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Increasing soil organic carbon (SOC) in agricultural soils can mitigate atmospheric CO2 concentration and also contribute to increase soil fertility and ecosystem resilience. The role of major nutrients on SOC dynamics is complex, due to simultaneous effects on net primary productivity (NPP) that influence crop residue carbon inputs and on the rate of heterotrophic respiration (carbon outputs). This study investigated the effect on SOC stocks of three different levels of phosphorus and potassium (PK) fertilisation rates in the absence of nitrogen fertilisation and of three different levels of nitrogen in the absence of PK. This was done by analysing data from 10 meta-replicated Swedish long-term field experiments (> 45 years).With N fertilisation, SOC stocks followed yield increases. However, for all PK levels, we found average SOC losses ranging from -0.04±0.09Mgha-1 yr-1 (ns) for the lowest to -0.09±0.07Mgha-1 yr-1 (p = 0.008) for the highest application rate, while crop yields as a proxy for carbon input increased significantly with PK fertilization by 1, 10 and 15%. We conclude that SOC dynamics are mainly output-driven in the PK fertilised regime but mostly input-driven in the N fertilised regime, due to the much more pronounced response of NPP to N than to PK fertilisation. It has been established that P rather than K is the element affecting ecosystem carbon fluxes, where P fertilisation has been shown to: (i) stimulate heterotrophic respiration, (ii) reduce the abundance of arbuscular mycorrhizal fungi and (iii) decrease crop root : shoot ratio, leading to lower root-derived carbon input. The higher export of N in the PK fertilised plots in this study could (iv) have led to increased N mining and thus mineralisation of organic matter. More integrated experiments are needed to gain a better understanding of the relative importance of each of the abovementioned mechanisms leading to SOC losses after P addition. [ABSTRACT FROM AUTHOR]

More than 70% of the potash fertilizer globally is produced by the froth flotation process, in which 4-dodecylmorpholine (DMP) serves as a reverse flotation agent. As the potash fertilizer production rapidly rises, the increased DMP levels in discharged brine pose a threat to the production of high-value chemicals. In this paper, composite particles of basic magnesium sulfate@TiO2 (BMS@TiO2) were prepared using a simple and mild loading method. These particles were utilized for the adsorption and photocatalytic degradation of DMP in brine. Compared with normal powdered materials, the granular BMS@TiO2 in this study can be easily separated from liquid, and the degradation intermediates will not enter the brine without causing secondary pollution. BMS@TiO2 consists of 5·1·7 phase (5Mg(OH)2·MgSO4·7H2O) whisker clusters embedding 2.3% TiO2. The adsorption equilibrium of DMP on BMS@TiO2 particles was achieved through hydrogen bonding and pore interception with the adsorption capacity of approximately 5 mg g−1 after 6 h. The photodegradation efficiency of DMP adsorbed on BMS@TiO2 reached about 92% within 16 h, which is compared with that of pure TiO2 nanoparticles. Additionally, excellent stability and recyclability of BMS@TiO2 were also observed in five cycle tests of adsorption and photocatalytic degradation of DMP, and the possible photocatalytic degradation pathways and mechanism of DMP are proposed following molecular electrostatic potential analysis. This work provides a sustainable and environmentally friendly approach for eliminating organic micropollutants from water environments. [ABSTRACT FROM AUTHOR]

More food is needed to meet the demand of the global population, which is growing continuously. Chemical fertilizers have been used for a long time to increase crop yields, and may have negative effect on human health and the agricultural environment. In order to make ongoing agricultural development more sustainable, the use of chemical fertilizers will likely have to be reduced. Microbial fertilizer is a kind of nutrient-rich and environmentally friendly biological fertilizer made from plant growth-promoting bacteria (PGPR). Microbial fertilizers can regulate soil nutrient dynamics and promote soil nutrient cycling by improving soil microbial community changes. This process helps restore the soil ecosystem, which in turn promotes nutrient uptake, regulates crop growth, and enhances crop resistance to biotic and abiotic stresses. This paper reviews the classification of microbial fertilizers and their function in regulating crop growth, nitrogen fixation, phosphorus, potassium solubilization, and the production of phytohormones. We also summarize the role of PGPR in helping crops against biotic and abiotic stresses. Finally, we discuss the function and the mechanism of applying microbial fertilizers in soil remediation. This review helps us understand the research progress of microbial fertilizer and provides new perspectives regarding the future development of microbial agent in sustainable agriculture. [ABSTRACT FROM AUTHOR]

In the context of the Chinese government's policy guidance, there is black soil protection and ecological environment protection. The purpose of this paper is to solve the problem that the soil ecology of the black soil in Northeast China is changing year by year, and it is necessary to explore the sowing and fertilization strategy under the new situation; most Chinese growers rely excessively on their personal experience in the process of soybean sowing and fertilization. In this study, we used "Heihe 43" soybeans and used regression experimental design methods to analyze the effects of planting density, nitrogen, phosphorus, and potassium fertilizer application on soybean yield and to determine the optimal planting density and fertilizer ratios. The study reveals that the optimal soybean planting density in Northeast China is 45.37 × 104 plants/ha, with nitrogen at 98.4 kg/ha, phosphorus at 218.96 kg/ha, and potash at 47.62 kg/ha. Under these conditions, soybean yields can reach 3816.67 kg/ha. This study can provide a theoretical method for decision-making to obtain the optimal planting density and fertilizer ratio for different regions of the farming system. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Irrigation & Drainage is the property of Journal of Irrigation & Drainage Editorial Office 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.)

The current paper presents the monitoring of soil and nutrient losses through runoff as the result of the climate change. The experimental results were recorded on the standard plots for runoff and erosion control. The results of the studies carried out highlight that total nitrogen losses range from 0.05 kg/ha to 12.60 kg/ha, potassium displaced from the plots has values between 0.02 and 1.35 kg/ha, the humus associated with the eroded soil includes values between 0.51 and 176.5 kg/ha, phosphorus is recorded with maximum values of 0.39 kg/ha, the total iron losses have values between 3.14 and 431.16 g/ha, manganese has losses from 1.69 to 290.82 g/ha, copper losses range from 0.15 to 7.62 g/ha, and, regarding zinc, the values are within the limits of 0.25–57.22 g/ha. The maximum values of the displacement of fertilizing elements from the sloping agricultural lands, by means of liquid and solid leaks, are registered at the plots left as permanent black fields, the plots practically unprotected against the rain erosion. The experiments were performed at the Soil Erosion Research and Development Station "Mircea Moțoc", Perieni/Staţiunea de Cercetare Dezvoltare pentru Combaterea Eroziunii Solului "Mircea Moţoc", Perieni (SCDCES—MM, Perieni), Vaslui County, an institution strategically located in an area subject to erosion soil. Additionally, the paper envisages how the National Rural Development Programme (NRDP) and the Common Agricultural Policy (CAP) can be of use in this area by analysing past lessons and providing an overview of what was done. [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of Oil Crop Sciences is the property of Oil Crops Research Institute of Chinese Academy of Agricultural Sciences 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 Irrigation & Drainage is the property of Journal of Irrigation & Drainage Editorial Office 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.)

