Application Of Phosphate Fertilizers Research Articles

Arbuscular mycorrhiza fungi applications and rock phosphate fertilizers enhance available phosphorus in soil and promote plant immunity in robusta coffee

ABSTRACT Many crops are colonized with arbuscular mycorrhizae fungi (AMF), which can efficiently absorb nutrient from the soil and induce plant immunity. The purpose of this study was to investigate the effects of AMF and rock phosphate (P) fertilizer applications on available P and some secondary plant metabolite in robusta coffee. The experiments were laid out in a 3 × 4 factorial randomized complete block design with AMF inoculants (control, Glomus intraradices LU3, Glomus sp. 2TS5) and rock phosphate fertilizer levels (0, 100, 200, and 400 g plant−1). Parameters measured root colonization percentage, available P in soil, total P in leaf, salicylic acid and phenolic compounds in leaves. The results showed that there was significant interaction between AMF and P in root colonization density, available P in soil, total P in leaves, and salicylic acid content. AMF (both Glomus intraradices and Glomus sp.) improved root colonization density (64–65%), available P in soil (30–50%), total P in leaves (37–40%), salicylic acid content (8–19%), and phenolic compounds in leaves (53–74%) compared to the control. Also, higher P at 400 g plant−1 increased root colonization density, available P in soil, total P accumulation in leaves, and salicylic acid. Therefore, AMF and rock P potentially represent an alternative way to promoting P uptake and plant immune in coffee.

Influence of dragon bamboo with different planting patterns on microbial community and physicochemical property of soil on sunny and shady slopes.

Dragon bamboo (Dendrocalamus giganteus) is a giant sympodial bamboo species widely distributed in Asia. However, it remains unclear how dragon bamboo and soil microbes interact to affect soil properties. In this study, we investigated the planting patterns (semi-natural and artificial) on different slopes (sunny and shady) to determine the effects on soil properties and microbial community. The results showed that the soil in which dragon bamboo was grown was acidic, with a pH value of ∼5. Also, the soil organic matter content, nitrogen hydrolysate concentration, total nitrogen, available potassium, and total potassium of the dragon bamboo semi-natural forest significantly improved, especially on the sunny slope. In contrast, the available phosphorus level was higher in the artificial bamboo forest, probably owing to the phosphate fertilizer application. The bacterial and fungal diversity and the bacterial abundance were all higher on the sunny slope of the semi-natural forest than those in the other samples. The microbial operational taxonomic units (OTUs) shared between the shady and sunny slopes accounted for 47.8-62.2%, but the core OTUs of all samples were only 24.4-30.4% of each sample, suggesting that the slope type had a significant effect on the microbial community. Some acidophilic microbes, such as Acidobacteria groups, Streptomyces and Mortierella, became dominant in dragon bamboo forest soil. A PICRUSt analysis of the bacterial functional groups revealed that post-translational modification, cell division, and coenzyme transport and metabolism were abundant in the semi-natural forest. However, some microorganisms with strong stress resistance might be activated in the artificial forest. Taken together, these results illustrated the influence of dragon bamboo growth on soil physicochemical property and microbial community, which might help understand the growth status of dragon bamboo under different planting patterns.

Cadmium phytoavailability from 1976 through 2016: Changes in soil amended with phosphate fertilizer and compost

This study aimed to determine cadmium (Cd) accumulation in arable soil, changes in Cd extractability and relevant soil properties, and Cd uptake by rice plants after long-term (50 years) application of phosphate (P) fertilizer and compost. A long-term field experiment was performed with rice crops from 1967 to 2016. Treatments included nitrogen and potassium fertilization (NK), nitrogen, phosphate, and potassium fertilization (NPK), nitrogen, phosphate, and potassium fertilization with compost application (NPK + compost), and control. Total Cd concentration in soil amended with NPK and NPK + compost continuously increased from 110 μg kg−1 up to 232 μg kg−1 from 1976 to 2016 but remained unchanged in control soil and soil amended with only NK. Plant-available Cd concentration in soil increased with year for all treatments, likely as a result of relevant changes in soil chemical properties. Cd concentrations in rice harvested in 2017 treated with NPK or NPK + compost were 212 μg Cd kg−1 and 223 μg Cd kg−1, respectively. These values exceed the maximum permissible level (200 μg Cd kg−1) established by the Ministry of Food and Drug Safety of Korea.

