Search

Spinach (Spinacia oleracea L.) is considered a nitrogen (N) intensive plant with high nitrate (NO3-) accumulation in its leaves. The current study via a two-year field trial introduced an approach by combining N fertilization from different sources (e.g., ammonium nitrate; 33.5% N, and urea; 48% N) at different rates (180, and 360 kg N ha-1) with the foliar spraying of molybdenum (Mo) as sodium molybdate, and/or manganese (Mn) as manganese sulphate at rates of 50 and 100 mgL-1 of each or with a mixture of Mo and Mn at rates of 50 and 50 mg L-1, respectively on growth, chemical constituents, and NO3- accumulation in leaves. Our findings revealed that the highest rate of N fertilization (360 kg N ha-1) significantly increased most of the measured parameters e.g., plant length, fresh and dry weight plant-1, number of leaves plant-1, leaf area plant-1, leaf pigments (chlorophyll a, b and carotenoids), nutrients (N, P, K, Fe, Mn, Zn), total soluble carbohydrates, protein content, net assimilation rate, and NO3- accumulation, but decreased leaf area ratio and relative growth rate. Moreover, plants received urea-N fertilizer gave the highest values of all previous attributes when compared with ammonium nitrate –N fertilizers, and the lowest values of NO3- accumulation. The co-fertilization of N-Mo-Mn gave the highest values in all studied attributes and the lowest NO3- accumulation. The best treatment was recorded under the treatment of 360 kg N-urea ha-1 in parallel with the combined foliar application of Mo and Mn (50+50mg L-1). Our findings proposed that the co-fertilization of N-Mo-Mn could enhance spinach yield and its quality, while reducing NO3- accumulation in leaves, resulting agronomical, environmental and economic benefits.

Se establecieron dos experimentos en las mismas parcelas desde 1 de mayo a 1 de diciembre de 1991 y 1992 para determinar la extracción mensual de nutrimentos y producción de materia seca en el ñame 'Gunung'. En el primer año las plantas fueron abonadas a razón de 0; 667; 1,333; 2,000 y 2,667 kg/ha con un fertilizante 15-5-15-5 (N, P2O5, K2O y MgO) suplementado con elementos menores. El segundo año no se aplicó fertilizante. Se efectuaron seis cosechas de biomasa a los 2, 3, 4, 5, 6 y 7 meses después de la siembra. En cada cosecha las plantas fueron excavadas y separadas en láminas de hojas, tallos y peciolos, raíces y tubérculos. Se determinó el peso húmedo y seco de ios componentes de la planta y se obtuvieron muestras de tejido. Luego estas muestras se analizaron para determinar su contenido de N, P, K, Ca y Mg. Independientemente del año, los tratamientos de fertilizantes no afectaron significativemente el rendimiento en peso seco de los tubérculos mercadeables. La extracción máxima de nutrimentos fue 214 kg/ ha de N, 19 kg/ha de P, 223 kg/ha de K, 95 kg/ha de Ca y 9 kg/ha de Mg. La producción máxima de materia seca fue 11,303 kg/ha de los cuales 8,672 kg/ ha se acumularon en los tubérculos mercadeables. La extracción máxima de N, K, y Ca ocurrió a los cinco meses después de la siembra. La producción máxima de materia seca fue a los siete meses. Las plantas del ñame utilizaron 24.7 kg/ha de N, 2.2 kg/ha de P, 25.7 kg/ha de K, 11.0 kg/ha de Ca y 1.0 kg/ha de Mg por cada 1,000 kg/ha de materia seca comestible producida.

The 100th anniversary of a leading nitrogen fixation technology developer like CASALE SA is a reason to reflect over the 20th century successful solution of the problem of world food supply, and to look out for solutions for sustainable developments with respect to ammonia production. We review the role of nitrogen as essential chemical constituent in photosynthesis and biology, and component of ammonia as it is used as fertilizer for primary production by photosynthesis for farming and food supply and its future role as energy carrier. While novel synthesis methods and very advanced synchrotron based x-ray analytical techniques are being developed, we feel it is important to refer to the historical and economical context of nitrogen. The breaking of the N N triple bond remains a fundamental chemical and energetic problem in this context. We review the electrochemical ammonia synthesis as an energetically and environmentally benign method. Two relatively novel X-ray spectroscopy methods, which are relevant for the molecular understanding of the catalysts and biocatalysts, i.e. soft X-ray absorption spectroscopy and nuclear resonant vibration spectroscopy are presented. We illustrate the perceived reality in fertilizer usage on the field, and fertilizer production in the factory complex with photos and thus provide a contrast to the academic view of the molecular process of ammonia function and production.

Warmer atmospheric temperatures (eT) will increase plant nutrient uptake, and elevated atmospheric CO2 (eCO2) is expected to enhance plant growth, whereas a multicomponent eTeCO2 effect should also be beneficial for agroecosystems. Our goal was to understand if single- (eT, eCO2) or multicomponent (eTeCO2) climate effects, predicted for southern Ontario, Canada, will affect soybean and soil properties differently when soil is amended with manure and biochar (MB) or with manure, nitrogen (N) fertilizer, and biochar (MNB) compared with the addition of manure and N fertilizer (MN). We hypothesized that biochar regulates climate effects and causes soybean and soil properties to be similar to ambient climate conditions than soil without biochar. However, soil amended with biochar functioned independently of single- or multicomponent climate effects. Soybean pod and shoot biomass, shoot height, and shoot:root ratio were greater (p 2 increased (p 4+ and NO3−), and the C/N ratio but increased (p

Liquid hog manure (LHM) and solid cattle manure (SCM) co-applied with biochar could beneficially influence soil nitrogen (N) and phosphorus (P) dynamics. A split-plot design was used at two sites (Brown and Black) in Saskatchewan to assess LHM and SCM (100 kg N·ha−1) applied alone or in combination with biochars (8 Mg carbon·ha−1) produced using slow or fast pyrolysis. Crop growth and nutrient uptake, along with fertilizer 15N recovery, were followed over four years in a cereal–oilseed rotation. Crop growth on the Brown soil was more responsive to the treatments than the Black soil, reflecting lower fertility of the Brown soil. The manure and biochar, applied alone or in combination, had little impact on available soil P. Manure and biochar effects on crop growth and nutrient uptake were attributed to temporal effects on soil N immobilization–mineralization influencing plant-available soil N. A negative impact of the fast pyrolysis biochar on growth and plant uptake was observed and attributable to its greater labile-carbon content, which likely promoted soil N immobilization. Synergism observed between SCM and the slow pyrolysis biochar may reflect enhanced net SCM-N mineralization and increased water-holding capacity. The majority (55%–80%) of plant 15N recovery occurred during the first year, with 86% of fertilizer 15N conserved within the soil–plant system after four years. Greater (40%) plant 15N recovery without biochar addition, coupled with increased (38%) soil 15N recovery with added biochar, suggests biochar-related immobilization and (or) sorption in the biochar-amended soils.

