Use Of Nitrogen Fertilizers Research Articles

NITROGEN USE EFFICIENCY IN SUNFLOWER (HELIANTHUS ANNUUS L.) INFLUENCED BY VARIOUS FERTIGATION AND BED PLANTING TECHNIQUES

Low nitrogen fertilizer use efficiency and high losses of nitrogen are the critical challenges being faced by sunflower grower. To address these concerns, an experiment was carried out during spring 2021 at the Agronomic research area of the Agriculture University, Faisalabad. The randomized complete block design experiment was used with three replications under split plot arrangement. The 5m x 3m net plot size was kept with sowing procedures retained in the main plot and nitrogen application techniques kept in the sub plot. The experiment was planted on 20-02-2021. The matured crop was reaped on 18 June, 2021 manually. The single row hand drill was used to sow sunflower crop. The 75 cm line to line and 25 cm plant to plant distance was maintained. The results indicated that plant population ranged from 73 to 74 with maximum plant height of 174.33 cm, stem diameter (3.70 cm), head diameter (23.13 cm), number of achenes per head (1237.6), 1000-achene weight (68.17 g), highest biological yield (10.92 t ha-1), achene yield (3.22 t ha-1), harvest index (29.48 %) and protein contents (29.03 %) was observed in treatment where nitrogen was applied by fertigation method and sunflower was sown on beds. But maximum oil contents (41.78 %) were observed where nitrogen was side dressed and flat sowing technique was adopted for crop sowing. It is found that use of fertigation method of nitrogen application and bed planting techniques proved to be the best combination for improving growth, yield & yield relating attributes and improve fertilizer use efficiency with lower nitrogen losses for sunflower (Hybrid-33) under agro-climatic conditions of Faisalabad.

Modelling and analysis of the biodenitrification process

Massive and excessive use of nitrogen fertilizers and sustained irrigation have been widely practiced in recent years. This strategy leads to a large transfer of nitrates to groundwater, leading to a major environmental problem of nitrate contamination in water, intended for drinking water consumption. One of the most effective solutions is the degradation of nitrites and nitrates, into gaseous nitrogen, using the heterotrophic bacteria during the denitrification process. In this paper, we present and study a mathematical model of the biodenitrification process taking into account the fixed and mobile bacteria. This process is modeled by a system of ordinary differential equations and requires the success of bacteria to colonize the reactor. We study the existence and the asymptotic behaviour of the solution. We show the existence of a value of the injected carbon concentration from which we ensure the success of the biodenitrification process and we propose a heuristic algorithm which serves to control the biodenitrification process over time. Finally, we present some numerical simulations in to support the theoretical results.

Anomalous increase in global atmospheric ammonia during COVID-19 lockdown: Need policies to curb agricultural emissions

The restrictions imposed on human activities during the COVID-19 lockdown (LD) period provided a new scenario to identify potential sources of atmospheric pollution. There are several studies that deal with changes in air quality around the world during LD, but very few on atmospheric ammonia (NH3). Therefore, we examine the changes in global NH3 during LD (April–May 2020) in comparison to the pre-lockdown (PreLD, April–May 2017–2019) and post-lockdown (PostLD, April–May 2021) periods, and assess the factors responsible for these changes. We observe an increase in NH3 during LD across the latitudes, with very high values in the western Europe, Eastern China (EC), the Indian subcontinent and the eastern United States of America (USA). However, a decline in NH3 is observed in some regions of South America (SA) and North America (NA). Similar changes in NH3 during LD are also observed in smaller spatial scales, as found in 3000 cities across the globe. The reduction of sulphur dioxide (SO2), nitrogen dioxide (NO2), nitric acid (HNO3), humidity and cloud cover as a result of restrictions on human activities, particularly in the western Europe and the USA, may have impeded the conversion of NH3 to particulates, which led to a higher NH3 there. Nevertheless, agricultural activities and livestock are the most prominent sources of atmospheric NH3, and were not under restriction during LD, show an enhancement in terms of the use of nitrogen fertilizer, crop production and area harvested, which also cause a rise in NH3 in these regions. Therefore, it is evident that the changes in meteorology and atmospheric composition, together with increased agricultural activities, led to the global increase in atmospheric NH3 during LD. That is, most pollutants show a decline during LD, but NH3 exhibits a rise due to its sources such as agricultural activities. Henceforth, environmental regulations, policies and advanced technologies are required in the agricultural sector, such as fertilizer deep placement using urea briquettes and restricted application of nitrogen fertilizers, to curb NH3 emissions.

