Application Of Chemical Fertilizers Research Articles

Bacillus Strains as Effective Biocontrol Agents Against Phytopathogenic Bacteria and Promoters of Plant Growth.

Modern crop production relies on the application of chemical pesticides and fertilizers causing environmental and economic challenges. In response, less environmentally impactful alternatives have emerged such as the use of beneficial microorganisms. These microorganisms, particularly plant growth-promoting bacteria (PGPB), have demonstrated their ability to enhance plant growth, protect against various stresses, and reduce the need for chemical inputs. Among the PGPB, Bacillus species have garnered attention due to their adaptability and commercial potential. Recent reports have highlighted Bacillus strains as biocontrol agents against phytopathogenic bacteria while concurrently promoting plant growth. We also examined Bacillus plant growth-promoting abilities in Arabidopsis thaliana seedlings. In this study, we assessed the potential of various Bacillus strains to control diverse phytopathogenic bacteria and inhibit quorum sensing using Chromobacterium violaceum as a model system. In conclusion, our results suggest that bacteria of the genus Bacillus hold significant potential for biotechnological applications. This includes developments aimed at reducing agrochemical use, promoting sustainable agriculture, and enhancing crop yield and protection.

Effects of Returning Green Manure-Chinese Milk Vetch on the Availability and Transformation of Zinc in Purple Tidal Mud Soil under Rice Cultivation

This study aimed to investigate the impact of different levels of Chinese milk vetch (Astragalus sinicus L.) incorporation on the availability and transformation of zinc in purple tidal mud soil under rice cultivation. A two-year pot experiment was conducted, comprising seven treatments: a control group without fertilizer, a control group with Chinese milk vetch application, a control group with chemical fertilizer application, and four treatment groups with varying levels of Chinese milk vetch application following chemical fertilizer application. Results showed that Chinese milk vetch application increased the content of available zinc (DTPA-Zn) in purple tidal mud soil. Sole application of Chinese milk vetch ultimately enhanced the transfer factor of zinc in purple tidal mud soil and reduced the distribution index. However, applying Chinese milk vetch after chemical fertilizer application ultimately decreased the transfer factor of zinc and increased the distribution index. Furthermore, sole application of Chinese milk vetch facilitated the conversion of zinc in purple tidal mud soil into available forms, while applying it after chemical fertilizer application promoted the transformation of zinc into ineffective forms, with a greater conversion observed at higher levels of Chinese milk vetch application.

A Study on the Impacts of Fertilizer Crisis on Paddy Cultivation in Five Selected Divisional Secretariat Divisions of Trincomalee District During Maha 2021/22

Rice is one of the most important cereal crops in the world. With population growth, farmers have to increase paddy production to meet existing as well as future demand. Fertilizer is the major input in rice production. Growth and yield traits of rice are affected by improper and imbalanced application of plant nutrients. Hence, suitable practices of adequate rate and timing of fertilizer application are needed to increase the rice yield. In May 2021, Imports & Exports (Control) Regulation No 07 of 2021 was issued, banning the importation of chemical fertilizers, pesticides, & herbicides in Sri Lanka. Low fertility of paddy soil created the need for adequate and constant supply of chemical fertilizers in paddy cultivation, which is a major threat to production and endangers the national food security and economy of Sri Lanka, especially in the major cropping season of Maha 2021/22. Therefore, a questionnaire survey was conducted to investigate the impact of the fertilizer crisis in major paddy-cultivating Divisional Secretariat divisions of the Trincomalee district. The random sampling method was used to select respondents for the survey, and the collected data were statistically analyzed by SPSS version 26.0 software. The results revealed that the majority of the farmers experienced a 50% yield reduction compared to the last cropping season of Maha 2020/21 in the entire five DS divisions. The seedling stage was highly affected during the fertilizer crisis in paddy cultivation in all five DS divisions. Further, the cost of production in paddy cultivation increased by more than 50% during the fertilizer crisis compared to the cost involved in Maha 2020/21. The potential for organic manure production is very poor, while the majority of farmers are interested in adopting the sustainable farming system of the Integrated Plant Nutrient System through the judicious application of chemical and organic fertilizers received on a subsidy basis, according to the present government’s fertilizer policy, which emphasizes 70% of inorganic fertilizers and 30% of organic manure application to improve sustainability in paddy cultivation in the country.

