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Organic additions help improve soil biophysical qualities, but they are insufficient to supply nutrient demand and could result in unintentional nutrient immobilization in soils, particularly soils with low fertility status. A 16-week laboratory incubation study was conducted to determine how the method of application of compost and inorganic fertilizers influence microbial respiration, nitrogen (N), and phosphorus (P) mineralization. Topsoil (500 g, 0–15 cm) was amended with compost (0, 5, and 10 g kg−1) and either inorganic N (50 kg N ha−1) or P (30 kg P ha−1). Two soil amendment strategies, applying compost and inorganic fertilizer separately to opposite sides of the soil using a divider and mixing them evenly throughout the soil, were compared for their effects on microbial activity and nutrient mineralization. The cumulative amounts of carbon dioxide (CO2) evolved were measured fortnightly using the static CO2 absorption method and inorganic N and P mineralization. N mineralization was unaffected by the method of compost and inorganic fertilizer application (p >.05), while at the end of day 42, available P in separate applications of compost and mineral N fertilizers was 33% greater than combined applications. Compost and inorganic P fertilizer had favorable N priming effects, but compost and inorganic N had negative effects. The different N priming effects of compost and inorganic N and P fertilizers may be attributable to microbial nutrient demand. The data suggest that composting with conventional fertilizers may change microbial nutrient demand and crop nutrient availability. [ABSTRACT FROM AUTHOR]

Despite the critical need for nitrogen (N) in cropping systems, excessive N fertilizer application has severe environmental consequences. The synergistic interaction between sulfur (S) and N in plant nutrition could be exploited to increase N utilization, thereby maximizing N recovery and reducing losses. In a three-year study at six locations across three countries (USA, Ghana, and Mali), we evaluated the effect of S availability on N leaching losses from N fertilizer application using corn as the study crop. The study consisted of three S sources (micronized elemental sulfur [MES], untreated elemental sulfur [ES], and ammonium sulfate [AS]); five S application rates [(i) site-specific recommended S rate (SR), (ii) ¼ of the recommended S rate (25%_SR) (iii) ½ of the recommended S rate (50%_SR), (iv) ¾ of the recommended S rate (75%_SR); and (v) 1¼ of the recommended S rate (125%_SR)]; and a single N application rate (site-specific recommended N rate). Regardless of the S source, N recovery progressively increased with increasing S application rate. For the AS and MES sources, leachate nitrate concentration from the treatments with S application ≥ SR was statistically similar to that of the background concentrations, and the highest concentrations occurred with the treatment with no S application. Thus, for environmental stewardship, a critical look into S application in cropping systems is a necessity due to its synergistic interaction with N. In addition to improving productivity and enhancing efficient recovery of applied N fertilizers, S availability will minimize nitrate leaching commonly associated with application of N fertilizers. [ABSTRACT FROM AUTHOR]

Growing nursery plants in containers usually requires the addition of fertilizer to achieve optimal growth. However, misconceptions among growers often lead them to apply quantities of fertilizers exceeding the recommended dose, resulting in nutrient runoff and increased production costs. Reducing fertilizer application is beneficial to have healthy plants and environment as well as to save on fertilizer costs. In this study, we wanted to determine the minimal level of phosphorus (P) required to grow bedding plants i.e. Lysimachia nummularia 'creeping jenny' (moneywort) and Vinca minor 'Bowles' (periwinkle) in nursery. The plants were grown within a greenhouse in a mixture of peat moss, vermiculite, and rice hulls (3:1:1 v/v) substrates and subjected to various P treatments. The treatments included single dose of 1, 3, or 6 mg/L of P, double doses of 3 or 6 mg/L of P, or a control that received 6 mg/L of P at each irrigation. The results indicated that single dose of 6 mg/L of P had similar fresh weight compared to control in both taxa. Reducing P application further to a single dose of 1 and 3 mg/L reduced fresh weight and leaf area in both groundcovers however did not reduce their stem length or physiological parameters such as Soil Plant Analysis Development (SPAD) and normalized difference vegetation index (NDVI). Phosphorus concentration in the plant tissue at maturity was lower in all treatments than control for both the taxa. During the study period, control plants received 26 times the dose of P compared to plants receiving 6 mg/L of P once. Therefore, this study outlines the possibility of reducing P fertilizer application while growing these groundcovers in nurseries for sale. [ABSTRACT FROM AUTHOR]

Nitrous oxide (N2O) is a long-lived greenhouse gas that mainly originates from agricultural soils. More and more studies have explored the sources, influencing factors and effective mitigation measures of N2O in recent decades. However, the hierarchy of factors influencing N2O emissions from agricultural soils at the global scale remains unclear. In this study, we carry out correlation and structural equation modeling analysis on a global N2O emission dataset to explore the hierarchy of influencing factors affecting N2O emissions from the nitrogen (N) and non-N fertilized upland farming systems, in terms of climatic factors, soil properties, and agricultural practices. Our results show that the average N2O emission intensity in the N fertilized soils (17.83 g N ha−1 d−1) was significantly greater than that in the non-N fertilized soils (5.34 g N ha−1 d−1) (p< 0.001). Climate factors and agricultural practices are the most important influencing factors on N2O emission in non-N and N fertilized upland soils, respectively. For different climatic zones, without fertilizer, the primary influence factors on soil N2O emissions are soil physical properties in subtropical monsoon zone, whereas climatic factors are key in the temperate zones. With fertilizer, the primary influence factors for subtropical monsoon and temperate continental zones are soil physical properties, while agricultural measures are the main factors in the temperate monsoon zone. Deploying enhanced agricultural practices, such as reduced N fertilizer rate combined with the addition of nitrification and urease inhibitors can potentially mitigate N2O emissions by more than 60% in upland farming systems. [ABSTRACT FROM AUTHOR]

Nitrogen (N) is the key macronutrient for sustainable growth and higher productivity of crops. Optimized nitrogen-use-efficiency (NUE) enhances productivity and reduces the environmental impacts as well as input cost of production. NUE can be improved by the site-specific application of nitrogen fertilizer. Variable rate nitrogenous fertilizer can be applied after assessing the real-time status of the plant nitrogen. The assessment of the plant nitrogen can be obtained by various destructive and nondestructive techniques. This article aims to provide a thorough overview of the approaches available for determining plant N levels. The destructive techniques (Kjeldahl method and Dumas combustion) are tedious and time-consuming but more accurate. The most adopted nondestructive methods such as the use of Leaf Color Chart (LCC), digital sensors (SPAD meter, CCM-200, GreenSeeker, Crop Circle and Yara N-Sensor, OptRx® Crop Sensor, ISARIA, CropSpec, Multiplex®) and digital imaging-based techniques of plants are rapid in N level estimation. Nondestructive techniques utilize the optical property of leaves to assess the N level of plants. However, digital sensor-based estimation has certain limitations, including chlorophyll saturation, illumination effect, less accuracy and the high initial cost of instruments. Furthermore, more research should be carried out to overcome these limitations and improve their efficiency. [ABSTRACT FROM AUTHOR]

Cassava (Manihot esculenta Crantz) is an important staple crop, especially for resource-poor populations. Cassava-based diets are rich in calories but grossly deficient in essential mineral elements. A field study in southeastern Nigeria aimed at increasing yields and concentrations of bioavailable mineral elements in a β-carotene cassava variety, UMUCASS 38 (TMS 01/1371), through agronomic biofortification. A randomized complete block design experiment in triplicate, with foliar application of Zn (3.0 kg ha−1 Zn as ZnSO4), I (4.0 kg ha−1 I as KI), Se (0.25 kg ha−1 Se as Na2SeO3) and Zn + Se + I in combination at vegetative, tuber initiation and bulking stages of cassava. Results indicated neither phytotoxicity nor altered physical and chemical soil properties. Application of Zn or Zn + Se + I at the vegetative stage significantly increased cassava tuber yields. More Zn, Se, and I accumulated in fresh and processed cassava tuber products (gari, lafun), especially when Zn + Se + I was applied at tuber initiation stage. The combined application of Zn + Se + I consistently outperformed sole applications indicating a synergistic interaction effect between the three elements. It is concluded that in the Zn-deficient soils of southeast Nigeria, yield of cassava root tubers can be significantly increased by foliar application of Zn-containing fertilizer at the vegetative stage, but for optimal accumulation of elemental Zn, Se, and I, a combined Zn + Se + I fertilizer be applied at the tuber initiation stage. [ABSTRACT FROM AUTHOR]