Measurement report: Exchange fluxes of HONO over agricultural fields in the North China Plain

Abstract. Nitrous acid (HONO) is a crucial precursor of tropospheric hydroxyl radicals, but its sources are not fully understood. Soil is recognized as an important HONO source, but the lack of measurements of soil–atmosphere HONO exchange flux (FHONO) has led to uncertainties in modeling its atmospheric impacts and understanding the reactive nitrogen budget. Herein, we conduct FHONO measurements over agricultural fields under fertilized (FHONO-NP, normal fertilization and irrigation) and non-fertilized (FHONO-CK, normal irrigation but no fertilization) treatments. Our results show that nitrogen fertilizer use causes a remarkable increase in FHONO-NP. FHONO-NP exhibits distinct diurnal variations, with an average noontime peak of 152 ng N m−2 s−1. The average FHONO-NP within 3 weeks after fertilization is 97.7±8.6 ng N m−2 s−1, around 2 orders of magnitude higher than before fertilization, revealing the remarkable promotion effect of nitrogen fertilizer on HONO emissions. We also discuss other factors influencing soil HONO emissions, such as meteorological parameters and soil properties/nutrients. Additionally, we estimate the HONO emission factor of 0.68±0.07 % relative to the applied nitrogen during the whole growing season of summer maize. Accordingly, the fertilizer-induced soil HONO emission is estimated to be 22.3 and 60.8 Gg N yr−1 in the North China Plain (NCP) and mainland China, respectively, representing a significant reactive nitrogen source. Furthermore, our observations reveal that soil emissions sustain a high level of daytime HONO, enhancing the atmospheric oxidizing capacity and aggravating O3 pollution in the NCP. Our results indicate that to mitigate regional air pollution effectively, future policies should consider reactive nitrogen emissions from agricultural soils.

Potassium and Micronutrient Fertilization for Enhancement of Tef Yield in Vertisols of Hawzen and Enderta Districts, Tigray Region, Ethiopia

Field study was conducted in Enderta and Hawzen districts of Tigray region on six farmers’ fields aimed at evaluating potassium and micro-nutrient effect on yield and yield components of the tested crop. The experiment comprised of eight treatments including control and recommended NP arranged in Randomized Complete Block Design with two replications. Phosphorus fertilizers were applied at planting, while the nitrogen fertilizer was applied in two splits. The micronutrients and Typrosine were applied in foliar forms. SAS version 9 statistical software was used for data analysis. The analyzed results depicted that Tef yield was increased with potassium and micro-nutrient application in both districts mathematically even though it was not consistent. In line to this, the highest grain and straw yields of Tef was recorded at recommended NP with application of 50 kg/ha K2SO4 and recommended NP with a foliar application of Typrosine, respectively. But this result was statistically similar with the recommended NP. Thus, application of additional fertilizer without yield increment is uneconomical rather than maximizing costs. Hence, potassium, copper, and zinc in the current sources were not Tef yield limiting nutrients in the study sites even though the soil statuses are low. On the other hand nitrogen and phosphorus were observed the Tef yield limiting nutrients in this study. For this reason maximizing the use of nitrogen and phosphorus fertilizers with detailed research on its level and their interactions, sources and application times is important to maximize the Tef productivity in the Vertisols of Enderta and Hawzen district.

