Effect Of Phosphorus Fertilization Research Articles

Fertilizer efficiency on wheat crops in the northwestern zone of the Kurgan region

The results of long-term (1968-2021) experiment on the use of fertilizers for the 10th and 11th rotations of grain and fallow crop rotation in the experimental field of the Kurgan region are presented. Crop rotation included fallow and three crops of wheat. Fertilizer efficiency varied depending on the combination of the nutrients, the place of wheat in the rotation, and the moisture conditions of the growing season. Moderate effect of phosphorus fertilizer and high effect of nitrogen fertilizer on heavy loamy leached chernozem of the experimental field in these rotations was observed on the crops distant from the fallow. The combination of nitrogen and phosphorus fertilizers gave a higher yield increase. Nitrogen fertilizer also had a positive effect on the quality of wheat, increasing the gluten content and the thousand-kernel weight. With the increase of gluten accumulation in wheat grain against the background of nitrogen fertilizer, the repeatability of wheat quality compliance with the requirements for the 3rd class of grain increased. The effect of fertilizers and the duration of their application on the agrochemical properties of soil became visible. The content of mobile nutrients, humus, total nitrogen and phosphorus increased more noticeably with the use of fertilizers, but the рНsan value decreased. High economic efficiency related to nitrogen fertilizer applied on the second and third wheat after fallow with a payback of 1 kg of nitrogen 12-19 kg of grain. The effect of phosphorus fertilizer was moderate, since the content of mobile Р2О5 in the topsoil remained high. The use of ammophos had a stronger effect on the yield of wheat when the plants were well supplied with nitrogen in the first fallow crops.

Effects of Phosphate Fertilizer Application on the Growth and Yield of Tartary Buckwheat under Low-Nitrogen Condition

This study aimed to clarify the effect of phosphorus fertilizer on the senescence and yield of Tartary buckwheat under low-nitrogen treatment. A two-year field experiment to investigate the characteristics was conducted on Tartary buckwheat (Qianku 5) under four phosphorus fertilizer application rates, 0(CK), 40(LP), 80(MP), and 120 kg·ha−1 (HP), in the absence of nitrogen treatment. Compared with CK, MP treatment increased the plant height, node number of main stem, branch number of main stem, root-morphology items, root activity, enzyme activity related to root nitrogen metabolism, leaf chlorophyll content, and antioxidant enzyme activity by an average of 27.82%, 36.00%, 31.76%, 70.63%, 103.16%, 45.63%, 19.42%, and 45.48%, respectively. MP treatment significantly decreased the malondialdehyde content by 23.54% compared with that of CK. Among all treatments, the HP treatment had the highest content. The grain number per plant, grain weight per plant, and yield under MP treatment were 1.54, 1.65, and 1.53 times those of CK, respectively. In summary, the appropriate phosphate fertilizer treatment (80 kg·ha−1) can delay senescence, promote the growth, and increase the yield of Tartary buckwheat at low nitrogen levels. Such treatment is recommended for use in production to jointly achieve the high yield and high nitrogen conservation of Tartary buckwheat.

P-fertiliser and rhizobial inoculation increased the concentration of mineral nutrients in the rhizosphere of two chickpea genotypes

ABSTRACT Co-application of fertilisers and biofertilisers increases solubility and concentration of nutrient elements in the soil. However, information on the effect of P fertiliser and rhizobium inoculation on the concentration of mineral elements in the rhizosphere of field-grown chickpea in contrasting soil types is lacking. We assessed the effect of phosphorus fertiliser, rhizobium inoculation, and rhizobium inoculation plus P fertilizer on the concentration of nutrients in the rhizosphere of 2 chickpea genotypes (ACC#1 & ACC#5) at clay and sandy soil sites in two consecutive years. ACC#5 accumulated higher amounts of rhizospheric nutrients than ACC#1 in both soil types despite the variable response to fertiliser treatment. Rhizobium inoculation plus P fertiliser resulted in higher accumulations of rhizosphere N (7-219%), P (20-348%), K (9-365%), Ca (2-155%) and Zn (15-259%) compared to the other fertiliser treatments suggesting an additive effect of P fertiliser and rhizobium inoculation. Moreover, the effect of fertiliser treatments was more pronounced in the clay than the sandy soil. Our investigation is the first to document the effects of fertiliser treatment, genotype, and soil type on the accumulation of rhizosphere nutrients in field-grown chickpea. However, we propose further studies, incorporating more cultivars and environments, before making practical recommendations.