Wheat (Triticum aestivum L.) is one of the most important staple food crops, and its sustained production and nutritional security have attracted much attention. Cadmium, a heavy metal toxic to plants and humans, can enter wheat in various ways. Foliar fertilization can reduce the cadmium content in plants, but how different fertilizers reduce the cadmium toxicity of plants is still unclear. In this study, the effects of foliar application of fertilizers on spring wheat yield, cadmium accumulation, and trace element contents were studied by applying three kinds of fertilizers (multi-element compound fertilizer, manganese-zinc micro fertilizer, and foliar silicon fertilizer) to spring wheat planted in mildly and moderately cadmium polluted areas. The results showed that the yield of wheat when fertilized with multi-element compound fertilizer, manganese-zinc micro fertilizer, and silicon fertilizer increased by 17.1%, 15.7%, and 16.9%, respectively, compared with the control. In addition, all three foliar fertilizers reduced the cadmium content in wheat grains to below the standard value of food pollutants (≤0.1mg/kg), and significantly reduced the transport of cadmium from glume to grain, among which manganesezinc micro fertilizer had the best effect, with a cadmium reduction rate of 41.7%. At the same time, manganese-zinc micro fertilizer significantly increased the absorption of trace elements in wheat organs. These results indicated that the foliar application of manganese-zinc micro fertilizer could be an effective way to increase wheat yield, inhibit cadmium accumulation, and increase nutrient absorption in mildly to moderately cadmium-polluted areas. [ABSTRACT FROM AUTHOR]

BACKGROUND: Rhodesgrass mealybug, Antonina graminis, is a serious pest of ultradwarf hybrid bermudagrass (Cynodon dactylon × C. transvaalensis) on golf course putting greens. A. graminis feeding damage appears as extensive yellowing of turfgrass blades and heavy thinning from mid‐to‐late summer into fall. Putting greens are intensively managed areas of the golf course where fertilizers are routinely applied to maintain and enhance turfgrass quality, playability and aesthetics. We hypothesize that A. graminis populations can be minimized by reducing nitrogen (N) fertilizer and then effectively managed using systemic insecticides. The objective of this study was to determine the effects of various levels of N fertilizer and flupyradifurone on the A. graminis population and turfgrass quality on the golf course putting green. The treatments were low, medium, and high N fertilizer rates with and without insecticide (flupyradifurone). RESULTS: Applying a high dose of N fertilizer improved turfgrass quality without increasing A. graminis densities on the golf course green. Although flupyradifurone application reduced A. graminis densities regardless of N fertilizer treatments, suppression of A. graminis densities improved at the high fertilizer dose with flupyradifurone. Additionally, the turfgrass quality on the putting green improved with high N fertilizer alone, regardless of flupyradifurone application. CONCLUSION: A. graminis populations can be managed using moderate to high levels of N fertilizer and applying a systemic insecticide. The low nitrogen fertilizer did not effectively reduce the A. graminis densities on the putting green. © 2024 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

This paper introduces a "Smart Fertilizing Using Internet of Things (IoT) Multi-Sensors" system to enhance fertilizer management in agriculture. The system has four main parts: the Nutro Determining Unit (NDU), the Nutro Sensing Unit (NSU), the Nutro UAV Variable Fertiliser Spray System, and a Variable Rate Unmanned Aerial Vehicle (UAV) Sprayer model. The NDU collects vital data on Soil Moisture (SM) and Environmental Conditions (EnC) using advanced IoT cameras, while the NSU consolidates and normalises the data for advanced analysis using Heuristic Decision Trees (HDT) and Random Forest (RF) algorithms. In India, a data-driven UAV system uses IoT and UAV technologies to determine nutrient needs and create a prescription map for fertilizer application. The approach caused increases in the efficient utilisation of resources, Crop Yield (CY), and ecological footprint when it underwent evaluation in a crop maize field that was 14 hectares in size. A fresh benchmark for Smart Farming (SF) techniques has been set up by this method of operation, which is motivated by data and symbolises an important innovation in modern and ecologically conscious SF methods. [ABSTRACT FROM AUTHOR]

BACKGROUND: Aerobic fermentation always suffers from nitrogen loss and low humification degree. The objective of this study was to investigate the promotion of phosphate buffer on organic matter degradation and precursor polymerization into humus (HS) in aerobic fermentation, and to analyze the key roles played by different precursors. In order to achieve this, sludge aerobic fermentation tests were conducted on control (CK), phosphate buffer addition treatment (KP) and potassium chloride addition treatment (K). RESULTS: The HS content of KP treatment exhibited a notable increase compared to the CK and K treatments, with a maximum increase of 38.29%. In addition, phosphate addition improved the nitrogen retention capacity and the complexity of the HS structure. Phosphate buffer enhanced both the polyphenol and Maillard humification pathways by promoting the condensation of precursors (polysaccharides, reducing sugars, polyphenols, amino acids and proteins). Among these precursors, reducing sugars, amino acids and proteins were identified as the key driving precursors of phosphate. CONCLUSIONS: Phosphate, as an exogenous additive to the fermentation system, reduces nitrogen loss while promoting precursor polymerization to form HS, which benefits the improvement of soil fertility and crop growth upon organic fertilizer application. © 2024 Society of Chemical Industry (SCI). [ABSTRACT FROM AUTHOR]

BACKGROUND RESULTS CONCLUSION Pear yield is a primary source of income for smallholder farmers in China, yet significant yield disparities exist among different smallholders. Systematic analyses of limiting factors and the feasibility of solutions at the smallholder level are limited. This study employs a novel DEED (Describe, Explain, Explore, and Design) research cycle centered on smallholders to formulate yield‐improving strategies.A comprehensive survey of 173 smallholders in the Yangtze River pear district, encompassing Zhejiang province, Jiangxi province, and Shanghai city, was conducted to delineate the current yield status. The boundary line analysis model was applied to elucidate the contributions of various yield‐limiting factors. Findings reveal an average yield ranging from 16.7 to 19.3 t ha−1, with a potential highest yield of 37.5 t ha−1. Fertilizer nitrogen (N) was identified as the most pervasive yield‐limiting factor, constituting 62.7% of the average limitation at the regional level and 37.7% at the individual smallholder level, surpassing other yield‐related factors in all three regions. Subsequently, a 2‐year field optimization experiment was conducted to explore the potential for yield improvement through adjustments in N fertilizer rates. Compared with traditional farmer management (FM), the N fertilizer optimization treatment (OPT) resulted in a 38.1% and 22.5% increase in yield for 2022 and 2023, respectively.These results identify N fertilizer application rate as the most important yield‐limiting factor and verify the feasibility of optimizing N fertilizer management practices for improving pear yield. This study integrates farmer surveys, boundary line models, and field experiments to provide valuable insights into addressing yield disparities among smallholders in the pear industry. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Nitrogen fertilizer application and increasing planting density have been recognized as essential measures to achieve higher wheat (Triticum aestivum L.) yields. However, inadequate management practices often lead to poor culm quality and lodging. We hypothesized that optimizing culm characteristics could be a feasible approach to improving both lodging resistance and yield. In this study, field experiments involved five nitrogen levels (0, 180, 240, 300, and 360 kg ha−1) and three planting densities (225, 375, and 525 × 104 ha−1). Two wheat cultivars with different lodging resistance were selected and their culm morphological characteristics, biochemical components, field lodging rate, and yield in different treatments were measured. We found that field lodging rate in wheat was negatively correlated with yield, and there was a contradiction between increasing spike number and lodging resistance. Culm carbohydrate accumulation affected field lodging rate by regulating culm quality rather than the center of gravity height. Compared with Xinmai 26, Xinhuamai 818 had higher culm carbohydrate accumulation, which increased the breaking strength and yield by 14.2% and 17.0%. Nitrogen application and planting density had significant effects on yield and lodging resistance. Compared with N0 treatment, increasing nitrogen application rate improved yield of 67.2%–83.2% by increasing spike number and grain number per spike, and the N2 treatment showed the largest increase. Planting density had little effect on yield. Reducing planting density can increase the culm carbohydrate accumulation and enhance lodging resistance. Compared with D3 treatment, the culm breaking strength was increased by 27.6% under the D1 treatment. This study determined that the optimal combination of nitrogen and density for improving wheat lodging resistance and yield is 240 kg ha−1 and 225 × 104 ha−1. This combination enhances culm breaking strength by increasing carbohydrate accumulation and achieves high yield by increasing grain number per spike, 1000‐grain weight, and stabilizing spike number. [ABSTRACT FROM AUTHOR]