Live Imaging of Phosphate Levels in Arabidopsis Root Cells Expressing a FRET-Based Phosphate Sensor.

Phosphorous (P) is an essential macronutrient in all organisms serving various fundamental biological processes, and is one of the least available plant nutrients in the soil. The application of inorganic phosphate (Pi) fertilizers is frequent, but it has a high environmental and financial cost. Breeding crops for improved Pi use-efficiency is a promising plant-based solution to pursue a reduction of fertilizer dependency. Availability of tools for monitoring changes of plant cellular Pi concentration in real-time can contribute to advancing knowledge on the molecular basis of Pi transport and homeostasis in plants. Genetically encoded fluorescent sensors have provided new insight on cellular processes. Here, we show that two Pi Fluorescence Resonance Energy Transfer (FRET)-based sensors from the FLIPPi family, the low-affinity FLIPPi-30m and the high-affinity FLIPPi-4µ, can be expressed and analyzed in Arabidopsis thaliana with wild-type background. These FLIPPi sensors had not been tested in plants, but only in mammalian cell lines. We show FRET response and live imaging of Pi levels in seedling roots of Arabidopsis FLIPPi-30m and FLIPPi-4µ lines. Our results reinforce that sensors from the FLIPPi family are valuable tools for studying mechanisms of Pi transport and homeostasis in plants, and for research towards a more sustainable use of Pi fertilization.

How C:N:P stoichiometry in soils and plants responds to succession in Robinia pseudoacacia forests on the Loess Plateau, China

Ecological stoichiometry in plants and soils is an important indicator of element cycling and ecosystem stability that has been used to indicate nutrient limitation. However, the stoichiometric responses of plants and soils along a chronosequence on the Loess Plateau of China has not been studied. In this study, we chose four stand ages (5–10 years old, YF; 10–20 years old, NF; 30 years old, MF; 40–50 years old, OF) of Robinia pseudoacacia and abandoned land (AC) as research subjects to illustrate the C:N:P stoichiometry interactions among soils, plant tissues (green leaves, leaf litter, and roots), and soil microbes. The results demonstrated that the soil organic C, total N, soil microbial biomass C (MBC), microbial biomass N (MBN), and microbial biomass P (MBP) contents increased significantly with afforestation age and reached a peak in the OF stand. The soil C:N ratio showed a significant increase from 9.2 to 13.1, while no significant differences were observed in the soil MBC:MBN ratios. Compared with the R. pseudoacacia forests, AC had the lowest soil C:N, N:P, and C:P ratios. Forest stand age had different influences on the C, N, and P contents in leaves, leaf litter, and fine roots. The most obvious trends were that the N contents in leaves and litter increased with stand age, indicating that old forests could accumulate more N in their leaves and litter. The leaf N:P ratio increased from 16 to 20 along the chronosequence, which demonstrated that P was the limiting element for the growth of R. pseudoacacia plantations on the Loess Plateau. The P demand increased with stand age. Therefore, our results indicated that R. pseudoacacia plantations enhance the C and N contents in soils and microbes in the first 30 years of growth and show an increasing demand for P over time. Therefore, attention should be paid to the application of phosphate fertilizer for the management of R. pseudoacacia plantations.

Long‐term phosphate fertilization strategies evaluation in a Brazilian Oxisol

AbstractThere are concerns related to the application of phosphate fertilizers to weathered soils that present low soil test phosphorus (STP) due to P adsorption in iron oxyhydroxides. Furthermore, long‐term trials are needed to evaluate crop response to corrective P fertilization and its interaction with different maintenance P fertilization strategies in these soils. An experiment involving the combination of three initial corrective P fertilization schemes (control without P correction or with the application of 105 kg P ha−1 as triple superphosphate [TSP] or reactive rock phosphate [RRP]), four P maintenance strategies (a control without the application of maintenance P, or 35 kg P ha−1 yr−1 as TSP, RRP, or a mix of both) and two application methods was cultivated during 16 yr at the Embrapa Cerrados experimental station in Planaltina, DF, Brazil. Corrective P fertilization promoted an early crop yield response. In contrast, high crop yields were only obtained in control treatments with no corrective P fertilization after soil P stocks were increased to a minimum level. With increasing P stocks, broadcast application resulted in slightly better yields. The required residual P stocks in soil to obtain high yields were estimated as equivalent to 113.6 and 205.2 kg P ha−1 for TSP and RRP, respectively. These values allow for STP contents to increase to critical levels, whose value for TSP of 4.1 mg kg−1 Mehlich‐1 P is below that recommended for the region, possibly due to the contribution of organic P forms in the long‐term no‐tillage system.

