Amount Of Fertilizer Research Articles

Optimal water and fertilizer amount for balancing greenhouse melon production efficiency and soil ecology based on TOPSIS-GRA coupling model

Optimal water and fertilizer amount for balancing greenhouse melon production efficiency and soil ecology based on TOPSIS-GRA coupling model

Effects of combined application of nitrogen, phosphorus, and potassium fertilizers on seed yield, seed quality and economic returns of Elymus nutans in alpine region.

The Qinghai-Tibetan Plateau (QTP), one of the most important ecological regions in the world, is experiencing a decline in ecological function as a result of severe grassland degradation. Elymus nutans is one of the ecological grass species for restoring degraded grasslands in QTP. The seed yield and seed quality are often limited by soil nutrients in QTP, so it is very important to optimize the application rates of fertilizer for E. nutans seed production. In this study, a "3414" fertilization experiment (nitrogen: 0 ~ 225kg N ha- 1; phosphorus: 0 ~ 180kg P2O5 ha- 1; potassium: 0 ~ 135kg K2O ha- 1) was established in the third year of planting E. nutans seed field based on the soil nutrient supply situation in the planting area to explore the effects of combined application of N, P and K fertilizers on the seed yield and seed quality of E. nutans. The results showed that the balanced application of N, P and K fertilizers significantly improved the seed yield, seed quality and seed vigour of E. nutans. The seed yield of E. nutans was regulated by the seed yield components. Under different fertilization treatments, the number of fertile tillers and thousand kernel weight had a greater contribution to seed yield, followed by the number of spikelets per panicle. Compared to the no fertilization treatment, the combined application of N, P, and K fertilizers increased the seed yield of E. nutans by 23.05%-90.49%. The seed size, seed nutrient content, germination percentage and seedling growth of E. nutans were positively affected by the combined application of N, P and K fertilizers. The seed vigour of E. nutans increased by 38.23%-89.85% compared to the no fertilizer treatment. Fertilizer application promoted seed nutrient storage and increased seed size thereby promoting seed germination and seedling growth. The crude protein, soluble sugar and starch content of E. nutans seed increased by 9.70%-54.05%, 6.70%-25.70% and 4.31%-35.88%, respectively. Nitrogen fertilizer had a greater effect on seed yield and seed quality of E. nutans than phosphorus and potassium fertilizers. The balanced nitrogen, phosphorus and potassium fertilizers at an application rate of 150kg N ha- 1, 120kg P2O5 ha- 1, 90kg K2O ha- 1 in the planting area of QTP was found to be the optimum fertilization amount for increasing seed yield, seed quality and net income. This study provides theoretical evidence and certain practical suggestions for sustainable forage seed production in alpine regions of QTP.

Reuse of Pretreated Household Wastewater for Decentralized Food Production

This study evaluates the feasibility of using pretreated domestic wastewater (PDW) for food production in a hydroponic system. In the face of increasing water shortage problems and rising fertilizer costs, PDW combined with a limited amount of fertilizer is evaluated for its effects on plant growth, biomass yield, and product safety. The results showed that lettuce grown with PDW and mineral fertilizers reached a fresh weight of 116, while the use of organic fertilizers increased the yield to 127 g, compared to only 54 g with raw water. Nitrate concentration (NO3) was higher in lettuce grown with organic fertilizers (1044.33 ± 144.04 mg/kg) than with mineral fertilizers (623.33 ± 85.62 mg/kg), but the values remained well below the acceptable limit of 5000 mg/kg for safe consumption. Analysis of heavy metals confirmed that levels of arsenic, cadmium, mercury, and lead were significantly lower than the maximum permissible values set by FAO and EU regulations. In addition, no phthalates were detected in the lettuce biomass, confirming the safety of the materials used in the hydroponic system. The use of PDW in hydroponic crops significantly reduces dependence on potable water and synthetic fertilizers, contributing to sustainable resource management. This approach not only reduces production costs, but also reduces the water footprint of crops, which is crucial in the context of global water availability problems. The findings support the validity of using PDW in decentralized food production as a sustainable solution for regions facing water and fertilizer shortages. Further research will focus on optimizing nutrient management and environmental conditions to increase system efficiency and food safety.