Introduction: The depth of fertilizer application significantly influences soil nitrate concentration (SNC), sunflower root length density (RLD), sunflower nitrogen uptake (SNU), and yield. However, current studies cannot precisely capture subtle nutrient variations between soil layers and their complex relationships with root growth. They also struggle to assess the impact of different fertilizer application depths on sunflower root development and distribution as well as their response to the spatial and temporal distribution of nutrients. Methods: The Agricultural Production Systems sIMulator (APSIM) model was employed to explore the spatial and temporal patterns of nitrogen distribution in the soil at three controlled-release fertilizer (CRF) placement depths: 5, 15, and 25 cm. This study investigated the characteristics of the root system regarding nitrogen absorption and utilization and analyzed their correlation with sunflower yield formation. Furthermore, this study introduced the modified Jaccard index (considering the compatibility between soil nitrate and root length density) to analyze soil-root interactions, providing a deeper insight into how changes in CRF placement depth affect crop growth and nitrogen uptake efficiency. Results: The results indicated that a fertilization depth of 15 cm improved the modified Jaccard index by 6.60% and 7.34% compared to 5 cm and 25 cm depths, respectively, maximizing sunflower yield (an increase of 9.44%) and nitrogen absorption rate (an increase of 5.40%). This depth promoted a greater Root Length Density (RLD), with an increases of 11.95% and 16.42% compared those at 5 cm and 25 cm, respectively, enhancing deeper root growth and improving nitrogen uptake. In contrast, shallow fertilization led to higher nitrate concentrations in the topsoil, whereas deeper fertilization increased the nitrate concentrations in the deeper soil layers. Discussion: These results provide valuable insights for precision agriculture and sustainable soil management, highlighting the importance of optimizing root nitrogen absorption through tailored fertilization strategies to enhance crop production efficiency and minimize environmental impact. [ABSTRACT FROM AUTHOR]

Rice is the most important crop in India and additionally the hub of food security of the worldwide population. Integrated application of manures and fertilizers played a pivotal role for improvement of soil physico-chemical properties under different cropping systems as well as nutrient accumulation and grain yield in rice. The present investigation was conducted in sandy loam soil at Agronomy Research Farm of Odisha University of Agriculture and Technology, Bhubaneswar, Odisha, India during 2018–2019 having sub-humid climate. Field experiment was designed to evaluate the effect of two date of transplanting, which were allotted to main plots and three combinations of nutrient management options allotted for sub plots on rice crop (var. Naveen). Among all the plant parts, leaf showed higher accumulation of nitrogen (3.69, 1.92%), stem showed higher accumulation of both phosphorus (0.43, 0.35%) and potassium (2.59, 2.09%) than other plant parts during vegetative stages, while panicle showed higher accumulation of nitrogen (1.22%), phosphorus (0.28%) during harvesting stages of the rice crop. Significantly higher nitrogen accumulation in different plant parts were optimized under Soil Test Based Fertilizer Recommendation (STBFR) + Green Manure (GM; Sesbania rostrata) (0.99, 0.46, 1.28%) method of nutrient management, while phosphorus (0.10, 0.11, 0.28%) and potassium (1.00, 1.64, 0.33%) accumulation were found to be significantly higher in different plant parts under STBFR + Farm Yard Manure (FYM) method of nutrient management. Thus, early transplanting and application of STBFR + GM/FYM could be recommended for higher nutrient accumulation in rice crop. [ABSTRACT FROM AUTHOR]

Introduction: The potato holds the distinction of being the world's largest non-cereal food crop and ensuring its sustainable production is imperative for global food security. Notably, China leads in both the planting area and output of potatoes globally, cementing its crucial role in the nation's agricultural economy. A scientific assessment of the effectiveness of organic fertilizers on potato cultivation can significantly contribute to the promotion of sustainable agriculture. Methods: This study utilizes a Propensity Score Matching (PSM) model and introduces a novel cost-efficiency approach to analyze and evaluate the production efficiency and economic impact of organic fertilizer application among 546 potato growers in Shandong. Results: The research findings reveal the following: Firstly, compared to the control group without organic fertilizer application, it is evident that the use of organic fertilizers enhances production technology efficiency, labor productivity, land productivity, and net profit per unit by 3.6%, 1588.47 kg/ person, 16346.77 kg/ha, and 16135.32 yuan/ha, respectively. Secondly, an examination of cost efficiency among growers with different production scales indicates that those with a planting scale of 0.667-1.333 hectares demonstrate relatively high production efficiency across multiple factors. Additionally, there is an observable inverted U-shaped trend in the relationship between planting scale and production efficiency. Thirdly, the continuous application of organic fertilizers proves advantageous in mitigating inefficiencies in investment techniques, leading to cost savings and efficiency improvements in potato cultivation. Discussion: Consequently, it is recommended that the government and relevant departments enhance technical support, elevate professional training programs, and optimize the allocation of input factors. These measures aim to encourage farmers to adopt organic fertilizers, thereby promoting sustainable agricultural practices. [ABSTRACT FROM AUTHOR]

Zinc (Zn) is an essential micronutrient that is found in almost all classes of enzymes. Its deficiency is a well-documented problem among cereal crops that causes decreased crop yields and nutritional quality. Therefore, an experiment was implemented in a randomized block design which included the treatments of bacterial inoculation consisting of T1 (Control), T2 (100% RDF;100:40:20), T3(100% RDF + 25 kg ZnSO4.7 H2O), T4(100%RDF+ ZnSB1– Bacillus sp. strain BAU_A2 @750 ml ha−1), T5 (100%RDF+ ZnSB2– Priestia megaterium strain BAU_A3 @750 ml ha−1), T6 (100%RDF+ ZnSB3-Bacillus subtilis strain BAU_A5@750 ml ha−1). The mineral NPK was applied as per treatments. The results indicated the maximum values of water soluble exchangeable Zn and organically bounded Zn in treatments consisting ZnSB1, ZnSB2 and ZnSB3, respectively. The WS+EXCH-Zn was significantly increased by 68.57%, 28.26%, 18%, 98.14%, 41.30%, 30.00% and 128.12%, 55.55%, 37.25%, 43%, 62.22% and 43.13% in first year (2018–19) and second year (2019–2020) under the soil treated with ZnSB1-Peribacillus simplex strain BAU_A1, ZnSB2-Bacillus sp. strain BAU__A2 and ZnSB3-Bacillus subtilis strain BAU_A5 along with 100%RDF over control, application of recommended dose of fertilizer with and without application of 25 kg ZnSO4 ha−1, respectively. However, the maximum decrement in Mn-oxide-bounded zinc (1.12 mg kg−1 soil) was observed with T6 which was significantly higher by 158%, 194.4%, 185.71% over control, 100% RDF with and without application of 25 kg ZnSO4 ha−1, which showed the solubilization of zinc with the activity of ZnSB in soil. The study may be beneficial to mitigate the zinc deficiency in soil and malnutrition in children. [ABSTRACT FROM AUTHOR]

Background: Nitrogen (N) is a crucial element for increasing photosynthesis and crop yields. The study aims to evaluate the photosynthetic regulation and yield formation mechanisms of different nodulating peanut varieties with N fertilizer application. Method: The present work explored the effect of N fertilizer application rates (N0, N45, N105, and N165) on the photosynthetic characteristics, chlorophyll fluorescence characteristics, dry matter, N accumulation, and yield of four peanut varieties. Results: The results showed that N application increased the photosynthetic capacity, dry matter, N accumulation, and yield of peanuts. The measurement of chlorophyll a fluorescence revealed that the K-phase, J-phase, and I-phase from the OJIP curve decreased under N105 treatment compared with N0, and WOI, ET0/CSM, RE0/CSM, ET0/RC, RE0/RC, φPo, φEo, φRo, and Ψ0 increased, whereas VJ, VI, WK, ABS/RC, TR0/RC, DI0/RC, and φDo decreased. Meanwhile, the photosystem activity and electron transfer efficiency of nodulating peanut varieties decreased with an increase in N (N165). However, the photosynthetic capacity and yield of the non-nodulating peanut variety, which highly depended on N fertilizer, increased with an increase in N. Conclusion: Optimized N application (N105) increased the activity of the photosystem II (PSII) reaction center, improved the electron and energy transfer performance in the photosynthetic electron transport chain, and reduced the energy dissipation of leaves in nodulating peanut varieties, which is conducive to improving the yield. Nevertheless, high N (N165) had a positive effect on the photosystem and yield of non-nodulating peanut. The results provide highly valuable guidance for optimizing peanut N management and cultivation measures. [ABSTRACT FROM AUTHOR]