Globally, there is growing interest to recycle organic waste using insect larvae into high-quality frass fertilizer through circular economy approach. This paper presents the first comparative report on the nutrient concentrations, fertilizing indices, nutrient supply potentials and compost maturity of nine edible insect frass fertilizers. Our results revealed that frass fertilizers from all the insect species had adequate concentrations and contents of macronutrients [nitrogen (N), phosphorus (P), potassium (K)], secondary nutrients (calcium, magnesium, and sulphur) and micro-nutrients (manganese, copper, iron, zinc, boron, and sodium). The fertilizing indices of the frass fertilizers were above 3. However, black soldier fly (BSF) frass fertilizer had significantly higher N (20–130%) and K (17–193%) concentrations compared to others. The P concentration of Gryllus bimaculatus frass fertilizer was 3–800% higher compared to those of frass fertilizers from other insect species. The potential N and K supply capacities of BSF frass fertilizer was 19–78% and 16–190% higher, respectively. The P supply capacity of cricket frass fertilizer was 17–802% higher compared to others. The highest seed gemination rate (> 90%) and germination index (267%) were observed in seeds treated with BSF frass fertilizer. Frass fertilizer obtained from the other eight insect species showed medium to high phytotoxicity. These findings demonstrate that insect frass fertilizers are promising alternatives to existing commercial fertilizers (i.e., mineral, and organic) for improved soil health and crop yield. [ABSTRACT FROM AUTHOR]

The role of nitrite (NO2−) and nitrate (NO3−) is essential in the global nitrogen cycle. Monitoring their concentration in environmental and industrial aqueous samples, surface water, soil, food and agricultural products are of high importance. Especially, the effect of anthropogenic emission, i.e., intensified agriculture is essential due to the overuse of nitrogen, phosphorus and potassium fertilizers. The most widely utilized methods for nitrate and nitrite determination are colorimetry, potentiometry, UV absorption and liquid chromatography. Among them, UV spectroscopy is the most frequently used technique due to the fact of its versatility and simplicity. However, there are industrial and academic needs to develop new methods to overcome some drawbacks of the currently used techniques such as an inadequate limit of detection and potential interferences with organic compounds in the sample. In this paper, we report on the development of a new analytical method based on capillary electrophoresis separation with high-sensitivity UV detection, capable of measuring trace concentrations of nitrite and nitrate well below the current limits of UV spectroscopy methods. During the development process special attention was paid to practical aspects, i.e., the method was tested to quantify nitrate and nitrite in various surface water samples. [ABSTRACT FROM AUTHOR]

This work presents a preliminary design of a two-stage vacuum evaporation process converting a diluted liquid digestate into concentrated liquid fertilizers. Digestate is produced in a 1 MW biogas plant during the anaerobic digestion of poultry manure and corn silage. Laboratory experiments showed that in the first evaporation stage, about three-quarters of input digestate can be stripped to a diluted ammonia solution, while the concentrate can be used as phosphorus-potassium PK-fertilizer. After neutralization with H2SO4, the ammonium sulphate solution is concentrated in the second evaporation stage. Feasible operating temperatures that allow heat integration between the two stages were determined in a laboratory environment at 40 °C for the first stage and 60 °C for the second. A preliminary process flow sheet was simulated in Aspen Plus to obtain data for heat integration and optimization of industrial-scale processes. The process was completely integrated by using the waste hot utility available at the site, while the external utilities demand was virtually zero. Optimizing the flow rate of the added sulphuric acid improved overall economic performance. The optimization and heat integration of the two-stage vacuum evaporation process within a biogas plant resulted in a circular and economically viable waste management technology. [ABSTRACT FROM AUTHOR]

Ageratina adenophora originating from central America has flooded forests, pastures, and farmland in more than 40 tropical and subtropical countries, causing huge ecological disasters and economic losses. In this paper, we intended to use a complex inoculum composed of Pseudomonas putita and Clostridium thermocellum to in-situ compost A. adenophora debris and then to compare the phytotoxicity of extracts from uncomposted and composted A. adenophora (UCA and CA respectively) to barley seed germination and young seedling growth. A field experiment was finally conducted to reveal the effects of UCA and CA on barley nutrients uptake, yield, grain quality, soil enzyme activities, microbial biomass and biodiversity. In-situ composting sharply decreased 4,7-dimethyl-1-(propan-2-ylidene)-1,4,4a,8a-tetrahydronaphthalene- 2,6(1H,7H)-dione(DTD) and 6-hydroxy-5-isopropyl-3,8-dimethyl-4a,5,6,7,8,8a-hexahydronaphthal en-2(1 H)-one(HHO) from 2096.3 and 743.7 mg kg-1 in uncomposted A. adenophora to 194.4 and 68.19 mg kg-1 in composted A. adenophora. UCAE showed negative influences on seed germination performances (except lower rates on germination percentage). The mechanism may be the inhibition of bio-macromolecules hydrolysis (including proteins, starch, and phytin) in endosperms and their hydrolysates for forming new plants. CAE promoted seed germination and seedling growth, increased chlorophyll levels in leaves, and stimulated dehydrogenase and nitrate reductase activities in plants, while UCAE got opposite performance. Compared with chemical fertilizers, application of CA in combination with chemical fertilizers significantly improved plant nutrient uptake (nitrogen, phosphorus, and potassium), yield, grain quality, quantity of 16S rDNA sequences, richness and diversity of bacterial communities in contrast to UCA which behaved otherwise. Taken together, the use of the microbial agent to in-situ compost A. adenophora may be an effective approach for agricultural use of A. adenophora debris as a plant-friendly organic fertilizer, being undoubtedly worth advocating. [ABSTRACT FROM AUTHOR]

Protecting endangered plant species is crucial to maintaining biodiversity. Currently, there is a rapid decline in the populations of many moisture-loving plant species throughout Poland. These include the entire genus Drosera, so this paper attempts to determine the main reasons for the decline of Drosera intermedia and Drosera anglica in the Łęczna-Włodawa Lake District. For this purpose, the habitat conditions, climatic factors of the sites, as well as the vegetation of their current and historically abundant occurrence were compared, and it was shown that an important reason for the receding of sundews may be changes associated with rising temperatures in the study area. In the case of Drosera anglica, a clear preference was observed for colonising sites associated with the shoreline of lakes, more hydrated and almost devoid of companion plants. For Droseraintermedia, on the other hand, it was revealed that it acclimatises to mid-forest peatlands, rich in magnesium, nitrogen, phosphorus, and manganese, with moderate carbon content, medium levels of groundwater and air temperature, and low concentrations of organic matter. In addition, it was noted that sundew sites are characterised by lower diversity indices but a greater number of rare and protected species and significantly lower concentrations of iron and potassium. [ABSTRACT FROM AUTHOR]

Potassium is among the three essential macronutrients for tea plants, along with nitrogen and phosphorous, and plays important roles in growth and stress response. Potassium is absorbed by plants in larger amounts than any other mineral element except nitrogen and, in some cases, calcium. At present, more than 59% of China's tea gardens are in a state of potassium deficiency, which negatively affects tea quality and yield. This paper reviews the effects of potassium deficiency on tea plant growth and stress response, details factors affecting potassium supply and demand in tea gardens, examines the interactions between potassium and other elements in soils, and provides strategies for optimizing potassium levels in soils. Potassium is positively correlated with the elements nitrogen, copper, and zinc. Sufficient potassium dramatically improves the yield and quality of tea: it accelerates metabolism, promotes synthesis of catechins, and strengthens biotic and abiotic resistance by activating and regulating different enzymes. Moderate application of potassium fertilizers, along with potassium-solubilizing bacteria, can regulate the ratio of different forms of potassium and increase available potassium in soils of tea gardens. We suggest that research on potassium occurring in soils and its interaction with other elements be strengthened, so as to improve the efficient use of potassium fertilizers in tea gardens and maintain the balance of elements in soils. [ABSTRACT FROM AUTHOR]

As one of the staple foods recognized by everyone, the quality of the potato determines the popularity of the potato. In order to grow healthy potatoes and improve the quality of potatoes, this research is based on multimodal sensor data fusion technology to achieve data detection and unified management. And it can analyze the data to find out the relationship between the application of nitrogen and potassium fertilizers and potato growth and quality, so as to have a reasonable plan for potato cultivation. This paper firstly described the research results of multimodal sensors, data fusion, nitrogen and potassium fertilizers, and potato quality, and then briefly introduced the multi-sensor data fusion technology, mainly including application areas, methods, and structures. Finally, the effects of nitrogen and potassium fertilizers on the growth and quality of potato were explained through the analysis of experimental data. And the experimental results showed that under different potassium treatments, Dongnong 311 had the highest starch content under K3 treatment, which was 13.9%. This study provides a certain reference for the application of nitrogen and potassium fertilizers in potato cultivation. [ABSTRACT FROM AUTHOR]