Effect of combined exposure of chemical fertilizer, bacterial inoculums, and compost on the growth of forest tree species in saline soil

Salinity is the leading abiotic stress, especially in India, where saline soil affects 6.727 million hectares. The study investigated the effects of different combinations of chemical fertilizers, bacterial inoculums, and compost on the growth of Prosopis cineraria and Toona ciliata in pot experiments using saline forest soil. Treatments included varying mixes of seeds, compost, bacterial inoculums, and chemical fertilizers. Soil analysis confirmed salinity with pH and electrical conductivity (EC) levels indicating saline conditions. Results showed that treatments incorporating compost and bacterial inoculums significantly enhanced plant growth, increasing shoot, and root lengths, as well as fresh and dry weights. The application of compost increased the root length of Toona ciliata. The dual application of Pseudomonas spp. and compost enhanced the biomass of the root, whereas the application of chemical fertilizer and compost improved the height of the plan. The study indicates that the combined application of compost, bacterial inoculum, and chemical fertilizer is superior in enhancing the growth and development of the vegetative growth of plants. Overall, the study underscores the potential of integrated nutrient management strategies involving compost, bacterial inoculums, and reduced chemical fertilizers to enhance productivity in saline and salt-affected soils.

CAN THE APPLICATION OF AGROFORESTRY AT MONOCULTURAL FOOD CROP AREAS SUPPORT MANUFACTURER CHEMICAL FERTILIZER REDUCTION PROGRAMS WITHOUT SACRIFICING FARMERS' INCOME?

In an agroforestry system, nutrients from the subsoil can be made available to food plants through the absorption process by trees with deep roots. However, shade from canopy tree plants can suppress photosynthesis and reduce food crop production and farmer income [INCM]. This antagonism needs to be evaluated when introducing agroforestry programs into monoculture food crop areas to reduce manufactured chemical fertilizers application. This research was carried out from June to August 2023 at Natar District, South Lampung Regency to determine the effect of tree strata (teak, acacia, and albizia), multi-proposed tree species or MPTS (Parkia speciosa, avocado, and jack fruit), shrubs (coffee and cacao), and ground cover (vegetables, peanut, and soybean) to [INCM]. Interviewing forty respondents who were still retaining one or more of these tree strata among food crops including upland rice, corn, and cassava. The OLS (ordinary least square) model was employed at 90% confidence level. To eliminate the model error, the variables ownership of productive assets (upland, cattle, sheep, and cock), fertilizer application (urea, ponska, KCl and liquid fertilizer), compost, and pesticide use were also incorporated in the model. The results suggest the significant effects: (1) that positive ones are acacia, teak, vegetables, peanuts, and, soybeans, respectively USD 86.4 (P=0.000); 88.3 (P=0.000); 109,5 (P=0.000); 114.6 (P =0.000); 145.1 (P=0.000); and (2) which negative were Albizia falcataria, Parkia speciosa, avocado, coffee, and cacao respectively of around USD 31,7 (P=0.002); 57.1 (P=0.000); 43.2 (P=0.003); 62,0 (P=0.000) and 96.37 (P=0.000).

Soil Microbial Community Characteristics and Their Effect on Tea Quality under Different Fertilization Treatments in Two Tea Plantations.

Fertilization is an essential aspect of tea plantation management that supports a sustainable tea production and drastically influences soil microbial communities. However, few research studies have focused on the differences of microbial communities and the variation in tea quality in response to different fertilization treatments. In this work, the soil fertility, tea quality, and soil microbial communities were investigated in two domestic tea plantations following the application of chemical and organic fertilizers. We determined the content of mineral elements in the soil, including nitrogen, phosphorus, and potassium, and found that the supplementation of chemical fertilizer directly increased the content of mineral elements. However, the application of organic fertilizer significantly improved the accumulation of tea polyphenols and reduced the content of caffeine. Furthermore, amplicon sequencing results showed that the different ways of applying fertilizer have limited effect on the alpha diversity of the microbial community in the soil while the beta diversity was remarkably influenced. This work also suggests that the bacterial community structure and abundance were also relatively constant while the fungal community structure and abundance were dramatically influenced; for example, Chaetomiaceae at the family level, Hypocreaceae at the order level, Trichoderma at the genus level, and Fusarium oxysporum at the species level were predominantly enriched in the tea plantation applying organic fertilizer. Moreover, the bacterial and fungal biomarkers were also analyzed and it was found that Proteobacteria and Gammaproteobacteria (bacteria) and Tremellomycetes (fungi) were potentially characterized as biomarkers in the plantation under organic fertilization. These results provide a valuable basis for the application of organic fertilizer to improve the soil of tea plantations in the future.