Phosphorus Fertilizer Effects on Near-Surface Soil Aggregation in Furrow-Irrigated Rice on a Silt-Loam Soil

Phosphorus Fertilizer Effects on Near-Surface Soil Aggregation in Furrow-Irrigated Rice on a Silt-Loam Soil

EFFECT OF TRADITIONAL AND NANO PHOSPHOROUS FERTILIZATION AND SOIL MOISTURE CONTENT ON THE GROWTH AND YIELD OF TWO WHEAT CULTIVARS, TRITICUM AESTIVUM L. IN CALCAREOUS SOIL FROM NINEVEH GOVERNORATE

A pot experiment was conducted under greenhouse conditions to study the effect of phosphorus fertilization under to soil moisture content on some growth indicators, yield and seed content of nitrogen and phosphorous for two wheat cultivars, Adnaniah and Sham-6, in calcareous soil suffering from a lack of available phosphorus. The results indicated that phosphorous fertilization led to an improvement in plant growth, as it caused an increase in the relative water content of leaves, chlorophyll percentage, nitrogen and phosphorous seed content, grain yield and protein percentage. Phosphorous fertilization played an important role in increasing the ability of the two wheat cultivars to withstand water stress conditions and reduce the negative impact resulting from the lack of water on plant growth, while the exposure of the two wheat cultivars to water stress there was a decrease in the values ​​of previous growth indicators, grain yield and its content of N and P elements. Sham 6 variety was more responsive than the Adnaniya variety, as this variety outperformed in all the studied traits, in addition to that it obtained the best growth and higher yield under conditions of water shortage.

Burkina Rock Phosphate Fertilization Increases Nodulation and Yield of Cowpea under Zaï Cultivation in Sahelian Agro-ecosystem of Burkina Faso

Cowpea occupies a considerable place in the nutritional and economic balance of the rural population of Burkina Faso. However, its cultivation is marked by yield instability linked to soil depletion of nutrients, especially N and P, and irregular rains. The objective of this study was to evaluate the effect of phosphorus fertilization with the rock phosphate named BurkinaP, on the spatial and temporal variability of cowpea nodulation and yield. A multilocation test was conducted in 12 and 16 farmers’fields in 2013 and 2014, respectively, in 3 villages of 3 provinces of the northern region of Burkina Faso. Two treatments were compared: zaï without (ZS) and zaï with BurkinaP (ZP). Overall, dry weights of nodules and shoots at flowering stage, and grain at harvest, were significantly increased by BurkinaP. It is concluded that in soils where low availability of P limits crop yields of cowpea especially in arid sud-saharan areas of West Africa, the input of BurkinaP can improve cowpea N2-fixation, and increase and stabilize cowpea yields.

UAV-Derived Spectral Indices for the Evaluation of the Condition of Rye in Long-Term Field Experiments