Mitigation of Cd accumulation in rice with water management and calcium-magnesium phosphate fertilizer in field environment.

Pollution of Cd has seriously threatened environmental safety and human health. The field experiment was conducted to investigate the effects of calcium-magnesium phosphate fertilizer and water management on bioavailability of Cd in soils and its accumulation in rice. The results revealed that continuous flooding has enhanced soil pH from 5.10 to 5.72 and reduced soil redox potential (Eh) from 164 to - 60mV. Application of calcium-magnesium phosphate fertilizer has significantly raised soil pH from 5.10 to 6.45 (P < 0.05). The treatment of calcium-magnesium phosphate fertilizer and continuous flooding has reduced available content of Cd in soils by 28.57%. The content of Cd in brown rice was significantly diminished by 51.36% (P < 0.05). The continuous flooding has promoted formation of residual Cd in soil with application of calcium-magnesium phosphate fertilizer. The biomass and grain production of rice was not significantly decreased compared with control.

Phosphorus speciation and iron mineralogy in an oxisol after 11 years of pig slurry application

Application of phosphate fertilizers beyond plants needs favors phosphorus (P) accumulation in soils, which may alter its reactivity and chemical speciation. The objective of this study was to assess the changes in P speciation in a Brazilian oxisol that received consecutive applications of varying rates of pig slurry (PS) over 11 years. The soils were treated with PS at rates of 50, 100 and 200 m3 ha−1 year−1, whereas a control plot received P and potassium (K) to replenish the amounts removed by harvest. The soils were sampled and characterized for its P sorption capacity (PSC) as determined by Langmuir sorption isotherms, P partitioning by sequential chemical fractionation (SCF), P chemical speciation via P K-edge XANES and iron (Fe) mineralogy via Fe K-edge EXAFS spectroscopies. Increases in applied PS rates were accompanied by increases in PSC at the 0 to 2.5 and 0 to 10 cm soil layers. P accumulation was observed to be restricted up to the depth of 20 cm, regardless of the PS rate applied. The P K-edge XANES analysis indicated that P accumulation in the topmost soil layers, occurred predominantly associated with Fe-(hydr)oxide minerals. In this soil layer (0 to 2.5 cm), the organic P pool was of particular importance likely due to no-tillage. A dramatic change in Fe mineralogy in the topmost soil layer was observed across the studied soils, with the predominance of hematite in the reference soil and in the control plot, whereas the occurrence of goethite and ferrihydrite was followed by the application of PS.

Heavy Metals in P Fertilizers Marketed in Brazil: Is This a Concern in Our Agroecosystems?

Fertilizers are key for sustainable use of land and for intensification of crop production, especially in tropical agroecosystems, which have soil fertility constraints that hamper agricultural production on weathered soils. Heavy metals (HM) occur in fertilizers in low concentrations, as contaminants. Yet, some HM are plant nutrients and are intentionally included in fertilizer formulations. Exposure to high levels of HM (nutrient or not) could pose a health risk to humans. This risk may be estimated by collecting data on HM content in soils and plants (e.g., edible parts) in the field, as well as thru modeling. This work presents information concerning HM contents - with a focus on cadmium - in Brazilian fertilizers and agroecosystems - including agricultural products -, aiming to contribute to a better definition of safe limits of HM in phosphate fertilizers, soils, and food. These limits are key not only for food safety purposes, but also for assuring fair trade. In addition, we demonstrate the usefulness of a tool - the software EtraceProDB -, for easy calculation of risk-based concentrations (RBC) of HM in inorganic fertilizers post application, which suggest safe limits for agricultural use. The purpose of this software is to calculate values of HM concentrations in inorganic fertilizers that may, flexibly, be used by regulators to protect human and soil health. The results obtained indicate that HM do not cause harm to human health when considering post application of phosphate fertilizers in Brazil. Also, a survey of HM contents in Brazilian food and food products evidenced the safety of agricultural crops with respect to their contents of As, Cd, and Pb. Our findings concerning RBC and analyses of HM in mixed fertilizers, as well as current information published in Brazil suggest that HM contents - Cd inclusive - in major agroecosystems as well as the HM limits currently established for P fertilizers by the Brazilian legislation are safe in terms of health risk assessment. Considering the great importance of Brazil as a global food provider, such results are relevant to show that fertilizer use in Brazilian agriculture is done in such a way as to guarantee the production of healthy crops as well as adequate food quality criteria.

