused by long-term NPK fertilization was a major factor for the variation in N-cycling microbial communities. The addition of alkaline manure, rather than wheat straw, stabilized the N-cycling microbial community structure presumably by alleviating soil acidification. These results revealed the strong impact of soil acidification on microbial N-cycling communities and illustrated the possibility of resolving nitrogen-related environmental problems by manipulating pH in acidified agricultural soils.

The role of spraying with NPK chemical fertilizer and organic fertilizer on some vegetative and floral indicators and the Active ingredients Origanum majorana

The experiment was carried out in the wooden canopy of the Department of Horticulture and Landscaping – College of Agriculture – Tikrit University for the autumn season 2021 , the experiment included studying the effect of tow overlapping factors , the first being spraying with chemical fertilizer NPK ( 0 , 1.5 gm L-1 ) and the second factor included the spraying of compost tea fertilizer ( poultry manure extract ) at levels ( 0 , 50 , 100 gm L-1 ) . The experiment designed by randomized complete block design ( RCBD ) with three replicates , the results showed the superiority of plants that were sprayed with chemical and organic fertilizers over plants that were not sprayed with either of them . The superiority of spraying with chemical fertilizer NPK at the level of F1 ( 1.5 g L-1 ) in plant height cm , number of leaves leaf plant-1 , leaf area cm2 , number of flowers flower plant-1 , weight of flowers mg , as it gave the highest values reached ( 69.25 cm , 2729.37 leaf plant-1 , 792.87 cm2 , 492.99 flower plant-1 , 0.529 mg ) straight , the lowest values were for the comparison treatment . Also , the same treatment outperformed in the mineral content of the plant , the percentage of volatile oil and the active ingredients . Also , the treatment of spraying with compost tea was superior in the mentioned characteristics at the level of E2 ( 100 g L-1 ) . The results of the interaction showed that there were significant differences in which the treatment was distinguished F1E2 ( 100g L-1 poultry offal extract + 1.5 g L-1 NPK ) it gave the highest values for the traits ( plant height 71.84 cm , number of leaves 2978.30 leaf plant-1 , total leaf area 862.92 cm2 , number of flowers 525.44 flower plant-1 , weight of flowers 0.556 mg flower-1 , N 2.520% , P 0.396% , K 2.020% , volatile oil 4.52% , Cymen 13.414 mg , Myrcene 3.129 mg , Sabinen 3.319 mg ) , the comparison treatment F0E0 gave the lowest values for the mentioned traits , which amounted to ( 57.41 cm , 2179.20 leaf plant-1 , 546.54 cm2 , 428.56 flower plant-1 , 0.418 mg flower-1 , 2.346% , 0.296% , 0.997% 3.47% , 11.622 mg , 1.407 mg , 1.508 mg ) straight .