Heavy metals and potential health risk assessment of Lactuca sativa and Daucus carrota from soil treated with organic manures and chemical fertilizer

The large-scale production of food crops with heavy application of chemical fertilizers in the effort to meet the astronomical increase in food demands may be counterproductive to the goal of food security. This study investigated the effect of different soil treatments on the levels of heavy metals (Cr, Cu, Fe, Ni, Pb, and Zn) in two types of vegetables Lactuca sativa (lettuce) and Daucus carrota (carrot). The potential carcinogenic and non-carcinogenic health risks from their consumption were also evaluated. Planting experiment was set up in a randomized block design, with different soil treatments of soil + cow dung (CD), soil + sewage sludge (SS), soil + chemical fertilizer (nitrogen-phosphorus-potassium (NPK)), and untreated soil (UNTRD). The vegetables were harvested at maturity, washed with distilled water, and subjected to an acid digestion process before the levels of heavy metals were measured by inductively coupled plasma spectrometry (ICP-MS). The mean concentrations of the metals in the vegetables across all treatments were below the maximum permissible limits. The pattern of heavy metal accumulation by the vegetables suggested that the lettuce from SS treatment accumulated higher concentrations of heavy metals like Cr (0.20 mg/kg), Cu (3.91 mg/kg), Ni (0.33 mg/kg), and Zn (20.44 mg/kg) than carrot, with highest concentrations of Fe (90.89 mg/kg) and Pb (0.16 mg/kg) recorded in lettuce from NPK treatment. The bioaccumulation factor (BAF) showed that lettuce, a leafy vegetable, has bioaccumulated more heavy metals than carrot, a root vegetable. The BAF was generally below the threshold value of 1 in both vegetables, except in lettuce from NPK and CD treatments and carrot from NPK treatments, with BAF values of 1.6, 1.69, and 1.39, respectively. The cancer risk assessment factors were well below the unacceptable maximum range of 10−4 suggesting that consuming these vegetables might not expose an individual to potential risk of cancer development. The hazard quotient estimations were below the threshold values of 1 for all heavy metals; however, the hazard index (HI) values of 1.27 and 1.58 for lettuce from NPK and SS treatments indicate a potential non-carcinogenic health risk to consumers from intake of all the heavy metals.

Reduction of chemical phosphate fertilizer application in a rice–rapeseed cropping system through continuous straw return

Context or problemStraw return has the potential to significantly contribute to nutrient recycling and utilization, thus reducing the reliance on chemical fertilizers. Extensive research has focused on nitrogen and potassium fertilizer management and the associated potential for reduction through straw return. However, the potential effect of straw return on reducing phosphorus (P) fertilizer application has been relatively overlooked due to the inherently low P content in straw.Objective or research questionThis study aimed to determine the potential benefits and underlying mechanism of reducing chemical P fertilizer application through straw return in a rice–rapeseed cropping system. MethodsWe conducted a five-year field experiment in a rice–rapeseed cropping system to investigate the effects of chemical P fertilizer reduction through straw return. Six fertilization treatments were investigated: no chemical P fertilization, 30, 60, 90, 120, and 60 kg P2O5 ha−1 with 6000 kg ha−1 straw return. ResultsThe result showed that continuous straw return increased yield, P uptake and P utilization during rice and rapeseed seasons. According to the P uptake level, the benefits from straw return were tantamount to applying 69.8–88.0 kg ha−1 of P fertilizer, which exceeded the actual amount of P input (64.5–70.3 kg ha−1) from fertilizer and straw. Straw C input mainly increased the content of soil microbial biomass C and P (MBC and MBP), which enhanced the supply capacity of available P, thereby increasing crop P uptake and reducing P fertilizer. The rapeseed season showed a higher chemical P fertilizer reduction rate (31.8%) than the rice season (14.0%). Moreover, rapeseed P uptake was more sensitive to soil Olsen-P, MBP and MBC than rice. The substitution efficiency of P fertilizer through the priming effect of straw C was higher in the rapeseed season (7.5 kg P2O5/1000 kg C) than in the rice season (2.1 kg P2O5/1000 kg C). ConclusionsOverall, under the rice–rapeseed cropping system, straw return increased soil MBC and MBP, thereby enhancing the supply capacity of available P. The C priming effect induced by straw return can partially reduce P fertilizer application. Compared with the rice season, straw return significantly substituted P fertilizer in the rapeseed season. IMplications or significanceThis study articulately delineates the role of straw return in enhancing soil P availability and crop P uptake and further highlights the potential of straw return as a strategy to reduce dependence on chemical P fertilizers in the rice–rapeseed cropping system.