A microbial ecosystem enhanced by regulating soil carbon and nitrogen balance using biochar and nitrogen fertiliser five years after application

The indiscriminate use of nitrogen fertiliser (NF) is a obstruction to improve soil quality and crop yields. However, the effect of biochar and NF on soil microbial ecosystem (SME) and crop yields is unknown. A five-year field experiment in China aimed to evaluate the effects of biochar and nitrogen fertiliser (NF) combination on soil structure, C-to-N ratio (CNR), microbial biomass, and spring maize yield. Biochar and NF were applied at different rates, and the combined application resulted in a soil solid–liquid–gas ratio closer to the ideal value. The use of biochar alone and in combination with NF significantly increased soil's C, N, and CNR. A moderate application of biochar and NF resulted in favourable biological and chemical properties of the soil. The application of biochar and NF at moderate levels led to an increase in SME, with the B8N150 producing the highest yield. The highest yield of B8N150 represents a 24.25% increase compared to the unfertilized control and a 9.04% increase compared to B0N150. Moderate use of biochar and NF could be beneficial in areas with similar climatic conditions.

Coinoculation with Growth-Promoting Bacteria Increases the Efficiency of Nitrogen Use by Irrigated Rice.

Considering the importance of rice (Oryza sativa L.) for global food and its significant production in Brazil, strategies for its sustainable production are focused on technologies to increase productivity and decrease the use of chemical nitrogen fertilizers. An alternative for this is the use of plant growth-promoting bacteria that have proven to be efficient for increasing production and nutrient promotion in cereals. This study reports the use of coinoculation with Azospirillum brasilense and Pseudomonas fluorescens to inoculate irrigated rice through seed treatment (ST) with inoculant and seed inoculation in planting furrow technology (PFT) in four field experiments. The inoculation technologies increased rice yields in the presence of A. brasilense + P. fluorescens and with a reduction in mineral N (30 kg of N ha-1), equal to or greater when nitrogen fertilizer was present alone. Our results demonstrate that coinoculation with A. brasilense (strain Ab-V6) and P. fluorescens (strain CCTB03) increases the efficiency of N use from a mineral source in irrigated rice, with an increase of 37% in economic production (grains per unit of N applied), providing better agronomic performance of the crop.

Development of machine-learning-based models for identifying the sources of nitrate and fluoride in groundwater and predicting their human health risks

AbstractThis research aimed to identify the main sources of groundwater pollution and assess the non-carcinogenic human health risk resulting from nitrate and fluoride contamination. These goals were achieved by employing unsupervised and supervised machine algorithms, including principal component analysis (PCA) and multilayer perceptron artificial neural networks (MLP-ANN). Thirty-seven groundwater samples were analyzed for twelve physical and chemical parameters, including pH, EC, TDS, TH, Cl, F, SO4, NO3, Ca, Mg, Na, and HCO3, and the initial investigation indicated that except for Cl, F, Ca, and Mg, all the parameters are above the guidelines of the World Health Organization (WHO). PCA indicated that mineral dissolution is the main source of F, while high NO3 concentration primarily resulted from agricultural operation due to extensive use of nitrogen and calcium-based fertilizers. Consequently, the non-carcinogenic human health risk (HHR) for children and adults is evaluated based on NO3 and F. The conventional approach for assessing HHR is time-consuming and often associated with errors in calculating hazard quotients (HQ) and hazard indices (HI). In this research, MLP-ANN is suggested to overcome these limitations. In the MLP-ANN modeling, the data were divided into two parts training (80%) and validation (20%), with NO3 and F concentration as inputs and HQ and HI as outputs. The performance of the resulting models was tested using root mean square error (RMSE) and coefficient of determination (R2). The model provided a satisfactory result with a maximum RMSE of 4% and R2 higher than 97% for training and validation. As a result, obtained HIs suggested that 97.3% of the groundwater samples in the study area are suitable for human consumption. The non-carcinogenic HHR is successfully assessed using machine learning algorithms, and the results have led to the conclusion that this approach is highly recommended for effectively managing groundwater resources.