Comprehensive analysis of nano-fertilizers in Indian agriculture - A review

This is a comprehensive review of studies of nano-fertilizers for their efficacy in stimulating plant growth, facilitating higher nutrient uptake and thus enhancing overall crop yield and productivity. The intricate insights into the mechanisms through which nano-fertilizers ensure sustained nutrient release, optimize nutrient absorption and augment nutrient utilization efficiency, have been reviewed. Several scientific studies indicate the potential of nanotechnology to enhance crop performance in terms of better crop growth and higher productivity. Regarding the economic implications of adopting nano-fertilizers, several findings indicate that nano-fertilizers could offer cost advantages over conventional fertilizers, potentially alleviating the government's subsidy burden and reducing import expenses on huge quantities of major commercial fertilizers. This comprehensive review also explores the challenges faced by Indian agriculture in crop production and the potential of nanotechnology to revolutionize productivity on a sustainable basis. The study emphasizes the urgent need for enhanced and sustained crop production and highlights the significance of nano-fertilizer application as an innovative and environmentally friendly solution. In conclusion, this comprehensive overview of the status of stagnant crop production in India identifies the challenges in augmenting productivity and proposes nanotechnology-based fertilizers and their utility in major agricultural crops cultivation as a promising solution. The findings underscore the need for further research and the widespread adoption of nanotechnology-based fertilizers in Indian agriculture to ensure sustainable and enhanced production and productivity.

A convolutional neural network model and algorithm driven prototype for sustainable tilling and fertilizer optimization

Tilling, a common agricultural practice, is being done excessively on farms leading to about 2.35 billion tons of soil erosion from US croplands annually, in addition to causing soil infertility, carbon release, nutrient runoff, and fertilizer over-usage. This paper evaluates whether optimizing tillage intensity, timing, and fertilizer quantity using a convolutional neural network model and algorithm will address these problems. The machine learning model utilizes a camera-captured field image to determine existing tilling intensity on a 7-point scale. This machine learning output, along with soil sensor and external forecast data, flows into a 10-parameter algorithm that determines optimal tilling and fertilizer levels. A fully functional tractor prototype demonstrates the above. A 30-year simulation comparing conventionally-tilled and algorithm-tilled farms showed a reduction in carbon emission by 57%, fertilizer usage by 43%, and runoff by 86% demonstrating the transformative potential of this algorithm. Additionally, a stationary prototype was deployed in 155 farms across 5 countries.

Silicon Nutrition Improves Lodging Resistance of Rice Under Dry Cultivation

Silicon (Si) has been proven to enhance the stress resistance of rice, but its effect on the lodging resistance of rice under dry cultivation (DCR) is still unclear. The purpose of this experiment is to clarify the appropriate amount of silicon fertilizer for DCR to resist lodging and to elucidate how it coordinates lodging resistance and yield. This experiment used the ‘Suigeng 18’ cultivar as the material and set six silicon fertilizers (SiO2) with dosages of 0, 15, 30, 45, 60, and 75 kg·ha−1 (Si0, Si1, Si2, Si3, Si4, Si5). Analyze the effects and key indicators of silicon on lodging resistance of DCR from the perspectives of plant weight distribution, stem structure and composition, and root architecture. The results showed that the Si3 treatment had the highest yield and the lowest lodging index (LI). Si3 increases the weight of the upper three leaves and 4–5 internodes, thereby promoting panicle weight and yield. An increase of 13.38% in 2/3PWSI (weight of the 4th–5th stems and upper three leaves/weight of the 1st–3rd stems and lower leaves) can reflect the promoting effect of silicon on stem and leaf development near the panicle. Si3 reduces the GA/IAA value, shortens the length of the second internode, and increases the diameters of the major and minor axes, thereby increasing culm thickness and section modulus (SM), achieving the effect of “short and thick”. Si3 also increases the content of silicon and non-structural carbohydrates (NSCs) in the second internode, and increases lignin and cellulose content by upregulating the expression levels of CAD7, PAL, COMT, and CesA4 genes, thereby increasing fullness and flexural strength (M), achieving “short, thick, and strong” and reducing LI. The 38.95% reduction in IFL (second internode length/fullness) reflects the positive effect of silicon on the “short, thick, and strong” stem. In the underground part, adding silicon reduces the CTK/IAA value of roots, and increases root length, root tip number, root surface area, and root weight. The key to coordinating the lodging resistance and yield of DCR with appropriate silicon dosage is to reduce the IFL in the second internode and increase 2/3 PWSI and root growth. The key to DCR and breeding is to focus on the relationship between basal internode length and fullness, as well as stem and leaf growth near the panicle.

