Conventional Chemical Fertilizers Research Articles

Integrated biofertilization using yeast with cyanobacteria on growth and productivity of wheat

BackgroundThe heavy use of conventional mineral fertilization considerably increased wheat growth and yield components. However, the excessive nitrogen fertilization accounts for large expenses on farmers’ budget and has negative environmental drawbacks to soil and water ecosystems. Recently, establishing wheat plants associations with a variety of N2-fixing cyanobacteria and/or growth promoting microorganisms in farming systems as nutrients source is seen as ecofriendly and economically feasible solution.ResultsIn this work, the influence of different nitrogen (N) levels (100% N, 75% N, and 50% N as urea) and cyanobacteria (Cy) and/or yeast (Y) inoculation each alone or both in combination with different nitrogen levels were assessed on two different wheat (Triticumae stivum L.) genotypes (Sids-14 and Giza-171) through field experiments over two consecutive seasons (2019/2020 and 2020/2021). Although, the full recommended dose (FRD) (100% N) showed the highest chlorophyll (Chl) a, b content during tillering stage, grains quality (NPK-uptake, protein%), and wheat yield components in both genotypes. The integrated inoculation of cyanobacteria and yeast with 50% N, 75% N-fertilization enhanced wheat growth characteristic (Chl a,b) and upgraded soil microbial community (nitrogenase activity and CO2 evolution) in Sids-14 and Giza-171. Cy combined with Y and partial N-fertilization levels enhanced NPK-uptake Kg/fed and protein% in wheat grains in the two wheat genotypes. Moreover, this combination recorded a wheat yield components (plant height, number of spikes/m2, number of grains/spike, 1000 grains wt (gm) and grains yield (tonne/fed) insignificantly different from those obtained by FRD in wheat cultivation.ConclusionThe integrated application of cyanobacteria with yeast and 50% N or 75% N-fertilization improved soil fertility index and promoted NPK- uptake, protein% and wheat yield components, showing comparable values to conventional chemical fertilization. Cyanobacteria combined with yeast inoculation had socio-economic benefits as it can save about 25–50% of the required mineral nitrogen fertilizers for wheat crop production.

Commercial organic fertilizer substitution increases wheat yield by improving soil quality

Traditional organic fertilizer substitution is an effective measure for increasing crop yield and soil quality while reducing chemical fertilizer input. However, the effects of commercial organic fertilizer substitution (COFS) on soil quality and wheat yield, and the underlying mechanisms, are unknown. In this study, agricultural fields with low fertility (LF) and high (HF) fertility soils were selected for a two-year (2018–2019) field experiment in the oasis region of Northwest China. Three fertilization treatments with three replications (no fertilization, CK; local conventional chemical fertilizer application, LCF; and 20 % of inorganic nitrogen (N) was substituted by commercial organic fertilizer, COFS) were established to study the effects of COFS on wheat growth, yield, nutrient-use efficiency and soil quality. The results showed that compared with LCF in 2018 and 2019, COFS in LF and HF promoted wheat growth, improved nitrogen use efficiency (NUE) and phosphorus use efficiency (PUE), and increased yield (by 1.52 %–3.05 % and 1.16 %–1.39 %) and soil quality (by 15.09 %–28.63 % and 22.53 %–64.82 %) by improving most soil indicators (e.g., soil organic matter (SOM) and available nutrients). Moreover, SOM and available nutrients significantly affect soil quality and wheat yield, which can monitor changes in soil quality and wheat yield. In conclusion, our study revealed that the mechanism of COFS in HF and LF increased wheat yield by improving soil quality. COFS is recommended for agricultural production, but its continuous application requires monitoring changes in SOM and available nutrients to adjust fertilization to guarantee soil quality and crop yield. This study provides guidance for the scientific application of COFS to improve farmland productivity and soil quality and helps to promote healthy and sustainable agricultural development.

Effects of Bacillus subtilis A-5 and its fermented γ-polyglutamic acid on the rhizosphere bacterial community of Chinese cabbage.