Phosphorous (P) plays the prominent role to promote the plants storage functions and structural roles, as it is recognized as a vital component of ADP, ATP, Cell wall as well as a part of DNA. Soils acts as the sink to supply P to plants because soil pH and its physical condition are the main factor which regulate the solubility and availability P element. Phosphorus is not deficient in Pakistani soils but its availability to plants is the serious matter of concern. A pot experiment was conducted to evaluate P dynamics in two different soil series of Pakistan (Bahawalpur and Lyallpur) using Maize as test crop. The treatments applied were T0: Control (without any fertilizer), T1: Recommended DAP @648 mg pot−1, T2: Half dose DAP @324 mg pot−1, T3: Recommended rate of TSP @900 mg pot−1, T4: Half dose TSP @450 mg pot−1. Soil analysis showed that Bahawalpur soil has sandy clay loam texture with 33% clay and Lyallpur series has sandy loam texture with 15.5% clay; furthermore, these soil contain 4.6 and 2.12% CaCO3 respectively. Results showed an increase in P concentration in roots (23 mg kg−1) with the application of half dose of TSP in Lyallpur series and lowest in Bahawalpur series (14.6 mg kg−1) at recommended dose of DAP. Concentration of P in shoots responded the same; increase at half dose of TSP (16.7 mg kg−1) and lowest at full dose of DAP in Bahawalpur series as (15.58 mg kg−1). Adsorbed P (17 mg kg−1) was recorded highest in Bahawalpur soil with more clay amount in pot with DAP application but lower in Lyallpur soil series (14 mg kg−1) with the application of applied TSP. The PUE was recorded highest in Lyallpur series with the application of half dose of TSP and it was 61% more than control and was Highest in Bahawalpur series was with the application of recommended dose of DAP is 72% more than control treatment. On estimation; results showed that applied sources made an increase in P availability than control, but TSP gave better P uptake than DAP unless of rates applied. Soil of Lyallpur series showed better uptake of P and response to applied fertilizers than Bahawalpur series which showed more adsorption of P by high clay and CaCO3 amount. Conclusively, the study suggested that soil series play a crucial role in choosing fertilizer source for field application.

Ammonium phosphate fertilizer is the compounds containing nitrogen and phosphorus that are usually produced through the neutralization reaction of phosphoric acid and ammonia. At present, there are a variety of products, such as slurry monoammonium phosphate (MAP), diammonium phosphate (DAP), industrial grade MAP, water soluble MAP, water soluble ammonium polyphosphate (APP) and so on. After more than 60 years of development, China’s ammonium phosphate fertilizer industry has experienced the road of from scratch and from weak to strong. The successful development of the slurry MAP technology ended the history that the high concentration phosphate fertilizer cannot be produced by using the medium and low-grade phosphate ore. The continuous, stable and large-scale production of DAP plant provides sufficient guarantee for diammonium products in China. The development of new ammonium phosphate fertilizer products, such as industrial grade MAP, water soluble MAP, water soluble APP, provides technical support for the transformation and upgrading of phosphorus chemical enterprises. In this paper, the production methods, the development history and the latest research progress of ammonium phosphate fertilizers were reviewed.

ADC12 aluminium dross and 6063 aluminium dross are the byproducts of aluminium production process. The processing of these dross is of great challenges due to its toxic nature. In the current study, neutralized dross was used as plant fertilizer. The planting efficiency of untreated and treated aluminium dross fertilizer at various contents up to 50 wt% was analyzed. Treated aluminium dross fertilizer showed enhancement in height and weight of Chinese cabbage than untreated fertilizer and control. The optimum content for plant growth enhancement was found to be 10 wt%. However, the plants treated with 30 wt% and 50 wt% of aluminium dross fertilizer were completely withered and desiccated after 10 days of growth. The growth enhancement was also observed in sweet corn, basil and spring onion. Hence, the aluminium dross after neutralization can be used as an environmentally friendly fertilizer as there is no existence of toxic heavy metal elements in the soil.

Zinc is an essential micronutrient that is required for optimum plant growth. It is present in soil in insoluble forms. Bacterial solubilization of soil unavailable form of Zn into available form, is an emerging approach to alleviate the Zn deficiency for plants and human beings. Zinc solubilizing bacteria (ZSB) could be a substitute for chemical Zn fertilizer. The present study aimed to isolate and characterize bacterial species from the contaminated soil and evaluate their Zn solubilizing potential. Zn resistant bacteria were isolated and evaluated for their MIC against Zn. Among the 13 isolated bacterial strains ZSB13 showed maximum MIC value upto 30mM/L. The bacterial strain with the highest resistance against Zn was selected for further analysis. Molecular characterization of ZSB13 was performed by 16S rRNA gene amplification which confirmed it as Pseudomonas oleovorans. Zn solubilization was determined through plate assay and broth medium. Four insoluble salts (zinc oxide (ZnO), zinc carbonate (ZnCO3), zinc sulphite (ZnS) and zinc phosphate (Zn3(PO4)2) were used for solubilization assay. Our results shows 11 mm clear halo zone on agar plates amended with ZnO. Likewise, ZSB13 showed significant release of Zn in broth amended with ZnCO3 (17 and 16.8 ppm) and ZnO (18.2 ppm). Furthermore, Zn resistance genes czcD was also enriched in ZSB13. In our study, bacterial strain comprising Zn solubilization potential has been isolated that could be further used for the growth enhancement of crops.

BACKGROUND Foliar application of highly concentrated ZnSO4 fertilizer improves Zn biofortification in wheat grains. However, excess ZnSO4 ·7H2 O concentration (≥ 5 g kg-1 , w v-1 ) has been associated with leaf burn and yield loss, necessitating the need for Zn sources with high threshold concentration. Therefore, the aim of this study, based on a 2-year field experiment conducted on wheat cultivated in acidic and alkaline soil, was to identify a suitable Zn formulation with a high Zn concentration or efficient adjuvant to achieve optimal Zn biofortification levels without compromising agronomic performance. RESULTS There was a continued increase in the Zn concentration of wheat grains and a decrease in grain yield with an increase in the concentration of the Zn foliar sprays in both soil types examined. Wheats treated with chelated Zn foliar sprays (ZnGly and ZnEDTA) had less foliar injury compared with those treated with unchelated Zn fertilizers. Furthermore, respective of wheat cultivars and soil types, ZnEDTA applied to wheat at a concentration of 10 g kg-1 achieved the highest grain Zn concentration without negatively affecting the wheat performance. Adjuvant type and concentration caused no significant variation in grain Zn concentration. CONCLUSION Overall, without foliar burn, wheat treated with 10 g kg-1 ZnEDTA foliar spray had the best performance with regards to grain Zn concentration and grain yield, which could have considerable implications for Zn biofortification of wheat grain. This article is protected by copyright. All rights reserved.

Selenium (Se) plays an important role in human health. Approximately 80% of the world’s population does not consume enough Se which recommended by WHO (World Health Organization). Wheat is an important staple food and Se source for most people in the world. This article summarizes literatures about Se from 1936 to 2020 to investigate Se in wheat farming soil, wheat, and its derived foods. Se fortification and the recommended Se level in wheat were also discussed. Results showed that Se contents in wheat farming soil, grain, and its derived foods around the world were 3.8–552 (mean, 220.99), 0–8,270 (mean, 347.30), and 15–2,372 (mean, 211.86) μg·kg−1, respectively. Adopting suitable agronomic measures could effectively realize Se fortification in wheat. The contents in grain, flour, and its derived foods could be improved from 93.94 to 1,181.92, 73.06 to 1,007.75, and 86.90 to 587.61 μg·kg−1 in average after leaf Se fertilizer application in the field. There was a significant positive correlation between Se content in farming soil and grain, and it was extremely the same between foliar Se fertilizer concentration rate and grain Se increased rate. The recommended Se fortification level in cultivation of wheat in China, India, and Spain was 18.53–23.96, 2.65–3.37, and 3.93–9.88 g·hm−2 respectively. Milling processing and food type could greatly affect Se content of wheat derived food and should be considered seriously to meet people’s Se requirement by wheat.TOC graphic