Evaluation of agricultural efficiency and influencing factors in the context of sustainable land management

Given the growing global focus on sustainable development, sustainable land management has emerged as a critical concern in contemporary agricultural development. The efficacy of agricultural production and its influencing factors in Shaanxi province of China, from 2012 to 2021, were analyzed using the Data envelopment analysis (DEA)-Banker, Charnes, Cooper model. Input and output indicators of agricultural production were selected for analysis. Inputs consist of land, machinery, water, and fertilizer. Specific indicators include the total sown area of crops, effective irrigated area, total power of agricultural machinery, and total reservoir capacity. Fertilizer inputs include the discounted amount of fertilizer applied for agricultural use. The output indicators considered include the gross output value of agriculture, forestry, animal husbandry, and fishery, the economic value added from agricultural production, and the production of cereal and fruit are all considered output indicators. From 2012 to 2018, the scale remuneration of agricultural production in Shaanxi province increased, suggesting gradual improvement in scale efficiency. Conversely, the efficiency of agricultural production has remained at the “DEA strong efficient” level from 2019 to 2021, suggesting effective management of scale efficiency. The investigation indicates that the allocation of resources and the administration of agricultural production in Shaanxi province have improved in recent years, contributing to the fostering of sustainable agricultural development.

Effect of Organic Fertilizer Replacing Nitrogen Fertilizer on Major Grain Yield in China

To comprehensively assess the changing pattern of organic fertilizer substitution with nitrogen fertilizer on the yield of major grains in China, with 102 literature as the research object, through Meta-analysis we quantitatively explored the impacts of soil physicochemical properties, climatic conditions, and different nitrogen fertilizer replacement rates and supplemental application amounts. The results showed that the replacement of nitrogen fertilizer by organic fertilizer could increase crop yields compared with those from the application of nitrogen fertilizer alone, and soil quick-acting potassium content, pH, and annual average temperature had the most significant effects on the yields of the three major grains. When the nitrogen fertilizer replacement rate and the amount of supplemental nitrogen fertilizer applied were 31.06% and 241.78 kg·hm-2, 26.52% and 173.31 kg·hm-2, and 39.23% and 149.17 kg·hm-2, the optimum yield increase ratios of 3.31%, 3.32%, and 1.08% were achieved for maize, wheat, and rice, respectively. Thus, the results of this study can provide a reference basis for rational fertilizer application in future crop production and help promote green agriculture.

Nitrogen content of herbarium specimens from arable fields and mesic meadows reflect the intensifying agricultural management during the 20th century

Abstract Arable fields and mesic meadows have been affected by intensifying agricultural management and nutrient input during the 20th century, but direct evidence for the long‐term impact of intensification on plant nutrient contents remains scarce. Non‐destructive novel spectroscopic methods can produce such data from herbarium specimens, making it possible to investigate how contents of leaf nutrient traits, especially nitrogen and phosphorus, changed over the last century, and what role habitat type and management practices play. We carried out a resurvey study of functional traits in arable field and mesic meadow communities. We used specimens from two German herbaria with a high coverage of their local floras: the herbaria Senckenberg Görlitz and Senckenberg Haussknecht in Jena. Following specimen information, the same plant species were resampled in the field in 2022 at the same locations. We employed near‐infrared spectroscopy to predict leaf nitrogen, phosphorus and carbon content of herbarium and field specimens. Nutrient content changes over time were compared with public records of regional P and N fertilization. Overall, 1270 specimens of 76 species from both herbarium and field were studied, the oldest from the 19th century. Leaf nitrogen and the leaf nitrogen:phosphorus ratio increased significantly through time, while leaf phosphorus and carbon content decreased significantly over time. Arable field species showed a stronger response in leaf phosphorus content and leaf nitrogen:phosphorus ratio than mesic meadow species. The total amount of nitrogen or phosphorus fertilizer applied per year on a regional scale was found to be significantly correlated with the respective leaf nutrient content levels. Synthesis: Our study shows a long‐term increase of leaf nitrogen in the studied habitats, paralleling increased chemical fertilizer applications in Germany. Our data indicate a shift from predominantly N‐limited towards more P‐limited growth conditions. The stronger response of species from arable fields compared to species from mesic meadows could indicate a faster adjustment to environmental pressures. This study thus also serves to showcase the potential of the combination of herbarium collections and NIR spectroscopy.