The aim of the study was to evaluate the effect of various fertilization treatments, including nitrogen, potassium and phosphorus fertilization, in long-term experiments for selected UAV (unmanned aerial vehicle)-derived spectral vegetation indices (NDVI—Normalized Difference Vegetation Index, NDRE—Normalized Difference Red Edge Index, VARI—Visible Atmospherically Resistant Index, TGI—Triangular Greenness Index, SIPI2—Structure Insensitive Pigment Index 2, LCI—Leaf Chlorophyll Index, BNDVI—Blue Normalized Difference Vegetation Index, GNDVI—Green Normalized Difference Vegetation Index, MCARI—Modified Chlorophyll Absorption in Reflective Index) based on multispectral (bands in the range of visible light and near infra-red) images of winter rye. The strongest effect on the studied vegetation indices was nitrogen fertilization, which discriminated values of most of the vegetation indices. The effect of phosphorus and potassium fertilization on the studied vegetation indices was much weaker. The treatments with nitrogen fertilization had significantly higher values of most vegetation indices in comparison to treatments without nitrogen. This was confirmed by principal component analysis (PCA), in which treatments without nitrogen fertilization were very different in comparison to all other treatments where nitrogen fertilization was applied. The effect of phosphorus and potassium fertilization on most of vegetation indices was relatively weak and not significant in most experiments. Only for rye cultivated in monoculture was the effect of phosphorus fertilization significant for most of vegetation indices in early growth stages. In later growth stages (heading and flowering) the effect of phosphorus fertilization was significant in rye monoculture for the SIPI2 vegetation index. Mean SIPI2 was higher for the fertilization treatment CaNPK in comparison to CaKN (without P fertilization). The effect of potassium fertilization on the studied vegetation indices was very weak, and in most cases not significant. The effect of nitrogen fertilization on vegetation indices was much stronger than effect of both potassium and phosphorus fertilization.

Influence of monoammonium phosphate on glyphosate adsorption-desorption in tropical soils: Effect of the order of sorbate additions.

Glyphosate and phosphate compete for the same adsorption sites in the soil because their adsorption mechanisms are similar as the herbicide contains a phosphate group. However, how this competition occurs in relation to the order of addition of the sorbate and the composition of the soils remains unclear. The effect of the soil clay composition and the order of glyphosate and monoammonium phosphate (MAP) additions on glyphosate sorption-desorption was investigated using three inceptisols collected from Colombian rice fields. Glyphosate adsorption isotherms were evaluated using the batch equilibrium method and were modeled applying the Freundlich equation. The values for glyphosate Kfa, when evaluated alone, ranged from 14.39 to 639.86mg1-na Lna kg-1. An agreement was found between adsorbed glyphosate, chlorites, and low initial phosphorous soil content. Preadsorbed MAP or simultaneous MAP-glyphosate additions to the soil revealed a drastic reduction in glyphosate Kfa values in soil containing the highest amount of 2×1 clays, but kaolinitic soils remained practically unaffected. Low desorption values could be associated with soils with the highest kaolinite content. Glyphosate remobilization was favored when the desorbing MAP solution was used in soils containing preadsorbed glyphosate. This study provides new knowledge on the effect of phosphorus fertilizers on glyphosate bioavailability in soils with different mineral compositions.

Effect of phosphorus fertilizer on phytoextraction using Ricinus communis L. in Cu and Cd co-contaminated soil

Mining activities have led to Cu and Cd contaminated of surrounding agricultural soil. To decrease the Cu and Cd accumulation in crops, the Ricinus communis L. (castor) has been used for phytoremediation. A pot experiment was served to investigate the effect of phosphate fertilizer (Ca(H2PO4)2) on the growth and Cu/Cd uptake of castor in contaminated soil. The results showed that the application of P fertilizer improved the leaf cell morphology, decreased the malonaldehyde (MDA) content of castor leaves, and increased the plant biomass (28.2–34.2%). Besides, phosphate fertilizer still facilitated accumulation Cu and Cd by castor. The addition of phosphate fertilizer increased the contents of Cu in the root of castor, improved the bioconcentration factor (BCF) of Cu, and observably enhanced the accumulation of Cu (up to 201 μg/plant) in castor. Applying phosphorus increased the percentage of residual Cd, diminished the percentage of acid extractable Cd in soil, and the accumulation of Cd in castor was not significantly increased. These results suggest that phosphorus alleviated the stress of heavy metals on castor leaves and enhanced the accumulation of Cu and Cd in castor by promoting the growth of castor.

EFFECT OF PHOSPHORUS FERTILIZATION ON SILAGE QUALITY OF PERSIAN CLOVER (TRIFOLIUM RESUPINATUM L.)