Fertilizer application has been one of the most important facilities to advance agricultural mechanization. Particularly, manual fertilization cannot fully meet the large-scale production in recent years. In this article, a chain reversal trenching and application device was presented for the organic fertilizer in orchards, in order to enhance the trenching depth and uniform fertilization. A reverse-chain trenching mechanism was employed with a fixed trenching blade that moved in the opposite direction of the chain. The soil cutting and simultaneous backfilling were allowed within the trench, as the device progressed. A trenching depth of up to 600mm was achieved in the chain trenching mechanisms. The separate backfilling was reduced to leave no visible trenches on the surface after completion. This design was also a streamlined operation. The mathematical analysis of the trenching blade was conducted to establish a mathematical model using Cartesian coordinate transformations. The relationship equation was derived for the cutting angle. Optimal angle parameters were also provided. According to the trenching depth analysis, the hydraulic adjustment cylinders were selected for the trenching device. A scrapertype fertilizer application mechanism was adopted to develop the discrete element simulation models for both upright and sideways fertilizer application modes. The fertilizer distribution patterns were analyzed under the two modes. While both modes were similarly distributed fertilizer, and the forward-facing mode was more suitable for the operations with the larger fertilizer widths, while the sideward-facing mode was with the smaller fertilizer widths. In the two fertilizer application modes, the sideways application mode had better uniformity, especially at the lower forward speeds. Therefore, the application mode of sideward-facing fertilizer was selected to ensure that all organic fertilizer accurately fell into the trench. A single-factor experiment was carried out to explore the effects of scraper height, angle, and spacing on the normal contact force and coefficient of variation. All three parameters shared a significant impact on the coefficient of variation. In a coefficient of variation of less than 15%, the optimal height, angle, and spacing of the scraper were selected to minimize the normal contact force, resulting in values of 20 mm, 90°, and 180 mm, respectively. According to these optimal parameters of the scraper, the simulation was conducted to yield a coefficient of variation of 6.02% and a normal contact force of 9.03 N, both of which were lower than those before optimization. Subsequently, a physical prototype was fabricated and field-tested. An average coefficient of variation of 8.34% was obtained for fertilizer distribution, indicating better uniformity. Furthermore, the maximum and minimum fertilizer application tests showed that the quantities ranged from 0.8 to 6 kg/m, thus meeting the fertilization requirements of different plots. The trenching performance tests show that the average trenching depths of two operations were 616.0 and 624.4 mm, respectively, with stability coefficients of 93.57% and 92.58%, respectively, both exceeding 90%. The average trenching widths were 305.4 and 295.4 mm, respectively, with consistency coefficients of 96.16% and 95.04%, respectively, both exceeding 95%. Therefore, the device exhibited excellent performance in the fertilizer distribution and trenching operations, fully meeting the agronomic requirements. The findings can provide a new tool for the deep application of organic fertilizers in orchards, indicating the promising potential prospects. Innovative design and efficiency can also offer valuable insights into the agricultural fields. [ABSTRACT FROM AUTHOR]

γ-polyglutamic acid (γ-PGA), as an environmentally sustainable material, is extensive applied in agriculture for enhancing water and fertilizer utilization efficiency, augmenting crop yield, and ameliorating soil conditions. However, the effect of γ-PGA in conjunction with sesame cake fertilizer on the soil environment remains uncertain.The aim of this study is to investigate the effect of γ-PGA on soil nutrients, water use efficiency (WUE) and nitrogen use efficiency (NUE), and maize yield across various levels of sesame cake fertilizer. Additionally, the study seeks to identify the optimal ratio to establish a theoretical and practical foundation for sustainable agricultural development and the promotion of ecological agriculture. Through field experiments, nine treatments were established, comprising three levels of sesame cake fertilizer application rates (B1 = 900 kg/hm2 for low fertility, B2 = 1100 kg/hm2 for medium fertility, and B3 = 1300 kg/hm2 for high fertility) and three levels of γ-PGA application rates (R1 = 200 kg/hm2, R2 = 400 kg/hm2, and R3 = 600 kg/hm2). The results can be outlined as follows: (1) When γ-PGA application rate increased, total nitrogen (TN) exhibited a synergistic effect under B1 treatment, but an antagonistic effect under B2 and B3 treatments. At the 6-leaf stage (V6), 12-leaf stage (V12), and tasseling stage (VT), available phosphorus (AP) exhibited antagonistic effects. However, at the filling stage (R2) and maturity stage (R6), AP in B1 and B2 treatments at various depths underwent partial transformation into a synergistic effect. The levels of available potassium exhibited a notable antagonistic effect, leading to a decrease in harvest index (HI). B2 treatment demonstrated superior results compared to the B1 and B3 treatments, with the highest levels observed under B2R1 treatment; (2) TN content in the 0–40 cm soil layer increased during the filling period, and it was uniformly distributed in the 40–60 cm soil layer. When the soil AP was located in the 0–60 cm soil layer, there was an increase in AP content during the mature period. Following the tasseling period, different treatments exhibited varying patterns of increase in response to the presence of potassium within the 0–60 cm soil layer. Consequently, in cases where the sesame cake fertilizer content is low, the interaction between γ-PGA can compensate for the deficiency of fertilizer, thereby enhancing water and nitrogen utilization efficiency. The optimal fertilization strategy for enhancing soil nutrient distribution, WUE and NUE, and yield is proposed to be the application of 1100 kg/hm2 sesame cake fertilizer and 200 kg/hm2 γ-PGA. [ABSTRACT FROM AUTHOR]

Introduction: Nitrogen (N) plays a pivotal role in the growth, development, and yield of maize. An optimal N application rate is crucial for enhancing N and carbohydrate (C) accumulation in waxy maize grains, which in turn synergistically improves grain weight. Methods: A 2-year field experiment was conducted to evaluate the impact of different N application rates on two waxy maize varieties, Jinnuo20 (JN20) and Jindannuo41 (JDN41), during various grain filling stages. The applied N rates were 0 (N0), 120 (N1), 240 (N2), and 360 (N3) kg N ha-1. Results: The study revealed that N application significantly influenced nitrogen accumulation, protein components (gliadin, albumin, globulin, and glutelin), carbohydrate contents (soluble sugars, amylose, and amylopectin), and activities of enzymes related to N and C metabolism in waxy maize grains. Notable varietal differences in these parameters were observed. In both varieties, the N2 treatment consistently resulted in the highest values for almost all measured traits compared to the other N treatments. Specifically, the N2 treatment yielded an average increase in grain dry matter of 21.78% for JN20 and 17.11% for JDN41 compared to N0. The application of N positively influenced the activities of enzymes involved in C and N metabolism, enhancing the biosynthesis of grain protein, amylose, and amylopectin while decreasing the accumulation of soluble sugars. This modulation of the C/N ratio in the grains directly contributed to an increase in grain dry weight. Conclusion: Collectively, our findings underscore the critical role of N in regulating kernel N and C metabolism, thereby influencing dry matter accumulation in waxy maize grains during the grain filling stage. [ABSTRACT FROM AUTHOR]

Late spring coldness (LSC) is the main limiting factor threatening wheat yield and quality stability. Optimal nutrient management is beneficial in mitigating the harms of LSC by improving wheat root physiology. This study proposed a nutrient management strategy that postponed the application of phosphorus (P) and potassium (K), effectively strengthening wheat's defense against LSC. This experiment used the winter cultivar "Yannong19" (YN 19) as plant material for two consecutive years (2021–2022 and 2022–2023). Two fertilizer treatments were used: traditional P and K fertilizers application (R1: base fertilizer: jointing fertilizer = 10:0) and postponed P and K fertilizers application (R2: base fertilizer: jointing fertilizer = 5:5); wheat plants at the anther connective formation stage shifted to temperature-controlled phytotrons for normal (T0, 11 °C/4 h) and low temperatures (T1, 4 °C/4 h; T2, −4 °C/4 h) as treatments of LSC. The results showed that under low temperature (LT) treatment, compared with R1, the R2 treatment increased the concentrations of osmotic adjustment substances (soluble sugars and soluble protein contents by 6.2–8.7% and 3.0–8.9%), enhanced activities of antioxidant enzymes (superoxide dismutase, peroxidase and catalase activities by 2.2–9.1%, 6.2–9.7% and 4.2–8.4%), balanced the hormone concentrations (increased IAA and GA3 contents by 2.8–17.5% and 10.4–14.1% and decreased ABA contents by 7.2–14.3%), and reduced the toxicity (malondialdehyde, hydrogen peroxide content and O2·− production rate by 5.7–12.4%, 17.7–22.8% and 19.1–19.1%) of the cellular membranes. Furthermore, the wheat root physiology in R2 significantly improved as the root surface area and dry weight increased by 5.0–6.6% and 4.7–6.6%, and P and K accumulation increased by 7.4–11.3% and 12.2–15.4% compared to R1, respectively. Overall, the postponed application of P and K fertilizers enhanced the physiological function of the root system, maintained root morphology, and promoted the accumulation of wheat nutrients under the stress of LSC. [ABSTRACT FROM AUTHOR]

Corn-soybean rotation is a cropping pattern to optimize crop structure and improve resource use efficiency, and nitrogen (N) fertilizer application is an indispensable tool to increase corn yields. However, the effects of N fertilizer application levels on corn yield and soil N storage under corn-soybean rotation have not been systematically studied. The experimental located in the central part of the Songnen Plain, a split-zone experimental design was used with two planting patterns of continuous corn (CC) and corn-soybean rotations (RC) in the main zone and three N application rates of 0, 180, and 360 kg hm-2 of urea in the secondary zone. The research has shown that RC treatments can enhance plant growth and increase corn yield by 4.76% to 79.92% compared to CC treatments. The amount of N fertilizer applied has a negative correlation with yield increase range, and N application above 180 kg hm-2 has a significantly lower effect on corn yield increase. Therefore, a reduction in N fertilizer application may be appropriate. RC increased soil N storage by improving soil N-transforming enzyme activity, improving soil N content and the proportion of soil organic N fractions. Additionally, it can improve plant N use efficiency by 1.4%-5.6%. Soybeans grown in corn-soybean rotations systems have the potential to replace more than 180 kg hm-2 of urea application. Corn-soybean rotation with low N inputs is an efficient and sustainable agricultural strategy. [ABSTRACT FROM AUTHOR]