Lately, researches in fertilizer fields focuses on reducing the negative impact of using them on the environment and consumers, and finding new, less costly fertilizer sources. The paper presents the results of the research regarding the realization of a technology for obtaining of peat based granular organo--mineral fertilizers. In order to improve the fertilizer role of the peat, the production formula used contains urea as a source of nitrogen, monoammonium phosphate (MAP) as a source of phosphorus and nitrogen, molasses from sugar beet as a source of organic nitrogen, potassium and vitamins, protein hydrolyzate, as a source of proteins, polypeptides and amino acids and other microelements [ABSTRACT FROM AUTHOR]

This paper presents the experimental results obtained from a long-term experience after 29 years of fertilization with nitrogen and phosphorus. The applied nitrogen derived from ammonium nitrate and phosphorus from concentrated superphosphate (in dosages of 0, 40, 80, 120, 160 kg/ha). The application of phosphorus fertilizers led to very significant increases of mobile phosphorus content for all application dosages. Mobile phosphorus values increased from 60 mg/kg for P0 to 204 mg/kg for P160 kg/ha. Total phosphorus presented very significant increases for the application dosages of 80, 120 and 160 kg/ha (from 0.094% P for the unfertilized control to 0.146% P for the 160 kg P/ha dosage). Mobile potassium level decrease in soil as a result of nitrogen and phosphorus fertilization. The ammonium nitrate determined a decrease of the soil reaction and varied depending on the applied dosage, from 5.75 for the unfertilized control to 5.37 pH units. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Soil Sciences & Agricultural Engineering is the property of Egyptian National Agricultural Library (ENAL) 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.)

The paper analyzes the positive and negative aspects of various technological solutions for the liquid brines used during the development of polymineral potash ore deposits and considers the problem of determining the choice of the optimal approach by considering geological, technical, environmental, and financial factors. The study of the issues of utilization and reduction of the liquid brines components of discharges in the production of potash fertilizers, the simultaneous reduction of valuable components loss with liquid discharges, and, due to this, increasing the production of potash fertilizers, and the usage in the technology of mine brines, are an urgent and important scientific and engineering challenge of the potash industry. Technologically, several alternative solutions can reduce the number of liquid by-products placed in sludge storage. The work used analytical methods, including statistical data processing, modeling, pre-design studies of technological solutions, and assessment of economic costs. Excess brines of potash mining and processing plants are liquid waste obtained during the production of potash fertilizers – MOP и SOP. The accumulation of excess brines in sludge storage facilities is estimated at millions of cubic meters per year. However, the expansion of the sludge storage facilities area and the construction of dams are only temporary solutions. They are associated with risks in the design, construction, and operation of hydraulic structures, increasing the risks of brine leakage into open and underground water basins. Therefore, it makes it necessary to use other methods of brine disposal. Depending on the nature of the processed polymineral potash ores, several methods can be combined to dispose of excess brines at once: backfilling, osmosis, injection into deep horizons, and multistage evaporation. The most optimal combination of brine reduction technologies for potassium-magnesium processing plant's raw materials is the following: 60% is disposed of by usage of vacuum evaporation units, 20 % by injecting excessive brines into deep absorbing horizons, and 10%—20% should be used for backfilling or additional products production. [ABSTRACT FROM AUTHOR]

Research carried out at the Mountain Grassland Research Basis of Blana (Bucegi Mountains) aimed at improving the grassland of Nardus stricta locate 1,800 m above sea level. Research started in the year 2000 with the establishment of a trial made up of five variants: T - natural grassland (control); A - natural grassland fertilised with NPK; B - natural grassland fertilised with NPK + animal folding; C - natural grassland, amended + fertilised with NPK + animal folding. The paper presents the effect of long-term treatments (applied every single year starting with the year 1995) on dry matter production and on the floristic composition in the year 2011. [ABSTRACT FROM AUTHOR]

The results of the field study with traditional mineral fertilizers and unconventional one, based on the processing of K-Mg ores, on seed potato planting are presented in this paper. The efficiency and aftereffect of potassium fertilizers (KCl and the processing product from clay-salt sludge) on the NP background were studied. The technology for the production of new fertilizer from clay-salt waste (sludge) remaining as a result of potassium fertilizers production from natural K-Mg ores, was elaborated in Mining Institute, the division of Perm Federal Research Center. The resulting product, containing K, Ca, Mg and trace elements, which has the properties of fertilizer and ameliorant, has received the name the cinder of clay-salt sludge. The main processes in the technology are waste enrichment and subsequent high-temperature calcination of the enriched concentrate. As a result, the product, with the properties of multiple slow-release fertilizer was formed on a chloride-free basis. It is undesirable to use for potato fertilizers containing chlorine, so it is useful to expand the range of potassium fertilizers. The field trials with cinder were fulfilled on the experimental plots of Perm Agricultural Scientific Research Institute, the division of Perm Federal Research Center, in 2018-2020 years. The experimental scheme included treatments: control (without fertilizers), NP - background; NP + KCl and NP + cinder. Potassium fertilizers were used in autumn (basic application) and in spring (pre-planting application). No fertilizers were used in 2020. The influence of mineral fertilizers on yield and quality of seed potato, as well as soil fertility parameters were studied. The obtained results showed that the direct effect of unconventional fertilizer (cinder) with its pre-planting application was approximately equal to the effect of traditional potassium chloride fertilization, provided that the rates in the active substance were equal (yield in 2019 - 46.0 and 47.1 t-1 ha, respectively). The use of cinder did not have a significant effect on the quality indicators of potato tubers both directly in the year of fertilization and after the storage period. Cinder, in contrast to the standard KCl fertilizer, had a positive effect on the content of exchangeable potassium in the soil. Research with unconventional mineral fertilizers based on K-Mg ore processing wastes should be continued with an emphasis on the study of long-term action as a complex ameliorant. [ABSTRACT FROM AUTHOR]

Introduction: In semiarid tropical locations, polyhalite (K2Ca2Mg(SO4)4H2O) and muriate potash (KCl) were tested for their ability to increase cane growth, yield, and recovery at potash (K)- and calcium (Ca)-deficient sites. Methods: The treatments involved control plots with no potash fertilizer (T1); T2 and T3 applied potassium through (muriate potash) MOP only at 80 and 120 kg K2O ha-1, whereas T4 and T5 applied potassium with half of MOP and polyhalite at 80 and 120 kg K2O ha-1, respectively. Results and discussion: At 35 days after harvest (DAH), T2 (10.82%), T3 (24.1%), T4 (34.9%), and T5 (34.9%) had a greater ratoon resprouting rate than did the control treatment, where it was just 37.0 out of 100 harvested canes. At 308 DAH, T2 (-5.9%), T3 (-5.7%), and T5 (-6.6%) presented greater leaf chlorophyll contents than did T1. The K-fertilized plots yielded 64.31 t ha-1 in T2 and 65.97 t ha-1 in T5, whereas the control plot yielded 61.5 t ha-1. Compared with the control plots, the T5 plots experienced fewer stalk borer (-28.6%), top borer (-23.3%), and early shoot borer (-23.3%) attacks. T2, T4, and T5 presented higher percentages of commercial cane sugar (CCS) (6.82, 8.83, and 8.74%, respectively) than did the control plots. T1 and T3 had similar CCSs (10.99 and 11.33%, respectively). The CCS weight per area ranged from 7.98 to 8.47 t ha-1 near maturity. T4 (8.59 t ha-1) and T5 (8.60 t ha-1) had significantly greater values than did T1-T3. Compared with the control, the applied potassium fertilizer increased the economic output by 8,711, 11,687, 13,485, and 13,857 INR ha-1 in the T2, T3, T4, and T5 plots, respectively. The higher cost of polyhalite than MOP has reduced its economic advantages. Thus, the T4 plots outperformed the other treatments in terms of growth, yield, and quality indices, but their higher values (120 kg K2O ha-1) were statistically equivalent. Conclusion: Finally, the study concluded that MOP and polyhalite at a 50% ratio of 80 kg K2O ha-1 may help improve sugarcane growth, yield, and quality in semiarid tropical locations. [ABSTRACT FROM AUTHOR]

