Triple Superphosphate Fertilizer Research Articles

Experimental dissolution of biopolymer-coated phosphorus fertilizers applied to a soil surface: Impact on soil pH and P dynamics

Biopolymer-coated phosphorus fertilizers have shown promising results in slowing the release of P. However, their dissolution behaviour has been studied mainly in water, and their impacts on soil properties have rarely been addressed. The aim of this study was to compare the dissolution of P from uncoated triple superphosphate (TSP) and biopolymer-coated TSP fertilizers at the surface of cropped Mediterranean soils and to evaluate their impacts on the soil pH and the distributions of several P pools. The experimental treatments were: no fertilizer, uncoated TSP, TSP coated with lignin and TSP coated with lignin and carrageenan. The spatial and temporal variations in the pH of the fertilized soils were investigated using optodes. The concentrations of different pools of P (available P, microbial P), and total P as well as P recovery at different distances from the granules were determined. The coated TSP acidified the soil to a radius of 14 mm around each fertilizer granule, while the acidification spread to 21 mm in the treatment with the uncoated TSP. Moreover, an increase in microbial P was observed in the soil treated with coated TSP, possibly due to the carbon input and the consequent increase in microbial biomass. However, slower P-release was observed from the coated TSP due to the effect of the coating barrier. The P recovery results showed P migration within a 21 mm radius from each granule, and the P recovery from the TSP coated with lignin alone was significantly greater than that from the uncoated TSP treatment.

Preferences of Pinus sylvestris seedling roots for different phosphorus sources under phosphorus-deficient conditions

PurposePhosphorus (P) is a limiting nutrient in many managed forests. To further understand the risks and benefits of biochars as sustainable P source in forest management, an improved mechanistic understanding of its interactions in root systems is required.MethodsA rhizobox experiment was conducted to observe root response of P. sylvestris (Scots pine) seedlings to different biochars in comparison to triple superphosphate (TSP) fertiliser as a P source. Three types of wood-derived biochar were compared: biochar from mixed softwood pellets (“Reference biochar”); from the vascular cambium zone of Picea sitchensis (“VCZ biochar”) and from mixed softwood pellets infused with TSP (“Processed biochar”). These biochars presented a range of available P from low to high. Seedling root development was spatially analysed using GIS software.ResultsThe total length of P. sylvestris roots did not significantly differ between treatments. However, seedling roots showed strong preference for soil proximal to VCZ biochar and strong avoidance to TSP fertiliser. There was a milder avoidance effect for Processed biochar. Differences in root responses could be explained by available P: roots favored a moderate, sustained P source and avoided high available P sources. The avoidance effect can be attributed partially to lower soil pH around TSP fertiliser.ConclusionThe extent concentration and duration of P availability affects the root response of P. sylverstris to P sources. Under P-deficient conditions, P. sylvestris root growth was markedly improved by introducing biochar with a certain P concentration, and VCZ biochar has potential as an effective source of P in forest establishment.

Improving Tropical Soil Productivity and Cowpea (Vigna unguiculata (L.) Walp) Performance Using Biochar and Phosphorus Fertilizer

ABSTRACT Studies on the effects of biochar and phosphorus fertilizer on soil productivity and yield of cowpea (Vigna unguiculata) are scarce. Therefore, experiments were conducted in 2019 and 2020 to evaluate the effects of sole and combined application of biochar and phosphorus fertilizer on soil properties, nodulation, growth, and yield of cowpea. The treatments consisted of: biochar at 10 t ha−1 (B10), biochar at 20 t ha−1 (B20), triple super phosphate fertilizer at 60 kg P ha−1 (P), biochar at 10 t ha−1 + P (B10 + P), biochar at 20 t ha−1 + P (B20 + P), and the control. The experimental design was a randomized complete block design with three replications. Results revealed that biochar and P fertilizer applied alone or in combination improved soil properties, growth, nodulation, and yield of cowpea compared with the control. Results also showed that combined applications of biochar with P fertilizer improved these properties most, especially at a higher rate of biochar (B20 + P). B20 + P increased grain yield of cowpea by 155%, 69%, 53%, 69%, and 21% respectively compared with the control, B10, B20, P fertilizer, and B10 + P. This was adduced to raise soil pH and reduced soil bulk density as a result of biochar application which induces P solubility and availability, increased N fixation, and enhanced root growth, increased nodulation leading to improved growth and yield of cowpea. Application of biochar with P fertilizer could therefore be used as a strategy for improving P availability in low pH soils of cowpea growing areas of the tropics.