Effects of cover crops and nitrogen fertilization on soil physical properties, carbon and nitrogen fractions, and winter wheat yield in the Chinese loess plateau: A 4-year field experiment

Context or problemLone-term application of chemical fertilizers in farmland ensure adequate or profitable crop yields but may damage soil structure. Cover crops (CCs) have great potentials to improve soil quality and promote sustainable crop production. However, the combined impacts of CCs with nitrogen fertilization on soil quality and crop yields are not clear. Objective or research questionWe aimed to examine the effects of CCs combined with N fertilization rates on soil physical properties, C and N fractions in both bulk soils and aggregates, and crop yields, and to find the best management practice that improve both soil quality and crop yields synthetically. MethodsA 4-year summer CCs - winter wheat field experiment was conducted in the Loess Plateau of China. CCs with different species and combinations (CC) were soybean (SB), sudan grass (SG), a mixture of both (SS), and no cover crop (CK) and N fertilizer (NR) were applied to winter wheat at rates of 0 (N0), 60 (N60), and 120 (N120) kg N ha−1. Soil physical properties and C and N fractions in both bulk soils and aggregates were evaluated at 0–10, 10–20, and 20–40 cm soil depths. ResultsSoil total porosity (TP), saturated water content (SWC), capillary water capacity (CWC), and C and N fractions decreased while bulk density (BD) increased with the increase of soil depth. The CC, NR, and their interaction (CC×NR) had significant effects on soil BD, aggregate size distribution and stability (MWD), and C and N fractions and only CC and CC×NR had significant effects on other physical properties. The incorporation of CCs significantly increased the proportions of > 5 mm aggregates and C and N fractions in both bulk soils and aggregates, especially in 0–10 and 10–20 cm. And SB and SS improved soil other physical properties more than SG, especially in 0–10 cm, which decreased BD by 13.2% and 12.6% while increased TP by 6.5% and 8.3%, SWC by 14.3% and 15.3%, CWC by 13.9% and 14.2%, MWD by 16.6% and 14.4%, respectively, compared to CK. Additionally, soil physical properties improved more with N60 while the C and N fractions in both bulk soils and aggregates increased more with N120. However, BD increased by 2.6% and 3.3% in N60 and N120 than N0, respectively. The correlations between the proportion of macro-aggregates and soil C and N fractions at 0–10 and 10–20 cm indicated the positive effects of CCs on improving soil structure and fertility simultaneously. Aggregated-associated C and N fractions decreased firstly and then increased with the reduced aggregate sizes, and were higher in micro-aggregates than in other size classes. N60-SB increased wheat yields by 98.7% compared with N0-CK. ConclusionsOverall, the incorporation of soybean residue was the best management practice for winter wheat yield and soil fertility under the reduced N fertilization. Implications or significanceThe selection of CCs species should depend on farmland managements, and the appropriate CCs with N fertilizer rates would target the improvements in soil quality, the sequestration of soil organic carbon, and crop yields synergistically.

Chlorella vulgaris improves growth of Abrometiella scapigera, Abrometiella brevifolia and Abrometiella chloranta and reduces root attack by nematodes

Research objective: The aim of this study is to investigate the effects of Chlorella extract as a biofertiliser on the growth of Abrometiella spp. seedlings and to assess whether it has a repellent effect against nematodes Materials and Methods: The experiments, which began in November 2024, were conducted in the CREA-OF greenhouses in Pescia (PT), Tuscany, Italy (43°54′N 10°41′E) on Abrometiella scapigera, Abrometiella brevifolia and Abrometiella chloranta. The plants were placed in ø12 cm pots; 30 plants per thesis, divided into 3 replicates of 10 plants each. The experimental groups were: i) group without algae, irrigated with water and previously fertilised substrate; ii) group with Chlorella vulgaris, previously fertilised substrate. On 2 April 2024, plant height, leaves number, vegetative weight, root weight, root lenght, number of new plantlets, chlorophyll content, leaf area, control of the nematodes Meloidogyne javanica and Meloidogyne incognita were measured. Results and Discussion: The experiment showed that the use of Chlorella vulgaris extracts can improve the vegetative and root growth of Abrometiella scapigera, Abrometiella brevifolia and Abrometiella chloranta plants grown in pots. The treatment also led to an increase in plant height, number of leaves, length of root hairs, leaf area and number of new seedlings. The trial also showed that the use of Chlorella in plant growing media can also increase the photosynthesis rate (SPAD index) and significantly reduce the presence of nematodes, in particular Meloidogyne javanica and Meloidogyne incognita. According to some researchers, the influence of Chlorella extract on cell metabolisms is mainly due to the physiological effect of major and minor nutrients, amino acids, vitamins, and plant growth regulators on cellular metabolisms in treated plants, which increase crop yields and growth. Chlorella plants have very high photosynthesis rates, dozens of times higher than other plants. The main reason why Chlorella can grow rapidly is because it contains Chlorella Growth Factor (CGF), which is quite rich in nucleoproteins, nucleic acids, ribonucleic acids (RNA), deoxyribonucleic acids (DNA), vitamins, amino acids, polysaccharides, complex protein bodies, enzymes, glycoproteins, plant hormones, etc. Its ability to promote plant growth may be due to this factor. Conclusions: Chlorella extract significantly increased Abrometiella seedling height, leaf number and leaf area. In particular, Abrometiella seedlings treated with chlorella extract developed better root system, chlorophyll a increased significantly and the root length and number of new seedlings also improved significantly. Based on the above results that Chlorella extracts contribute to the growth and development of Abrometiella plants, we can conclude that with the treatment of Chlorella extracts, the application of chemical fertilisers in the production of succulents such as Abrometiella can be reduced.