The aim of the research was to determine the effect of phosphorus fertilization (0, 30, 45, 60, 75 and 90 kg ha-1) on silage yield and quality traits of Persian clover (Trifolium resupinatum L.). The experiment was conducted at Yoruk village of Malkara-Tekirdag with three replications in randomized block design in 2021. Silage yield (t ha-1), dry matter (%), crude protein (%), crude ash (%), acid detergent fiber (ADF, %), neutral detergent fiber (NDF, %), P (%), K (%), Ca (%), Mg (%), digestible dry matter (DDM, %), dry matter intake (DMI, %), relative feed value (RFV), total digestible nutrients (TDN), net energy-lactation (NEl), net energy-maintenance (NEm), net energy-gain (NEg) and flieg score were determined. Silage yield, dry matter, pH, crude protein, ADF, NDF, P, Mg, DDM, DMI, RFV, TDN, NEg and Flieg Score were determined statistically significant at P˂0.01. The highest silage yield (72.83 t ha-1) and ADF ratio (25.36 %) were obtained from 30 kg P ha-1. The highest dry matter (39.92 %), DDM (70.30 %), DMI (3.22 %) RFV (175.056) and TDN (68.90) were found at application of 90 kg P ha-1. The highest flieg score was determined at application of 60 kg P ha-1. The highest crude protein (15.50-15.51 %) was found at application of 45 and 60 kg P ha-1.

Canary in the coal mine: Lessons from the Jarrah Forest suggest long-term negative effects of phosphorus fertilizer on biodiverse restoration after surface mining

Despite nutrient enrichment having widely reported negative impacts on biodiversity, fertilizer is routinely applied in post mining restoration to enhance plant growth and establishment. Focusing on surface mine restoration (predominately bauxite and mineral sands), we outline the long-term negative impacts of fertilizer, particularly phosphorus fertilizer, on plant community composition, species richness, fire fuel loads, and belowground impacts on nutrient-cycling. We draw from extensive research in south-western Australia and further afield, noting the geographical coincidence of surface mining, phosphorus impoverished soil and high plant biodiversity. We highlight the trade-offs between rapid plant-growth under fertilisation and the longer-term effects on plant communities and diversity. We note that the initial growth benefits of fertilisation may not persist in water-limited environments: growth of unfertilised forests can eventually match that of fertilised forest, throwing doubt on the premise that fertilisation is necessary at all.

Influence of phosphorus fertilizers on the yield of soybean varieties in the conditions of Uzbekistan

Soybean varieties are being studied in Uzbekistan, and cultivation technologies are being improved and new ones are being created. In this research, the effect of phosphorus fertilizers on soybean varieties was studied in the conditions of meadow-swamp soils of Tashkent region. The field experiments were carried out in 4 rows, the piles were 20 m long, 3.6 m wide, with 6 rows, of which 2 rows were marked in the middle and 4 rows were marked as protective rows at the edges. The results showed that when the norm of nitrogen and potassium-based phosphorus fertilizers was 80 kg, the leaf surface averaged 42.6 thousand m2/ha in the Nafis variety. In the second variant, when the phosphorus content was increased to 40 kg, the leaf surface was found to be 2,000 m2/ha higher. In the Vilana variety, the leaf surface area was 42.4 thousand m2/ha at low phosphorus levels, while the leaf surface was found to be 2.2 thousand m2/ha when the phosphorus level was increased by 40 kg.