The Impact and Regulatory Mechanisms of Nitrogen Fertilizer on Soil Carbon Cycling

Modern agriculture must increase production to meet the growing global demand for food. However, excessive use of nitrogen fertilizer has led to a series of environmental issues. The impact of nitrogen fertilizer on soil carbon cycling is of particular concern, as agriculture is a major global carbon reservoir, and soil carbon cycling is crucial for maintaining ecosystem functionality. Previous research indicates that nitrogen fertilizer not only affects soil carbon storage but also alters the structure and function of soil microbial communities, thereby influencing carbon decomposition rates. Nevertheless, the specific mechanisms underlying the effects of nitrogen fertilizer on soil carbon cycling remain elusive. This study aims to comprehensively and systematically analyze the impact of nitrogen fertilizer on soil carbon cycling and elucidate its regulatory mechanisms. Nitrogen fertilizer exerts complex effects on soil, potentially promoting organic carbon accumulation, yet under certain conditions, it may also lead to carbon losses, closely intertwined with its impact on soil microbial communities. Regional and seasonal variations in the response to nitrogen fertilizer highlight the intricate dynamics of soil carbon storage, emphasizing the need for a thorough spatiotemporal investigation. Nitrogen fertilizer also influences soil microbial diversity, resulting in the excessive enrichment of certain microbial populations, disrupting the balance of microbial diversity in the soil. Moderate use of nitrogen fertilizer stimulates soil microbial metabolic activity, whereas excessive use may lead to a decline in metabolic activity. The regulation of soil carbon decomposition rates involves soil enzyme activity and organic matter decomposition pathways, with moderate nitrogen fertilizer application promoting soil carbon cycling, while high concentrations may impede carbon decomposition pathways. In conclusion, nitrogen fertilizer management should be guided by scientific principles to avoid excessive use. Establishing a systematic monitoring system that considers soil nutrients, microbial communities, and other factors is essential for achieving sustainable nitrogen fertilizer use. This approach aims to promote sustainable agriculture, reduce the burden on ecosystems, and enhance soil health and carbon storage.

Impacts of reduced synthetic fertiliser use under current and future climates: Exploration using integrated agroecosystem modelling in the upper River Taw observatory, UK

The intensification of farming and increased nitrogen fertiliser use, to satisfy the growing population demand, contributed to the extant climate change crisis. Use of synthetic fertilisers in agriculture is a significant source of anthropogenic Greenhouse Gas (GHG) emissions, especially potent nitrous oxide (N2O). To achieve the ambitious policy target for net zero by 2050 in the UK, it is crucial to understand the impacts of potential reductions in fertiliser use on multiple ecosystem services, including crop production, GHG emissions and soil organic carbon (SOC) storge. A novel integrated modelling approach using three established agroecosystem models (SPACSYS, CSM and RothC) was implemented to evaluate the associated impacts of fertiliser reduction (10%, 30% and 50%) under current and projected climate scenarios (RCP2.6, RCP4.5 and RCP8.5) in a study catchment in Southwest England. 48 unique combinations of soil types, climate conditions and fertiliser inputs were evaluated for five major arable crops plus improved grassland. With a 30% reduction in fertiliser inputs, the estimated yield loss under current climate ranged between 11% and 30% for arable crops compared with a 20–24% and 6–22% reduction in N2O and methane emissions, respectively. Biomass was reduced by 10–25% aboveground and by <12% for the root system. Relative to the baseline scenario, soil type dependent reductions in SOC sequestration rates are predicted under future climate with reductions in fertiliser inputs. Losses in SOC were more than doubled under the RCP4.5 scenario. The emissions from energy use, including embedded emissions from fertiliser manufacture, was a significant source (14–48%) for all arable crops and the associated GWP20.