With the increasing focus on irrigation management, it is crucial to consider cost-effective alternatives for soil water monitoring, such as multi-point monitoring with low-cost soil moisture sensors. This study assesses the accuracy and functionality of low-cost sensors in a sandy loam (SL) soil amended with biochar at rates of 15.6 and 31.2 tons/ha by calibrating the sensors in the presence of two nitrogen (N) and potassium (K) commercial fertilizers at three salinity levels (non/slightly/moderately) and six soil water contents. Sensors were calibrated across nine SL-soil combinations with biochar and N and K fertilizers, counting for 21 treatments. The best fit for soil water content calibration was obtained using polynomial equations, demonstrating reliability with R 2 values greater than 0.98 for each case. After a second calibration, low-cost soil moisture sensors provide acceptable results concerning previous calibration, especially for non- and slightly saline treatments and at soil moisture levels lower than 0.17 cm3cm−3. The results showed that at low frequencies, biochar and salinity increase the capacitance detected by the sensors, with calibration curves deviating up to 30% from the control sandy loam soil. Due to changes in the physical and chemical properties of soil resulting from biochar amendments and the conductive properties influenced by fertilization practices, it is required to conduct specific and continuous calibrations of soil water content sensor, leading to better agricultural management decisions. [ABSTRACT FROM AUTHOR]

Background: Potassium (K) is an essential nutrient for plant growth and development. Maize (Zea mays) is a widely planted crops in the world and requires a huge amount of K fertilizer. Arbuscular mycorrhizal fungi (AMF) are closely related to the K uptake of maize. Genetic improvement of maize K utilization efficiency will require elucidating the molecular mechanisms of maize K uptake through the mycorrhizal pathway. Here, we employed transcriptome and gene family analysis to elucidate the mechanism influencing the K uptake and utilization efficiency of mycorrhizal maize. Methods and results: The transcriptomes of maize were studied with and without AMF inoculation and under different K conditions. AM symbiosis increased the K concentration and dry weight of maize plants. RNA sequencing revealed that genes associated with the activity of the apoplast and nutrient reservoir were significantly enriched in mycorrhizal roots under low-K conditions but not under high-K conditions. Weighted gene correlation network analysis revealed that three modules were strongly correlated with K content. Twenty-one hub genes enriched in pathways associated with glycerophospholipid metabolism, glycerolipid metabolism, starch and sucrose metabolism, and anthocyanin biosynthesis were further identified. In general, these hub genes were upregulated in AMF-colonized roots under low-K conditions. Additionally, the members of 14 gene families associated with K obtain were identified (ARF: 38, ILK: 4, RBOH: 12, RUPO: 20, MAPKK: 89, CBL: 14, CIPK: 44, CPK: 40, PIN: 10, MYB: 174, NPF: 79, KT: 19, HAK/HKT/KUP: 38, and CPA: 8) from maize. The transcript levels of these genes showed that 92 genes (ARF:6, CBL:5, CIPK:13, CPK:2, HAK/HKT/KUP:7, PIN:2, MYB:26, NPF:16, RBOH:1, MAPKK:12 and RUPO:2) were upregulated with AM symbiosis under low-K conditions. Conclusions: This study indicated that AMF increase the resistance of maize to low-K stress by regulating K uptake at the gene transcription level. Our findings provide a genome-level resource for the functional assignment of genes regulated by K treatment and AM symbiosis in K uptake-related gene families in maize. This may contribute to elucidate the molecular mechanisms of maize response to low K stress with AMF inoculation, and provided a theoretical basis for AMF application in the crop field. [ABSTRACT FROM AUTHOR]

The online detection of fertilizer solution information is a crucial link in the implementation of intelligent and precise variable fertilization techniques. However, achieving simultaneous rapid online detection of multiple fertilizer components is still challenging. Therefore, a rapid detection method based on spectrophotometry for qualitative and quantitative identification of four fertilizers (typical N, P, and K fertilizers: KNO3, (NH4)2SO4, KH2PO4, and K2SO4) was proposed in this work. Full-scan absorption spectra of fertilizer solutions at varying concentrations were obtained using a UV–visible/near-infrared spectrophotometer. By assessing the linear fit between fertilizer concentration and absorbance at each wavelength within the characteristic band, the characteristic wavelengths for KNO3, (NH4)2SO4, KH2PO4, and K2SO4 were identified as 214 nm, 410 nm, 712 nm, and 1708 nm, respectively. The identification method of fertilizer type and the prediction model of concentration were constructed based on characteristic wavelength and the Lambert–Beer law. Based on the above analysis, a four-channel photoelectric sensor was designed with four LEDs emitting wavelengths closely matched to characteristic wavelengths for fertilizer detection. A detection strategy of "qualitative analysis followed by quantitative detection" was proposed to realize the online detection of four fertilizer types and their concentrations. Evaluation of the sensor's performance showed its high stability, with an accuracy of 81.5% in recognizing fertilizer types. Furthermore, the relative error of the sensor detection was substantially less than ±15% for the fertilizer concentrations not exceeding 80 mg/L. These results confirm the capability of the sensor to meet the practical requirements for online detection of four fertilizer types and concentrations in the field of agricultural engineering. [ABSTRACT FROM AUTHOR]

Applying long term vinasse without pre-treatment to soil causes eutrophication to water and soil. The paper aims to process vinasse of the alcohol industry as an effective growing medium of environmental-friendly microorganisms that can be used in the organic fertiliser manufacture. The effective microorganism has some benefits such as becoming a soil enhancer when applied directly to the soil or an accelerator in the maturation of the organic fertiliser. This research starts with the chemical content characterisation of vinasse and the addition of microorganisms nutrients. After the media is ready, the EM inoculum is added and the breeding result is used for the manufacture of organic fertiliser based on goat farm waste. The EM culture analysis reveals an increase of the microbial number. Moreover, the organic fertiliser obtained has a content of an organic matter, nitrogen, phosphate, and potassium referring to 43.42 %, 3.05 %, 0.40 % and 1.23 %, respectively. It is in accordance with the Indonesian government regulation. [ABSTRACT FROM AUTHOR]

The role of natural factors and the interaction of anthropogenic resources with them was researched. The meadow agroecosystems based on income balance, accumulation, and expenditure of energy yield were assessed. The study has been carried out during 2011-2015 at the long-term (47 years) field experiment of the Institute of Agriculture of the Carpathian region, which includes permanent and temporary grasslands. The dry matter (DM) yield and energy yield (EY) of permanent grassland, mainly depend on mineral fertilization. Application of NPK which includes 60 kg P per ha, 90 kg K per ha, and 90 kg N per ha promotes the acquisition of 8.22 t/ha DM with 155.4 GJ/ha EY. The sum of energy yield from the aboveground mass (71.5 GJ/ha), the root (65.9 GJ/ha) and the soil energy (112.7 GJ/ha) is 250.1 GJ/ha. Production of gross energy is 260.1 GJ/ha from this grassland. The use of phosphorus and potassium fertilizers, lime and growth enhancer has a positive impact on the DM yield, soil fertility, and EY of temporary legume-grass grasslands. This combined fertilizer yields 6.65 t/ha DM and 260.3 GJ/ha of EY. Grasslands for the accumulation of total EY used 91-96% of energy from renewable, that is, natural factors provide a positive balance of energy in the Earth biosphere processes. [ABSTRACT FROM AUTHOR]