Fluorine and white clover: Assessing fluorine's impact on Rhizobium leguminosarum.

The soil fluorine (F) concentration in New Zealand agricultural soils has increased with time as a direct result of the widespread application of phosphate fertilizer to land. Elevated soil F concentrations may potentially harm soil microorganisms, which are important for nutrient cycling and soil formation. Rhizobium leguminosarum is a N2 -fixing soil bacterium that is a fundamental component in New Zealand legume-based pastoral farming. Any impact of F on Rhizobium leguminosarum would have an adverse effect on New Zealand pasture production. In this study, F toxicity to Rhizobium leguminosarum was examined as a first step to develop F guideline values for New Zealand agricultural soils. Bottle-based experiments were conducted to examine the effect of the F- ion on Rhizobium-white clover (Trifolium repens L.) symbiosis by observing nodule morphology and growth. Results indicate that the F- concentration that causes 10% inhibition of Rhizobium respiration (IC10 ) for F- toxicity to Rhizobium leguminosarum was >100mg F- L-1 . Significant morphological changes occurred when Rhizobium was exposed to F concentrations of 500 and 1000mg L-1 . Both light and transmission electron micrographs confirmed that the Rhizobium leguminosarum-white clover interaction was not influenced by F- concentrations >100mg L-1 . The toxic F- concentration for Rhizobium leguminosarum determined in this study is orders of magnitude higher than the F- concentration in New Zealand agriculture soils under "normal conditions." There appears to be no indication of imminent risk of soil F to Rhizobium leguminosarum.

Accumulation of potentially toxic elements in agricultural soil and scenario analysis of cadmium inputs by fertilization: A case study in Quzhou county

Fertilizer application has greatly increased crop yield, however impurities in mineral or organic fertilizers, such as heavy metals, are being added to agricultural soils, which would pose a high risk for soil and crop production. 115 soil samples were collected from Quzhou, a typical agricultural county in the North China Plain, to investigate the total content of cadmium (Cd), arsenic (As), lead (Pb), nickel (Ni), copper (Cu), zinc (Zn) and chromium (Cr) in soils. The contamination levels and source apportionment of studied elements were explored by the pollution indices, multivariate statistical approaches and geostatistical analysis. The ranges of Cd, As, Pb, Ni, Cu, Zn and Cr were between 0.08 and 0.35, 5.34–15.9, 7.34–38.9, 12.9–61.3, 7.80–27.0, 31.4–154, and 17.0–50.5 mg/kg and with the mean values 0.16, 9.20, 16.0, 24.7, 17.6, 61.1, and 29.5 mg/kg, respectively. The studied area was slightly polluted mainly by Cd, and higher pollution was found in soils under vegetable crops. The application of mineral phosphate fertilizer and livestock manure were the main source of Cd and Zn, and other elements (As, Pb, Ni and Cu) might originate from soil parent materials. Scenario analyses were performed using the R programming language, based on the cadmium contents in mineral phosphate fertilizers and livestock manures. The results showed that the long-term application of phosphate fertilizers would lead to some Cd enrichment in soil without risk of substantial pollution. Compared to pure mineral fertilizers, the long-term application of blended fertilizers (30% livestock manures and 70% phosphate fertilizers) or livestock manures would incur a higher Cd pollution risk within a short period, with a maximum probability of Cd risk of 55.21%. Mitigation measurements and scientific agronomic practices should be developed to minimize the risk of potential toxic elements in agricultural soil.