Effects of Different Nitrogen Fertilizer Application Rates on Soil Microbial Structure in Paddy Soil When Combined with Rice Straw Return.

Metagenomic sequencing of the microbial soil community was used to assess the effect of various nitrogen fertilizer treatments in combination with constant rice straw return to the soil in the tiller layer of Northeast China's black paddy soil used for rice production. Here, we investigated changes in the composition, diversity, and structure of soil microbial communities in the soil treated with four amounts of nitrogen fertilizers (53, 93, 133, and 173 kg/ha) applied to the soil under a constant straw return of 7500 kg/ha, with a control not receiving N. The relationships between soil microbial community structure and soil physical and chemical properties were determined. The results showed that the available K content of the soil significantly (p < 0.05) increased in soil receiving the lowest N-fertilizer dose. When applied at high amounts, N-fertilizer changed the Chao1 and ACE indices of the soil microorganisms (p < 0.05), and the treatments resulted in significant differences in the β-diversity of the soil microorganisms. By NMDS analysis it was demonstrated that the treatment significantly affected the structure of the soil microbial communities. Redundancy analysis showed that the main physicochemical drivers behind these differences were total nitrogen, total potassium, ammonium nitrogen, total phosphorus, and available potassium. The soil microbial communities in the control treatment were negatively correlated with nitrate and ammonium nitrogen; the lowest N-fertilizer treatment produced positive correlations with total nitrogen, total potassium, and total phosphorus and negative correlations with ammonium nitrogen; the highest dose negatively correlated with total nitrogen, available potassium, available phosphorus, total phosphorus, and pH. This study showed that moderate N fertilizer application is an effective way to increase soil microbial diversity and improve soil quality. This experiment provides technical support for the application of the alternative fertilizer technology of straw return to the field and provides a theoretical basis for rational fertilization of paddy fields in a cold climate.

An Empirical Analysis of the Impact of Pesticide and Fertilizer Pollution on Household Income

In agricultural production, agricultural non-point source pollution threatens the safety of water supply and food safety, restricts the sustainable development of the agricultural economy and rural ecological environment, and is the bottleneck of agricultural development in China. To explore the impact of this situation on the real income of rural households, the paper is based on the data from China Family Panel Studies (CFPS) from 2014 to 2018. With the pollution status in agricultural production as the explanatory variable and the total value of household agricultural and sideline products as an explanatory variable, a fixed effect model was established to estimate the influence of fertilizer and pesticide application on labor income level. The results show that the income brought by pesticide and fertilizer input is low efficiency, and some farmers have achieved high yields with low input. In addition, the education level of the agricultural population and the size of the family had no significant effect on this. Considering the output problem, the application of pesticides and fertilizers is necessary, but the cognition that pesticides and fertilizers can increase crop yield and income makes the application of pesticides continue to increase, which is not conducive to the increase of agricultural output value. It is necessary to attach importance to new methods of increasing agricultural production based on the application of small amounts of fertilizers and pesticides and use technological reform and professional agricultural education to promote the rational use of pesticides and fertilizers and achieve rapid development of agriculture.