Assessing Groundwater Quality and Diagnosing Nitrate Pollution in the Sidi Allal Region: A GIS-Based Approach Utilizing the Groundwater Pollution Index

Groundwater is a critical resource for various human activities, yet it faces contamination risks from agricultural, industrial, and domestic sources. This study aimed to evaluate groundwater in Morocco’s Sidi Allal region using the groundwater pollution index (GPI) and diagnose nitrate pollution. The study included 45 groundwater wells from the study area, and physicochemical parameters such as pH, electrical conductivity, cations, and anions were examined in the laboratory. The geographic information system (GIS) was used to determine the spatial distribution of groundwater quality parameters. The groundwater pollution index and nitrate pollution index (NPI) were determined. The inverse distance weighting method (IDW) was used to create a spatial distribution map. The results indicated that the calculated GPI values ranged from 0.856 to 7.416, with an average of 2.06. About 40% of groundwater samples were highly polluted and unsuitable for drinking. The NPI values ranged between −0.74 and 10.5, with an average of 5.1. About 64% of the total groundwater samples were considered highly polluted according to the NPI classification, suggesting that the groundwater was unsuitable for drinking purposes. The spatial distribution map revealed the availability of appropriate groundwater in the central area of the study area and inappropriate groundwater near the Esbou River and Nassour Canal. The findings of this study revealed high concentrations of nitrates in groundwater samples in the central part of the study area, indicating that this increase in nitrates may be due to intensive use of nitrogen fertilizers in agricultural activities and sewage waste.

Insights from Farmers’ Rice Culture Practices under Integrated Rice–Crayfish Farming System in the Hongze Lake District of China

In recent years, rice–crayfish integrated farming has expanded rapidly in the Hongze Lake district of China as the booming consumer market of crayfish. However, the current rice cultivation technology limits rice yield and the economic profits of rice–crayfish integrated farming, and the characteristics and farmers’ practices of rice culture under the rice–crayfish integrated farming system are unknown. To understand the present rice culture practices in rice–crayfish integrated farming by farmers and their perceptions and provide direction for improvement, a survey was carried out in 2019 and 2020 in Xuyi County, a representative region of rice–crayfish integrated farming in the Hongze Lake district of China, comprising 208 farmers engaged in RCIF, and detailed and complex information was obtained using face-to-face conversations. Based on the survey results, we found that farmers have limited knowledge of the rice cultivation request in a specific RCIF mode and well-suited rice varieties and mechanical transplanting equipment and corresponding techniques are lacking in RCIF. In addition, farmers had no reliable and scientific methods for the use of nitrogen fertilizers and pest management schemes. In accordance with the constraints mentioned above, we put forward the following suggestions for rice culture improvement: (i) the local agricultural extension department should strengthen the RCIF mode and extend techniques and training; (ii) researchers should develop RCIF-suited rice varieties, mechanical transplanters, and related seedling-raising methods; (iii) researchers should clarify the occurrence regularity of soil properties and rice pests with continuous RCIF practices and provide corresponding guidance for nitrogen application and pest control schemes.

Аналіз лінійно-вагових показників річкових раків (Astacus) у водоймах Дніпропетровської області

This research focuses on studying the narrow-clawed crayfish in the Dnipropetrovsk region. The narrow-clawed crayfish, Astacus leptodactylus, is a crucial component of industrial fisheries and plays a significant role in the development of aquatic ecosystems. Within the territory of the Dnipropetrovsk region, crayfish inhabit various freshwater bodies, including rivers, lakes, floodplains, and ponds. It is known that water bodies in the Dnipro region undergo substantial anthropogenic impact, leading to alterations in the life cycles and reproductive features of hydrobionts. Investigated areas of reservoirs were characterized by diverse levels and factors of pollution, such as contamination of water with chemical and radioactive substances, oil products, wastewater, and the use of nitrogen and phosphorus fertilizers. These anthropogenic interventions may result in a decrease in populations of aquatic organisms, posing a serious threat to water ecosystems. The sensitivity to environmental changes makes crayfish a valuable bioindicator species. Fertility indicators and morphometric characteristics can be considered as bioindicators. The analysis of linear-weight parameters revealed that crayfish extracted from the Zaporizhzhia Reservoir had a body length 15–18% greater than those from the Kamianske and Samara Bay. Additionally, they exhibited larger cephalothorax dimensions by 18–20%, and their mass was almost 50% higher compared to individuals from other water bodies. Samara Bay demonstrated significantly lower fertility indicators compared to the Zaporizhzhia Reservoir, with crayfish fertility being reliably 63% lower. The established differences in morphometric indicators between crayfish from the Zaporizhzhia Reservoir, Samara Bay and Kamianske Reservoir may indicate heterogeneity in the living conditions within the water bodies of Dnipropetrovsk and might be induced by anthropogenic pressures.