BACKGROUND Rapeseed (Brassica napus) is highly sensitive to nitrogen (N) and boron (B) deficiency; however, the synergistic effects of these elements on rapeseed production are poorly understood. The aim of this study was to investigate the effects of co-application of N and B on seed yield, N uptake and N use efficiency (NUE) of rapeseed. Three rapeseed cultivars (W10, ZS11 and HG) were treated with different N and B application rates, and the seed yield, N uptake and NUE were examined in two-year field experiments. RESULTS The application of B fertilizer (4.5, 9 kg borax ha-1 ) improved N uptake, NUE and seed yield. However, the magnitude of increase in seed yield by B fertilization was dependent upon the rate of N supply and genotype. The benefit of B was much greater at 180 kg N ha-1 than at 0, 60 kg N ha-1 . The combination of N and B also improved N remobilization from sources (stems and husks) to sinks (seeds) and increased N recovery efficiency (NRE). Compared with the B-inefficient cultivar W10, the B-efficient cultivars ZS11 and HG were superior in growth, seed yield, N uptake and NUE on B deficient soils. Furthermore, B-efficient cultivars showed great potential in saving N input, and the yield increased by more than 40% under B deficiency conditions. CONCLUSION This study highlights a markedly synergistic effect of N and B nutrition on rapeseed NUE and yield production and shows that B-efficient genotypes can increase yield and reduce N inputs under B-deficient conditions. This article is protected by copyright. All rights reserved.

Deep placement of nitrogen fertilizer is a key strategy for improving nitrogen use efficiency. A two-year field experiment was conducted during the early rice growing seasons (March–July) of 2016 and 2017. The experimental treatments comprised two rice cultivars: Wufengyou 615 (WFY 615) and Yuxiangyouzhan (YXYZ), and three N treatments: mechanical deep placement of all fertilizers as basal dose at 10 cm soil depth (one-time deep-placement fertilization, namely OTDP fertilization); manual surface broadcast (the common farmer practice) of 40% N fertilizer at one day before sowing (basal fertilizer) followed by broadcast application of 30% each at tillering and panicle initiation stages; and no fertilizer application at any growth stage as a control. One-time deep-placement fertilization increased grain yield of both rice cultivars by 11.8%–19.6%, total nitrogen accumulation by 10.3%–13.1%, nitrogen grain production efficiency by 29.7%–31.5%, nitrogen harvest index by 27.8%–30.0%, nitrogen agronomic efficiency by 71.3%–77.2%, and nitrogen recovery efficiency by 42.4%–56.7% for both rice cultivars, compared with the multiple-broadcast treatment. One-time deep-placement fertilization reduced CH4-induced global warming potential (GWP) by 20.7%–25.3%, N2O-induced GWP by 7.2%–12.3%, and total GWP by 14.7%–22.9% for both rice cultivars relative to the multiple-broadcast treatment. The activities of glutamine synthetase and nitrate reductase were increased at both panicle-initiation and heading stages in both rice cultivars following one-time deep-placement fertilization treatment. Larger leaf area index at heading stage and more favorable root morphological traits expressed as larger total root length, mean root diameter, and total root volume per hill were also observed. One-time deep-placement fertilization could be an effective strategy for increasing grain yield and nitrogen use efficiency and lowering greenhouse-gas emissions under mechanical direct-seeded cropping systems.

Only 47% nitrogen of fertilizer is taken up by a plant whereas more than 40% nitrogen of total applied fertilizer is lost to environment that causes several environmental as well as economic consequences. Slow-release fertilizers are considered as a possible large-scale solution for nitrogen loss. The present study aims to stabilize urea by coating with four different materials including calcium phosphate (CP), gypsum powder (GP), calcium nitrate (CN), and gelatin (G) individually and in combination for slow release of nitrogen to sorghum crop. The physical and chemical characteristics of coated urea were examined by FT-IR, powder XRD, SEM, and rushing strength. Results showed that coating of CP, GP, and CN over urea was uneven and rough while G coating was smooth and admirable, and no pore was observed on the surface and indicated a weak water-urea interaction. Similarly, CPG coating over urea showed a maximum crushing strength of 2.38 N/m2. Slow-release and soil leaching analysis revealed that G coated urea showed the maximum 39.12 and 779.36 ppm nutrient loss after 15- and 480-min treatment, respectively which is much better than uncoated urea (99.81 and 993.65 ppm). Results reported that the maximum plant height, diameter, and chlorophyll were observed as 132.91 ± 1.52 cm, 24.56 ± 1.00 mm, and 56.30 ± 1.03 mg/m2 with CNG coated urea. Similarly, CNG also revealed the maximum dry matter yield (DMY) of 25226.15 kg/ha in shoots and 2633.50 kg/ha in roots, nitrogen uptake (NU) of 18153.75 kg/ha in shoots and 233.99 kg/ha in roots, and apparent nitrogen recovery (ANR) of 71.14% in shoots and 4.55% in roots. It is concluded that CNG coated urea showed better DMY, NU, ANR, and pot analysis, and it is recommended as a slow-release fertilizer for large scale application to minimize nutrient loss and maximize crop production.

Cadmium (Cd) has become the primary pollution factor in farmland, which seriously threatens crop growth and food safety. A pot experiment was conducted to investigate the effect of combined application with biochar and P fertilizer on soil Cd availability and translocation, in which biochar was 0 (C0) and 20 g kg-1 (C20), P fertilizer was 0 (P0), 20 (P20), and 40 mg P kg-1 (P40). Results showed that, compared with C0 level, the content of DTPA-Cd in soil was significantly decreased with biochar addition after 60 days of cultivation, under C20 level, soil DTPA-Cd in C20P40 treatment were significantly increased. Under both C levels, the percentage of exchangeable Cd fraction at P40 rate was significantly lower than that at P20 rate, because the excess P in soil could precipitate Cd. The percentage of residual-Cd fraction was significantly increased with the combined addition of biochar and P fertilizer, particularly in C20P40 treatment, which was 75.95%, while it was only 61.65% in C0P0 treatment. The Cd translocation factor (TF) and bioconcentration factor (BCF) were also significantly reduced in C20P20 and C20P40 treatments compared with C0P0 treatment. Therefore, the combined high P and biochar application was a good choice in inhibiting soil Cd availability and plant Cd uptake, which benefited to the safe utility of the Cd contaminated soil.

Intercropping of maize (Zea mays L.) and peanut (Arachis hypogaea L.) often results in greater yields than the respective sole crops. However, there is limited knowledge of aboveground and belowground interspecific interactions between maize and peanut in field. A two-year field experiment was conducted to investigate the effects of interspecific interactions on plant growth and grain yield for a peanut/maize intercropping system under different nitrogen (N) and phosphorus (P) levels. The method of root separation was employed to differentiate belowground from aboveground interspecific interactions. We observed that the global interspecific interaction effect on the shoot biomass of the intercropping system decreased with the coexistence period, and belowground interaction contributed more than aboveground interaction to advantages of the intercropping in terms of shoot biomass and grain yield. There was a positive effect from aboveground and belowground interspecific interactions on crop plant growth in the intercropping system, except that aboveground interaction had a negative effect on peanut during the late coexistence period. The advantage of intercropping on grain came mainly from increased maize yield (means 95%) due to aboveground interspecific competition for light and belowground interaction (61%72% vs. 28%-39% in fertilizer treatments). There was a negative effect on grain yield from aboveground interaction for peanut, but belowground interspecific interaction positively affected peanut grain yield. The supply of N, P, or N + P increased grain yield of intercropped maize and the contribution from aboveground interspecific interaction. Our study suggests that the advantages of peanut/maize intercropping for yield mainly comes from aboveground interspecific competition for maize and belowground interspecific facilitation for peanut, and their respective yield can be enhanced by N and P. These findings are important for managing the intercropping system and optimizing the benefits from using this system. (C) 2021 Crop Science Society of China and Institute of Crop Science, CAAS. Production and hosting by Elsevier B.V. on behalf of KeAi Communications Co., Ltd.