Synergistic Benefits of Combined Application of Manures and Chemical Fertilizers: Enhancing Growth and Yield of Rice and Wheat

The incorporation of compost and manure with chemical fertilizer has become a key concern to sustain soil fertility. Because the nutrients are continuously depleting from the soil and consequently creating a risk to preserving soil health. Aims: This study assesses the response of different doses of cowdung (CD), municipal solid waste compost (MSWC), oil cake (OC), and poultry manure (PM), incorporated with fertilizers on the growth, yield and protein content of BRRI dhan49 rice and BARI Gom-24. Study Design: RCBD with 8 treatments and 3 replications. Place and Duration of Study: Field experiment and nutrient analysis were carried out at Bangladesh Agricultural University (BAU), Mymensingh. Wheat was grown during the rabi season from October 2018 to March 2019. Again, rice was cultivated during kharif II season from August 2019 to December 2019 on the same field. Then the laboratory analysis was performed till June 2020. Methodology: Eight treatments i.e., T0 Control (no fertilizer), T1 Recommended Fertilizer Dose, T2 (CD + NPK), T3 (MSWC + NPK), T4 (OC + NPK), T5 (PM + N), T6 (MSWC + N), T7: (CD + OC) were accommodated. Data on the growth parameters including grain and straw yields were documented after the harvest of the fully matured crop simultaneously determining the nitrogen (N) and protein content. Results: Adoption of various combinations of compost and manures with fertilizer accorded an increase in yield contributing characters as well as the N and protein content. Integrating MSWC @ 10 t ha-1+N projected the highest grain yield (7.11 t ha-1 in rice; 4.84 t ha-1 in wheat) and straw yield (8.8 t ha-1 in rice; 5.55 t ha-1 in wheat). It also promisingly secured the highest protein content compared to all other treatments. Conclusion: The appliance of MSWC @ 10 t ha-1 with the recommended dose of N may be endorsed for rice and wheat cultivation in the AEZ-9 region and retaining the physicochemical properties of Old Brahmaputra Floodplain soils.

Direct nitrous oxide emissions from a crop rotation of maize and mung bean after different long-term fertilizer applications in Thailand

Nitrous oxide (N2O) is a greenhouse gas primarily released by fertilizers used in crop cultivation. In Thailand, cropland occupies the majority of the arable land but studies on N2O emissions from cropland remain scarce. The present study aimed to evaluate the N2O emissions, soil characteristics, and crop productivity resulting from different long-term fertilizer applications in a crop rotation of maize and mung bean. A long-term experimental field managed through crop residue incorporation combined with different fertilizer applications over 45 years was utilized in this study. It consisted of four distinct treatments: no fertilizer (CON), 134 kg N ha−1 from organic fertilizer (ORG), 188 kg N ha−1 from chemical fertilizer (CHE), and 322 kg N ha−1 from a combination of organic and chemical fertilizers (OAC). Long-term application of chemical fertilizer induced soil acidification, whereas the use of organic fertilizer maintained soil pH and enhanced soil carbon accumulation. Results showed that the OAC, CHE, and ORG practices significantly (p < 0.05) increased direct N2O emissions from the soil, particularly during the maize cultivation period. Annual cumulative N2O emissions were enhanced on average by 204 % (3.22 kg N2O ha−1) in OAC, 181 % (2.98 kg N2O ha−1) in CHE, and 79.4 % (1.90 kg N2O ha−1) in ORG compared with CON (1.06 kg N2O ha−1), indicating that larger N input rates induced larger N2O emissions. Chemical fertilizer induced significantly (p < 0.05) larger and faster N2O emissions than organic fertilizer. When considering N2O emissions per N application rate in all treatments as the emission factor, the use of N fertilizers combined with crop residues in the soil over two years averaged 0.61 % (± 0.13 %). This value was approximately 39 % lower than the default value recommended by the Intergovernmental Panel on Climate Change, which is currently used in Thailand. The consecutive addition of fertilizers significantly (p < 0.05) increased maize grain yield compared with the CON. However, no significant differences were observed among the various fertilizer treatments. Despite all fertilizer applications induced larger N2O emissions, they also produced greater crop yields. Consequently, this study recommended the practice of ORG as a means to mitigate emissions without compromising crop yield and soil quality.

Partial substitution of chemical fertilizer by organic fertilizer increases yield, quality and nitrogen utilization of Dioscorea polystachya.