Sowing date and soil fertility are very important factors in the overwintering and production performance of alfalfa (Medicago sativa L.), yet there's a knowledge gap in knowledge on how late-seeded alfalfa responds to phosphorus (P) fertilization. A field study was conducted in Inner Mongolia from 2020 to 2022 using a split-plot design. The main plots consisted of five sowing dates (31 July, 8, 16, and 24 August, and 1 September), while the subplots involved five P application rates (0, 40, 70, 100, and 130 kg P2O5 ha−1). Throughout the growing seasons, the overwintering rate, root traits, forage yield, and yield components were measured. The results revealed a consistent decrease in overwintering ability and productivity with the delayed sowing. This reduction in overwintering rate was mainly due to diminished root traits, while the decrease in forage yield was largely associated with a reduction in plants per square meter. However, P fertilizer application to late-seeded alfalfa demonstrated potential in enhancing the diameter of both the crown and taproot, thus strengthening the root system and improving the overwintering rate, the rate of increase ranges from 11.6 to 49%. This adjustment could also improve the shoots per square meter and mass per shoot, increasing by 9.4–31.3% and 15.0–27.1% respectively in 2 years, which can offset the decline in forage yield caused by late sowing and might even increase the forage yield. Regression and path analysis indicated that alfalfa forage yield is primarily affected by mass per shoot rather than shoots per square meter. This study recommended that the sowing of alfalfa in similar regions of Inner Mongolia should not be later than mid-August. Moreover, applying P fertilizer (P2O5) at 70.6–85.9 kg ha−1 can enhance the forage yield and persistence of late-seeded alfalfa. Therefore, appropriate late sowing combined with the application of P fertilizer can be used as an efficient cultivation strategy for alfalfa cultivation after a short-season crop harvest in arid and cold regions. [ABSTRACT FROM AUTHOR]

The combination of hydrogel and fertilizer as slow release fertilizer hydrogel (SRFH) has become one of the most promising materials to overcome the shortcomings of conventional fertilizer by decreasing fertilizer loss rate, supplying nutrients sustainably, and lowering the frequency of irrigation. The hydrogel based on carboxymethyl cellulose (CMC) and polyacrylic acid (PAA) (CMC/PAA) was synthesized. All materials, Vinasse, hydrogel (CMC/PAA) and (Vinasse/CMC-PAA) were characterized by FTIR, XRD, and SEM. The formed hydrogel was applied to control the salinity of Vinasse to use it as a cheap and economical fertilizer. The results showed that using the prepared hydrogel with Vinasse (V/CMC-PAA) as a slow-release organic fertilizer decreased the EC value through the first six hours from 1.77 to 0.35 mmohs/cm. Also, using V/CMC-PAA can control and keep the potassium as fertilizer for 50 days. The productivity per feddan from the sugar cane crop increased by about 15%, and the number of irrigations decreased from 5 to 4 times. [ABSTRACT FROM AUTHOR]

Fengdan (Paeonia × suffruticosa Andrews), a woody oil crop abundant in unsaturated fatty acids, notably linolenic acid, holds promise in agriculture. However, selenium deficiency in Chinese soil poses a challenge to its growth. This study investigated the impact of Selenium nanoparticles (SeNPs) on Fengdan's physiological traits and selenium enrichment. Employing a randomized complete block design, five SeNPs spraying levels were tested on Fengdan cultivar Feng Dan. Results showed substantial enhancements in photosynthetic parameters with Se application, particularly at 6.00 g/ha (S3) and 8.25 g/ha (S4). Moreover, Se application improved protein, soluble sugar, and proline solubility, along with increased activities of SOD and POD, while decreased MDA content. Se content in Fengdan organs notably increased with SeNPs concentration, especially in the testa, leaf, and kernel. In conclusion, comprehensive SeNPs fertilizer application positively affected Fengdan's growth, photosynthesis, and selenium enrichment. The most effective treatments were observed at 6.00 g/ha (S3) and 8.25 g/ha (S4). This study offers valuable insights into selenium enrichment strategies for oil crops, stressing the significance of Se application dosage and organ specificity in biological Se enrichment. [ABSTRACT FROM AUTHOR]

The effect of long-term use of mineral fertilizers on changes in the content of total phosphorus and its organic, mineral, and mobile compounds in soddy-podzolic heavy loamy soil (Albiс Retisol (Abruptic, Aric, Loamic)) was analyzed. The studies were performed in a long-term stationary experiment initiated in Perm krai in 1978. The variants were: 0 (without fertilizers), N90, P90, K90, N90P90, N90K90, P90K90, N90P90K90, N30P30K30, N60P60K60, N120P120K120, and N150P150K150. Ammonium nitrate or urea, double or simple superphosphate, and potassium chloride were used in the experiment. It was established that long-term use of superphosphate during five eight-field crop rotations (P90, P90K90, N90P90, and N90P90K90) resulted in a significant increase in the contents of the total phosphorus, mineral phosphorus (by 1.3–1.8 times), and mobile phosphorus (by 1.9–2.7 times) compounds in the plow layer (0–20 cm). The use of nitrogen fertilizers (N90, N90K90, N90Р90, and N90Р90K90) affected the accumulation of organic phosphorus compounds in the soil. The increase in the content and reserves of both mineral and organic phosphorus compounds was significant only in the case of using complete mineral fertilizer N90P90K90. Different combinations of superphosphate with nitrogen fertilizers and potassium chloride, as well as the rate of fertilizer application, affected the accumulation intensity of mobile phosphorus compounds in the soil during rotations and the changes in their contents in the soil profile. The application of low fertilizer rates ((NPK)30–60) resulted in an increase in the content of mobile phosphorus compounds mainly in the plow layer, whereas higher rates ((NPK)90–150) caused changes in the 80-cm-thick soil layer. Long-term use of nitrogen and potassium fertilizers resulted in an increase in the content of mobile phosphorus compounds in the plow layer over time. [ABSTRACT FROM AUTHOR]

Struvite (MgNH4PO4·6H2O), a mineral with low water solubility that can be recovered from industrial wastewater, has the potential to be used as a slow-release phosphorus (P) fertilizer. However, the effect of struvite on the yield and P uptake efficiency of different crops remains unclear. In this study, the effects of struvite, diammonium phosphate (DAP), and a mixed fertilizer consisting of struvite + DAP (MIX) on biomass, P uptake, and soil P fractions of Chinese cabbage, cowpea, and maize were investigated in pot experiments. The results showed that compared to DAP, the mixed fertilizer reduced the biomass of Chinese cabbage by 47%, while there was no difference in the biomass of cowpea and maize under P fertilizer application. There was no difference in total P concentration in Chinese cabbage and cowpea plants between DAP and MIX, while total P concentration in maize under mixed fertilizer treatment decreased by 16.73% compared to DAP treatment. Compared to DAP, the MIX treatment reduced total P uptake in Chinese cabbage and maize by 45.82% and 33.41%, respectively, with no direct difference in cowpea. Soil Olsen-P and CaCl2-P concentrations were highest in DAP among the different treatments. The MIX treatment significantly increased the water-soluble P in Chinese cabbage and cowpea by 5.87% and 5.23%, respectively, while the water-soluble P in maize was lower in the mixed fertilizer treatment than in the DAP treatment. In addition, mixed fertilizer significantly increased soil pH and soil phosphatase activity compared to DAP. This result suggested that among the three treatments of struvite, DAP, and MIX, struvite had the weakest effect on crop growth. In addition, among the three crops, Chinese cabbage, cowpea, and maize, the compatibility between struvite and maize was the highest. These results provide valuable insights for the future application of struvite in agricultural production for achieving stable yields while mitigating environmental risks. [ABSTRACT FROM AUTHOR]