Background Phosphogypsum is a waste product from production of phosphorus and is stored in a containment pond. Phosphogypsum wastewater still contains a usable amount of phosphorus. In addition to phosphorus, this water contains a small amount of arsenic, which prevents direct use of this water in agriculture. Method Recycling of phosphorus from phosphogypsum wastewater was performed by struvite (NH4MgPO4•6H2O), precipitation. Arsenostruvite (NH4MgAsO4•6H2O) has always occurred naturally in the presence of struvite. The properties of arsenostruvite in comparison with struvite were monitored. The effect of selected reductants (SnCl2, ascorbic acid, K2S2O5) on the potential of reducing the concentration of As in the struvite crystallized from phosphogypsum wastewater, was monitored. Findings When recovering phosphorus from phosphogypsum wastewater in the form of struvite the results showed that a ratio of As to P was lower by 50% compared to the original wastewater. K2S2O5 proved to be the most effective reducing agent for reducing the arsenic content of the product, but it was still not sufficient for the product to be used as a fertilizer without any further treatment.

The burning of agricultural waste is a major cause of environmental pollution. In this study, we sought to prepare biochar from agricultural waste as a source material for the preparation of carbon nanoparticles (CNPs). Surface morphology, hydrodynamic particle size, and purity and crystallinity of CNPs were extensively investigated using transmission electron microscopy (TEM), zeta sizing, and X-ray diffraction (XRD) spectroscopy, respectively. The CNPs were subsequently immersed in a solution of potassium nitrate (KNO3) to prepare a CNPs/NK nanocomposite (CNPs loaded with nitrogen (N) and potassium (K)) as a nanocomposite fertilizer for common bean (Phaseolus vulgaris L.). The CNPs/NK nanocomposite was sprayed as a foliar fertilizer at 0, 10, 20, 30, and 40 mg L–1 on common bean plants 25 d after sowing on a farm in Shebin El-Kom, El-Monifia, Egypt. The growth, yield, and quality of common bean were investigated during two successive growing seasons (2017 and 2018). The highest seed yields of 2.04 and 2.01 t ha–1 and the highest values of growth parameters including plant height of 61.5 and 59.2 cm, number of leaves per plant of 35 and 35, number of flowers per plant of 83.3 and 82.7, and plant fresh weight of 148.7 and 152.8 g plant–1 were obtained when using the CNPs/NK nanocomposite at a concentration of 20 mg L–1 during the 2017 and 2018 growing seasons, respectively.

A factorial experiment consisting of three factors, namely six fertilizer doses including different combinations of potassium (K) and silicon (Si) along with nitrogen (N) and phosphorus (P) and the control (NP100 [control], NP100 + K100, NP100 + Si100, NP100 + K75 + Si25, NP100 + K50 + Si50, NP100 + K25 + Si75), three soil water potential levels (0, –15, –30 kPa), and two cultivation methods (wet direct seeding, transplanting), was conducted to evaluate the response of rice in terms of growth, physiological traits, yield, and water productivity. The experiment was laid out in a completely randomized design with three replications and the data were collected on selective growth parameters, physiological traits, yield components, and grain yield of rice. Supplementing N and P with only K (NP100 + K100) helped in alleviating the harmful effect of water-deficit stress, and resulted in 11%, 8%, 47%, 40%, 40%, and 42% higher leaf greenness, leaf relative water content, net photosynthetic rate, free proline content (wet direct-seeded plants), grain yield (wet direct-seeded plants), and water productivity, respectively, than NP100 at – 30 kPa, while transpiration rate was reduced by 22% for the same treatment combinations. Silicon supplementation either with NP100 alone or in combination with different proportions of K also promoted rice growth, physiological traits, and grain yield; however, the response of rice was largely similar among different K and Si combinations, except for NP100 + K25 + Si75. Inclusion of K and Si with N and P in a fertilizer management program where the share of K is at least 50% could be a promising approach to minimize the harmful impact of water-deficit stress in rice cultivated through either wet direct seeding or transplanting method.

In the context of black soldier fly (BSF) rearing, often the residues from production — mainly faeces but also undigested substrate — are addressed as frass in a broader sense. As BSF production is expanding, the valorization of BSF frass as organic fertilizer is gaining importance. However, in contrast to established organic fertilizers, little is known on the properties and variation of this by-product, which is essential for assessing possible application purposes. To elaborate a first overview on this relatively new waste stream, BSF frass analyses from the literature and anonymized frass analyses enquired from BSF producers were compiled. For a possible agricultural use as a fertilizer, their nutrient patterns were assessed. With a balanced nitrogen:phosphorous pentoxide:potassium oxide (N:P2O5:K2O) ratio of 1:0.9:1.1, BSF frass can be characterized as a slightly alkaline (pH 7.5), nutrient-rich compound fertilizer, with the nutrient and especially the micronutrient contents showing high variation. The comparably high carbon-to-nitrogen ratio and low shares of ammonium nitrogen indicate a limited immediate nutrient release and point to possible applications of frass as a long-term fertilizer. The use of frass as an organic fertilizer as one element in a fertilization strategy is promising. By improving nutrient cycling back to the field, BSF frass can represent an important element of sustainable circular agriculture. However, more information on BSF feed and production systems needs to be combined with the nutrient analyses to better understand the variation in frass nutrient contents.

Foliar application of fertilizers can guarantee nutrient availability to beans, leading to higher yield and seed quality. Different approaches including glycine have been used to improve mineral nutrient status of plants toward safer products and improved human health. However, limited research has been undertaken to understand the response of beans to amino Zn and Mg foliar fertilizer application in Ghana. This study was conducted to investigate the effect of zinc, magnesium, and combined zinc and magnesium foliar fertilizer application on two improved common bean (Phaseolus vulgaris L.) varieties locally referred to as Adoye and Nsroma in the forest (Fumesua) and forest-savannah transition (Akumadan) agro-ecological zones of Ghana during the 2018 and 2019 cropping seasons. The treatments were arranged in split-plot design with the two improved common bean varieties as the main plot, and foliar fertilizer options (zinc, 200 g/ha; magnesium, 224 g/ha; combined zinc and magnesium, 100 g/ha Zn and 112 g/ha Mg) and water spray (control) as the subplot treatments. The zinc and combined zinc and magnesium treatments had similar and significantly ( P ≤ 0.05 ) higher plant height of 37.1 cm and 38.7 cm compared to the control and magnesium treatments. The results also showed that chlorophyll content was approximately 15.6% higher in plants treated with zinc plus magnesium compared to the other treatments. Similarly, stomatal conductance was significantly ( P ≤ 0.05 ) increased by 35.6% with zinc plus magnesium treatment relative to the other treatments. The improved chlorophyll content and stomatal conductance in those treatments resulted in ∼55.3–80.6% increase in crop biomass and seed yield. Crop performance parameters such as plant height, canopy spread, and chlorophyll content were significantly higher ( P ≤ 0.05 ) at Akumadan, resulting in a greater seed yield of 1486.2 kg/ha compared to 1365.3 kg/ha at Fumesua. Combined application of zinc and magnesium appears to be a potential soil improvement strategy for common bean production in tropical soil environment of Ghana.