Recycling-derived Phosphorus Fertilizers as a Sustainable Alternative to Triple Superphosphate Fertilizers

Microbial activity is adamant for the nutrient cycling in soil. Generally, mineral phosphorus (P) fertilizer is applied to soil to improve plant growth, however, significant amounts are immobilized quickly. Mineral fertilizer can cause soil degradation, affecting the microbial community. Alternative, recycling-derived fertilizers (RDFs) need to be evaluated as suitable replacement for finite mineral P fertilizer. The impact of four RDFs (two ashes, two struvites) on the soil microbiome in comparison with a P-free control and triple superphosphate (TSP) as mineral fertilizer was investigated in a pot trial and a subsequent microcosm trial (subset of samples). For both experiments, perennial ryegrass was cultivated for 54 days. The pot trial was conducted at P fertilization rates of 20 and 60 kg P ha-1 in quadruplicates. After the pot harvest, the bulk soil was stored until the microcosm trial was conducted, using the control, TSP and the two ashes at 60 kg P ha-1 in six replicates. Struvites displayed highest P bioavailability at high P application rates in the pot trial, yielding higher biomass on average. Furthermore, P solubilization from tri-calcium phosphate was enhanced in the RDFs treatments, while the TSP treatments were negatively affected. For the microcosm trial, most probable number (MPN) analysis showed that phytate-utilizing bacterial abundance was significantly increased in one of the ashes. Non-metric multidimensional scaling (NMDS) analysis of phoD illumina sequencing data showed significant separation between all treatments of the microcosm trial. Understanding the impact of RDF application on the soil P cycle is vital to sustainable agriculture.

Biology and life table parameters of Callosobruchus maculatus (F.) on Vigna unguiculata (L.) Walp. fertilized with some mineral- and bio-fertilizers

Callosobruchus maculatus (F.) (Coleoptera: Chrysomelidae), a major pest of stored cowpea Vigna unguiculata (L.) Walp., causes critical losses by decreasing the grain weight, germination ability and nutritional quality. Improving host plant resistance by the application of appropriate fertilizers would be effective in reducing C. maculatus infestation. The effects of some mineral- (triple superphosphate (TSP) and urea) and bio-fertilizers (Bradyrhizobium japonicum, Pseudomonas putida, mycorrhizal fungi, and a mixture of them) were evaluated on the susceptibility of stored cowpea grains to C. maculatus. Cowpeas fertilized with examined fertilizers were cultivated at farm conditions. Then, the mature, dry grains were harvested and used to investigate the pest's life cycle and life table characteristics under 28 ± 1 °C, 65 ± 5% R.H., and total darkness. Developmental time of C. maculatus on TSP-treated grains was shorter than on control and P. putida treated ones. However, the lowest immature survival and fecundity (number of deposited eggs) was on TSP-fertilized grains. The intrinsic rate of increase (r) and net reproductive rate (R0) were the lowest on the grains treated with TSP. The highest tannins and starch content in the grains fertilized with TSP may be the critical reasons for their resistance to C. maculatus in storage. Application of TSP fertilizer can be recommended to increase cowpea resistance to this pest.

Phosphate fertilization affects rhizosphere microbiome of maize and sorghum genotypes.

Despite the lower reactivity of natural phosphates compared to soluble fertilizers, their P bioavailability can increase over the cultivation years, due to the physicochemical processes and the activity of soil microbiota. Therefore, this work aimed to evaluate the α and β diversity of the rhizosphere microbiota of maize and sorghum genotypes grown under different sources and doses of phosphate fertilizers. Four commercial maize and four sorghum genotypes were grown under field conditions with three levels of triple superphosphate (TSP) and two types of rock phosphate sources: phosphorite (RockP) and bayóvar (RP) during two seasons. Maize and sorghum presented a significant difference on the genetic β diversity of both rhizosferic bacterial and arbuscular mycorrhizal fungi. Moreover, P doses within each phosphate source formed two distinct groups for maize and sorghum, and six bacterial phyla were identified in both crops with significant difference in the relative abundance of Firmicutes and Proteobacteria. It was observed that RockP fertilization increased Firmicutes population while Proteobacteria was the most abundant phylum after TSP fertilization in maize. In sorghum, a significant impact of fertilization was observed on the Acidobacteria and Proteobacteria phyla. TSP fertilization increased the Acidobacteria population compared to no fertilized (P0) and RockP while Proteobacteria abundance in RockP was reduced compared to P0 and TSP, indicating a shift toward a more copiotrophic community. Our results suggested that the reactivity of P source is the predominant factor in bacterial community' structures in the maize and sorghum rhizosphere from the evaluated genotypes, followed by P source.