Effects of Phosphorus Fertilization on Growth Characteristics, Fatty Acid Composition, and Seed Yields of Fengdan (Paeonia ostii T. Hong & J. X. Zhang)

Paeonia ostii T. Hong & J. X. Zhang is a perennial oil and medicinal plant with great importance as well as landscaping. P. ostii is being extensively planted in China, but the soil fertility limits the yield and quality. There is little information available on the effects of phosphorus fertilization on productivity, physiological characteristics, and seed yield and quality. This study investigated the influence of different phosphorus levels, 0 kg·hm−2 (CK), 90 c−2 (P1), 135 kg·hm−2 (P2), 180 kg·hm−2 (P3), 225 kg·hm−2 (P4), and 270 kg·hm−2 (P5), on the photosynthesis, morphology, physiological parameters, and yield of P. ostii. The results indicated that the net photosynthetic rate, stomatal conductance (gS), and transpiration rate of P. ostii increased significantly with the application of P4, which increased by 34.77%, 65.72%, and 21.00% compared with CK, respectively. Simultaneously, the contents of soluble sugar, soluble protein, and photosynthetic pigment in P4 were the highest compared with other treatments. In addition, thousand-grain weight (326.4 g) and seed yield per plant (37.33 g) of P4 were significantly higher than the control. However, the total amount of unsaturated fatty acids in P4 was lower compared with other treatments. The indexes of high correlation coefficients with Dim 1 and Dim 2 were gS and superoxide dismutase (SOD), respectively. The results showed that phosphorus levels improved plant photosynthetic capacity and increased antioxidant capacity as well as seed yield. Furthermore, phosphate fertilizer had significant effects on the oil composition. Moreover, the effect of phosphorus application rate on the growth index of P. ostii was greater than that of the physiological index.

Effects of Phosphorus Fertilizer on Agronomic, Grain Yield and Other Physiological Traits of Some Selected Legume Crops

Phosphorous is another nutrient that is critically important for legumes and the clover plants that are fixing nitrogen, but all plants need phosphorous as they do nitrogen. Legumes need a higher level of P fertility than the neighbouring grass plants. Phosphorus is vital for plant growth, and is a component of the nucleic acid structure of plants and bio-membranes. Therefore, it is important in cell division and tissue development. It is also involved in the energy metabolism of cells and is required for the biosynthesis of primary and secondary metabolites in plants. Legume crops requires less nitrogen but application of phosphorus and potassium plays a vital role in getting high yield per unit area. The application of phosphorus increases dry matter at harvest, number of pods plant -1 , seeds pod -1 , 1000 grain weight, seed yield and total biomass of mung bean. The experimental results of different authors stated that the highest number of pod plant -1 and grain yield of soyabean were obtained from maximum level of phosphorus as compared to other treatments. common bean crop dependent on nitrogen fixation needs more inorganic phosphorus than the same crop provided with mineral nitrogen. Common beans are therefore especially susceptible to low soil phosphorus when accompanied by low soil. Phosphorus also plays an important role in biological nitrogen fixation, for the symbiotic fixation of nitrogen to occur, the roots have to interact with compatible rhizobia in the soil and factors that affect root growth or the activity of the host plant would affect nodulation. however, the rate of phosphorus is varied from place to place, or it’s governed by the amount of P status in the soil. Since, legume crops demanding more P than other nutrient, we have to apply it obtained best grain yield. Keywords: Bacteria, Dry matter, Grain yield, Legume and Nodule DOI: 10.7176/JBAH/12-12-01 Publication date: June 30 th 2022

Effect of Phosphorus Fertilization on Yield of Chipping Potato Grown on High Legacy Phosphorus Soil