Background: Striga asiatica (L.) O. Kuntze is a traditional medicinal plant rich in flavonoids, which has various pharmacological effects such as anti-hepatitis and antioxidant activities. However, there is a scarcity of resources, and artificial cultivation has not yet been achieved. This study explored the association between flavonoid metabolites and soil physicochemical properties and trace elements in different habitats, with the aim of offering theoretical guidance for the high-quality artificial cultivation of S. asiatica. Results: The results showed that S. asiatica has low requirements for soil fertility and prefers to grow in acidic soil with high contents of potassium and available potassium, while low contents of phosphorus, nitrogen and alkali hydrolyzed nitrogen. Additionally, 1592 kinds of metabolites were identified from S. asiatica, including 78 flavonoids. Conclusions: The flavonoid metabolites were strongly related to soil factors. Reasonable application of nitrogen and potassium fertilizers as well as controlling the contents of sodium, manganese and boron in the soil, can promote the synthesis of flavonoid metabolites in the plant. Moreover, kaempferide, glycitein, luteolin, apigenin and genistein may be the metabolic markers for identifying different regions. [ABSTRACT FROM AUTHOR]

This article explores the impact of boron contamination on spinach plants and the potential mitigating effects of silicon and NPK fertilizer. The study found that increasing levels of boron in the soil led to a decrease in plant growth and various physiological parameters. However, the addition of silicon and fertilizer helped alleviate the negative effects of boron toxicity and improved plant growth. The research suggests that silicon and NPK application can be effective in reducing boron toxicity in spinach plants. [Extracted from the article]

Endophytic bacteria, recognized as eco-friendly biofertilizers, have demonstrated the potential to enhance crop growth and yield. While the plant growth-promoting effects of endophytic bacteria have been extensively studied, the impact of weed endophytes remains less explored. In this study, we aimed to isolate endophytic bacteria from native weeds and assess their plant growth-promoting abilities in rice under varying chemical fertilization. The evaluation encompassed measurements of mineral phosphate and potash solubilization, as well as indole-3-acetic acid (IAA) production activity by the selected isolates. Two promising strains, tentatively identified as Alcaligenes faecalis (BTCP01) from Eleusine indica (Goose grass) and Metabacillus indicus (BTDR03) from Cynodon dactylon (Bermuda grass) based on 16S rRNA gene phylogeny, exhibited noteworthy phosphate and potassium solubilization activity, respectively. BTCP01 demonstrated superior phosphate solubilizing activity, while BTDR03 exhibited the highest potassium (K) solubilizing activity. Both isolates synthesized IAA in the presence of L-tryptophan, with the detection of nifH and ipdC genes in their genomes. Application of isolates BTCP01 and BTDR03 through root dipping and spraying at the flowering stage significantly enhanced the agronomic performance of rice variety CV. BRRI dhan29. Notably, combining both strains with 50% of recommended N, P, and K fertilizer doses led to a substantial increase in rice grain yields compared to control plants receiving 100% of recommended doses. Taken together, our results indicate that weed endophytic bacterial strains BTCP01 and BTDR03 hold promise as biofertilizers, potentially reducing the dependency on chemical fertilizers by up to 50%, thereby fostering sustainable rice production. [ABSTRACT FROM AUTHOR]

Microbial-driven N turnover is important in regulating N fertilizer use efficiency through the secretion of metabolites like glycolipids. Currently, our understanding of the potential of glycolipids to partially reduce N fertilizer use and the effects of glycolipids on crop yield and N use efficiency is still limited. Here, a three-year in situ field experiment was conducted with seven treatments: no fertilization (CK); chemical N, phosphorus and potassium (NPK); NPK plus glycolipids (N+PKT); and PK plus glycolipids with 10% (0.9 N+PKT), 20% (0.8 N+PKT), 30% (0.7 N+PKT), and 100% (PKT) N reduction. Compared with NPK, glycolipids with 0–20% N reduction did not significantly reduce maize yields, and also increased N uptake by 6.26–11.07%, but no significant changes in grain or straw N uptake. The N resorption efficiency under 0.9 N+PKT was significantly greater than that under NPK, while the apparent utilization rates of N fertilizer and partial factor productivity of N under 0.9 N+PKT were significantly greater than those under NPK. Although 0.9 N+PKT led to additional labor and input costs, compared with NPK, it had a greater net economic benefit. Our study demonstrates the potential for using glycolipids in agroecosystem management and provides theoretical support for optimizing fertilization strategies. [ABSTRACT FROM AUTHOR]

To explore how endophytic microbial compositions in amaranth roots are influenced by various fertilization methods and to determine whether these microbes are associated with amaranthin formation, we conducted an analysis of the endophytic microbial community structure. The roots of amaranth plants subjected to different fertilization treatments—conventional fertilization without potassium (NP), conventional fertilization without phosphorus (NK), conventional fertilization without nitrogen (PK), and balanced fertilization (NPK)—were examined. The results showed that the proportions of Streptomyces, Actinospica, and Burkholderia-Caballeronia-Paraburkholderia in the amaranth roots under the balanced fertilization (NPK) treatment were all greater than those in the amaranth roots under the nitrogen (PK), phosphorus (NK), and potassium (NP) deficiency fertilization treatments. In contrast, the proportions of Phenylobacterium, Acrocalymma, Neocosmospora, Fusarium, Acidovorax, Gibellulopsis, Cladosporium, Dactylonectria, and Gibberella in the amaranth roots under the nutrient deficiency fertilization (NP, NK, and PK) treatments were higher than those in the amaranth roots under the balanced fertilization treatment. Additionally, a significantly positive correlation was found between Streptomyces and the amaranthin content. Furthermore, Acrocalymma, Neocosmospora, and Fusarium exhibited significantly negative correlations with the amaranthin content. The above results suggested that endophytes could easily colonize in amaranth roots as beneficial microorganisms under balanced fertilization conditions. In other words, the balanced fertilization (N, P and K fertilizers are 188.0, 53.0 and 50.0 kg·hm−2, respectively) could recruit more beneficial endogenous microorganisms in amaranth roots for improving their growth and quality. [ABSTRACT FROM AUTHOR]

The influence of mineral fertilizers on the seasonal dynamics of exchangeable potassium in the soil, potash status and productivity of trees was studied in field experiment with sour cherry trees cv. 'Turgenevka' in soil-climatic condition of Central Russian upland in 2018-2019. The urea and potassium sulfate were applied annually in early spring at doses of N30K40, N60K80, N90K120, and N120K160 kg/ha. The potassium level in soil-plant system depended on weather conditions, the doses of fertilizers and uptake of the element by trees. The reserves of exchangeable potassium in loamy Haplic Luvisol at the level of 100-200 mg/kg were sufficient to ensure the sour cherry yield in the start of fruiting. Fertilization by doses of N60K80 and higher increased the content of exchangeable potassium in root zone (more than 200 mg/kg), but the features of potassium seasonal dynamics were similar to unfertilized plots. With increase in the average fruit load from 4.6 (2018) to 8.3 (2019) kg/tree, the uptake of potassium by young trees increased, which led to a significant decrease in the concentration of potassium in the soil and leaves during the fruit development period (June and July). Fertilization reduced this effect but did not significantly influence on the productivity of trees and fruit potassium status. [ABSTRACT FROM AUTHOR]