Chemical fertilizers can improve crop productivity, but irrational fertilization often results in low crop quality and yield, poor soil fertility, and severe environmental pollution. Nevertheless, little research has been conducted with a close focus on the cultivation of radish in high mountain regions, a widely cultivated root vegetable known for its nutritional value and economic importance. Here, a method of reducing chemical fertilizers combined with the application of organic fertilizers is proposed upon studying four different ratios of chemical and organic fertilizers, including control (375 kg·ha−1 chemical fertilizer + 4500 kg·ha−1 organic fertilizer) and combinations (T1: 12% reduction in chemical fertilizer + 4500 kg·ha−1 organic fertilizer; T2: 20% reduction in chemical fertilizer + 4500 kg·ha−1 organic fertilizer; T3: 28% reduction in chemical fertilizer + 4500 kg·ha−1 organic fertilizer). Their effects on radish quality, yield, and soil environment were investigated. Compared with the control group, T2 significantly increased radish yield by 12.92% and improved the contents of vitamin C, soluble sugars, sulforaphane soluble solids, and titratable acidity in the radish roots by 10.62%, 2.15%, 50.00%, 26.90%, and 43.90%, respectively. The soil nutrient content was increased by the T2 treatment, with a 7.69% and 14.29% increase in total nitrogen and total phosphorus content, respectively, compared with the control. Moreover, soil urease activity, sucrase activity, alkaline phosphatase activity, and catalase activity were significantly enhanced by the T2 treatment, showing an improvement of 11.13%, 44.30%, 26.41%, and 9.33% compared with the control, respectively (p < 0.05). The relative abundance of beneficial bacterial phyla such as Proteobacteria and Actinobacteria was increased in the T2 treatment, potentially helping to maintain better soil health and long-term fertility. In summary, a promising fertilizer management strategy is herein unveiled through the reduction of chemical fertilizers and the application of organic fertilizer that not only improves radish yield and quality but also optimizes the soil environment, providing an effective means for sustainable crop production. [ABSTRACT FROM AUTHOR]

Water and nitrogen are crucial for producing spring maize. Currently, irrigation and fertilization systems often rely on a single indicator, resulting in inefficient practices. This study aims to determine an optimal nitrogen application rate for shallow buried drip irrigation (SBDI) to balance growth characteristics, yield (Y), water use efficiency (WUE), and soil nitrogen levels. In a typical semi-arid region of Northeast China, we conducted controlled experiments from 2022 to 2023, adopting a two-factor quadratic saturation D-optimal design method to study the effects of different irrigation amounts (145.40, 271.70, 348.20, and 436.20 mm) and nitrogen fertilizer application amounts (34.80, 185.90, 277.40, and 382.80 kg·hm−2) on spring maize. The results indicate that increasing both irrigation and nitrogen application rates can enhance dry matter accumulation (DMA) from 15.17% to 32.70%. The impact of irrigation and fertilization on the net photosynthetic rate (Pn) of spring maize was greater for the irrigation applications than the nitrogen applications, particularly at 9:00 a.m. and 13:00 p.m. and slightly less so at 11:00 a.m. and 15:00 p.m. Concurrently, there were significant increases in total nitrogen (TN1 by 20.85% in the 0–20 cm soil layer; TN2 by 33.33% in the 20–40 cm soil layer) and alkali-hydrolyzed nitrogen (AHN1 by 14.65% at 0–20 cm; AHN2 by 28.86% at 20–40 cm). Y improved from 12.02% to 44.09%, and WUE increased from 20.08% to 140.07%. The optimal water and fertilizer management mode for spring maize SBDI in semi-arid areas was determined through comprehensive analysis using the TOPSIS entropy weight method. When the irrigation amount is 436.20 mm, and the nitrogen fertilizer application amount is 277.40 kg·hm−2, it can significantly promote the DMA, Y, WUE, photosynthetic characteristics, and soil nitrogen content of spring maize. This study provides a theoretical basis for the practical application of SBDI water–fertilizer coupling for spring maize. [ABSTRACT FROM AUTHOR]

A 2-year field experiment was conducted to test the effects of individual and co-application of biochar and inorganic fertilizer on soil quality using the principal component analysis (PCA) technique. The dry season field experiments were performed with biochar applied at 0 and 20 t ha−1, and fertilizer at 300 and 0 kg ha−1 (control). The factorial combinations of the above-mentioned treatments were subjected to irrigation at 60, 80, and 100% of irrigation amounts (IAs). Soil hydro-physical and chemical properties and grain yield were determined at harvest. Results from the PCA indicated that the soil total nitrogen (N) and moisture content (MC) were the soil properties mostly affecting the grain yield. The amendments' effects on the soil physico-chemical properties and maize yield were in the order control < biochar < fertilizer < biochar + fertilizer. The derived comprehensive soil quality index (CSQI) from the PCA showed that the soil quality increased by 76, 100, and 200% in treatments individually applied with biochar, inorganic fertilizer, and the co-applications. This study therefore showed that the PCA revealed the actual dynamics in soil properties, in terms of the SQI upon the soil amendment addition, as well as their relationship with maize yield under different weather conditions. [ABSTRACT FROM AUTHOR]

The necessity for efficacious, sophisticated methodologies to facilitate agricultural intensification in the context of global population growth is widely accepted. One of the principal methods for enhancing the yield of plant agricultural products is the application of fertilizers. In light of the rapid advancement of nanotechnology over recent decades, the potential of utilizing fertilizing systems based on nanoparticles and nanomaterials—termed "nanofertilizers"—as an alternative to classical mineral fertilizers is increasingly being explored. Due to their unique properties, nanofertilizers demonstrate a number of qualities useful for agriculture. These include high activity, more accurate dosing, targeted delivery of fertilizers to plants, reduced accumulation in soils and groundwater, high durability, and so forth. This review presents a synthesis of data on the efficacy of nanofertilizers over the last decade, focusing on macro-based (N, P, K, Ca, Mg, S) and micro-based (Fe, Zn, Mn, B, Cu, Mo) nanoformulations for agricultural crops. We analyzed over 200 publications, published mainly over the last decade, on the topic of "nanofertilizers". An analysis of published data on the effectiveness of using nanoparticles as applied fertilizers was carried out, and the effectiveness of using nanofertilizers was compared with traditional chemical fertilizers for a number of elements. [ABSTRACT FROM AUTHOR]

In this study, we investigated if reducing the amount of chemical fertilizer by combining it with organic fertilizer in Hemerocallis citrina Baroni (H. citrina) cultivation could improve plant growth and photosynthetic capacity and, consequently, increase yield and quality. A continuous two-year field experiment was conducted at a research farm in Zhangzhou City, China, during 2021–2022. Six fertilization levels with two locally grown H. citrina cultivars, "Taidong 6" and "Shibage", were tested. The results showed that 100% of the recommended dose of chemical fertilizer (RDF) with bio-organic fertilizer yielded superior effects in promoting both vegetative and reproductive growth in comparison to RDF alone. However, reducing the application rate of chemical fertilizers, especially by more than 40%, resulted in a significant decline in certain agronomic traits such as plant width, leaf width, and scape length. Compared to RDF, the use of 100% or 80% RDF in combination with bio-organic fertilizer significantly increased chlorophyll content, net photosynthetic rate, and transpiration rate as well as yield production, while excessive reductions in chemical fertilizer rate produced results that demonstrated an opposite trend. The co-application of chemical and bio-organic fertilizer enhanced the contents of soluble sugar and lowered total acidity, whereas excessive chemical fertilizer reduction decreased vitamin C, total flavonoids, and soluble protein levels. Utilizing radar chart analysis for a comprehensive assessment of yield and quality demonstrates that the application of bio-organic fertilizer with 80% RDF could be a better field fertilization regime for H. citrina cultivation. [ABSTRACT FROM AUTHOR]

Northeast China is an important commercial grain base for China, but also the largest japonica rice production area. However, N, and K fertilizer application and unreasonable application times are prominent contradictions that restrict the development of japonica rice. This study aimed to investigate how to rationally apply N and K fertilizers to affect grain filling and ultimately increase the quality of the rice. In this field study, two N application levels and three K application ratios were set in 2020 and 2021 using Shennong 265 (SN265) and Meifengdao 61 (MF61). We found that the final seed growth and filling rate of SN265 were higher than those of MF61, and their filling characteristics were slow in the early stage and fast in the later stage, with large fluctuations. Appropriate reductions and increases of N and K fertilizer applications, respectively, in the early stage could improve grain filling. Compared with SN265, MF61 had a 3.2% increase in head rice rate, lower amylose and protein content, a decrease of chalkiness degree and chalkiness percentage by 23.96 and 34.00%, respectively, and more reasonable protein components. With the N application increase, the processing quality improved, the amylose and protein content and chalkiness increased, the protein components increased except for the milled rice glutelin, and the rice taste value decreased. At low N levels, increasing the proportion of K application was consistent with the effect of increasing N. The taste value of SN265 decreased linearly with the increase in the ratio of N application to pre-application of K, the highest taste value was obtained when the N fertilizer was applied at a rate of 180 kg ha−1, and the ratio of before and after K fertilizer application was about 1:2. The taste value of MF61 decreased linearly with the N application increase and showed a trend of increasing and then decreasing with the K application increase in the early stage. The taste peak gradually shifted back with the N application increase, and the highest taste value was obtained when N fertilizer was applied at 180 kg ha−1; the ratio of before and after K fertilizer application was about 3:2. By constructing the grain-filling quality evaluation system, the characteristic parameters of superior and inferior grains at the early and late stages of grain filling, respectively, greatly affected the rice taste value. Additionally, the percentage of the rice grain weight at the maximum grain-filling rate to the final rice grain weight (I) of superior grains, glutelin content, and value of the RVA profile characteristics were all critical reference indicators for rice taste quality. [ABSTRACT FROM AUTHOR]