Effect of combined application of organic and inorganic phosphatic fertilizers on dynamic of microbial biomass in semi-arid soil

1. Achat, D., Bakker, L.M.R., Morel, C., Augusto, L., Pellerin, S., Gallet-Budynek, A., Gonzalez, M., 2010. Assessing turnover of microbial biomass phosphorus: Combination of an isotopic dilution method with a mass balance model. Soil Biology and Biochemistry 42, 2231–2240. https://doi.org/10.1016/j.soil.... CrossRef Google Scholar

Evaluation of the Effect of Dolomitic Lime Application on Pastures—Case Study in the Montado Mediterranean Ecosystem

The Montado ecosystem, predominant in the Mediterranean region, consists of poor soils, a sparse cover of cork and holm with an understory of natural biodiverse pastures, grazed by animals in extensive regime. The recommended procedure for increasing productivity of these pastures is based on the application of phosphate fertilizer. One of the main productivity-limiting factors is, however, associated with soil acidity. The objective of this work was to evaluate the simultaneous effect of the holm oak canopy and the application of dolomitic lime on the productivity and quality of a permanent biodiverse pasture, grazed by sheep, in an acid soil (pH = 5.4 ± 0.3). Pasture was monitored at the end of autumn 2018 and winter and spring 2019. The results show that amendment of soil acidity is a slow and gradual process that improves soil Mg/Mn ratio and has a positive impact on pasture productivity and quality. Pasture crude protein availability (CP, kg·ha−1), which is based on both pasture dry matter yield (kg·ha−1) and quality (CP, %), proved to be a very practical indicator of the contributions of tree canopy and soil acidity correction to the holistic management of the Montado ecosystem.

Effects of Fertilizer Reduction and Application of Organic Fertilizer on Soil Nitrogen and Phosphorus Nutrients and Crop Yield in a Purple Soil Sloping Field

The reduction in chemical fertilizers combined with organic fertilizers is a national strategy to achieve environmental friendliness and maintain the quality of cultivated land. It is of great significance for the prevention and control of soil pollution and the sustainable development of agriculture. In this study, purple soil and sloping land in the Three Gorges Reservoir area was studied. The field experiment method was used to study the control, conventional fertilization, optimized fertilization, biochar (fertilizer combined with biochar), and straw under rapeseed/corn rotation mode. The effects of five treatments on soil nitrogen/phosphorus form, crop nitrogen and phosphorus content, fertilizer utilization rate, and crop yield were studied in the field (fertilizer reduction combined with straw returning). The results showed that the soil ammonium nitrogen content was the highest in the rapeseed season, which was 4.51 mg·kg-1. The contents of ammonium nitrogen and alkali nitrogen in the treated corn season were significantly higher than those in the rape season. The reduction in chemical fertilizers can guarantee and increase the total nitrogen content of the soil. Among them, the total nitrogen content in the rapeseed and corn seasons treated with straw was the highest (0.56 g·kg-1 and 0.60 g·kg-1, respectively). The soil treated with straw in the rapeseed season had the highest available phosphorus content (0.76 mg·kg-1). Compared with conventional treatment, the reduction of chemical fertilizers combined with organic fertilizer did not significantly reduce the total phosphorus content of soil. The reduction of fertilization combined with organic fertilizer showed a slight increase in yield but showed the highest yield of rapeseed treated by biochar (2328 kg·hm-2) and the highest yield of conventionally treated maize (5838 kg·hm-2). However, there was no significant difference in each treatment (P>0.05). Regardless of the rapeseed season or the corn season, the reduction of fertilization treatment generally improved the agronomic utilization rate of nitrogen fertilizer and phosphate fertilizer. In the purple soil area, the combination of chemical fertilizer reduction and biochar and straw returning were beneficial to improve soil nutrients, improve fertilizer utilization, and reduce the effects of nitrogen fertilizer and phosphate fertilizer application on crop yield.