Potato (Solanum tuberosum L.) has low phosphorus (P) use efficiency as compared with other vegetable crops. This study was conducted at two commercial chipping potato farms (A and B) in Northeast Florida to evaluate different P rates for potato production. Plot size was 0.62 and 0.49 hectares for Farms A and B, respectively. The total trial area was 13.32 hectares per growing season for three consecutive years from 2018 to 2020. The randomized complete block design (RCBD) was employed with four replications per P rate. The chipping potato variety, ‘Atlantic’ was cultivated with three P rates: 0, 24.5, and 48.9 kg P ha−1 in 2018, and 12.2, 24.5, and 48.9 kg P ha−1 in 2019 and 2020. The soil of Farm A contained 497 mg kg−1 Mehlich-3 extractable P and 946 mg kg−1 aluminum (Al), and that of Farm B had 220 mg kg−1 Mehlich-3 extractable P and 253 mg kg−1 Al. The results showed that a P rate of 48.9 kg P ha−1 significantly improved tuber yield as compared to 0 in 2018 or 12.2 kg P ha−1 in 2019 and 2020. Application of 48.9 kg P ha−1 fertilizer P significantly increased the soil P level in 2018 and 2020, while the application of 24.5 kg P ha−1 fertilizer P increased the soil P level significantly in 2018 only. Tubers with 48.9 kg P ha−1 showed significantly lower external quality issues than 0 or 12.2 and 24.5 kg P ha−1. However, there were no significant differences in specific gravity, internal tuber quality, and tuber size among the different P rates. The tuber yield data show that potato plants grown on soil with high legacy P still require approximately 50 kg ha−1 P application for sustainable potato production in the area. This high P requirement results from the combination of high concentrations of active metals (Al and iron (Fe)) and a decrease in pH of one unit in the growing season. New P-fertilization programs with post-plant applications rather than with pre-plant application are urgently needed for minimizing P-immobilization by Al and Fe and improving P-use efficiency for potato production in the state.

Novel intra-boll yield components and Q-score can further evaluate the effect of phosphorus fertilizer on cotton yield and fiber quality

Novel intra-boll yield component traits and fiber quality indices have been used by breeders to select suitable Gossypium hirsutum L. lines, but there is little research on how these traits change during cultivation practices, especially fertilizer application. We hypothesized that these novel traits have obvious responses to phosphorus (P) fertilizer, which would explain the variation in yield and fiber quality under different P conditions. To address this hypothesis, a field test was conducted with a low-P sensitive cotton cultivar (Lu 54) and a low-P tolerant cotton cultivar (Yuzaomian 9110) under different P fertilizer rates (0 as control, 100, and 200 kg P2O5 ha−1) from 2016 to 2018. The results showed that P fertilizer application (100, and 200 kg P2O5 ha−1) increased the lint yield, and bolls per ha contributed most to the increase in lint yield, followed by boll weight and lint percentage. The increased bolls per ha under P fertilizer application was due to the accelerated process of boll forming and the slowing of shedding process. The increased boll weight under P fertilizer application could be explained by the higher seed biomass per boll and fiber biomass per boll, especially the latter. The higher seed biomass per boll was due to the increased seeds per boll, and higher fiber biomass per boll should be attributed to the increased fibers per seed under P fertilizer application. The positive contribution of lint percentage to lint yield formation under P fertilizer application could be attributed to the increased fiber biomass per seed. P fertilizer application decreased fiber micronaire, indicating that fiber thickness was decreased by extra P fertilizer, which might be associated with the negative effects of increased fibers per seed and fiber density. In addition, P fertility application promoted the elongation of fiber cells and fiber length uniformity, and increased fiber strength. The end result was an increase in the comprehensive fiber quality index (Q-score) after P application. Moreover, compared to Yuzaomian 9110, yield traits including lint yield, bolls per ha, seeds per boll, seed index, and SSA, and quality indices including fiber length, fiber strength, and Q-score were more sensitive to P fertilizer application in Lu 54.

Phosphorus Fertilization Enhances Productivity of Forage Corn (Zea mays L.) Irrigated with Saline Water.