In order to analyze the pollution characteristics and human health risks of heavy metals in water around Poyang Lake, 18 surface water samples were collected around Poyang Lake. The sources and distribution of heavy metals in water were analyzed, and the health risks of heavy metals in water were evaluated according to the risk assessment model of the United States Environmental Protection Agency (USEPA). The main cations of the water in the study area are Ca2+, and the anions are HCO3, SOf-- and Cl-. The hydrochemical genesis is mainly rock weathering and mineral hydrolysis, which is partly controlled by atmospheric precipitation. The average concentration of heavy metal elements in surface water is Fe>Ea>Mn〉Mo>Zn>Cu>Ni>Pb. Fe, Mo, Ni and Mn have different degrees of exceeding the standard, which mainly comes from fertilizer application, factory emissions and other activities. The HQder and HI>1 of Mo for children and adults, and the HQder and HI〉1 of Ba for children, it will causes great harm to human health. The study provides a scientific basis for the protection of water resources around Poyang Lake. [ABSTRACT FROM AUTHOR]

Accurate modeling of site-specific crop yield response is key to providing farmers with accurate site-specific economically optimal input rates (EOIRs) recommendations. Many studies have demonstrated that machine learning models can accurately predict yield. These models have also been used to analyze the effect of fertilizer application rates on yield and derive EOIRs. But models with accurate yield prediction can still provide highly inaccurate input application recommendations. This study quantified the uncertainty generated when using machine learning methods to model the effect of fertilizer application on site-specific crop yield response. The study uses real on-farm precision experimental data to evaluate the influence of the choice of machine learning algorithms and covariate selection on yield and EOIR prediction. The crop is winter wheat, and the inputs considered are a slow-release basal fertilizer NPK 25–6–4 and a top-dressed fertilizer NPK 17–0–17. Random forest, XGBoost, support vector regression, and artificial neural network algorithms were trained with 255 sets of covariates derived from combining eight different soil properties. Results indicate that both the predicted EOIRs and associated gained profits are highly sensitive to the choice of machine learning algorithm and covariate selection. The coefficients of variation of EOIRs derived from all possible combinations of covariate selection ranged from 13.3 to 31.5% for basal fertilization and from 14.2 to 30.5% for top-dressing. These findings indicate that while machine learning can be useful for predicting site-specific crop yield levels, it must be used with caution in making fertilizer application rate recommendations. [ABSTRACT FROM AUTHOR]

Earthworms benefit plant growth and play a vital role in shaping soil microbial communities. However, how earthworms modify the soil microorganisms and thus affect plant growth is still unclear. Although fertilizers alter the assembly of microbial communities, further investigations are required to test the effect of fertilizer type on the relationship between earthworms, soil microbial communities and plants.We evaluated the role of earthworms in soil microorganisms and maize plant growth characteristics under organic or chemical fertilizers in field and greenhouse experiments. We explored the relationships between earthworms, soil microbial community and plant growth under different fertilizer types.We found that the presence of earthworms promoted plant growth, increased the amount of plant root exudates, and enhanced the connections between rhizosphere bacterial, fungal and protist communities. Both earthworms and fertilizer application significantly changed the structure of soil bacterial, fungal and protist communities. The complexity of the soil microbial community network increased under organic, compared to chemical fertilizer application. The greenhouse experiment showed that the effect of earthworms on plant growth was weakened when maize plants were grown in sterilized soil under organic or chemical fertilizers.Synthesis and applications: Our study provides solid evidence that earthworms largely depend on soil microorganisms for their effects on plants under the application of different fertilizer conditions. This may provide new insights into reducing the amounts of fertilizer used by enhancing the role of earthworms and soil microorganisms. [ABSTRACT FROM AUTHOR]

Nutrient management in coffee-based agroforestry systems plays a critical role in soil nitrogen (N) cycling, but has not been well documented. The objective of this study was to evaluate the effect of coffee canopy management and fertilization on soil N dynamics. This study used a randomized complete block design (2 × 3 × 2) with four replications. There were three factors: 1) coffee canopy management (T1: Pruned, T2: Unpruned), 2) fertilizer type (O: Organic, I: Inorganic; M: 50% Organic + 50% Inorganic), and 3) fertilizer dose (D1: low, D2: medium, D3: high). Soil N dynamic indicators (i.e., total N, ammonium (NH4+), nitrate (NO3−), net N-NH4+, net N-NO3−, soil microbial biomass N) were measured at two soil sampling depths (0–20 cm and 20–40 cm). Results showed that pruning increased soil total N and microbial biomass N (MBN) by 10–56% relative to unpruned coffee trees. In contrast, the unpruned coffee canopy had 15–345% higher NH4+, NO3−, net N-NH4+, net N-NO3−, and microbial biomass N concentration than pruned coffee. Mixed fertilizer application increased NO3− and net N-NH4+ accumulation by 5–15% relative to inorganic and organic fertilizers. In addition, medium to high dose fertilization led to a 19–86% higher net N-NO3− concentration and microbial biomass N as compared to low dose fertilization. The treatment of no pruning and mixed fertilizer at low to medium doses was the optimal management strategy to maintain soil available N, while pruning combined with organic fertilizer has the potential to improve soil total N and MBN. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Agro-Environment Science is the property of Journal of Agro-Environment Science Editorial Board and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Agro-Environment Science is the property of Journal of Agro-Environment Science Editorial Board and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

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The Upper Mississippi Basin, which includes Illinois, has highly fertile soils and experiences intensive agricultural practices. Although fertile, the soils do not drain well, resulting in the installation of tile-drainage systems. The practices of tile systems coupled with the application of nitrogen-rich fertilizers have led to the excessive export of nitrate from the agricultural fields into surface waters, contributing to eutrophication and the development of hypoxic zones in aquatic environments. Saturated riparian buffer zones (SRBs) have been proposed as a means to reduce the amount of nitrate discharged from tile-drained waters into streams. Previous works show a reduction in the nitrate as waters travel through an SRB, but in situ measurements of travel times are limited. Using the results from a 52-day tracer test, we developed a mathematical model combining endmember mixing of a tracer, chloride, and concentrations of nitrate as nitrogen (NO3-N) to determine the travel time of the tile waters in an SRB and to quantify the amount of NO3-N reduction occurring within an SRB. For the first 30 days, dissolved oxygen (DO) concentrations indicated aerobic conditions within the waters of most of the SRB, which saw a concomitant increase in NO3-N concentrations along groundwater pathways. As DO concentrations decreased below 4.5 mg/L, NO3-N concentrations began to lower along the flow pathways, resulting in NO3-N reductions ranging from 23 to 97 percent. [ABSTRACT FROM AUTHOR]

Purpose: Nitrogen (N) fertilizer is a critical factor in achieving high rice yields, but it can also contribute to increased CH4 emissions from rice paddies. Determining how to utilize N fertilizer to effectively balance the contradiction between methane (CH4) emissions and rice yield remains an urgent need in the face of unstoppable climate change. Materials and methods: In this study, the response of CH4 fluxes in rice paddies to elevated carbon dioxide (CO2) concentration (e[CO2]) and reduced N application were investigated. The rice biomass and yield, CH4 fluxes, soil properties, and methanogenic characteristics were observed in control (CK) (ambient CO2 concentration + application of 250 kg N ha−1 urea), C+ (e[CO2] by 200 ppm + 250 kg N ha−1 urea), N− (ambient CO2 concentration + 150 kg N ha−1 urea), and C+N− (e[CO2] by 200 ppm + 150 kg N ha−1 urea) treatments. Results and discussion: The results revealed that the C+ and C+N− treatments significantly increased the CH4 emissions/yield by 20.0% and 18.8%, respectively, while the N− treatment significantly suppressed the CH4 emissions/yield by 13.3% compared to CK. The N− treatment weakened the promotion effect of C+ on the rice total biomass, the soil dissolved organic carbon (DOC) concentration and invertase activity, and the CH4 emissions/yield. Moreover, the C+N− treatment significantly reduced the soil DOC concentration and the abundance of the mcrA gene in the grain-filling stage compared to C+. Conclusions: Overall, under climate change conditions, N reduction can mitigate CH4 fluxes from rice paddies by affecting rice growth, soil methanogenic characteristics, and the C substrate. [ABSTRACT FROM AUTHOR]