Uneven rainfall and high temperature cause drought in tropical and subtropical regions which is a major challenge to cultivating summer mung bean. Potassium (K), a major essential nutrient of plants can alleviate water stress (WS) tolerance in plants. A field trial was executed under a rainout shelter with additional K fertilization including recommended K fertilizer (RKF) for relieving the harmful impact of drought in response to water use efficiency (WUE), growth, yield attributes, nutrient content, and yield of mung bean at the Regional Agricultural Research Station, BARI, Ishwardi, Pabna in two successive summer season of 2018 and 2019. Drought-tolerant genotype BMX-08010-2 (G1) and drought-susceptible cultivar BARI Mung-1 (G2) were grown by applying seven K fertilizer levels (KL) using a split-plot design with three replications, where mung bean genotypes were allotted in the main plots, and KL were assigned randomly in the sub-plots. A considerable variation was observed in the measured variables. Depending on the different applied KL and seed yield of mung bean, the water use efficiency (WUE) varied from 4.73 to 8.14 kg ha−1 mm−1. The treatment applying 125% more K with RKF (KL7) under WS gave the maximum WUE (8.14 kg ha−1 mm−1) obtaining a seed yield of 1093.60 kg ha−1. The treatment receiving only RKF under WS (KL2) provided the minimum WUE (4.73 kg ha−1 mm−1) attaining a seed yield of 825.17 kg ha−1. Results showed that various characteristics including nutrients (N, P, K, and S) content in stover and seed, total dry matter (TDM) in different growth stages, leaf area index (LAI), crop growth rate (CGR), root volume (RV), root density (RD), plant height, pod plant−1, pod length, seeds pod−1, seed weight, and seed yield in all pickings increased with increasing K levels, particularly noted with KL7. The highest grain yield (32.52%) was also obtained from KL7 compared to lower K with RKF. Overall, yield varied from 1410.37 kg ha−1 using 281 mm water (KL1; well-watered condition with RKF) to 825.17 kg ha−1 using 175 mm water (KL2). The results exhibited that the application of additional K improves the performance of all traits under WS conditions. Therefore, mung beans cultivating under WS requires additional K to diminish the negative effect of drought, and adequate use of K contributes to accomplishing sustainable productivity. [ABSTRACT FROM AUTHOR]

BACKGROUND AND OBJECTIVES: The global competitiveness of the cocoa processing industry is enhanced through the implementation of technical policies as a sustainable economic sector. The effort is motivated by the potential of large cocoa production and the international market demands for the industry to apply innovative, effective technology and comply with sustainability standards (environment, social, and economic). Therefore, this study aimed to analyze the environmental impact assessment of cocoa production from upstream to downstream processes in North Luwu Regency, South Sulawesi. METHODS: Data were collected from 321 respondents actively working and had at least 8 years of experience in cocoa cultivation and production. Respondents included staff of the Masagena Farmers' Cooperative from Chalodo Sibali Resoe Industry, Masamba City, and North Luwu Regency, and the secondary data were obtained from a literature review. In addition, the environmental impact was determined using the Midpoint Recipe method and the ecoinvent 3.8 database. This was conducted based on the International Standard Organization of life cycle assessment 14040 and 14044 with a function unit of 1 kilogram chocodate cashew production. FINDINGS: The results showed that reducing chemical fertilizer was environmentally preferable to decreasing all the impact categories assessed since the total potential global warming impact from chocodate cashew production was 2.092 kilogram carbon dioxide equivalent. In this context, electricity and fertilizer were the main contributors to environmental pollution, accounting for 0.438 kilogram carbon dioxide equivalent and 0.215 kilogram carbon dioxide equivalent at 20.97 percent and 10.27 percent, respectively. CONCLUSION: The reduction in the use of inorganic nitrogen, phosphate, potassium fertilizer, from 3.75 to 1.25 kilogram perkilogram cocoa, or the adoption of bio-based nitrogen, phosphate, potassium fertilizer at a rate of 2.5/kilogram, could substantially mitigate the environmental impact. This mitigation resulted in a 16 percent decrease in global warming potential, reducing from 2.092 to 1.745 kilogram carbon dioxide equivalent. In addition, valuable insights were provided into the scope of life cycle assessment studies and contributed to the selection of sustainable cacao farming systems. These results could be relevant to life cycle assessment practitioners, stakeholders, and governments in offering valuable insights for the formulation of policies and programs for developing cacao farming in the future. [ABSTRACT FROM AUTHOR]

Reasonable nitrogen (N) and potassium (K) application rates can effectively improve fertilizer use efficiency, rice yield and quality. A two-year field experiment was conducted with combined application of three N rates (135, 180, and 225 kg ha-1, denoted as N1-N3) and four K rates (0, 90, 135, and 180 kg ha-1, denoted as K0-K3) using super indica hybrid rice cultivar Yixiangyou (YXY) 2115 to explore the effects of co-application of N and K on rice growth and development. The results indicated that the combined application of N and K had significantly interactive effects on dry matter (DM) accumulation, nutrients absorption, N harvest index (NHI), K harvest index (KHI), spikelets per panicle and most rice quality indexes. The highest total DM accumulation (17998.17-19432.47 kg ha-1) at maturity stage was obtained under N3K2. The effect of co-application of N and K on nutrients absorption and utilization varied between the two years and within each year. The highest total N and K accumulations at maturity stage were observed under N3K1 and N3K2, respectively, while the highest N recovery efficiency (NRE) and K recovery efficiency (KRE) were observed under N1K3. High expression levels of N and K metabolism-related genes in rice grains were observed under N3K2 or N3K3, consistent with N and K uptake. Co-application of N and K increased rice yield significantly and the highest yield (6745.02-7010.27 kg ha-1) was obtained under N2K2. As more N was gradually applied, rice appearance quality improved but milling, cooking and eating quality decreased. Although appropriate application of K could improve rice milling, cooking and eating quality, it reduced appearance quality. The optimal milling, cooking and eating quality were obtained under N1K2, while the best appearance quality was obtained under N3K0. Overall, a combination of 135-210 kg ha-1 N and 115-137 kg ha-1 K application rates was recommended for achieving relatively higher yield and better quality in rice production. [ABSTRACT FROM AUTHOR]

Reducing fertilizer usage is a crucial measure for achieving high-quality development in Chinese agriculture. Utilizing panel data from 31 Chinese provinces spanning from 2004 to 2019, this study empirically analyzes the dynamic relationship between fertilizer application and grain production, exploring the underlying mechanisms. The study findings reveal that the application of fertilizers maintains a positive impact on grain production. The two variables will demonstrate a dynamic alternation between "strong decoupling" and "retreat decoupling," suggesting that grain production may either increase or gradually decline, while fertilizer application exhibits a decreasing trend. Mechanism analysis reveals a distinct substitution relationship between fertilizer use efficiency and application quantity. Increasing fertilizer use efficiency while reducing application quantity still facilitates the stable and increased production of grains. Heterogeneity analysis indicates that the efficiency of fertilizer use has a more pronounced impact on grain yield in the eastern and western regions. Increasing fertilizer quantity is detrimental to wheat yield but has a promoting effect on corn yield. However, in the main grain-producing areas, increasing fertilizer quantity can enhance wheat yield but is unfavorable for the overall grain yield. Additionally, nitrogen fertilizer input has exceeded the optimal level compared to potassium fertilizer. Continuously increasing nitrogen fertilizer input will hinder the increase in grain yield. Therefore, there is a need to shift from the notion of "more fertilizer is better" and focus on improving fertilizer use efficiency to transition from the emphasis on "quantity" to "quality" of fertilizer application. [ABSTRACT FROM AUTHOR]

Salinity adversely affects plant growth and productivity worldwide. To overcome salinity and other abiotic stresses, safe, ecofriendly biofertilizers that stimulate productivity have been experiencing rising demand, alongside decreasing use of mineral fertilizers. The purpose of this study was to examine changes in the growth, yield, physiological and biochemical parameters of wheat crop as a response to two potassium-solubilizing microorganisms (KSMs), Trichoderma asperellum and Bacillus circulans, with 50% or 75% of the recommended amount of K fertilizer (potassium sulphate), combined with no or 25% feldspar as well as 1.5% potassium sulphate (K-leaf) as foliar application, and all treatments were compared with a control treatment under salt-affected soil conditions, during two winter seasons in 2019–2020 and 2020–2021. The randomized complete block design (RCBD) was used to set up the experiment. Results showed that the vegetative growth, yield, physiological and biochemical parameters were affected under salt-affected soil conditions. Nevertheless, inoculation with T. asperellum and B. circulans with potassium application mitigated the deleterious effect of salt-affected soil conditions by improving growth parameters, photosynthetic pigment content, antioxidant enzymes (superoxide dismutase, ascorbate peroxidase, catalase and peroxidase) content, total soluble sugars, relative water content, potassium content in leaves, grains yield, and some biochemical constituents in the grains and straw. Meanwhile, these treatments decreased proline content, Na+ content in leaves, and the Na+/K+ ratio as compared to the control treatment. The most pronounced treatment, inoculation by B. circulans with 1.5% K-leaf as foliar application, significantly increased grain yield by 16.41% relative to the control treatment. It could be concluded that inoculating wheat with KSMs T. asperellum and B. circulans with 1.5% K-leaf as foliar application will increase wheat salinity tolerance and wheat productivity and decrease the detrimental effect of salinity on wheat growth and grain yield quantity and quality under salt-affected soils conditions. [ABSTRACT FROM AUTHOR]