Potential of Reinoculation Using R. tropici Applied under Cover to Increase Bean Yield

The common bean is known to require nitrogen, with mineral fertilizer being the main form of supply to the plants. However, more efficient inoculants containing strains of Rhizobium tropici that are potentially more efficient in fixing atmospheric N2 could replace the use of nitrogen fertilizers as long as some of the existing challenges in the application methodology are overcome (for example, ensuring the existence of active nodules in the most demanding crop phases: flowering and grain filling). This study aimed to verify the responses of common bean plants subjected to reinoculation using Rhizobium tropici in topdressing applied at different stages in a greenhouse and in a field between March and April 2020 and in the spring–summer harvest of 2020/2021, respectively. A randomized block design was used, along with four replications: T1 = uninoculated control; T2 = inoculation via seed (VS); T3 = VS + reinoculation at the V4 stage; T4 = VS + reinoculation at the R5 stage; T5 = VS + reinoculation at the R6 stage; T6 = VS + reinoculation at the V4 and R5 stages; T7 = VS + reinoculation at the V4 and R6 stages; T8 = VS + reinoculation at the R5 and R6 stages; T9 = VS + reinoculation at the V4, R5, and R6 stages; and T10 = mineral nitrogen fertilization. Nodulation and morphological variables were evaluated at the R7 stage, and agronomic variables were evaluated at the R9 stage at harvest. The use of reinoculation, in addition to inoculation, positively influenced the bean nodulation process. The morphological characteristics of the plants showed good development with the supply of N (carried out via inoculation and reinoculation), equivalent to the development that could be achieved via the addition of a mineral nitrogen fertilizer. Reinoculation from the R5 to R7 stages proved ineffective in supplying N to the common bean crop. Inoculation in the seed associated with reinoculation in coverage at the V4 stage provided higher yields (3.271 kg ha−1), reinforcing the potential for mineral nitrogen fertilizers to be replaced. The use of the seed inoculation technique with subsequent reinoculation under cover can completely replace the use of nitrogenous mineral fertilizers in fertilizing bean plants, making the cultivation of this fabacea more sustainable in terms of the associated costs and environmental problems.

Economic analysis of rhizobia and azospirilla co-inoculation in common beans

BackgroundCommon bean has high production cost, mainly due to the use of inputs like nitrogen fertilizers. An alternative to replace the use of nitrogen fertilizers is the co-inoculation technique. This work aimed to evaluate the economic performance of the co-inoculation of Rhizobium tropici and different doses of Azospirillum brasilense applied at the V2–V3 stage of the common bean.MethodsThe economic analysis was carried out based on data from five field experiments in five locations in the state of Goiás in Brazil. Treatments consisted of absolute control (AC), N-fertilizer treatment (NfT), single inoculation of R. tropici (Rt), R. tropici + one dose of A. brasilense (Rt + Ab1l), R. tropici + two doses of A. brasilense (Rt + Ab2l), R. tropici + three doses of A. brasilense (Rt + Ab3l) and R. tropici + four doses of A. brasilense (Rt + Ab4l). The economic analysis was carried out based on prices and market indexes, depending on the grain yield of the different treatments.ResultsThe best economic performance was obtained by the co-inoculation Rt + Ab3l, which provided the highest average values of gross revenue (2.471 US$ ha−1), net revenue (2.220 US$ ha−1), and benefit–cost ratio (1.4 US$ US$−1).ConclusionsCo-inoculation Rt + Ab3l also showed the lowest production costs (451 US$ ha−1), while the nitrogen treatment with 80 kg ha−1 of N resulted in the highest average production cost (499 US$ ha−1).