Chemical fertilizer reduction combined with novel and green agricultural inputs has become an important practice to improve microecological health in agricultural production. Given the close linkages between rhizosphere processes and plant nutrition and productivity, understanding how fertilization impacts this critical zone is highly important for optimizing plant–soil interactions and crop fitness for agricultural sustainability. Here, by using a pot experimental system, we demonstrated that nitrogen fertilizer reduction and microbial agent application promoted plant fitness and altered the microbial community structure in the rhizosphere soil with the following treatments: no fertilization, CK; conventional chemical fertilizer, CF; 30% reduced nitrogen fertilizer, N; 30% reduced nitrogen fertilizer with pure γ-PGA, PGA; 30% reduced nitrogen fertilizer with Bacillus subtilis A-5, A5; 30% reduced nitrogen fertilizer with γ-PGA fermentation broth, FJY. The PGA, A5, and FJY treatments all significantly promoted crop growth, and the FJY treatment showed the strongest positive effect on Chinese cabbage yield (26,385.09 kg/hm2) (P < 0.05). Microbial agents affected the α diversity of the rhizosphere bacterial community; the addition of B. subtilis A-5 (A5 and FJY treatments) significantly affected rhizospheric bacterial community structure. Urease activity and soil pH were the key factors affecting bacterial community structure and composition. The FJY treatment seemed to influence the relative abundances of important bacterial taxa related to metabolite degradation, predation, and nitrogen cycling. This discovery provides insight into the mechanism underlying the effects of microbial agent inputs on rhizosphere microbial community assembly and highlights a promising direction for the manipulation of the rhizosphere microbiome to yield beneficial outcomes.

Is Dairy Effluent an Alternative for Maize Crop Fertigation in Semiarid Regions? An Approach to Agronomic and Environmental Effects.

Simple SummaryDairy effluent can be an environmental problem if it is not properly managed. Several application technologies exist for its reuse as a source of nutrients in agricultural crops. Our study provides new information on GHG emissions after the application of dairy effluent through a subsurface drip irrigation system on a semiarid soil of the southern Pampean Region (Argentina). In addition, some edaphic properties are compared with conventional chemical fertilization on the yield of a corn crop, contributing as a proposal for an improvement in agricultural sustainability.The reuse of effluents from intensive dairy farms combined with localized irrigation techniques (fertigation) has become a promising alternative to increase crop productivity while reducing the environmental impact of waste accumulation and industrial fertilizers production. Currently, the reuse of dairy effluents through fertigation by subsurface drip irrigation (SDI) systems is of vital importance for arid regions but it has been poorly studied. The present study aimed to assess the greenhouse gas (GHG) emissions, soil properties, and crop yield of a maize crop fertigated with either treated dairy effluent or dissolved granulated urea applied through an SDI system at a normalized N application rate of 200 kg N ha−1. Fertilizer application was divided into six fertigation events. GHG fluxes were measured during fertigation (62-day) using static chambers. Soil properties were measured previous to fertilizer applications and at the harvest coinciding with crop yield estimation. A slight increase in soil organic matter was observed in both treatments for the 20–60 cm soil depth. Both treatments also showed similar maize yields, but the dairy effluent increased net GHG emissions more than urea during the fertigation period. Nevertheless, the net GHG emissions from the dairy effluent were lower than the theoretical CO2eq emission that would have been emitted during urea manufacturing or the longer storage of the effluent if it had not been used, showing the need for life-cycle assessments. Local-specific emission factors for N2O were determined (0.07%), which were substantially lower than the default value (0.5%) of IPCC 2019. Thus, the subsurface drip irrigation systems can lead to low GHG emissions, although further studies are needed.

Attapulgite can improve yield and total ferulic acid content of Angelica sinensis by adjusting source-sink relationship

Attapulgite(ATP), as a fertilizer slow-release agent and soil conditioner, has shown remarkable effect in improving the utilization rate of fertilizer and the yield and quality of agricultural products and Chinese medicinal materials. This study aims to explore the effect of ATP on the growth and root quality of Angelica sinensis. To be specific, Mingui 1 was used, and through the pot(soil culture) experiment in the Dao-di producing area, the effects of conventional chemical fertilizer added with ATP on the morphology, photosynthesis, soil respiration, and content of ferulic acid and volatile oil in roots of Mingui 1 were detected. The underlying mechanism was discussed from the perspective of source-sink relationship. The results showed that ATP, via the fertilizer slow-release effect, could meet the needs of A. sinensis for nutrients at the root expansion stage, improve the net photosynthetic rate of leaves and aboveground biomass of plants, and promote the transfer and accumulation of nutrients from the aboveground part(source) to the underground root(sink) in advance during the dry matter accumulation period of roots, so as to improve the root weight per plant. ATP can increase the content of total ferulic acid(the sum of free ferulic acid and coniferyl ferulate), the main effective component of Angelicae Sinensis Radix, by promoting the synthesis of ferulic acid in the roots and the transformation to coniferyl ferulate. However, it had little effect on the content of volatile oil. ATP had certain influence on soil respiration, which needs to be further explored from root activity, rhizosphere microorganisms, and soil microorganisms. This study can lay a basis for soil remediation and improvement and ecological cultivation of A. sinensis.