The fertilizing effects of biodigestate produced from biogas plants on crop and soil productivity are very scarce. Hence, a field study was conducted in 2022 at the Teaching and Research Farm of Bowen University, Iwo, Osun State, Nigeria. The study evaluated the effects of biodigestate fertilizer, applied alone or in combination with urea, single superphosphate, or muriate of potash fertilizers at low (N1, K1, and P1) and high (N2, P2, and K2) rates on soil chemical properties, growth, and yield of maize (Zea mays (L.)). The treatments were biodigestate alone (D), D + N fertilizer (urea) at 60 kg·ha−1 (DN1), D + N at 120 kg·ha−1 (DN2), D + P fertilizer (single superphosphate) at 30 kg·ha−1 (DP1), D + P at 60 kg·ha−1 (DP2), D + K fertilizer (muriate of potash) at 30 kg·ha−1 (DK1), D + K 60 kg·ha−1 (DK2), D + N1 + P1 + K1 (DN1P1K1), D + N2 + P2 + K2 (DN2P2K2) (10), and control. The 10 treatments were arranged in a randomized complete block design and replicated three times. Results showed that both low and high rates of fertilizer application improved soil chemical properties, growth parameters, and yield of maize compared with the control. High fertilizer rates (N2, P2, and K2) significantly enhanced soil chemical properties and growth parameters, but lower rates (N1, P1, and K1) resulted in higher maize yield. DN1 fertilizer significantly increased maize yield compared with DN2, DP1, DP2, DK1, and DK2. Overall, the treatment of DN1P1K1 demonstrated the highest grain yield, likely due to optimal nutrient supply from N, P, and K fertilizers, along with an improved soil environment facilitated by the biodigestate. The study recommends a balanced and sustainable fertilizer application strategy of 60 kg·N·ha−1, 30 kg·P2O5·ha−1, and 30 kg·K·ha−1 with 2500 L·ha−1 of biodigestate to enhance maize production while minimizing cost and environmental impact. However, for those aiming for maize fodder production, a higher fertilizer rate of 120 kg·N·ha−1, 60 kg·P2O5·ha−1, and 60 kg·K·ha−1 with 2500 L·ha−1 of biodigestate is advised. [ABSTRACT FROM AUTHOR]

In order to improve carrot quality and soil nutrition and reduce the environmental pollution caused by intensive carrot production, more comprehensive combined water–fertilizer management strategies are necessary. This study hypothesizes that optimal management of water and fertilizer can improve carrot yield and quality and reduce greenhouse gas emissions and soil nutrient residues. Thus, coordinated water–fertilizer management strategies were tested for carrot production on the North China Plain over two consecutive growing seasons. Four treatments were tested: local standard fertilization and irrigation practices (FNP); optimized irrigation and chemical nitrogen, phosphorus, and potassium fertilizer (OPT); OPT treatment with partial replacement of chemical fertilizer with peanut shell (PS); and OPT treatment with partial replacement of chemical fertilizer with mushroom residue (M). Compared to the FNP treatment, there were statistically significant increases in soluble sugars (12–27%) and free amino acids (14–26%), and decreases in the nitrate content (7–17%) of fleshy root in the OPT, PS, and M treatments. In autumn carrots, the OPT and M treatments decreased yield, whereas PS increased yield; spring carrot yield was significantly decreased in the OPT, PS, and M groups compared to the FNP group. There were no significant effects of the treatment group on carrot growth rates, nutrient accumulation, or nutrient distribution. However, the OPT, PS, and M treatments were associated with significantly increased partial productivity of phosphate fertilizer (233–363%), reduced residual levels of nitrate and available phosphorus in the top 80 cm of soil, and decreased greenhouse gas emissions by 8–18% compared to the FNP treatment. These results highlight the effectiveness of partial organic fertilizer substitution and integrated water–fertilizer management to produce high-quality carrots with minimal environmental damage. [ABSTRACT FROM AUTHOR]

Secondary fertilisers are becoming an important alternative to conventional mined fertilisers. For the first time, the struvite "relative" hazenite (KNaMg2(PO4)2·14 H2O) has been artificially synthesised. A pot trial assessed whether hazenite-fertilised ryegrass had comparable potassium (K), magnesium (Mg), or phosphorus (P) uptake and shoot yields with treatments receiving conventional K (muriate of potash), Mg (kieserite) or P (triple superphosphate, TSP) fertilisers. Ryegrass shoot biomass production and K/Mg uptake in replicates receiving hazenite were as good as or superior to those amended with conventional fertilisers. Phosphorus uptake of plants whose P source was TSP was significantly higher than that of the hazenite-amended replicates without significantly higher shoot biomass, indicating luxury P uptake. Hazenite's constituent sodium (Na) makes it a potentially useful soil amendment for forage grasses or natrophilic crops such as sugar beet. Its component Mg would also be desirable in forage grasses to pre-empt ruminant hypomagnesemia or in crops with a relatively high Mg demand, for example, maize. Furthermore, hazenite represents a good alternative to KCl for chlorophobic crops such as potatoes. However, given its unusual ratio of Mg, P, and K, the ideal application of hazenite would probably be in combination with other fertilisers. [ABSTRACT FROM AUTHOR]

The main aim of the study was to systematize and summarize archival data on yields from main field crops from multiple fertilizer experiments of Nikola Poushkarov ISSAPP on various soil types in Bulgaria. A large set of results from the field fertilizer experiments carried out on four different soil types: Calcareous Chernozem (Trastenik village), Haplic Chernozem (Gorni Dabnik village), Haplic Luvisol (Nikolaevo village) and Planosol (Sekirovo village) in the geographical network of Bulgaria of the Nikola Poushkarov ISSAPP has been accumulated. Eight fertilization variants were tested with annual application of potassium (0, 8, 16 and 32 kg/da K2O) on two backgrounds of nitrogen (N) and phosphorus (P) fertilization. Crop rotation during the individual years was as follows: wheat (Triticum aestivum L.), maize (Zea mays L.), sunflower (Helianthus annuus L.) and sugar beet (Beta vulgaris L.), grown under non-irrigation conditions. Optimum rates of fertilization with the main nutrients, N, P and K have been established for the different soil types. There are complex interactions between the different rates of fertilization with the main macronutrients and this has a significant impact on the quantity and quality of agricultural crop yields. The difference in yields between the two investigated periods (1963-1970 and 1971-1975), at the same levels of fertilization, shows that the level of yields and accordingly, the use of nutrients are also determined to a significant extent by the climatic conditions. With an increase in the fertilizer rate, the yields also increase, and the rates of 16 kg and 32 kg K2O remain the most effective, regardless of the occurrence of potassium accumulation in these variants. This was also confirmed by the results of the analysis of variance of the yields of cultivated crops. There was a pronounced increase of the effect of potassium fertilization in soils less supplied with this element, i.e. the Haplic Luvisol (Nikolaevo village) and Planosol (Sekirovo village). The effect of the potassium fertilization increases and expands in well supplied with potassium soils, but possessing unfavorable conditions for nutrition with this element, as in the case with the Calcareous Chernozem (Trastenik village). There was also an effect of potassium fertilization, although inconsistent, in soils well supplied with potassium, such as Haplic Chernozem (Gorni Dabnik village). [ABSTRACT FROM AUTHOR]