This field experiment aimed to investigate the effects of different ratios of organic and inorganic fertilizers with maintaining equal nitrogen application rates on the yield, quality, and nitrogen uptake efficiency of Dioscorea polystachya (yam). Six treatments were set, including a control without fertilizer (CK), sole application of chemical fertilizer (CF), sole application of organic fertilizer (OM), 25% organic fertilizer + 75% chemical fertilizer (25%OM + 75%CF), 50% organic fertilizer + 50% chemical fertilizer (50%OM + 50%CF), and 75% organic fertilizer + 25% chemical fertilizer (75%OM + 25%CF). The experiment followed a randomized complete block design with three replications. Various yield parameters, morphology, quality indicators, and nitrogen utilization were analyzed to assess the differences among treatments. The results indicated that all fertilizer treatments significantly increased the yield, morphology, quality indicators, and nitrogen utilization efficiency compared to the control. Specifically, 25%OM + 75%CF achieved the highest yield of 31.96 t hm-2, which was not significantly different from CF (30.18 t hm-2). 25%OM + 75%CF exhibited the highest values at 69.23 cm in tuber length and 75.86% in commodity rate, 3.14% and 1.57% higher than CF respectively. Tuber thickness and fresh weight of 25%OM + 75%CF showed no significant differences from CF, while OM and 50%OM+50%CF exhibited varying degrees of reduction compared to CF. Applying fertilizer significantly enhanced total sugar, starch, crude protein, total amino acid, and ash contents of D. polystachya (except ash content between CK and OM). Applying organic fertilizer increased the total sugar, starch, crude protein, total amino acid, and ash contents in varying degrees when compared with CF. The treatment with 25%OM+75%CF exhibited the highest increases of 6.31%, 3.78%, 18.40%, 29.70%, and 10%, respectively. Nitrogen content in different plant parts followed the sequence of tuber > leaves > stems > aerial stem, with the highest nitrogen accumulation observed in 25%OM + 75%CF treatment. Nitrogen harvest index did not show significant differences among treatments, fluctuating between 0.69 and 0.74. The nitrogen apparent utilization efficiency was highest in 25%OM + 75%CF (9.89%), followed by CF (9.09%), both significantly higher than OM (5.32%) and 50%OM + 50%CF (6.69%). The nitrogen agronomic efficiency varied significantly among treatments, with 25%OM + 75%CF (33.93 kg kg-1) being the highest, followed by CF (29.68 kg kg-1), 50%OM + 50%CF (21.82 kg kg-1), and OM (11.85 kg kg-1). Nitrogen partial factor productivity was highest in 25%OM + 75%CF treatment (76.37 kg kg-1), followed by CF (72.11 kg kg-1), both significantly higher than 50%OM + 50%CF (64.25 kg kg-1) and OM (54.29 kg kg-1), with OM exhibiting significantly lower values compared to other treatments. In conclusion, the combined application of organic and inorganic fertilizers can effectively enhance the yield, quality, and nitrogen utilization efficiency of D. polystachya. Particularly, the treatment with 25% organic fertilizer and 75% chemical fertilizer showed the most promising results.

Effect of NPK Fertilizers, Farmyard Manure (FYM) and Bio-fertilizers on Quality Parameters of Onion (Allium cepa L.) Grown in Jaipur, Rajasthan

The current experiment was conducted in loamy sand soils of the Horticulture farm, Vivekanand Global University Jaipur, during Rabi season of 2020-21 and 2021-22. The experiment comprised of 32 treatment combinations replicated three times, was laid out in split-plot design (SPD) with four fertility levels of NPK (0, 50, 75 and 100% of recommended dose of NPK) and two levels of FYM (without FYM and with FYM @ 25 t ha-1 were added in main plots. Four bio-fertilizer levels (No inculcation N2 fixer Azotobacter, PSB inculcation and N2 fixer Azotobacter + PSB inoculation) were added in sub plots. The results of the study have clearly shown that application of chemical fertilizer up to 100% RDF increased all the quality attributes (pungency, chlorophyll content and TSS), NPK and S content and uptake and availability of N, P and K in soil after harvest the crop. With application of FYM @ 25 t ha-1 significantly improved all quality attributes (Allyl propyl disulphide, chlorophyll and TSS), N, P, K and S content and uptake and availability of N, P and S in soil after harvest the crops. Use of biofertilizers (N2 fixers and PSB) alone or in combination increased all the quality attributes (Allyl propyl disulphide, chlorophyll and TSS content), NPK and S content and uptake and availability of N, P and K in soil after harvest the crop.