Effect of sewage polluted by heavy metal on domestic crops

The application of sewage water (SW) to irrigate and feed agricultural crops in Mexico is widespread due to the problem of scarcity in the country, and in the world. Agricultural crops not eaten raw irrigated and fed with SW benefit and/or harm directly or indirectly by the chemical composition that in industrial cities that includes heavy metals of risk to human health. The objective of this work was to analyze the effect of sewage with heavy metals on the growth and yield of an agricultural soil of "El Canada" N.L. Mexico. Compared with plant growth and yield in a soil from Cadereyta, Nuevo León, Mexico in greenhouse irrigated with ground water and conventional chemical fertilization. For which the concentration of heavy metals of the SW in the plant and the soil was determined. The results show that the SW used in the irrigation of agricultural crops supported plant growth. With no evidence that heavy metals caused any negative effect on plant growth and yield, despite the length of SW use, it is believed that some of these crops have developed tolerance to heavy metals regarding the risk to be consume by humans and animals

A Review of Synthetic and Earth's Resource-Based Slow-Release Fertilizers and Their Potential Role in Reducing Groundwater Pollution

Groundwater is an essential water source for humans. Unfortunately, some groundwater resources have been contaminated by wastes from various sectors. Fertilizer also contributes to groundwater contamination. The nutrients from fertilizer that are not absorbed by the plant move towards groundwater reservoirs and contaminate the groundwater. Slow-release fertilizer is a solution to reduce groundwater pollution while maintaining fertilizer’s function as the sources of nutrients for plants. This paper discusses and reviews the relevant literatures related to groundwater, fertilizer, slow-release fertilizer, and earth’s based slow-release fertilizer. The release rate of nutrient elements from different types of fertilizer is also presented. The synthetic base slow-release fertilizers and earth’s resource-based slow-release fertilizers can hold nutrients longer than conventional chemical fertilizers when exposed to water. Two particular minerals that can be used as raw materials in slow-release fertilizer synthesis are analyzed using XRD. They are from hydrothermal silica and obsidian. The XRD analysis of hydrothermal silica and obsidian shows the presence of amorphous silica and other minerals. Silica in compacted slow-release fertilizer can control the release rate of nutrient elements from fertilizer.

Recycling of isabgol (Plantago ovata Forsk.) straw biomass and mineral powder with bio-inoculants as an effective soil amendment for isabgol cultivation

Efficient utilization of isabgol ( Plantgo ovata Forsk.) straw biomass through preparation of bio-active organic fertilizer in a natural composting process has not been studied. In this study, phosphate rock and silicate mineral (mica) powder were used as natural sources of phosphorus (P) and potassium (K), respectively. Cow dung slurry as a natural decomposer was mixed with the straw biomass at a 10:1 (weight/weight) ratio along with mineral powder. Then, nutrient-mobilizing bio-inoculants were used in the composting process after attaining thermal stabilization. The agronomic effectiveness of the resulting bio-active compost (BAC) as a bio-organic fertilizer was compared with that of conventional organics (farmyard manure and vermicompost) and chemical fertilizer (CF) by growing isabgol under field conditions. Composting with the natural sources of P and K along with the bio-inoculants increased the total nitrogen (13.6 g kg -1 ), P (38.7 g kg -1 ), and K (31.2 g kg -1 ) contents in the final product ( i.e ., BAC) compared with composting without the mineral powder and bio-inoculants. Application of BAC remarkably improved the seed yield (2.5%) and husk quality of isabgol in comparison with conventional organics and CF. Compared with CF, BAC significantly boosted the economic yield of isabgol by improving the husk recovery (2.5%) and mucilage yield (4.12%). Furthermore, BAC significantly improved the soil quality by increasing organic carbon (C), available nutrients, and microbial biomass C contents, as well as enzyme activity. The positive correlation between soil and plant parameters also highlighted the benefits of BAC for isabgol production through soil quality improvement. Therefore, it can be considered as a zero-waste technology, whereby a large quantity of straw biomass generated from isabgol cultivation, which contains essential nutrients, can be recycled back to the soil. Furthermore, BAC can be effectively used as a bio-active organic fertilizer, particularly in systems where chemical inputs are restricted, such as organic agriculture.