Development of Tractor Drawn Single Row Irish Potato Planter with Fertilizer Applicator

Irish potato planting in Nigeria has been accomplished by traditional method of planting potato tubers on the field, which is labor intensive, time consuming and produce low yields of potato per hectare. This is due to lack of suitable row planting machine. In order to solve the above problem, this study aimed to develop a prototype of Irish potato planter with fertilizer applicator which is capable of planting potato tubers in rows at desired depth and spacing and applying fertilizer simultaneously. The developed tractor drawn single row Irish potato planter with fertilizer applicator consists of main frame, tuber hopper, fertilizer hopper, cup feed seed metering mechanism, shovel type furrow opener, ground wheel, seed tube and spring loaded furrow cover. This machine has an edge over existing irish potato planting machine with additional of spring loaded furrow opener, rubber coated metering cup to avoid injuring of the tubers and incorporation of fertilizer applicator which saves the farmer additional cost of applying fertilizer after planting. The performances of tractor drawn single row Irish potato planter with fertilizer applicator was evaluated in the laboratory and field at a tractor walking speed of 3.5 km/hr and moisture content of 13.41%. At the tractor speed of 3.5 km/hr when the moisture content was 13.41%; the average depth of planting was 133.3 mm, the average intra row spacing of the planted potato seedling was 291.2 mm, the average number of potato per drop of the planted potato seedling was 1, quantity of fertilizer per drop was 10.6 g, the average percentage of missing was 2.46%, the average height of ridge was 285.7 mm, the average depth of fertilizer dropping was 133.3 mm, the average fuel consumption was 10.3 l/ha and the average field efficiency was 75.04%. The implement is recommended for small scale and medium scale farmers.

A review on the production of nanofertilizers and its application in agriculture.

Due to the rapid rise in the worldwide population, the need for food is expanding constantly. To boost agricultural productivity large amounts of synthetic fertilizers are used. However, the extensive use of these synthetic fertilizers leads to various environmental and health problems. Nanotechnology (NT) offers significant improvement in the fertilizer fabrication with optimal chemical compositions, enhances nutrient usage competence, reduces environmental influence, and increased plant productivity. Nano fertilizers (NF) are nanomaterials (NM) that contrast significantly from their corresponding bulk materials. The concept of NF technology is highly innovative, utilizing physical, chemical, and biological methods for formulation. Additionally, the precise application and targeted delivery of nano-fertilizers ensures a more sustainable and accurate approach to agriculture. The purpose of this review is to provide an overview of the various types of nano fertilizers and their synthesis by different methods. In addition, applications of the NF and advantages are also given over the conventional pesticides. Information is also given on the current applications and challenges of the NF. NF are more effective and efficient than conservative fertilizers. The use of NF is expanding owing to the positive influence on nutritional superiority and stress resistance in plants.

The Effect of water level and cow manure fertilizer application method on rice yield and Cyperus rotundus weed

Climate change is a global issue that affects rice production. Rice production in Indonesia experiences fluctuations due to several factors, such as water availability, nutrients, and weeds. The study aims to examine the effect of high water levels and organic fertilizer application methods on rice growth and yield and the growth of Cyperus rotundus weeds. The research used a completely randomized design of two factors arranged factorially and three replications. The first factor was the high water level with three levels, namely 0-1, 1-2, and 2-3cm. The second factor was applying organic fertilizer with three levels: immersing it 5 cm, spreading it on the surface of the ground, and mixing it evenly with the soil. The combination of water level and organic fertilizer application method affects the number of productive rice tillers. The lower the water level (0-1 cm), the higher the amount of organic fertilizer mixed with soil, which shows the highest number of rice tillers. he higher the water level, the higher the plant, but the weight of dry rice grains decreases. Applying manure mixed with soil can increase the number of productive panicles per plant and reduce rice grains’ dry weight but reduce Cyperus rotundus weeds’ growth.

A mechanistic model for determining factors that influence inorganic nitrogen fate in corn cultivation.