Phosphorus (P) accumulation in croplands resulting from ever-increasing input of P fertilizer strongly influences soil microbial growth and activities, which is expected to alter the soil priming effect (PE) induced by plant residue. However, the effect of P availability on the magnitude and direction of PE remains largely unexplored and the underlying microbial mechanisms are still unclear. Therefore, a 40-day incubation experiment was established by adding C4-maize straw to C3-soils with or without long-term P fertilizer inputs to investigate PE and accompanied dynamics of microbiota. The results revealed that in both soils, straw application caused positive real PEs via a “microbial co-metabolism” mechanism, accompanied by a microbial succession from the dominance of r- and K-strategists to K-strategists (mainly fungi). In addition, long-term amendment with P increased PE by 83.2% compared with no P fertilization control, which was mainly mediated by K-strategists, especially the fungal families Chaetomiaceae and Myrmecridiaceae. The increased PE was accompanied by enhanced microbial biomass carbon, extracellular enzyme activities, and bacterial gene abundance, confirming the “stoichiometric decomposition” theory. Meanwhile, deviating from the conventional paradigm, higher phosphatase activity and lower enzymatic stoichiometry of carbon (C)-to-P ratios in high-P soil compared with that in low-P soil suggested stronger “P mining” with high-P availability.

Atmospheric concentrations of carbon dioxide (CO2) have steadily increased over recent decades. The fertilization effect of elevated CO2 concentrations (E-[CO2]) is known to increase the biomass production and also the nitrogen (N) demand of paddy rice, which affects the rice N use efficiency. This study was conducted to elucidate the fertilizer-derived N use of paddy rice (Oryza sativa L.) for two varieties, japonica cv. Koshihikari and indica cv. Takanari, with and without E-[CO2] using a free-air CO2 enrichment (FACE) facility in central Japan. To quantify the fate of fertilizer-derived N directly, polymer-coated 15N-labeled urea was used with a one-shot application rate of 80 kg N ha–1 incorporated into the plowed layer at the basal fertilization before transplanting of rice seedlings. The biomass, total N concentrations, and 15N abundance in each part of the rice plants were measured at the panicle initiation, heading, and maturing stages. The total N content and 15N abundance in the soil were measured at the maturing stage to evaluate the N balance of the rice–soil system. While E-[CO2] significantly increased the whole plant biomass and the total N content in panicles, it did not increase the total N and the fertilizer-derived N content in the whole plant. The recovery efficiency (fertilizer-derived N in the whole plant to applied N, RE) ranged between 64.9% and 68.7%, and the agronomic efficiency (fertilizer-derived N in panicles to applied N, AE) ranged between 37.8% and 43.8%. The effect of CO2 on RE and AE was not significant. The REs, higher in Koshihikari, and the AEs, higher in Takanari indicated that Takanari preferentially allocated fertilizer-derived N to panicles. The REs, 69% at the maximum in this study, implies an upper limit of use efficiency of N fertilizer, even for polymer-coated (controlled-release) fertilizer. E-[CO2] significantly increased the rice N uptake from sources other than fertilizer, of which mineralization was the most-likely source. Monitoring of soil fertility and appropriate fertilization management are, therefore, necessary for sustainable rice production avoiding long-term decline in soil N fertility.

A better understanding of the fate of nitrogen (N) fertilizer is critical for designing appropriate N management and for evaluating the total N use efficiency under plastic mulching on farmland. A two-year field experiment was conducted to determine the effects of manure and plastic mulching on the fate of 15 N-labelled urea. Urea was applied at the same rate to spring maize (Zea mays L.) growing in soils under three different treatments (no film mulching + mineral fertilizer, CK; film mulching + mineral fertilizer, FN; and film mulching + mineral fertilizer + cow manure, FNM) in 2018 and 2019, but 15 N-labelled urea was applied in 2018 only. FN and FNM increased the maize grain yields for both years. FN increased the total N uptake in the aboveground biomass by 20% in 2018, whereas no significant difference in 15 N uptake was observed in 2018 compared with that of the CK. The residual 15 N in the 0–1 m soil layer fell within a range of 8–20% two years later and was mostly retained in the top 0.2 m. FN and FNM significantly increased the total N uptake after two years, while the opposite trend was observed for potential N loss. The decreases in potential loss were 6% under FN and 39% under FNM. Therefore, our results indicate that plastic film mulching combined with manure application could not only increase maize grain yields and N uptake but also reduce the loss of fertilizer N, affecting the fate of urea-N in maize production.

Iron (Fe) and manganese (Mn) remain intractable in the fertilizer design due to the incompatibility with phosphorus (P). Herein, we proposed a nanoscale hierarchical structure, where traditional io...

Atmospheric ammonia (NH3) is a precursor to fine particulate matter and a source of nitrogen (N) deposition that can adversely affect ecosystem health. The main sources of NH3 – agriculture and biomass burning – are undergoing are or expected to undergo substantial changes in Africa. Although evidence of increasing NH3 over parts of Africa has been observed, the mechanisms behind these trends are not well understood. Here we use observations of atmospheric NH3 vertical column densities (VCDs) from the Infrared Atmospheric Sounding Interferometer (IASI) along with other satellite observations of the land surface and atmosphere to evaluate how NH3 concentrations have changed over Africa from 2008 through 2018, and what has caused those changes. In West Africa NH3 VCDs are observed to increase during the late dry season, with increases of over 6 % yr−1 in Nigeria during February and March (p

Ethylenediaminetetraacetic acid is increasingly used to improve heavy metal mobility and bioavailability in soil for phytoremediation, although little empirical data exist on its potential effects on soil properties essential to phytoremediation success and ecosystem health. In this study, field-based ethylenediaminetetraacetic acid-, nitrogen–phosphorus–potassium fertilizer-, and combination of ethylenediaminetetraacetic acid and nitrogen–phosphorus–potassium fertilizer-assisted phytoremediation were used to determine the effects of ethylenediaminetetraacetic acid on some soil physicochemical and biological parameters. Ethylenediaminetetraacetic acid reduced the levels of pH, organic matter, calcium, potassium, magnesium, total fungi and bacteria and improved microbial carbon and nitrogen as well as nitrate and ammonium contents. However, it had no effect on soil field capacity. In general, ethylenediaminetetraacetic acid had a greater explanatory power for the variations in pH, organic matter and total bacteria relative to the other treatments and time. Nitrogen–phosphorus–potassium fertilizer reduced the effects of ethylenediaminetetraacetic acid on soil pH, organic matter, potassium, phosphorus, microbial carbon and nitrogen. Hence, combination of ethylenediaminetetraacetic acid and nitrogen–phosphorus–potassium fertilizer was the most effective in improving the soil conditions for phytoremediation. The most significant changes in the effects of the treatments on all but nitrogen were observed in the first six months of the study, corresponding with the wet season, suggesting the need to consider the season or timeframe when designing field-based assisted phytoremediation. The results broadly demonstrate the effectiveness of nitrogen–phosphorus–potassium fertilizer in compensating for the potentially negative effects of ethylenediaminetetraacetic acid on soil properties during phytoremediation.

The mixed application of pesticides and foliar fertilizer has been widely used in the production of cucumber, however, their effects on plant growth and pesticide dissipation are still unclear. In this study, the effects of mixed application of pymetrozine, tebuconazole and foliar fertilizer on the cucumber plant growth and pesticide dissipation were investigated simultaneously. The results show that the mixed use of pymetrozine, tebuconazole, especially adding foliar fertilizer, improved the physiological indexes (i.e., area, nitrogen content and chlorophyll content of the leaves, and root growth) of cucumber plants compared to those with the application of single pesticide. Meanwhile, it can significantly affect the dissipation of pymetrozine even in the slower growth matrices (lower leaves, stems, and plants). The residue of tebuconazole in cucumber plants was affected by the combination of formulation type and foliar fertilizer. This study can provide data for scientifically guiding the mixed application of pesticide and fertilizer.