Effects of organic supplementation to reduced rates of chemical fertilization on soil fertility of Zanthoxylum armatum

Soil acidification, fertility depletion, food insecurity, and environmental pollution all are con­sequences of the extensive use of chemical fertilizers (CF) in intensively managed plantations. Recent studies have shown that incorporating organic manure (OM) to partially replace CF can help to maintain productivity and soil health. There are no reports on integrated fertilizer management of Zanthoxylum ar­matum, for optimal ecological services and economic profitability. A pot experiment with Z. armatum was performed to investigate the possibility of incorporating OM in reducing CF use, enhancing soil fertility, and increasing plant growth. For this, seven treatments were designed: NPK, PK, NP, NK, OM, MNPK (50%NPK+50%OM), and control (CK, no fertilizer application). The results showed that NPK application significantly (P &lt; 0.05) increased plant growth, soil nitrate-N, ammonium-N and available K compared to CK. However conventional CF application induced soil acidification. OM application raised the soil pH from 5.50 (CK) to 6.58 and significantly enhanced soil fertility by increasing alkali-hydrolysable N (2.3 times), ammonium-N (1.4 times), available P (4.3 times), the activity of invertase (1.5 times), catalase (2.8 times), acid phosphatase (1.5 times), and count of soil culturable microbes (2.9 times) compared to CK. Conversely, sole OM application did not result in optimum plant growth. Integrating OM with NPK (MNPK), on the other hand, not only provided the highest growth comprehensive value (0.84), but also substantially higher soil fertility comprehensive value (0.71) than traditional CF treatments. Correlation analysis also indicated a positive and significant correlation between soil microbes, enzyme activities and available nutrients. Therefore, OM+NPK could be an optimum measure to get maximum benefits regard­ing soil fertility, growth of Z. armatum, fertilizer savings and sustainable agroecology.

Effect of nitrogen and zinc nanofertilizer with the organic farming practices on cereal and oil seed crops

Sustainable and precision agriculture practices are essential to meet the global food demand with minimal impact on soil, air and water. In the present study, nanofertilizers of nitrogen and zinc was used with the organic farming practice under field condition for the cereal i.e. wheat, pearl millet, and oil seed crops i.e. mustard, sesame. The field trial was compared with chemical fertilizer based agricultural settings. A total of 160 field demonstrations were conducted at two locations: Khaliyawas (28.19° N, 76.76° E) and Khatawali (28.22° N, 76.76° E) of Haryana, India with a total area of 1225 acre and randomized block design. It was found that an average yield was recorded 5.35% higher in wheat, 24.24% higher yield in sesame, 4.2% higher in pearl millet and 8.4% higher yield in mustard by applying nanofertilizers of nitrogen and zinc along with the organic farming practice. The increased yield corroborated with the development parameters of plants such as wheat tillers, ear head length of pearl millet, capsule number per plant in sesame and siliquae number per plant in mustard. The trial observation suggests that the fields with applied organic manure, bio-fertilizer and nanofertilizers in combination resulted in higher yield and better plant growth performances when compared to the fields under conventional chemical fertilizer practice. The results suggest that the intervention of nanotechnology along with organic farming practice can help in minimizing the mass volume requirement of conventional chemical fertilizer while improving crop production.

STUDIES ON THE EFFECT OF VARIOUS LEVELS OF NITROGENOUS FERTILIZER ALONG WITH SOME NITROGEN FIXING BLUE GREEN ALGAE ON SOME YIELD ATTRIBUTES OF RICE VARIETIES CV. PUSA 1509 AND PUSA SHARBATI

Nitrogen is indispensible ingredient of animal food and comes initially from plant. In fact, plant converts the nitrogen of soil in two forms suitable for nutrition of animals. After water, nitrogen is the second limiting factor for plant growth in many fields and deficiency of this element is met by fertilizers. The excessive use of chemical fertilizer has generated several environmental issues. These problems can be tackled by use of Bio-fertilizers. Bio-fertilizers are different from Chemical fertilizers. Bio -fertilizer on the application remains in soils, multiply and keep benefiting the growing crops. Blue green algae (BGA) or Cyanobacteria, the free-living photosynthetic N-fixing organism, are distributed worldwide and contribute to the soil fertility in many agricultural ecosystem. Cyanobacteria function as a Bio-fertilizer due to the property of nitrogen fixation (conversion of molecular nitrogen into nitrogen compound). The mass production of Cyanobacteria is much cheaper and easy than that of conventional chemical fertilizer and their inorganic requirement is very simple. To test the efficacy of nitrogenous fertilizer along with BGA on the yield attributes of rice, a field experiment was conducted with rice variety Pusa 1509 and Pusa sharbati. Two fields of 2.0 m into 3.0 m were prepared one without BGA as control and other with BGA. For this field experiment recommended dose of BGA is 10 kg/ ha after the transplantation of rice seedlings. Inoculates contains the mixture of Gloeocapsa, Plectonema, Oscillatoria, Anabaena, Nostoc, Cylindrospermum, Scytonema, Calothrix, Anabaenopsis, Aulosira, Eisherella etc. As compared with control tillers were seen after 80 days, food grains were thick, elongated and healthy and 10-30 percent grain yield found to be increased over control. The observation clearly indicates that the BGA can be the good option to increase the growth and crop production in Rice.