Salinity is a major problem affecting crop production in many regions in the world including Morocco. Agricultural practices such as fertilization could be useful to overcome this problem and improve crop productivity. The objective of our study was to evaluate the combined effect of phosphorus fertilization and irrigation water salinity on growth, yield, and stomatal conductance of forage corn (Zea mays L.) cv. “Sy sincerro”. Field experiments were carried out for two years testing four levels of irrigation water salinity (ECw = 0.7; 2, 4, and 6 dS·m−1) and three rates of phosphorus (105, 126, and 150 kg P2O5·ha−1) fertilization conducted in a split-plot design with three replications. The obtained results show that irrigation water salinity had a negative effect on all monitored parameters. For instance, the dry matter yield reduced by an average of 19.3 and 25.1% compared to the control under saline irrigation with an EC value equal to 4 and 6 dS·m−1, respectively. The finding also showed that phosphorus applications tend to increase root weight, root length, stem length, leaf stomatal conductance, grain yield and dry matter yield under salinity conditions. For example, the addition of phosphorus with a rate of 126 and 150 kg P2O5·ha−1 respectively improved dry matter yield by an average of 4 and 9% under low salinity level (ECw = 2 dS·m−1), by 4 and 15% under medium salinity (4 dS·m−1), and by 6 and 8% under a high salinity level (6 dS·m−1). Our finding suggests that supplementary P application could be one of the best practices to reduce the adverse effects of high salinity on growth and development of forage corn.

Arsenic hyperaccumulator Pteris vittata shows reduced biomass in soils with high arsenic and low nutrient availability, leading to increased arsenic leaching from soil

Plant-soil interactions affect arsenic and nutrient availability in arsenic-contaminated soils, with implications for arsenic uptake and tolerance in plants, and leaching from soil. In 22-week column experiments, we grew the arsenic hyperaccumulating fern Pteris vittata in a coarse- and a medium-textured soil to determine the effects of phosphorus fertilization and mycorrhizal fungi inoculation on P. vittata arsenic uptake and arsenic leaching. We investigated soil arsenic speciation using synchrotron-based spectromicroscopy. Greater soil arsenic availability and lower nutrient content in the coarse-textured soil were associated with greater fern arsenic uptake, lower biomass (apparently a metabolic cost of tolerance), and arsenic leaching from soil, due to lower transpiration. P. vittata hyperaccumulated arsenic from coarse- but not medium-textured soil. Mass of plant-accumulated arsenic was 1.2 to 2.4 times greater, but aboveground biomass was 74% smaller, in ferns growing in coarse-textured soil. In the presence of ferns, mean arsenic loss by leaching was 195% greater from coarse- compared to the medium-textured soil, and lower across both soils compared to the absence of ferns. In the medium-textured soil arsenic concentrations in leachate were higher in the presence of ferns. Fern arsenic uptake was always greater than loss by leaching. Most arsenic (>66%) accumulated in P. vittata appeared of rhizosphere origin. In the medium-textured soil with more clay and higher nutrient content, successful iron scavenging increased arsenic release from soil for leaching, but transpiration curtailed leaching.

Short-term effects of phosphorus fertilization on Amazonian tree species in a mixed plantation

Short-term effects of phosphorus fertilization on Amazonian tree species in a mixed plantation

Interactive effects of phosphorus fertilization and salinity on plant growth, phosphorus and sodium status, and tartrate exudation by roots of two alfalfa cultivars.

Soil phosphorus (P) deficiency and salinity are constraints to crop productivity in arid and semiarid regions. Salinity may weaken the effect of P fertilization on plant growth. We investigated the interactive effects of soil P availability and salinity on plant growth, P nutrition and salt tolerance of two alfalfa (Medicago sativa) cultivars. A pot experiment was carried out to grow two cultivars of alfalfa in a loess soil under a combination of different rates of added P (0, 40, 80 and 160 mg P kg-1 soil as monopotassium phosphate) and sodium chloride (0, 0.4, 0.8 and 1.6 g NaCl kg-1 soil). Plant biomass, concentrations of P ([P]), sodium ([Na]) and potassium ([K]) were determined, and rhizosheath carboxylates were analysed. There were significant interactions between soil P availability and salinity on some, but not all, of the parameters investigated, and interactions depended on cultivar. Plant growth and P uptake were enhanced by P fertilization, but inhibited by increased levels of salinity. Increasing the salinity resulted in decreased plant P-uptake efficiency and [K]/[Na]. Only soil P availability had a significant effect on the amount of tartrate in the rhizosheath of both cultivars. Increased salinity aggravated P deficiency. Appropriate application of P fertilizers improved the salt tolerance of alfalfa and increased its productivity in saline soils.