Basis for the breeding of low-Cd wheat varieties

Among heavy metals, cadmium (Cd) is highly toxic to plants and it is even considered as one of the most toxic elements released into environments at very low concentrations. The development of industry and agriculture have led to the increase of Cd content in soil environment. Cd is released into the soil through application of phosphate fertilizer, animal manures, waste water etc. Cadmium is a non-essential element for plant nutrition but because of its strong toxicity can seriously affects crop growth and development. Due to the high mobility of Cd in soil, the concentration of this element above the critical level can strongly inhibit the growth of plants as well as damage cell structure by interfering with different biochemical and physiological processes. Accumulation of Cd to phytotoxic levels may cause significant growth and yield decrease. If plants are grown in soil contaminated with Cd, they produce products containing this heavy metal, and such plant products are the main source of Cd entering the human body through the trophic chains. Thus, Cd may be an element with high residue, difficult to degrade and easy to accumulate, which may seriously threaten the health of human beings and animals. Cereals such as wheat, rice and maize are the main food crops in the world. Among them, wheat is the source of staple food for more than half of the world's population. Compared with other heavy metals, cadmium is more easily absorbed and accumulated by wheat. This poses a serious threat to human health. Wheat products are the main source of Cd intake by human. Wheat mainly uptakes Cd through the root system, and then it migrates to the above-ground part, and finally accumulates in the wheat grain. Agronomic management practices have been used to reduce Cd uptake and toxicity in wheat. However, these measures could pose some problems, such as large investment, high energy consumption, difficult operation and easy to produce secondary pollution. Low-Cd wheat varieties are the most effective and economic way to reduce the risk of cadmium to human health associated with food consumption. In the traditional breeding process, the selection of Cd-tolerant wheat samples is carried out on the basis of morphological, physiological or biochemical characteristics associated with Cd stress. It is of great significance to study the molecular mechanism of Cd absorption, transport of wheat and the creation of wheat varieties with low Cd accumulation for ensuring food security and food safety. Using molecular breeding technology and their successful integration with traditional breeding methods to select crop varieties with low accumulation of Cd will have a potential impact on the development of low Cd wheat germplasm and important practical significance for ensuring safe agricultural production of Cd contaminated soil. The objective of the present review is to discuss the Cd impact on wheat growth and development, Cd toxicity and tolerance mechanisms and some possible breeding strategies to alleviate Cd toxicity in wheat. The paper reviewed the effects of cadmium on the growth and development of wheat, the absorption, transport and distribution of cadmium in wheat, the tolerance mechanism and the molecular biological level of cadmium in wheat plant. To provide strategies and possible schemes for breeding wheat varieties with low cadmium accumulation

Geochemical data handling, using multivariate statistical methods for environmental monitoring and pollution studies

Abstract This study utilized multivariate statistics such as hierarchical cluster and principal component analyses to monitor water and stream sediments pollution. Three Principal components loadings: PC1, PC2 and PC3 were generated from water samples data yielding eigen values of 20.563, 8.477, and 7.635 respectively. PC1 explained 28.56% of the total variance with high positive loadings for EC, turbidity, Br, Cl, SO 4 2 − , Ce, Dy, Er, Eu, La, Lu, Nd, Pr, Sm, Tb, Tm, Yb, Al, Ba, Bi, Co, Co, Cs, Mn, Th, Ti, U, V and Y. PC2 explained 11.77% of the total variance with high positive loadings for Hf and high negative factor loadings for Hg. PC3 explained 10.60% of the total variance and positively loaded for P, NO3, Cd, Ge, Ni, Pb, Sn, and Zn. PC1 is related to saline waters intrusion and geological nature of the aquifer. PC2 is controlled by high field strength element (HFSE) Hofnium (Hf) due to mineralization. PC3 contributed to pollution due to anthropogenic activities caused by chemical nitrogenous and phosphate fertilizer applications, to the soil and mineralogical constituents of the aquifer rock. Four principal components were identified in stream sediments and possessed eigen values of 12.29, 5.47, 3.19 and 2.10 respectively. PC1 explained 39.65% of the total variance and had significant positive loadings for Mo, Cu, Pb, Ni, Zn, Fe, U, Th, V, Ba, Ti, Sn, Nb, Be, Sc, Li, Zr, Rb and Hf. This suggest the occurrence of heavy mineral phases such as garnet, barite, zircon and monazite in mafic and ultramafic rocks and resistive heavy minerals. PC2 accounted for 17.65% of the total variance with moderate positive loadings for Mo, Cu, As and Ba, but with moderate negative loadings for Th, La and Ba. This component shows lithogeochemical input representative of weathering and mobility of sediments related mineralization. PC3 accounted for 10.29% of the total variance with positive high loadings for Mn, Bi and Y. PC3 may be related to anthropogenic activities such as agriculture, industry and urban life in the study area. PC4 accounted for 6.78% of the total variance with positive high loading for Ta. PC4 indicates the mineralization acquired by this component.