Little is known about the effect of the long-term application of organic and inorganic fertilizers on P-use efficiency, P budget, and the residual effect of P fertilizer. To clarify the effect of different fertilization on soil P balance in a rice (Oryza sativa L.)–wheat (Triticum aestivum L.) rotation system is helpful to promote the sustainable development of agriculture. Thus, a thirty-five-year fertilizer experiment was conducted with eight treatments, including an unfertilized control (CK); chemical nitrogen (N), phosphorus (P), and potassium (K) fertilizers; and organic manure (M) either alone or in combination treatments (N, NP, NPK, M, MN, MNP, and MNPK). The results indicated that crop yields and P uptake were higher in the combined application of manure and chemical fertilizer treatments than in the manure or chemical fertilizer alone treatments. Soil P budget indicated a 23.4–55.4 kg P ha−1 yr−1 surplus in the organic combined with or without mineral fertilizer treatments, but the soil P budget indicated a 20.0 and 21.9 kg P ha−1 yr−1 deficit in the control and N treatments. The proportion of residual fertilizer P converted to soil available P in NP, NPK, M, MN, MNP, and MNPK treatments was 4.5%, 4.8%, 19.1%, 19.0%, 11.5%, and 13.3%, respectively, over a 35-year period. Furthermore, according to the higher P content and crop uptake in organic manure treatment compared with chemical P fertilizer alone, an organic addition could effectively reduce the use of chemical fertilizer and become an effective way of sustainable development in practice. Therefore, the combined application of organic and inorganic fertilizer will be a practical method to increase crop yields and soil P status in a rice–wheat planting system. [ABSTRACT FROM AUTHOR]

In contemporary agriculture, enhancing the efficient production of crops and optimizing resource utilization have become paramount objectives. Garlic growth and quality are influenced by various factors, with fertilizers playing a pivotal role in shaping both aspects. This study aimed to develop classification models for distinguishing garlic fertilizer application differences by employing statistical and machine learning techniques, such as partial least squares (PLS), based on data acquired from a ground-based hyperspectral imaging system in the agricultural sector. The garlic variety chosen for this study was Hongsan, and the fertilizer application plots were segmented into three distinct sections. Data were acquired within the VIS/NIR wavelength range using hyperspectral imaging. Following data acquisition, the standard normal variate (SNV) pre-processing technique was applied to enhance the dataset. To identify the optimal wavelengths, various techniques such as sequential forward selection (SFS), successive projections algorithm (SPA), variable importance in projection (VIP), and interval partial least squares (iPLS) were employed, resulting in the selection of 12 optimal wavelengths. For the fertilizer application difference model, six integrated vegetation indices were chosen for comparison with existing growth indicators. Using the same methodology, the model construction showed accuracies of 90.7% for PLS. Thus, the proposed model suggests that efficient regulation of garlic fertilizer application can be achieved by utilizing statistical and machine learning techniques. [ABSTRACT FROM AUTHOR]

The effects of localized fertilizer (LF) application on changes in root system architecture (RSA) of upland rice seedlings under upland condition were evaluated, and root traits important for deep root development were identified using three root box experiments (Exps). Fertilizer was homogeneously mixed and broadcasted on the soil surface in two control treatments, while in three LF treatments, it was point-placed at 2.5, 7.5 and 12.5 cm below the soil surface. Nitrogen (N) fertilizer in Exp. 1, phosphorus (P) fertilizer in Exp. 2 and compound fertilizer with nitrogen, phosphorus and potassium (NPK) in Exp. 3 were used to compare the effects of LF. Localized N and NPK application altered the RSA through root proliferation and increasing root length percentage around the fertilizer-applied area, whereas localized P application had no effect on both root and shoot development. Deep root and shoot development were decreased with localized NPK application compared to homogeneously mixed control treatment but were maintained with localized N application, when applied at deeper soil depths. Furthermore, the increase in deep root length (DRL) was closely related to the increase in both total root length (TRL) and deep root length ratio (DRR). DRR increased with TRL in Exps. 2 and 3, while it was independent from TRL in Exp. 1, suggesting that DRL can be promoted by increasing DRR regardless of TRL. These results showed that localized N application at deeper soil depths could modify RSA of upland rice seedlings grown under upland condition without affecting shoot growth. [ABSTRACT FROM AUTHOR]

Charcoal-based fertilizer could be used extensively and is environmentally friendly. An experiment was designed to investigate the effects of different charcoal-based fertilizer application methods on soil microbiology and grape quality in a vineyard to guide the cultivation of 'Shine-Muscat'. A control treatment without fertilization and six other treatments were set up. Four treatments applied carbon-based fertilizer as a base fertilizer with or without potassium fulvic acid, a complex microbial agent, or Bacillus subtilis, and two treatments were only applied with two applications of carbon-based fertilizer or compound fertilizer during the expansion period. The results showed that the bacterial phyla were mainly Proteobacteria and Bacteroidetes. Ascomycota, Basidiomycota, and Mortierellomycota dominated the fungal community. At the genus level, the composition of fungi, compared to bacteria, varied significantly, while the dominant flora differed among fertilization practices. Application of charcoal-based fertilizer enriched beneficial microorganisms, while chemical fertilizers enriched pathogenic microorganisms. The addition of microbial fungicides and biostimulants for a period reduced the size of the microbial network, lowered positive correlations, and enhanced resistance to adverse conditions and diseases and there was no significant correlation between agronomic traits and microbial network topology. A combination of soil microbial and grape agronomic traits suggests that a charcoal-based fertilizer base, with microbial fungicides applied, is the optimal fertilization regimen for grape. [ABSTRACT FROM AUTHOR]

To assess the effect of pure castor meal and a mixture of castor meal with ground hydrothermalized phonolite rock (CM+HP mixture) in providing nutrients, particularly N and K, and optimizing yield and quality of sweet potato, a field experiment was conducted using a randomized block design. Treatments were the absence and presence of synthetic N and K fertilizers (ammonium nitrate and KCl) combined with rates of organic fertilizers (1.2 and 2.4 Mg ha−1 of castor meal, 2.25 and 4.5 Mg ha−1 of CM+HP mixture, plus a treatment without organic fertilizers). The CM+HP mixture maintained adequate N and K status in plant leaves. Organic fertilizers increased the number of storage roots per plant and the sweetness of the storage roots, while synthetic fertilizers increased the storage root mean weight. Castor meal combined with synthetic fertilizers improved soil health (increased organic matter and enzyme activity in the soil). The combined application of synthetic fertilizers with 2.4 Mg ha−1 of castor meal or 4.5 Mg ha−1 of CM+HP mixture had the greatest benefit on storage root yield, with an average increase of 128% (10.9 Mg ha−1) on marketable storage root yield, and the nutrient removal compared with the sole application of organic fertilizers. [ABSTRACT FROM AUTHOR]

Nitrogen application significantly affects microorganisms in agricultural ecosystems. However, it is still unclear how nitrogen application affects soil chemical properties and microbial communities in purple mudstone weathering products. In this study, a field soil column experiment was conducted in a typical purple soil area with four nitrogen fertilizer application gradients of 0 [CK], 280 [N1], 560 [N2], and 840 [N3] N kg ha−1. Nitrogen addition decreased the bacterial chao1 value and increased the bacterial evenness index. For both α- and β-diversity, the effect of nitrogen addition on bacteria was much greater than that on fungi. Nitrogen addition significantly increased the relative abundance of Proteobacteria, Gemmatimonadetes, Bacteroidetes, and Ascomycota and decreased the relative abundance of Actinobacteria, Cyanobacteria, and Basidiomycota. Both pH and TC are the most important soil chemical properties influencing the bacterial and fungal communities. With the increases in the nitrogen application rate, the co-occurrence network complexity increased and then decreased. In summary, nitrogen fertilizer application could significantly change the soil chemical properties, microbial community diversity, composition, and co-occurrence network of purple mudstone weathering products. Among them, the N2 treatment (560 N kg∙ha−1) can more effectively stimulate the soil nutrients, enhance microbial network complexity, and promote further weathering of purple mudstone. [ABSTRACT FROM AUTHOR]

Nitrogen (N) is one of the most crucial elements for crop yields. N management is incredibly important because it’s a major component of crop productivity. It is challenging to control due to the large field variability of the innate soil N and the differences in crop demand at various crop growth stages. Additionally, N’s partial factor production is deteriorating day by day. Furthermore, crop, cultivar, and environmental factors affect how much N is needed. Therefore, crop production depends heavily on applying N at the right rate for the crop’s needs. Precision N management increases N use efficiency while reducing N loss from runoff, ammonia volatilization, and leaching. By providing N during crucial growth phases, real-time N management increases use efficiency by applying N based on need at the appropriate time and amount. One aspect of real-time N management is the application of the leaf color chart (LCC). The LCC is a relatively basic, low-cost, portable, and user-friendly gadget that contrasts the color of the leaf with the device’s color hues. Because farmers typically prefer dark-colored leaves, they apply N regardless of need, which poses serious risks to the ecosystem and contaminates the surface and groundwater. The sustainability of output is threatened by the declining soil health caused by increased fertilizer application. Therefore, for small and marginal farmers, employing a leaf color chart for site-specific N management is a more practical solution. [ABSTRACT FROM AUTHOR]