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Saline-alkali soil is a major threat to global food security. Phosphorus (P) fertilizer is essential for crop growth and yield production. Nevertheless, the optimal phosphate fertilizer application rates for summer maize under coastal saline–alkali soil are still unclear. A field experiment with five phosphate application rates (0, 45, 90, 135, and 180 kg ha−1, referred to as T1, T2, T3, T4, and T5, respectively) was conducted during the 2018–2020 summer maize seasons study the effects of phosphate rates on the grain yield, biomass, and nitrogen (N), P and potassium (K) accumulation, and N, P, and K physiological efficiency (denoted as NPE, PPE and KPE, respectively). Results showed that P application notably improved maize grain and biomass yield, the total uptake of N, P, K, and NPE and KPE across three seasons. As the P addition increased to 135 kg ha−1, the grain yield achieved a maximum of 7168.4 kg ha−1, with an average NPE of 2.15 kg kg−1, PPE of 0.19 kg kg−1, and KPE of 1.49 kg kg−1. However, PPE continuously decreased with the input of phosphate. P application rates exceeding 135 kg ha−1 were not considered effective due to a decline in grain yield, nutrient uptake, and NPE. Furthermore, the effect of the planting season was significant on the total uptake of N and K, and the use efficiency of N, P, and K. TOPSIS revealed that a phosphate application rate of 90–135 kg ka−1 was the optimal pattern for maize production. These results may give a theoretical basis for the phosphate management of maize production in saline–alkali soil. [ABSTRACT FROM AUTHOR]

The current paper intends to interpret from a technical point of view the data and yield functions which resulted from applying different fertilizer doses with nitrogen and phosphorus. The analyzed parameters (yield, yield increase, marginal increase) represent basic elements with determining role in establishing the doses and approximating the economic efficiency when applying fertilizers. The data comes from a long time experience with chemical fertilizers at Agricultural Research and Development Station (A.R.D.S.) Secuieni, Neamţ county, Romania, since 1975 and examines the results obtained between 2010-2012. As a result of nitrogen and phosphorus chemical fertilizers application (compared to the unfertilized version N0P0), were achieved yield increases of 5-56%, representing 234-2342 kg/ha. The resulted yield have been influenced by the fertilizer's type but also by the weather conditions in the research period. The use of phosphorus fertilizers in doses of P40-P160 brought medium yield increases compared to the unfertilized version P0 of 5-13% representing 256-681 kg/ha, and those with N40-N160 nitrogen brought medium increases (compared to the unfertilized version N0) of 15 -35% representing 599-1584 kg/ha. The production increases were directly correlated with the doses used, establishing highly significant correlations. The yield increases achieved by applying 1 kg of fertilizer active matter had medium values of 4.25-8.82 kg wheat/kg active matter P2O5 at phosphorus fertilizers and 9.9-14.97 kg wheat/kg active matter N at nitrogen fertilizers. These increases were indirectly correlated with the applied doses. [ABSTRACT FROM AUTHOR]

Multiple interactions between different species in the potash flotation. As the main resource of potash fertilizer, high grade of sylvite (KCl) is mainly separated from halite (NaCl) in soluble potash ores using flotation. An effective flotation collector determines the separation efficiency of sylvite. However, the collector adsorption mechanism is still the subject of much debate due to high ions concentration in the flotation pulp. This paper studies the hydration status of KCl, the flotation behavior of KCl and NaCl with lauric acid and the interfacial water structure of the soluble salts to provide further insights into the fundamental mechanisms at play. The contact angle measurements and laboratory micro-flotation experiments have shown that both the hydration status of KCl and the flotation soluble salts with lauric acid were dependent on the solution composition. Specifically, it was determined that the addition of Na-ions had an adverse effect on the hydrophobicity of KCl crystals. Both KCl and NaCl can be floated with lauric acid. However, flotation of NaCl is greatly enhanced with the addition of K-ions whereas the flotation of KCl is suppressed with the addition of Na-ions. Sum frequency generation (SFG) measurements have found, most strikingly, more disordered water molecules dominating the "structure maker" salt surfaces in a saturated NaCl solution. "Collins Concept" is employed to explain the specific ion binding behaviors in the flotation pulp. [ABSTRACT FROM AUTHOR]

The nutritional status of winter oilseed rape (WOSR) during its vegetative period is crucial for plant growth and can be used for the seed yield prediction. This hypothesis was verified based on the data from long-term field experiments. The experiment consisted of four potassium (K) treatments based on the progressive K supply potential to plants from soil and fertilizer and two magnesium treatments (-Mg, +Mg) conducted in 2013-2015. The content of nutrients (Ntot, P, K, Mg, Ca, Fe, Mn, Zn, Cu) was determined at the rosette stage (BBCH 30) for leaves and separately for leaves and stems in the late stage of inflorescence growth (BBCH 57-59). The low K content appeared as the key limiting nutrient in WOSR plants in the rosette stage due to the insufficient soil fertility level, depended even more on weather conditions. This negative K nutritional trait persisted through the whole vegetative WOSR growth. Its detection was possible, because stems were included in the diagnostic procedure. The most reliable prognosis of WOSR yield was conducted based on the nutritional status of stems in the late stage of the inflorescence development. [ABSTRACT FROM AUTHOR]

In the last 20 years, due to a significant reduction in industrial emissions and changes in the assortment of available fertilizers, a progressive sulphur deficiency has been observed in the soils of Poland and other parts of the world. This creates the need to supplement NPK fertilizers with sulphur and to conduct research on the optimization of its use as a fertilizer component. A three-year field study was carried out on Haplic Luvisols with low content of sulphur available to plants. The aim of the study was to assess the effect of sulphur-containing fertilizers (ammonium sulphate, potassium sulphate and Wigor S) applied at rates of 20 and 40 kg S/ha on the yield of grain, straw and protein of spring barley. The study showed that application of sulphur, irrespective of its form, generally significantly increased the yield of spring barley grain and straw as compared to the control. However, no significant differences were found in the effects of the fertilizers on yield depending on either the fertilizer type or application rate. Protein content in the grain of the plants fertilized with sulphate sulphur was on average about 6% higher than in the grain of non-fertilized plants. As a result of the beneficial effect of sulphur on the yield of spring barley grain and on its protein content, the protein yield increased. The highest increases were obtained following application of sulphate fertilizers, especially at a 40 kg S/ha. The research suggests that irrespective of the form used, sulphur fertilization in the conditions of deficiency of this nutrient in the soil, with relatively high temperatures and high soil moisture, significantly affects the yield of spring barley grain and straw and the accumulation of protein in the grain. [ABSTRACT FROM AUTHOR]

Schima superba is a dominant species in the lower subtropical evergreen broad-leaved forest community at Dinghushan. In order to understand the construction mechanism of lower subtropical evergreen broad-leaved forest community, we have established a 20 hm2 forest biodiversity monitoring plot at Dinghushan National Nature Reserve. The data presented in this paper are based on four field investigations of all S. superba individuals from 2005 to 2017. We further analyzed the distribution characteristics of its death rate according to diameter class and habitat type. The results were as follows:(1)The number of S. superba individuals was largely reduced from 2005 to 2017.(2)Mortality rate and growth rate of S. superba showed different patterns depending on diameter class. The relative growth rate of the individuals of 1-10 cm DBH was high and rapidly decreased, while the mortality rate increased and maintained at a high level. With the increase of DBH class, the relative growth rate of the individuals of 10-50 cm DBH rose and decelerated, and then decreased, while the mortality rate decreased. The mortality rate of those individuals above 50 cm DBH was large while the growth rate was little.(3)The mortality rate of the individuals in each habitat in 2010 was not apparently different. However, in 2015, the mortality rate of individuals in high-altitude habitats(high slopes, ridges, and valleys)was greater than those in low-altitude habitats(low slopes and valleys), while those in low-altitude habitats in 2017 were higher than those in the high-altitude habitats.(4)The mortality rate was significantly positively correlated with soil pH and negatively correlated with soil organic matter, total nitrogen, total phosphorus, available potassium, and available nitrogen content. [ABSTRACT FROM AUTHOR]