Conventional practices for inorganic nitrogen fertilizer are highly inefficient leading to excess nitrogen in the environment. Excess environmental nitrogen induces ecological (e.g., hypoxia, eutrophication) and public health (e.g., nitrate contaminated drinking water) consequences, motivating adoption of management strategies to improve fertilizer use efficiency. Yet, how to limit the environmental impacts from inorganic nitrogen fertilizer while maintaining crop yields is a persistent challenge. The lack of empirical data on the fate and transport of nitrogen in an agriculture soil-crop system and how transport changes under varying conditions limits our ability to address this challenge. To this end, we developed a mechanistic model to assess how various parameters within a soil-crop system affect where nitrogen goes and inform how we can perturb the system to improve crop nitrogen content while reducing nitrogen emissions to the environment. The model evaluates nitrogen transport and distribution in the soil-corn plant system on a conventional Iowa corn farm. Simulations determine the amount of applied nitrogen fertilizer acquired by the crop root system, leached to groundwater, lost to tile drainage, and denitrified. Through scenario modeling, it was found that reducing application rates from 200 kg ha-1 to 160 kg ha-1 had limited impact on plant nitrogen content, while decreasing wasted nitrogen fertilizer by 25%. Delayed application until June significantly increased the f-NUE and denitrification while reducing the amount of fertilizer leached and exported through tile drainage. The value in a model like the one presented herein, is the ability to perturb the system through manipulation of variables representative of a specific scenario of interest to inform how one can improve crop-based nitrogen management.

Evaluation of drain quality and nutrient load management scenarios by using QUAL2kw model.

The examination of wastewater and effluents flowing into receiving water bodies is crucial for identifying pollutant sources and implementing scenarios to reduce them. In this study, QUAL2kw was used to identify, assess, and predict the pollutant load of a drainage canal located 6 km away from Anzali Wetland. Initially, the model was calibrated and validated with data collected in 2017. The NRMSE of the values was mostly less than 20%, except for flow accounting for 37% during calibration. The model did well in simulating EC and ammonium levels, but there is room for improvement in predicting nitrate and inorganic P concentrations. Field visits and sampling were done during the rice growth period in April-June 2021. The model was simulated for a three-time series in 2021; the simulation showed that May was the most critical, as the levels of nitrates, ammonium, and phosphates were at their highest. This study focused on the employment of QUAL2kw to drainage canals, emphasizing its suitability for regions with limited data availability. Scenarios were employed to explore ways to enhance water resource quality, showcasing how targeted interventions can effectively mitigate nutrient loads. Scenarios were considered to reduce nutrient loads. Reducing the amount of fertilizer led to a 9-27% while applying water stress resulted in a 0.1-1% reduction in the discharge outflow from the drain and less than 1% reduction in the amount of ammonium and nitrate. It is concluded that reduction in fertilization is more efficient in reducing concentrations and pollutant loads at the exit point of the canal to water resources compared to applying water stress since urea fertilizer contains a high percentage of nitrogen, and declining water application can enhance the soil's nutrient retention ability but only to a small degree.

The Restoration Effect of Degraded Grassland Depends on the Response of Species Root Distribution to Resource Availability

Nitrogen (N) fertilization is an effective practice for restoring degraded grasslands, which might strongly depend on the rooting system and resource competition of individual plant species. The purpose of this study is to explore a method to distinguish the response of various plant root architectures to the resource availability in a mixed ecosystem in situ. Field experiments were conducted using isotope techniques in conjunction with a specialized experimental design at a semiarid grassland location featuring heavily grazed (HG) and moderately grazed (MG) grassland sites with different dominant species. The same amounts of water and 15N-labelled fertilizer were uniformly supplied by a tube fertigation system at soil depths of 0, 15 and 45 cm. At both the HG and MG sites, there was a significant increase in aboveground net primary production (ANPP), water use efficiency (WUE) and 15N use efficiency (15NUE) at the community level with increasing depths of fertigation. The ANPP and plant N uptake exhibited higher values at the HG site compared to those at the MG site, while 15NUE and 15N abundance were significantly lower at the HG site. The annual species Salsola collina Pall. exhibited the highest aboveground biomass (AGB) and 15N abundance compared to all other species. Furthermore, the 15N enrichment of S. collina increased with greater depths of 15N-labelled fertilization, indicating that S. collina might develop a more extensive root system in response to water and N addition in the degraded grassland. Our study highlights that using isotope methods could indirectly distinguish root distribution and resource acquisition. In the recovery of degraded grassland by N fertilizer, we should not only consider the aboveground biomass but also pay special attention to the resource competition of individual plant species due to the possible discrepancy in rooting systems.