Response of bacterial communities, enzyme activities and dynamic changes of soil organic nitrogen fractions to six-year different application levels of biochar retention in Northeast China

Composition and availability of soil organic nitrogen play a key role in soil N retention and supply. The application of traditional chemical fertilizers can improve soil production and crop yields. However, it also leads to low N utilization efficiency and soil solidification. Previous studies have shown that fertilizers added with biochar can improve soil fertility and facilitate soil nutrient transformation by regulating soil biological indicators. However, whether biochar used with fertilizers can promote nutrient cycling in the long term, which remains to be tested. Therefore, this study aims to explore the long-term effects of biochar with different levels used with fertilizers on soil fertility, N supply potential of organic N, and microbial communities, thus, providing a theoretical reference for the rational management of biochar applications. In this study, a field experiment was carried out from 2013 to 2018 assess dynamic changes in organic N fractions and diversity and richness of microbial communities under the impacts of chemical fertilizers combined with different levels of biochar. Biochar with no amendment (CK), biochar with 15.75 t ha−1 (BC1), biochar with 31.5 t ha−1 (BC2), and biochar with 47.25 t ha−1 (BC3) are four biochar levels that were tested in this study. The results show that compared with CK, those other three biochar levels can increase soil organic matter, C/N, and pH values. Acid-hydrolysable N (AHN) makes a major contribution to organic N in soil. Biochar retention for six years has significantly affected AHN levels, as well as its four fractions, namely, amino acid N (AAN), acid-hydrolysable ammonium N (AN), amino sugar N (ASN), and hydrolysable unknown N (HUN). Some vital biological characteristics, with which each AHN fraction is primarily regulated, can be altered with the application of biochar. That is, AAN is mainly controlled by enriched Verrucomicrobia, Cyanobacteria, Glucosylbacteria, and Nitrospira, and reduced soil urease, while AN is mainly controlled by enriched Verrucomicrobia, Bacteroidetes, Gemmatimonadetes, Acidobacteria, and Proteobacteria. ASN is regulated by enriched Acidobacteria and depleted soil protease, while HUN is regulated by Gemmatimonadetes and enriched soil nitrate reductase. It has been found that microbial and soil enzyme activities are involved in N cycle processes, indicating that the formation of AHN fractions is closely associated with biochar-induced specific microbial and enzyme activities. This study has provided new insights into the influences of biochar with different levels on distribution of soil organic N fractions, and shifts in soil enzyme activities and microbial communities.

Effect of Biogas Slurry on the Soil Properties and Microbial Composition in an Annual Ryegrass-Silage Maize Rotation System over a Five-Year Period.

Soil health is seriously threatened by the overuse of chemical fertilizers in agricultural management. Biogas slurry is often seen as an organic fertilizer resource that is rich in nutrients, and its use has the goal of lowering the amount of chemical fertilizers used while preserving crop yields and soil health. However, the application of continuous biogas slurry has not yet been studied for its long-term impact on soil nutrients and microbial communities in a rotation system of annual ryegrass-silage maize (Zea mays). This study aimed to investigate the impacts on the chemical properties and microbial community of farmland soils to which chemical fertilizer (NPK) (225 kg ha-1), biogas slurry (150 t ha-1), and a combination (49.5 t ha-1 biogas slurry + 150 kg ha-1 chemical fertilizer) were applied for five years. The results indicated that compared to the control group, the long-term application of biogas slurry significantly increased the SOC, TN, AP, and AK values by 45.93%, 39.52%, 174.73%, and 161.54%, respectively; it neutralized acidic soil and increased the soil pH. TN, SOC, pH, and AP are all important environmental factors that influence the structural composition of the soil's bacterial and fungal communities. Chemical fertilizer application significantly increased the diversity of the bacterial community. Variation was observed in the composition of soil bacterial and fungal communities among the different treatments. The structure and diversity of soil microbes are affected by different methods of fertilization; the application of biogas slurry not only increases the contents of soil nutrients but also regulates the soil's bacterial and fungal community structures. Therefore, biogas slurry can serve as a sustainable management measure and offers an alternative to the application of chemical fertilizers for sustainable intensification.

Green finance reform and application intensity of chemical fertilizer and pesticide: policy evidence from China.

The environmental hazards resulting from the excessive application of pesticides and fertilizers have been an inevitable agricultural production issue in various countries around the world. New technologies and policies are constantly trying to improve their application efficiency. This paper utilizes panel data of the provincial level in China from 2009 to 2019 to empirically study the effect of green finance reform policies on the chemical fertilizer application intensity (FAI) and pesticide application intensity (PAI). Standard difference-in-differences (DID), synthetic DID, difference-in-difference-in differences (DDD), and spatial DID models are constructed for specific empirical analysis. The findings can be concluded as follows: (1) A unit of the green finance reform policy reduces FAI by 0.0144 and PAI by 1.7921 by promoting green technology innovation. (2) Government financial extractive capacity hinders the reduction effect of green finance on PAI. (3) Coastal geographical location is conducive to reducing PAI through green finance reform. (4) FAI and PAI show positive spatial autocorrelations, and the influence of green finance reform overflows to surrounding areas. The research results can provide policy references for countries around the world to promote the green development of agriculture and reduce environmental pollution.