Identification and functional characterization of the sugarcane (Saccharum spp.) AMT2-type ammonium transporter ScAMT3;3 revealed a presumed role in shoot ammonium remobilization

Sugarcane (Saccharum spp.) is an important crop for sugar and bioethanol production worldwide. To maintain and increase sugarcane yields in marginal areas, the use of nitrogen (N) fertilizers is essential, but N overuse may result in the leaching of reactive N to the natural environment. Despite the importance of N in sugarcane production, little is known about the molecular mechanisms involved in N homeostasis in this crop, particularly regarding ammonium (NH4+), the sugarcane’s preferred source of N. Here, using a sugarcane bacterial artificial chromosome (BAC) library and a series of in silico analyses, we identified an AMMONIUM TRANSPORTER (AMT) from the AMT2 subfamily, sugarcane AMMONIUM TRANSPORTER 3;3 (ScAMT3;3), which is constitutively and highly expressed in young and mature leaves. To characterize its biochemical function, we ectopically expressed ScAMT3;3 in heterologous systems (Saccharomyces cerevisiae and Arabidopsis thaliana). The complementation of triple mep mutant yeast demonstrated that ScAMT3;3 is functional for NH3/H+ cotransport at high availability of NH4+ and under physiological pH conditions. The ectopic expression of ScAMT3;3 in the Arabidopsis quadruple AMT knockout mutant restored the transport capacity of 15N–NH4+ in roots and plant growth under specific N availability conditions, confirming the role of ScAMT3;3 in NH4+ transport in planta. Our results indicate that ScAMT3;3 belongs to the low-affinity transport system (Km 270.9 µM; Vmax 209.3 µmol g−1 root DW h−1). We were able to infer that ScAMT3;3 plays a presumed role in NH4+ source–sink remobilization in the shoots via phloem loading. These findings help to shed light on the functionality of a novel AMT2-type protein and provide bases for future research focusing on the improvement of sugarcane yield and N use efficiency.

Hydrochemical Appraisal and Driving Forces of Groundwater Quality and Potential Health Risks of Nitrate in Typical Agricultural Area of Southwestern China

Elucidating the hydrogeochemical processes and quality assessment of groundwater holds significant importance for its sustainable development. In this paper, 53 groundwater samples were collected from a typical agricultural area in the northeastern Chongqing municipality in SW China. The integration of multivariate statistical analysis, ion ratio analysis, geomodelling analysis, the entropy water quality index, health risks assessment, and sensitivity analysis was carried out to explore the hydrochemical processes and quality assessment of groundwater in this study. The statistical results reveal that the cationic concentrations followed the order of Ca2+ &gt; Mg2+ &gt; Na+ &gt; K+, while the anionic components were in the order of HCO3− &gt; SO42− &gt; NO3− &gt; Cl−. Based on the Piper trilinear diagram, the hydrochemical types were shown as Ca-HCO3 and Ca-Mg-HCO3 types. Hierarchical cluster analysis indicated that the groundwater samples could be categorized into three groups. The hydrochemical compositions were primarily influenced by water–rock interactions (e.g., carbonate dissolution and silicate weathering). In terms of irrigation suitability, the sodium adsorption ratios (SARs) ranged from 0.05 to 1.82, and the electrical conductivity (EC) varied from 116 to 1094 μs/cm, indicating that most groundwater samples were suitable for irrigation. The entropy-weighted water quality index ranged from 15 to 94, suggesting that the groundwater samples were suitable for drinking purposes. Non-carcinogenic human health risks followed the order of children &gt; adult females &gt; adult males, within the average values of 0.30, 0.21, and 0.18, respectively. Sensitivity analysis showed that the parameters had the weight order of NO3 &gt; body weight (BW) &gt; ingestion rate (IR) &gt; exposure frequency (EF). Hence, we recommend prioritizing the management of areas with high salinity levels, while avoiding the excessive use of nitrogen fertilizers, raising awareness among local residents about safe groundwater, and providing robust support for the sustainable development of groundwater in typical agricultural areas.