The Factors Affecting Cassava Productivity in Wonogiri Regency

Wonogiri Regency is the main cassava production center in Central Java Province. The obstacle of Wonogiri Regency as a central district is the low productivity of cassava. The low productivity of cassava is caused by several factors. This study aims to determine the influence of fertilization frequency factors, type of fertilizer, type of variety, type of soil, amount of fertilizer, amount of urea and planting distance on cassava productivity in Wonogiri Regency. Data for this quantitative research were obtained by interviewing research samples. The data analysis method used in this study is Multiple Linear Regression. The results showed that the type of fertilizer, the amount of urea and the planting distance had a real effect on the productivity of cassava, while the factors of fertilization frequency, variety type, soil type, and amount of fertilizer had no effect on cassava productivity in Wonogiri Regency. Based on the results of the research, more efforts are needed in cassava cultivation techniques so that they can produce high productivity.

THE LAST 15-YEAR PROSPECTS OF THE CREATION OF BIOSTIMULATORS BASED ON NITROGEN FIXING MICROORGANISMS

In order to create ecologically safe food products by improving the bioecological system based on microorganisms, it is important to breed nitrogen-fixing and phosphate-mobilizing bacteria on the basis of biotechnological methods and create biopreparations from strains for use in agriculture. As a result of the influence of various abiotic, biotic and anthropogenic factors of the environment on plants, the cultivation of useful plants in agriculture causes a number of problems every day. As a result of intensive demographic growth, the population's demand for food is increasing. The decrease in productivity due to the low production of plant products may lead to the problem of food shortage in the future. As a result of the use of large amounts of synthetic fertilizers to increase productivity, soil fertility has decreased and salinity has increased. Therefore, many studies are currently focused on improving plant-microorganism-soil system mediation relationships. Representatives of other classes of plants need nitrogen fixers. Treating them with biostimulators prepared on the basis of associative and free-living AFB living in the rhizosphere allows not to use synthetic fertilizers beyond the permissible limit in the future, thus improving soil fertility and growing environmentally friendly products.

Meta-analysis of Organic Carbon in Sandy Soil in Response to Amendment Application

Proper application of soil amendments can effectively increase the accumulation of soil organic carbon （SOC） in poor soils, thereby enhancing soil fertility level. The impacts of different types of amendments on the SOC content of sandy soils varies widely. Investigating the effects of various amendments on the SOC content of sandy soils and associated key controlling factors provides a scientific basis for formulating strategies to enhance the fertility of sandy soils. A data set was established with 617 pairs of data from 114 published studies that reported the effects of amendment application on SOC content of sandy soil during 1987 and 2023. Meta-analysis was used to quantitatively analyze the effects of amendment application on the SOC content of sandy soil globally under the conditions of various amendment types and application rates, climates, and soil properties. This study also investigated the major controlling factors for the changes in SOC in sandy soil after amendment application using regression analysis and random forest model. The research results showed that： ① Amendment application significantly increased SOC content by 61% on average in sandy soils and the application of inorganic amendment increased SOC in sandy soils （161%） to a significantly greater extent than that of organic amendment （37%） and compound amendment （54%）. ② The application amount and duration of inorganic amendments had no significant effect on the increase of SOC in sandy soil. Among the organic amendments, the increase of SOC in sandy soil was enhanced with the increase in the application amount of biomass carbon and organic fertilizer and decreased with the application duration of the amendment. ③ Climatic conditions, the amount and duration of amendments, and soil physicochemical properties combined explained 88% of the variability in SOC response in sandy soils. The magnitudes of SOC change due to amendment application significantly decreased with increased average annual temperature, initial SOC content, and soil pH, however, positively correlated with aridity, soil bulk density, and sand content. The application of amendments significantly increased SOC content in sandy soils. The type and application amounts of amendments, climatic conditions, and soil properties strongly regulated SOC in response to amendments. Therefore, the type and amounts of amendment, climate, and soil conditions should be comprehensively considered when applying amendments to effectively increase the organic carbon content and fertility level of sandy soils.