Effects of the reduction in chemical fertilizers on soil phosphatases encoding genes (phoD and phoX) under crop residue mulching

Phosphorus (P) within crop residues is released to soils and thus is expected to partially replace the application of chemical P. However, whether and how P availability responds to a reduction in chemical P under crop residue mulching is still poorly understood. In this study, conventional chemical fertilizer (NPK), NPK plus crop residue (NPKStr), NPKStr combined with 20% reduction in only chemical P (NPmKStr) and NPKStr combined with 20% reduction in chemical NPK fertilizers (mNPKStr) were used. The abundance and diversity of the phoD and phoX genes encoding phosphatases were evaluated using quantitative PCR and high-throughput sequencing. The results showed that variations in the abundance and α-diversity were detected in phoD rather than phoX, while the composition of phoX-harbouring bacterial communities changed between treatments. Specifically, NPmKStr resulted in an increase in the abundance and α-diversity of phoD while mNPKStr stimulated phoD abundance. In addition, NPmKStr decreased the activities of alkaline phosphomonoesterases (ALPs) and mNPKStr increased phosphodiesterase (PDE) activities. Moreover, phoD- and phoX-harbouring bacterial species were highly correlated, especially bridged by particular species belonging to Alphaproteobacteria and Cyanobacteria, in response to reduced amounts of chemical fertilizer. Last, structural equation modelling suggested that the activities of both ALP and PDE showed negative feedback towards increased available P by virtue of phoX-harbouring bacterial species. These results indicated that a balanced reduction in chemical fertilizers may be more reasonable for maintaining the ability to hydrolyse organic P under crop residue mulching and that phoX played an intermediary role in this process.

Morphological and physiological response of sour orange (Citrus aurantium L.) seedlings to the inoculation of taxonomically characterized bacterial endophytes

Entophytic bacteria (EBs) are very diverse and found in virtually all plant species studied. These natural EBs live insides the host plant and can be used to maximize crop and fruit yield by exploiting their potential. In this paper, EBs characterization from various citrus genotypes andtheir influence on the morphological and physiological functioning of sour orange (Citrus aurantium) seedlings are described. To assess the influence of 10 distinct EBs, three different techniques (injection, soil mix, and spray) were applied for single and mixed inoculation on sour orange (C. aurantium) seedlings. The selected strains were identified as firmicutes (Enterococcus faecalis, Bacillus safensis, Bacillus cereus, Bacillus megaterium, Brevibacillus borstelensis &Staphylococcus haemolyticus), and gamma Proteobacteria (Enterobacter hormachaei, Proteus mirabilis, Pseudomonas aeruginosa, &Pseudomonas sp.) by 16S rRNA gene sequencing. To investigate the influence of these EBs on host plant morphology, different parameters (morphometric) were recorded after five WOI (weeks of inoculation), including shoot/root length, shoot/root fresh and dry biomass, and biophysical analyses i.e., relative water content (RLWC). Physiological markers such as chlorophyll & carotenoid content, protein content, proline content, phenolics, and flavonoids were also analyzed to determine the influence of endophytes on sour orange seedlings. Five strains such as SM-34, SM-20, SM-36, SM-68, and SM-56 significantly improved the development and physiology of sour orange seedlings. Bacillus cereus and Pseudomonas aeruginosa produced the best outcomes in terms of plant growth. The relative quantification of bacterial inoculums was determined using real-time PCR. A rise in the number of bacterial cells in inoculated treatment suggests that bacterial strains survived and colonized successfully, and also shown their competitiveness with native bacterial community structure. As per the results of inoculation methods,soil mixing, and injection methods were determined to be effective for bacterial inoculation to plants but a variable trend was found for different parameters with test bacterial strains. After testing their impact on field conditions, these strains can be applied as fertilizers as an alternative to conventional chemical fertilizer, although in the context of mixed inoculation of bacterial strains, 5 M and 6 M performed best andenhancedplant growth-promoting activity.