Влияние различных уровней азота на рост и урожайность кукурузы в северном регионе Афганистана

This article discusses the impact of nitrogen fertilizers on the growth, development and yield of corn when grown in the northern region of Afghanistan. The study was conducted in 2020-2022 with the use of urea nitrogen fertilizer (urea) with increasing doses: N0 (control), N140, N180, N220 and N260 kg/ha. In all variants of the experiment, an increase in plant height and the number of corn leaves relative to the control was observed against the background of the use of nitrogen fertilizer. The sharpest increase in the accumulation of dry matter by the time of harvest was observed in variants where nitrogen fertilizer was applied at a dose of N260 kg/ha -176.7 c/ha, which is 56.25% more relative to the control over an average of three years of research. Analysis of the elements of the structure of the corn crop showed that the use of increased doses of nitrogen fertilizer (N260 and N220 kg / ha) contributed to an increase in the number of grains in the cob, the mass of 1000 grains, and as a result, higher yields of grain and corn straw. The yield index at N260 and N220 kg/ha of urea doses was 40.07 and 40.52%, which is 10.42-11.66% more painful relative to control on average over three years of research. Keywords: CORN, CROP, NITROGEN FERTILIZERS, UREA, CARBAMIDE

THE IMPORTANCE OF BREEDING PROGRESS IN WINTER WHEAT PRODUCTION

The impact of breeding on winter wheat yields and the use of the generated yield potential in production were assessed. The results of trials of Research Centre for Cultivar Testing (COBORU) from 1966-2022, data from the Seed Inspection (IN) from 1986-2001 and Plant Health And Seed Inspection (PIORiN) from 2002-2023 regarding the varietal structure of seed production of winter wheat and production data on wheat yield in production were used according to Statistics Poland. To assess the effects of breeding, the method of changing the yield potential of varieties was used. In this method, we use indexes determining the yield-producing capacity of individual varieties in relation to the standard. Changes in yield trends in variety experiments and production were analyzed. The growing importance of the variety as a factor enabling further increase in yield and the effect of breeding on the increase in yield potential has been demonstrated despite limitations in the use of nitrogen fertilization and chemical plant protection products. The existing yield gap between trials and production, amounting to approximately 55%, indicates great opportunities to further increase yields in production through better use of the yield potential of varieties created by breeding.

Intercropping on French farms: Reducing pesticide and N fertiliser use while maintaining gross margins

Experimental studies to date have demonstrated the agronomic and environmental benefits of intercropping, making it a key diversification method for reducing chemical inputs in agriculture. However, intercropping is still a niche practice in European cropping systems, particularly for arable crops. Few studies have focused on farmers’ perspectives or used farm data to assess the on-farm performances of intercropping. Here, we present an analysis of data collected from farms of the DEPHY network, a demonstration farm network that aims to show that pesticide use can be reduced through changes in farming practices. We focused our study on four main species in France: winter wheat (Triticum aestivum L.), winter barley (Hordeum vulgare L.), pea (Pisum sativum L.) and rapeseed (Brassica napus L.). We carried out paired comparison tests between sole crops and intercrops for each species (16 pairs for winter wheat, 12 for winter barley, 15 for peas and 31 for rapeseed) to compare the use of pesticides (herbicides, fungicides, insecticides and all pesticides combined), mineral nitrogen fertiliser and the gross margin. We showed that pesticide use was reduced on average by 40–50% in the case of wheat- and barley-based intercrops compared with sole wheat and barley crops, respectively. Pesticide use for peas was reduced by 72% on average. Nitrogen fertiliser use was also reduced by up to 38% for wheat. On the other hand, in the case of rapeseed, which is mainly intercropped with unharvested companion plants, we found no significant differences in pesticide or fertiliser use between the sole crops and intercrops. This suggests that farmers must choose companion plants carefully depending on their objectives and desired services. Finally, our findings show that intercropping negatively affects gross margins for wheat, but gross margins are maintained for barley-, pea- and rapeseed-based intercrops compared to sole crops.