Pre-emergence (PRE) herbicides are commonly applied simultaneously with fertilizers to turfgrass; however, the influence of PRE herbicides on nitrogen (N) uptake and leaching from turfgrass remains unclear. The hypothesis of this study was that PRE herbicides applied simultaneously with N fertilizers increase N leaching from Tifway 419 bermudagrass [Cynodon dactylon (L.) Pers. × C. transvaalensis Burtt-Davy, 'Tifway'] above that from fallow soil. A nutrient leaching study was conducted from June 2017 through June 2019 in Fort Lauderdale, FL. Treatments consisted of indaziflam (25 g a.i. ha-1 ), prodiamine (540 g a.i. ha-1 ), and oxadiazon (4,480 g a.i. ha-1 ); a nontreated turfgrass control (turfgrass fertilized but not treated with PRE herbicides); and a fallow soil. Fertilizer (15-2-12) was applied every 60 d at 49 kg N ha-1 , and PRE herbicides were applied every 120 d. Pre-emergence herbicides resulted in a 3.6- and 5.5-fold increases in NO3 -N concentration compared with fallow soil during June 2017 and January 2018, respectively, whereas fallow soil resulted in increased NO3 -N concentration during 10 mo and ranged from 3.8- to 15-fold greater than that from turfgrass plots. Turfgrass plots resulted in reduced N leaching of ∼7% during 5 mo compared with fallow soil and did not result in increased N leaching during any month. Cumulative N leached from turfgrass plots ranged from 75 to 120 kg ha-1 and did not differ from fallow soil. Turfgrass growth rate and N uptake were not influenced by PRE herbicide. The results indicated that fertilizers applied with PRE herbicides does not result in increased N leaching or reduced N uptake.

The present article, based on reverse logistic, provides an environmentally beneficial and cost-effective method of producing calcium phosphate bioceramics (potassium calcium phosphates) aimed for soil conditioning, by a free-solvent mechanochemical process between eggshell waste and KH2PO4. The K3CaH(PO4)2 and possibly CaKPO4 phases formed provide a better nutrient management of P, K and Ca, when applied in soil system the material first release K and form hydroxyapatite and important P and Ca bioavailable source at pH ∼ 5, which comprises a large part of many countries soils.

Zinc deficiency is the most common abiotic stress observed worldwide and its omission from fertilizer schedule reduces crops yields, productivity, and quality of crop produces. Zinc use efficiency is generally low (

Tillering is an important phenological stage, which is strongly related to the yield in spike components and final grain yield during winter wheat growth. Precipitation during the fallow season (fallow precipitation) influences tillering in winter wheat on the semi-arid Chinese Loess Plateau. However, little work has been done regarding tiller number changes under various types of fertilization and amounts of fallow precipitation on a long-term scale. Effects of fallow precipitation and fertilization on tiller were investigated in a winter wheat (Triticum aestivum L.) system in a 28-year field study (1990 to 2017) in a semiarid agro-ecosystem. Tiller number, spike number and grain yield were measured in four fertilization conditions: control without fertilizer (CK); mineral nitrogen fertilizer alone (N); mineral phosphorus fertilizer alone (P); mineral nitrogen and phosphorus fertilizer together (NP). Based on the long-term annual fallow precipitation, dry years (mean annual fallow precipitation) were distinguished. Phosphorus fertilization alone significantly increased the mean annual tiller number (23%), and the increase in tiller number was higher in wet years (29%) than in the dry years (17%). However, nitrogen fertilization alone had little effect on mean tiller number, while nitrogen and phosphorus together significantly increased mean annual tiller number (30%), mean tiller number in wet years (45%) and mean tiller number in dry years (17%). Tiller number was significantly and positively correlated with fallow precipitation in dry years for all fertilizer treatments, whereas it was weakly and either positively or negatively correlated with fallow precipitation in wet years depending on the treatment. This study found positive correlations between tiller number and fallow precipitation in the CK and NP treatments, and it found negative correlations between tiller number and fallow precipitation in the treatments with nitrogen fertilization alone or phosphorous fertilization alone in wet years. Understanding the impacts of fallow precipitation and fertilization on tiller development shed light on ways to improve crop production in rain-fed agricultural regions.

The aims of the present study were to provide scientific bases for rational use of crop straw to substitute chemical potassium (K) input. The effects of potassium fertilization and straw incorporation on soil K balance and K supplying in a long-term (14 years) field experiment. Five treatments were examined: (1) no fertilization (CK); (2) mineral fertilizing (NPK); (3) straw 6000 kg h m−2 (S); (4) NPK with straw 3000 kg h m−2 (NPK1/2S); and (5) NPK with straw 6000 kg h m−2 (NPKS). K composition, K balance and quantity-intensity (Q/I) relationship were studied. Under no fertilization or low straw returned conditions, soil K was unbalanced and deficienct seriously. Straw return at 6000 kg h m−2 per season with fertilization improved the soil potassium supply and K balance. Long-term K surplus (4 or 5 years), compared with NPK, the NPKS significantly increased non-special K adsorption (Knsa) and non-exchangeable K (Kne) by 5.7–11.2 mg kg−1 and 65.7–128.1 mg kg−1, respectively. Q/I relationship showed cropping without straw K or without fertilizer K resulted in lower quantity (nonspecifically and specifically held K i.e. – ∆K0 and Kx) and intensity (equilibrium activity ratio i.e. CR0K) of K in tested soils. K-fertilization with straw maintain higher exchangeable K (EK0) and a higher difference between EK0 and minimum exchangeable K(EKmin), and would help to prevent depletion in non-exchangeable pool of soil K under intensive cropping. Additionally, The straw return mainly decreased potential buffering capacity for exchangeable pool (PBCKn), 43.92–48.22% of added K in soil might be converted to exchangeable pool while it was 25.67–29.19% be converted to non-exchangeable pool. The contribution of exchangeable K towards plant K uptake would be higher in the soil with straw than the soil without straw and the non-exchangeable K would be the long-term fixed K as a supplement to the potassium pool. K fertilizer with 6000 kg h m−2 straw return in each crop season increased soil available K and slowly available K. The findings underlined importance of the straw return and contribution for sustain K supplying ability of soils.

In this work, a novel slow-release and water-retention nitrogen (N) fertilizer (SRWRNF) was prepared using moldy steamed bread-based starch-g-poly(acrylic acid-co-acrylic amide) (SBS-g-P(AA/AM)) as the skeleton and urea-formaldehyde oligomers (UF) incorporated as the slow-release N source by semi-interpenetrating methods. Various analysis technologies including scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, thermogravimetric analysis, and differential scanning calorimetry were used to characterize the structure and properties of SRWRNFs. Swelling measurements indicated that the maximum water absorbency of SBS-g-P(AA/AM)-UF samples was 104.2 g/g in distilled water. The water-retention study showed that the SBS-g-P(AA/AM)-UF improved the maximum soil water content by 15.3–17.6% while improving soil water-retention capacity. N release experiments confirmed that SBS-g-P(AA/AM)-UF enabling offered a gradual N supply in soil. In comparison to conventional urea and UF fertilizers, the maize yield of SBS-g-P(AA/AM)-UF was increased by 20.3 and 9.7%, respectively. This study implies that the SRWRNFs provide a promising feasibility for large-scale applications in agriculture.