Complementarity in Rubber-Salacca Intercropping System under Integrated Fertilization Mixed with Organic Soil Amendments

The replanting practice of rubber monocropping in Southern Thailand has depleted soil fertility. Most rubber planted areas in the region were under intensive chemical fertilization resulting in less soil organic matters and root proliferation. With the instability of rubber prices, some rubber farmers converted from monocropping into intercropping. Integrated fertilization in which mixed organic-inorganic fertilizers are combined with organic soil amendments could be considered in a rubber-based intercropping system to increase land productivity with cost-saving fertilization by rehabilitating soil properties. A study was conducted at a rubber-salacca intercropping farm comprised of 14-year-old mature rubber trees associated with eight-year-old salacca palms to identify the consequences of the integrated fertilization combined with two organic soil amendments: humic acid (HSA); chitosan (CSA). Changes in soil organic matter (SOM), leaf area index (LAI), fine root traits, tree physiological status, and crop productions under the two integrated fertilization were compared against the controlled application of conventional chemical fertilizer. The CSA application increased the SOM in the topsoil layer by 80%. In the 21 – 40 cm soil depth, the rubber roots treated with HSA and the salacca palm roots treated with CSA showed greater fine root length density (FRLD). Under CSA, the physiological status of the rubber trees showed less stress. The treatments of HSA and CSA showed 145% and 72%, respectively, higher in total production of salacca palm than that of the chemical fertilization. Improvements in the soil fertility, the root’s function, the crops’ yields, and the tree physiological status were consequences as complementarity in the system under the integrated fertilizations.

Influence of PGPR, AM Fungi and Conventional Chemical Fertilizers Armament on Growth, Yield Quality, Nutrient’s translocations and Quercetin Content in Onion Crop Cultivated in Semi-Arid Region of India

The rhizosphere is the thin region of the soil that is directly affected by secretion from the roots and the microbes accompanying the soil, known as the root microbiome. The rhizosphere involving the pores of the soil includes many beneficial bacteria and other diverse microorganisms. The field experiment was conducted during the Kharif season at the Lasalgaon taluka of Nashik district farmers’ field, Maharashtra, India, to determine the influence of biofertilizers on onion. To study the effect of five combinations of biofertilizers compared with the recommended rate of chemical fertilizers on cash crop onion cv. Nashik Red. The treatments were control (100% RRF), Azotobacter + AM fungi, Azospirillum + AM fungi, Azotobacter + Azospirillum, Azotobacter + Azospirillum + AM fungi and Bio consortium (NPK) + Azospirillum + AM fungi. Height (64.24 ± 3.22 cm) and the number of leaves (13.58 ± 3.12) of the plant was maximum with the application of the consortium (NPK) + Azospirillum + AM fungi. The maximum leaf area (84.45 ± 2.44 cm2) was recorded in T6 and the minimum in T4 (82.45 ± 2.25). Different doses of onion plants inoculated with biofertilizers showed a significant increase in quality parameters such as neck thickness (1.12 ± 0.22cm), bulb diameter (14.45 ± 0.53cm), bulb size index (19.45 to ± 0.51 cm2), bulb weight (68.15 ± 2.27g), bulb length (6.21 to ± 1.48 cm), bulb scale (11.23 ± 1.23) was maximum in the consortium (NPK) + Azospirillum + AM fungi treated onion. Biofertilizers such as consortium treatments such as consortium (NPK) + Azospirillum + AM fungi resulted in a better morphological character, quality yield, TSS, starch, reduction sugar, quercetin contents among root colonization of mycorrhizae compared to the uninoculated control (100% RRF). The consortium (NPK) + Azospirillum + AM fungi and 100% RRF provided a maximum bulb length of 6.21 ± 1.48cm and 6.12 ± 1.59cm, respectively. The maximum number of scales per bulb (11.23 ± 1.23) was counted by the consortium (NPK) + Azospirillum + AM fungi. Plants treated with the consortium (NPK) + Azospirillum + AM fungi produced the maximum bulb weight (68.15 ± 2.27g) and the minimum (64.23 ± 2.39 g) in Azotobacter + Azospirillum. The maximum TSS (13.354 %) was noticed in T6 and the minimum in T3. The maximum percentage of starch (6.65%) and the highest percentage of reducing sugars (1.98%) were detected by Azotobacter + Azospirillum + AM fungi. Total pooled weight loss (%) up to 60 days was found to be minimal (11.87%) by Azotobacter + AM fungi followed by Azotobacter + Azospirillum (14.40%). The maximum colonization of mycorrhizae (79.9%) was recorded in the consortium (NPK) + Azospirillum + AM fungi and the minimum in the control (46.67%). It was therefore concluded that the combination of the consortium (NPK bioinoculum) + Azospirillum + AM fungi are improved for onion quality and productivity than the others in terms of sustainable production and environmental consideration.