Populations of two annual clover species evolved in response to 13 years of grazing management and phosphate fertilizer application

AbstractA Syrian grassland was subject to 13 years of replicated management treatments, namely a factorial design of 0 or 60 kg/ha annually of phosphate fertilizer, combined with relatively low or high sheep stocking intensities. Previous work found that differences in grazing intensity and phosphate induced changes in the structure of the legume community, presumably due to changes in competitive relationships. The aim of this study was to investigate how the populations of the predominant clover species, Trifolium campestre and Trifolium tomentosum, changed as a consequence of management treatments. We hypothesized that the populations from the fertilized or low grazing intensity treatments would express phenotypic traits associated with increased competitive ability and/or with risk mitigation. Populations of both ruderal‐type clover species provided evidence of evolution but were largely responsive to different management factors. Assuming that heavy grazing and no fertilizer are the natural state of the grassland, addition of phosphate led to T. tomentosum plants that were wider and had larger seeds, traits associated with improved competitive ability. The populations from the fertilized paddocks had increased fecundity and a trend towards greater dormancy, traits associated with risk mitigation. In contrast, T. campestre plants became wider and more erect when stocking intensities were reduced and had greater seed dormancy in fertilized paddocks. The implication of this work is that the collection of germplasm from grasslands with a history of heavy grazing and fertilizer application may assist agronomists to find genotypes that are better adapted to pastures within ley farming systems in Australia.

Application of Phosphate Fertilizer Modified by Zinc as a Reusable Efficient Heterogeneous Catalyst for the Synthesis of Biscoumarins and Dihydropyrano[3,2-c]Chromene-3-Carbonitriles under Green Conditions

This study presents a simple, efficient, and ecological procedure for the synthesis of biscoumarins and 3,4-dihydropyrano[c]chromenes under green conditions using Zn3(PO4)2.4H2O as a heterogeneous catalyst. In fact, Zn3(PO4)2.4H2O was prepared for the first time from triple superphosphate fertilizer (TSP) (Ca(H2PO4)2) and zinc sulfate (ZnSO4). Then, it was characterized by spectroscopic and microscopic technics such as X-ray diffraction (XRD), infrared spectroscopy (IR), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDX). The synthesis derivatives of biscoumarins and dihydropyrano[c]chromenes, in the optimal reaction conditions (nature of the solvent, amount of catalyst and temperature), was performed. The obtained results are excellent in terms of time (15–30 min) and yields (81–87%). Besides, Zn3(PO4)2.4H2O can be reused at least six times without significant loss of its catalytic activity, because of its long-term durability.

Evaluation of arbuscular mycorrhiza inoculation potential for sustainable production of aerobic rice &lt;i&gt;var.&lt;/i&gt; MR1A

A pot culture experiment was carried out to evaluate the effect of different mycorrhiza inoculants and phosphate fertiliser application on the growth and nutrient uptake of aerobic rice var. MR1A. The contribution of mycorrhizae has been well acknowledged in sustainable agriculture. Mycorrhizae can influence the key ecosystem process of soil aggregation, act as an acquisition of soil nutrient absorption to improve the plant growth via their hyphae and alter the morphology of a root system by forming more branches and adventitious roots that functionally extend the root system of the plant. The results indicated that arbuscular mycorrhizal fungi (AMF) had increased the efficiency of phosphate fertiliser uptake by the plant. This is due to the ability of MR1A seedlings to form a symbiotic relationship with AMF inoculums. Thus, the information gathered from this study herein will help us to understand the role of AMF towards sustainable agriculture.

Evaluation of arbuscular mycorrhiza inoculation potential for sustainable production of aerobic rice &lt;i&gt;var.&lt;/i&gt; MR1A

A pot culture experiment was carried out to evaluate the effect of different mycorrhiza inoculants and phosphate fertiliser application on the growth and nutrient uptake of aerobic rice var. MR1A. The contribution of mycorrhizae has been well acknowledged in sustainable agriculture. Mycorrhizae can influence the key ecosystem process of soil aggregation, act as an acquisition of soil nutrient absorption to improve the plant growth via their hyphae and alter the morphology of a root system by forming more branches and adventitious roots that functionally extend the root system of the plant. The results indicated that arbuscular mycorrhizal fungi (AMF) had increased the efficiency of phosphate fertiliser uptake by the plant. This is due to the ability of MR1A seedlings to form a symbiotic relationship with AMF inoculums. Thus, the information gathered from this study herein will help us to understand the role of AMF towards sustainable agriculture.