Fertilization is one of the most common applications in agricultural fields for achieving high yield. Fertilizer is the important input of agriculture. Raw material costs are nearly 80% of the production costs in chemical fertilizers. Because of high prices, fertilizer usage has started to decrease. The utilization of industrial wastes in the production reduces the costs. Not only is fertilizer expenditure significant, but also the physical properties should be considered. In this study, the physical characteristics of composited fertilizer containing boron which was obtained from the reaction between the diammonium phosphate and borogysum industrial waste were examined. Under laboratory conditions, diammonium phosphate was composited with borogysum at the mole ratio of 1:1 and during this process, the solid/liquid (S/L) ratio, temperature, time, pH of the pulp and speed were 1/3, 40°C, 90 min, 5.5 and 500 rpm respectively. The moisture content, grain (granule) size, tight and loose volume weights, granular fracture resistance and the agglomeration angle of the new product including boron were evaluated. As a consequence, the grain size was in range of 3 and 4 mm, loose volume weight was 1363.32 kg/m3, the granular fracture resistance was 2.92 kg/granule, agglomeration angle was 89.9 kg/granule and Granulometric Spread Index (GSI) and Uniformity Index (UI) were recorded as 16 and 76.9. These findings were compatible with National and International Standards.

As the overuse of nitrogen fertilizer has caused series of environmental problems, improving the nitrogen use efficiency of rice crop has been drawing much attention. Since developing nitrogen-efficient rice genotypes is a feasible solution, illustrating the microbiological characteristics of the nitrogen-efficient rice genotypes is of great importance. We performed a field experiment, and planted 16 genotypes of rice. The nitrogen utilization efficiencies and yields of rice were examined. Real-time PCR and Illumina sequencing were employed to investigate the abundance of the nitrogen-cycle related genes and the bacterial community structure of the rhizosphere. The results revealed that rice genotypes enriched specific bacterial communities to inhabit in the rhizosphere at both the taxonomic and functional levels. The enriched bacteria were mainly involved in the functions of nitrogen transformation, ferric iron reduction, organic compound biodegradation, and sulfur transformation. We observed a strong correlation between the yield and the abundance of rhizospheric functional bacteria, especially the groups of Proteobacteria and Chloroflexi. The analysis of nitrite reductase and denitrifying genes showed that the denitrification activity in the rhizosphere inversely correlate with the efficiency of nitrogen utilization. We reason that a smaller denitrifying bacteria population leads to less the nitrogen loss in the rhizosphere, thus an increase of available nitrogen and a higher rice yield. This research revealed how functional bacteria assembled in the rhizosphere of rice genotypes with varied nitrogen use efficiencies, which may provide valuable information with regard to the improvement of nitrogen use efficiency and reduction of fertilizer application.

The development of chemicals to slowly release hydrogen sulfide would aid the survival of plants under environmental stressors as well as increase harvest yields. We report a series of dialkyldithiophosphates and disulfidedithiophosphates that slowly degrade to release hydrogen sulfide in the presence of water. Kinetics of the degradation of these chemicals were obtained at 85 °C and room temperature, and it was shown that the identity of the alkyl or sulfide group had a large impact on the rate of hydrolysis, and the rate constant varied by more than 104×. For example, using tert-butanol as the nucleophile yielded a dithiophosphate (8) that hydrolyzed 13,750× faster than the dithiophosphate synthesized from n-butanol (1), indicating that the rate of hydrolysis is structure-dependent. The rates of hydrolysis at 85 °C varied from a low value of 6.9 × 10–4 h–1 to a high value of 14.1 h–1. Hydrogen sulfide release in water was also quantified using a hydrogen sulfide-sensitive electrode. Corn was grown on an industrial scale and dosed with dibutyldithiophosphate to show that these dithiophosphates have potential applications in agriculture. At a loading of 2 kg per acre, a 6.4% increase in the harvest yield of corn was observed.

Enhancing agricultural and environmental benefits of biochar through physical, chemical, or thermal modifications is frequently employed, but information on the concentration, transformation rate, and half-life of available phosphorus (P) in chemically modified-biochar amended P-fertilized calcareous soils is yet lacking. For this reason, we investigated here the effect of citric acid–modified biochar (CAMB) derived from low-ash agricultural wastes (wheat straw) on P transformation and changes in its plant availability indices in a calcareous sandy soil. An incubation experiment comprising three biochar treatments, viz. control (CK, unamended soil), soil amended with 4% CAMB (CAMB1), and soil amended with 8% CAMB (CAMB2), was conducted under laboratory conditions. The soil samples were incubated at 80% soil moisture (v/w) for 9, 18, 27, 36, 46, and 54 d at 25 ± 1 °C, and Olsen-P was measured after each incubation period. Soil pH and EC were also measured after 9 and 54 days of incubation. To describe the release of P and to determine its rate of transformation, first-order equation, parabolic diffusion, power function, and simple Elovich were used. Parabolic equation exhibited a good ability to describe the decrease in P release in soil (0.82 R2 and 0.2 SE). Plant available P in CAMB-amended soil was substantially higher than the unamended soil. The lower pH and P transformation rate indices and the release of available P for a more extended period were found in CAMB-amended soils. The half-life of available P in the CAMB-amended soils exceeded 80% over unamended soil. The rate of P diffusion in CAMB-amended soils was lower (0.05–0.06 day−1) than the unamended soil (0.2 day−1). Integrated use of citric acid–modified biochar with inorganic P in calcareous sandy soil acts as a slow-release fertilizer, has a low cost, and is a clean alternative to mineral fertilization.

Microalgae, Botryococcus braunii in particular, have received increasing interest owing to their potential as biofuel sources. Although the fertilizer components present in wastewater are useful in reducing the cost of commercial production of microalgae, the ammonium nitrogen (NH4+-N) acidifies the medium and may inhibit the growth of B. braunii. In this study, we aimed to investigate the effectiveness of calcium carbonate in preventing the growth inhibition of B. braunii by suppressing pH decrease caused by NH4+-N. Four types of modified Chu13 media were prepared: a control, one with NH4+-N, one with calcium carbonate, and one with calcium carbonate and NH4+-N. Then, the pH, NH4+-N concentration, B. braunii growth, and hydrocarbon content were measured. We found that in the NH4+-N treatment without calcium carbonate, the pH decreased to approximately 4, and there was almost no algal growth even after 20 days. In contrast, there were no differences in the growth rate and medium pH (7–8) between the treatment with calcium carbonate and the control medium. In addition, calcium ions were leached into the medium with calcium carbonate as the culture progressed, confirming the effectiveness of calcium carbonate in maintaining a constant pH and thus preventing growth inhibition. As such, the addition of calcium carbonate effectively prevents B. braunii growth inhibition by suppressing pH decrease and is more cost-effective than aggressive pH adjustment with alkali or acid or by adding buffer solutions into the medium. This simple and inexpensive method can be used for the removal of ammonia from wastewater.

Phosphorus (P) is an essential macronutrient required for the survival and reproduction of all living organisms. Its inorganic form (Pi) is taken up by the roots to support plant growth and development, and its availability directly determines agricultural productivity. The primary source of P replenishment in agriculture is chemical phosphate (Pi) fertilizers. While application of Pi-fertilizers to croplands ensures high yield agriculture, its intensive use leads to several environmental implications, including loss of soil fertility and pollution of water bodies with runoff fertilizer. Global non-renewable P-reserves are finite and would last for only a few hundred years. Therefore, a holistic approach is needed to combine Pi-use efficient germplasm with the targeted fertilization, agronomically superior fertilizer formulations for better P-management. The latest technologies to reclaim Pi from alternative sources need to be explored. In the present review, we first outline the challenges and environmental consequences of Pi-intensive fertilization, followed by plants' response and adaptive strategies to Pi starvation. Next, we discuss the role of microbes and Pi-nanofertilizer to plant Pi nutrition. Finally, a few cutting-edge technologies and innovative solutions available for reclaiming Pi from waste are argued.