Effects of Continuous Cropping and Application of Bio-organic Fertilizers on Growth, Yield and Quality of Sugar Beet under Reduced Chemical Fertilizer Application

Effects of Continuous Cropping and Application of Bio-organic Fertilizers on Growth, Yield and Quality of Sugar Beet under Reduced Chemical Fertilizer Application

Effect of NPK through Chemical Fertilizers Combination with Farm Yard Manure (FYM) and Bio-fertilizers on Yield Attributes of Onion (Allium cepa L.) in Jaipur Region of Rajasthan, India

The field experiment was conducted in loamy sand soil of the Horticulture farm, Vivekanand Global University Jaipur, during Rabi season of 2020-21 and 2021-22. The experiment comprises of 32 treatment combinations replicated three times was laid out in split-plot design (SPD) with four fertility levels of NPK (0, 50, 75 and 100% of recommended dose of NPK) and two levels of FYM (without FYM and with FYM @ 25 t ha-1) were added in main plots. Four bio-fertilizer levels (No inculcation, N2 fixer Azotobacter, PSB inculcation and N2 fixer Azotobacter + PSB inoculation) were added in sub plots. The treatments comprised of Chemical fertilizers, FYM and biofertilizers with ten treatments Viz., F0- Control, F1-50% of recommended dose of NPK, F2-75% of recommended dose of NPK, F3-100% of recommended dose of NPK, M0- Without FYM, M1- With FYM @ 25 t ha -1, B0- No inoculation, B1- N2 fixer Azotobacter, B2- PSB inoculation and B3- N2 Fixer Azotobacter + PSB inoculation, respectively. The results of the study have clearly shown that application of chemical fertilizer up to 100% RDF increased the entire yield and its attributes viz. (neck length, bulb diameter, number of scales, fresh weight of bulb, volume of bulb). With application of FYM @ 25 t ha-1 yield significantly improved with its attributes. Use of biofertilizers (N2 fixers Azotobacter + PSB inoculation) in combination or alone increased all yield and its attributes. Integrated system approach is not only the liable for attaining fairly high productivity with substantial fertilizer economy but also a concept of soundness leading to sustainable agriculture .

Study on the Effects of Reducing Nitrogen Fertilizer: Stabilizing Yield and Carbon Sequestration by Synergistic Utilization of Chinese Milk Vetch and Rice Straw in Double-Cropping Rice Area

The excessive application of chemical fertilizers in rice fields exacerbates soil degradation and poses a threat to food security. Achieving an increase in rice production and minimizing environmental costs are inevitable requirements for achieving sustainable rice production. The synergistic utilization of rice straw (RS) and Chinese milk vetch (MV) is a sustainable measure to improve soil quality in Southern China. How this management strategy impacts agricultural productivity and soil carbon (C) sequestration under different fertilization conditions is unclear. Several treatments, including only chemical fertilizer (F), F + MV (FM), F + RS (FS), and F + MV + RS (FMS) under a standard rate of nitrogen (N100) and 40% reduced nitrogen (N60) levels were designed to explore changes in rice yields and soil organic carbon (SOC) concentrations, stocks, and soil labile organic C fractions (permanganate oxidizable C) during 2018–2020 in a double-rice-cropping system. The results show that the FMS treatment reduced soil bulk density to alleviate soil compaction and improved the soil carbon management index. The synergistic utilization of MV and RS replacing 40% of the chemical N fertilizer could still maintain the rice yield. Compared to the F treatment, the average annual grain yield was significantly increased by 9.82% and 5.84% in the FMS treatment; SOC concentration was increased by 16.05% and 19.98% on average (p &lt; 0.05), and SOC stock was increased by 1.78 Mg C ha−1 and 2.37 Mg C ha−1 under the N60 and N100 levels, respectively. The random forest regression model and correlation analysis demonstrated that the inputs of chemical N, organic N and C, and appropriate C/N ratio promoted soil C accumulation. Furthermore, the structural equation model analysis exhibited that the C input affects the highly labile organic carbon (HLOC) and total labile organic carbon (LOC); the HLOC had a positive effect on SOC (p &lt; 0.05). N input had a significant effect on LOC and yield. Our results suggest that the synergistic utilization of MV and RS plays an important role in ensuring stable grain production, improving soil C sequestration capacity, and maintaining soil environmental health in Southern China.