Nanobiotechnology-mediated sustainable agriculture and post-harvest management

• We describe nanotechnology applications in various fields of agriculture, namely seed storage, seed germination, plant growth, priming, fertigation and crop productivity. • We emphasize the use of nanomaterials for the post-harvest management of fruits and vegetables. • Nanomaterials used as intelligent delivery systems for crop productivity, stress tolerance and plant adaptation are discussed. • Nanomaterials used as sensors for precision agriculture and crop protection. Humans directly depend on food and agriculture. However, an estimated one- third of agricultural produce is wasted every year post-harvest loss. The major reasons for post-harvest loss include microbial contamination, moisture content, degradation, and adverse effects of the physical and chemical methods used for storage. Conventional post-harvest methods do not adequately prevent the loss of agricultural produce therefore, new strategies are increasingly needed to address the shortcomings of traditional agricultural post-harvest practices. In this regard, nanotechnology (the manipulation of materials at <100 nm) has emerged as a promising field to replace traditional practices. The use of engineered nanoagroparticles greatly enhances agricultural productivity and mitigates the environmental issues posed by conventional chemical fertilizers. This review aims to describe applications of nanotechnology in various fields of agriculture including seed storage, seed germination, plant growth, priming, fertigation and crop productivity. In addition, nanomaterials used as intelligent delivery systems for crop productivity, stress tolerance and plant adaptation are discussed. Moreover, nanomaterials used as sensors for precision agriculture and crop protection are described in detail. Importantly, we discuss the use of nanomaterials as fertilizers to replace chemical fertilizers in sustainable agriculture. Finally, we emphasize the use of nanomaterials for the post-harvest management of fruits and vegetables.

Effectiveness of green microalgae as biostimulants and biofertilizer through foliar spray and soil drench method for tomato cultivation

The over-use of synthetic chemical fertilizer has an adverse effect on humans. To overcome this issue, there is a need for organic farming. The present study is intended for identifying the possibilities of microalgal (Chlorella vulgaris) application on tomato (Solanum lycopersicum L.) cultivation as a suitable biofertilizer as well as biostimulant. The application of Chlorella vulgaris by foliar spray method, soil drench method with and without cowdung and control (untreated). Soil is suitable for tomato cultivation according to the soil analysis. Laboratory cultured Chlorella vulgaris enriched with carbohydrate (40.75±0.55), protein (29.56±0.72), lipids (30.20±0.25), total chlorophyll (0.531±0.42), carotenoids (0.261±0.35) and also other elements such as carbon (26.03±0.21), nitrogen (4.18±0.48), sodium (5.63±0.54) and potassium (6.94±0.17). Mixed treatment of cowdung with C. vulgaris shows enhanced growth than other groups. The higher concentration (100%) of foliar spray, C. vulgaris by soil drench and C. vulgaris + cowdung, elicits fruit length of about 8.8 ± 0.36, 10.5 ± 0.61 and 11.7 ± 0.35 cm, fruit diameter of about 13.3 ± 0.73, 14.2 ± 0.24 and 16.7 ± 0.31 cm, number of seeds/fruit of about 89±0.45, 118±0.98 and 153±0.96 g and seed weight/fruit of about 4.5 ± 0.14, 5.2 ± 0.19 and 6.5 ± 0.28 g respectively. The quality of the tomato was attributed to the increased total soluble solid of about 5.78±0.39, 6.27±0.92 and 7.09±0.75 g/100 g, total soluble sugar of about 4.30±0.76, 5.37±0.57 and 7.40±0.90 g/100 g, l-Ascorbic acid of about 14.6 ± 0.86, 17.9 ± 0.93 and 19.23±0.69 g/100 g, total protein of about 4.88±0.36, 5.82±0.88 and 6.37±0.23 g/100 g and moisture of about 94.1 ± 0.81, 95.5 ± 055 and 96.5 ± 0.42 g/100 g in foliar spray, C. vulgaris by soil drench and C. vulgaris + cowdung methods of applications respectively. There is a significant increase in mineral content such as phosphorus, potassium, calcium and magnesium in treated fruits as compared to control. Similarly shelf life (days) of foliar spray (5.0 ± 0.19), soil drench (6.0 ± 0.55), mixed treatment (7.0 ± 0.16) was increased than control(4 ± 0.65). Among three treatments, C. vulgaris + cowdung showed better results than other treatment. Soil drench method of application shows better outcomes than foliar spray application. Microalgae Chlorella vulgaris can be applied as biofertilizer/biostimulants in tomato cultivation by replacing conventional chemical fertilizer.