El balance nutrimental, es un enfoque para generar recomendaciones de fertilización, el cual requiere menos recursos y tiempo para su implementación, se basa en que la dosis de fertilización depende de la demanda del nutrimento por el cultivo, el suministro del nutrimento por el suelo y la eficiencia de recuperación del nutrimento aplicado como fertilizante. El objetivo fue evaluar el modelo conceptual de fertilización para generar dosis nitrogenadas en maíz en la Costa del Golfo de México. Este consistió en el balance entre demanda de nitrógeno del cultivo, menos el suministro de nitrógeno por el suelo entre la eficiencia del fertilizante en cuatro tratamientos (VS-536 y V-537 C con y sin fertilizante). Los parámetros fisiotécnicos evaluados en las localidades Jamapa, Paso Real y El Rincón, del municipio de Jamapa, Veracruz fueron: demanda del cultivo, suministro de nutrimentos por el suelo y eficiencia del fertilizante. La demanda de nitrógeno con fertilizante fue estadísticamente superior a la no fertilizada; el suministro en ambos tratamientos fue estadísticamente similar. La eficiencia del fertilizante nitrogenado fue menor al 50% en las tres localidades. Las dosis de nitrógeno estimadas con el modelo conceptual fueron diferentes en las tres localidades (Jamapa 85, Rincón 55, y Paso Real 72 kg N ha-1, respectivamente) en comparación con la dosis aplicada (150 kg N ha-1), lo que representa una sobrefertilización del 44%, 64% y 52% para Jamapa, Rincón y Paso Real. Se concluye que este modelo permitió generar dosis adecuadas de Nitrógeno en menor tiempo y con una menor inversión.

This study reports on a wide-scale, systematic sampling program over two consecutive years investigating As and Cd and associated implications for human health in farming areas of the dry zone, Sri Lanka, where chronic kidney disease with unknown etiology (CKDu) is endemic. Surface soil (0–15 cm), fertilizer and rice seed samples were collected in 2017 and 2018 from three CKDu affected areas [Medawachchiya (M), Padaviya (P) and Giradurukotte (G)], and a non-affected control site [Hambanthota (H)]. All inorganic fertilizer samples showed low As (

This study aims to investigate the utilization status of nitrogen (N), potassium (K) and phosphorus (P) fertilizers at molecular level in field conditions. Maize cultivar Luyu 16 was planted in 41-year-old plots treated with different fertilizer combinations: unfertilized (control), N fertilizer (N), N fertilizer with P (NP), N fertilizer with K (NK), and N fertilizer with P and K (NPK). The ear leaves at grain filling stage were harvested for transcriptome analysis using RNA-Seq techniques. Results showed that NPK enhanced the contents of chlorophyll, soluble sugar, and protein, and improved the activities of antioxidant enzymes but reduced malondialdehyde (MDA) content much, relative to other treatments. There were 1258, 4438, 5177, and 4505 differentially expressed genes (DEGs) identified from the paired comparisons of NvsCK, NKvsCK, NPvsCK and NPKvsCK, respectively. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses showed that DEGs identified from different paired comparisons but involved in the same biological or metabolic process were having significant differences in numbers, transcript levels, and expression pattern. Many promising genes related to absorption, transport, and metabolism of N, P and K were identified. The combination of N together with K and/or P fertilizers induced more differential genes than sole N fertilizer application. This study would deepen our understanding of macronutrient utilization efficiency in crops.

Angelica acutiloba (Siebold & Zucc.) Kitag., the source plant of the crude drug Angelicae acutilobae radix, is traditionally cultivated in western regions of Japan. Since A. acutiloba is now also grown in Hokkaido, the northernmost prefecture of the country, the cultivation method, especially the quantity of fertilizer, needs to be adapted because of the cooler climate and shorter growing period. In this study, we compared plant growth and harvest yield of A. acutiloba cultivated with different amounts of nitrogen (N) fertilizer. When plants were fertilized with 24 kg N/10 a, the aerial part was lush, and the diameter at the top of the root was about 1.3 times thicker than that in plants treated with 12 kg N/10 a. On the other hand, the weight of the harvested root grown with 24 kg N/10 a was slightly, although not significantly, less than that in plants grown with 12 kg N/10 a. In addition, we found that the content of (Z)-ligustilide, a major essential oil contained in A. acutiloba root, is affected by nitrogen application. Interestingly, it increased with increasing amounts of supplied nitrogen. However, the importance of Angelicae acutilobae radix as the crude drug is not limited to its (Z)-ligustilide content, and there are also other crucial quality features, such as having thick lateral roots, which were generated in this study with a moderate nitrogen application. We conclude that about 12 kg N/10 a is the optimal amount of nitrogen for healthy growth of A. acutiloba in Hokkaido.

Optimum fertilizer is essential for obtaining high yields of watermelon. This three location study was conducted to investigate the effect of nitrogen and phosphorus (NP) fertilizer on the growth a...

Soil P testing has been widely used to predict crop yields, P uptake, and fertilizer demands in agriculture. Diffusive gradients in thin films (DGT) provides a zero-sink soil P test which mimics diffusion-controlled plant uptake and has previously been found to predict P availability to crops better than conventional quantity-based P tests in highly weathered Australian, though not in European soils. Here we tested the performance of DGT and the Austrian and German standard P quantity test calcium acetate lactate (CAL) to explain the variation of crop yield and P uptake response of winter wheat (Triticum aestivum L.) and spring barley (Hordeum vulgare L.) in long-term P fertilization experiments at four different sites in eastern Austria. Phosphorus extracted with DGT (P-DGT) and CAL (P-CAL) correlated well in similar soils but not across sites with large variation in soil and site properties such as carbonate equivalent and water availability. The predictive power of DGT for barley (R2 = 0.42) and wheat grain yield (R2 = 0.32), and P uptake in wheat grains (R2 = 0.36) was clearly superior to that of the CAL, and less dependent on soil properties. The better performance of DGT compared to the quantity test is consistent with diffusion-limited P uptake in the water-limited cultivated soils of eastern Austria. The critical values of P deficiency derived from the Mitscherlich-type fits for barley and wheat at 80% relative yield are 64.9 and 26.2 µg L−1, respectively, consistent with differential P demands of the crops.

Arbuscular mycorrhizal fungi (AMF) allow plants to make better use of water and minerals. This alliance concerns the majority of crops and might greatly limit their dependence on fertilizers. In this work, AMF contribution and moderate fertilization were assessed for their impact on root colonization, growth, yield, number of fruits and soluble dry matter of tomato (Solanum lycopersicum L. var. Fahla F1) in a Mediterranean agroecosystem (El-Tarf, Algeria). The soil had a low available phosphorus content and a low mycorrhizal potential. Tomato seedlings were uninoculated (M−) or inoculated (M+) with a commercial AMF inoculum. Three NPK (10.42.10) fertilizer rates corresponding to 0, 2000 and 4000 mg plant−1 were applied. Mycorrhizal inoculation significantly increased root colonization levels (+48%), height (+8.78%), shoot dry biomass (+21.5%), root dry biomass (+34.45%), total yield (+8.07%) and number of fruits (+19.05%). NPK decreased root colonization levels; however, it enhanced significantly tomato growth with the highest shoot dry biomass obtained with 2000 mg plant -1. Total yield and number of fruits increased with increasing NPK rate; the highest yield occurred with 4000 mg plant−1. Soluble dry matter was not affected by AMF or NPK. Tomato inoculation combined to a reduced fertilization can provide appreciable gains in terms of growth and yield in a low P soil with a low mycorrhizal potential, which enhances agricultural sustainability due to a decreased impact of fertilizers.