Composite Polymers from Leather Waste to Produce Smart Fertilizers.

The leather industry is facing important environmental issues related to waste disposal. The waste generated during the tanning process is an important resource of protein (mainly collagen) which can be extracted and reused in different applications (e.g., medical, agricultural, leather industry). On the other side, the utilization of chemical fertilizers must be decreased because of the negative effects associated to an extensive use of conventional chemical fertilizers. This review presents current research trends, challenges and future perspectives with respect to the use of hide waste to produce composite polymers that are further transformed in smart fertilizers. Hide waste contains mostly protein (collagen that is a natural polymer), that is extracted to be used in the cross-linking with water soluble copolymers to obtain the hydrogels which are further valorised as smart fertilizers. Smart fertilizers are a new class of fertilizers which allow the controlled release of the nutrients in synchronization with the plant’s demands. Characteristics of hide and leather wastes are pointed out. The fabrication methods of smart fertilizers and the mechanisms for the nutrients release are extensively discussed. This novel method is in agreement with the circular economy concepts and solves, on one side, the problem of hide waste disposal, and on the other side produces smart fertilizers that can successfully replace conventional chemical fertilizers.

Heavy Metal Accumulation in Soil and Water in Pilot Scale Rice Field Treated with Sewage Sludge

Widespread use of chemical fertilizers in agricultural activities poses a high risk of multi-micro metal contamination in soils and potentially causes health issues through consumption of contaminated foods. Bio-organic fertilizers from sewage sludge have been regarded as a suitable substitute for chemical fertilizer for rice farming. In this study, we investigated accumulation of heavy metals (Cu and Zn) in soil, water and rice plant in three pilot-scale rice paddy fields treated with different fertilization schemes. The control field was treated with conventional chemical fertilizers while the soil of two treatment fields was mixed with biological sewage sludge obtained from a local wastewater treatment system in Vietnam at different ratios (1% and 3%). Initial results showed that heavy metals accumulated in the soil, water, and rice plant at varying levels and most of the Cu and Zn contents found in soils, water and rice products exceeded permissible Vietnamese standards (QCVN 03: 2008) and US EPA 503. Notably, the rice field whose soil was treated with sludge at 3% ratio showed a significantly lower accumulation of heavy metals in soil, water and in rice plant. However, treatment of sludge at this level seemed to cause higher heavy metal retention in soil after one harvest. Semi-quantitative risk analysis revealed that the risk of metal contamination in soil and water of the control field ranged from medium (RQ index between 0.1 and 1) to high risk (RQ index higher than 1) and that fertilization methods would also affect the level of risk to the environment.

The Effect of Organic, Inorganic Fertilizers and Their Combinations on Fruit Quality Parameters in Strawberry

Strawberry (Fragaria × ananassa Duch.) is widely grown and highly appreciated by consumers around the world for its delicious, soft, and highly nutritious fruits. Turkey is one of the most important strawberry producers in the world. Strawberry cultivation in Turkey typically involves the use of chemical fertilizers and more recently organic and organic + chemical fertilizers have been started to use in commercial production to produce healthier fruits. Therefore, in this study, we investigated the effect of organic, chemical, and organic + chemical fertilizer treatments in strawberry (cvs. ‘Albion’, ‘San Andreas’ and ‘Monterey’) fruit quality parameters including fruit color (L*, a*, b*, C and h°) parameters, soluble solids content, total acidity, fruit firmness, vitamin C, specific sugars and organic acids. Results showed that in particular fruit color parameters, soluble solid content (SSC), total acidity, fruit firmness, and vitamin C (L-Ascorbic acid) in fruits of three strawberry cultivars were significantly affected by different fertilizer applications (p &lt; 0.05). Compared with conventional chemical fertilizer treatment, the organic fertilizer treatment produced fruit with significantly higher contents of SSC and glucose but decreased fruit firmness and vitamin C. Organic fertilizer also gave more intense colored strawberry fruits with high Chroma values (47,948 in organic fertilizer application and 39,644 and 39,931 in organic + chemical fertilizer and chemical fertilizer, respectively). Citric acid was identified to be the predominant organic acid in strawberry fruits but treatments were found insignificant on citric acid content.