Uptake of Phosphorus from Modified P-Enriched Douglas Fir Biochar and Its Effects on Crop Growth and P Use Efficiency

The potential use of biochar as a sustainable soil amendment has recently gained global recognition. The use of biochar as a soil additive is attributed to its ability to improve soil chemical, physical and biological properties. Studies have shown that biochar amendments can enhance soil nutrient retention and availability, pH, water holding capacity, microbial activity and sequester carbon. In this study using corn (Zea mays L.) as an experimental crop, the influence of P availability from modified P enriched Douglas fir biochar (PEB), triple super phosphate fertilizer (SPF), and modified Douglas fir biochar (MB) on plant growth and P Use Efficiency (PUE) were compared. The rate of P applied (0, 30, 60, 90 and 120 kg·ha-1) was calculated based on % P content of each soil additive. Except for MB treatments, P recovery, crop growth and P Use Efficiency increased with application rates. The maximum above ground dry matter yields corresponding to PEB, SPF and MB treatments were estimated at 3488 kg·ha-1, 2449 kg·ha-1 and 639 kg·ha-1, while their respective agronomic P use efficiency (AGE) rates were 32 kg·kg-1, 17 kg·kg-1, 0.5 kg·kg-1. Also, recovery of K, Mg, Ca, Zn, Fe, Cu, B and Mn improved in both PEB (p value 2 > 0.9) and SPF (p value 2 > 0.9) treatments. More studies at field scale are needed to demonstrate the practicability of using modified P enriched Douglas fir biochar for soil amendments.

Effect of Various Rates of P from Alternative and Traditional Sources on Butterhead Lettuce (Lactuca sativa L.) Grown on Peat Substrate

Previous research indicated the potential use of struvite (STR) as an alternative source of phosphorus (P) in crop production. A greenhouse experiment was conducted to evaluate the effect of STR and triple superphosphate (TSP) on the growth and chemical composition of butterhead lettuce grown on peat substrate over a three-month period (May–July). Both alternative (STR) and conventional (TSP) fertilizers were applied at three rates: (1) recommended rate based on the elemental content of substrate and crop nutritional need; (2) reduced rate (50% lower than recommended); and (3) increased rate (50% higher than recommended). Unfertilized (control) plants were also grown in the pot experiment. As expected, fertilizer application tended to increase the content of heavy metals in the substrate. Thus, an increase in Zn, Pb, and Cu content in peat substrate was found following STR amendments. However, compared with unfertilized plants, the applied rates of the STR and TSP fertilizers did not increase the content of Cd and Cu in the plant leaf, while Hg content was below the detection limit. In addition, Zn content in the plant leaf significantly decreased following STR and TSP applications. In comparison to unfertilized plants, both alternative and conventional fertilizers increased the content of P and nitrate nitrogen (N-NO3−) in the plant leaf while their effect on Mg content was negligible. The increased rate of STR was the best fertilizer treatment because it produced the largest number of leaves, which were also characterized by the highest P content. Our findings showed that STR was an effective source of P in butterhead lettuce cultivation without adverse effects on heavy metal accumulation.

Influence of phosphorus fertiliser blends on grain yield, nutrient concentration, and profitability of soyabeans in the southern Guinea Savannah of Ghana

We conducted on-farm trials in the southern Guinea savannah of Ghana in 2016 and 2017 to evaluate soyabean response to three fertiliser blends to guide farmers towards profitable adoption of appropriate phosphorus fertiliser blend for improved soyabean production. Old Yara Legume, New Yara Legume and Triple Superphosphate fertiliser blends were evaluated. In both years, the phosphorus fertiliser blends were evaluated in a Randomised Complete Block Design with 20, 30, and 40 kg P ha−1 application rates together with control. Phosphorus fertiliser application increased soyabean yields by 1 070 kg ha−1. In 2016, fertiliser blend use efficiency ranged from 2.9 kg grain per kg fertiliser blend applied with the New Yara Legume applied at 40 kg P ha−1 to 7.4 kg grain per kg fertiliser blend applied with the Triple Superphosphate applied at 40 kg P ha−1 with significant differences between treatments. In 2017, blend use efficiency ranged from 2.5 kg grain per kg fertiliser blend applied with Old Yara Legume applied at 40 kg P ha−1 to 9.2 kg grain per kg fertiliser blend applied with the Triple Superphosphate applied at 40 kg P ha−1 with significant differences between treatments. However, phosphorus use efficiency did not significantly differ between the different treatments both in the 2016 and 2017 trials. In both 2016 and 2017 trials, the highest benefit cost ratio was attained at the lowest application rate for all the three fertiliser blends suggesting the need to review the current application rate of 30 kg P fertiliser ha−1 promoted in northern Ghana. Furthermore, the provision of credit and/or subsidy for farmers by the government is required to enable uptake and utilisation of fertilisers by farmers.

Phosphorus availability from magnesium‐modified P‐enriched Douglas fir biochar as a controlled release fertilizer

AbstractPhosphorus (P) is one of the essential elements required for plant growth and development. However, worldwide, many agricultural soils can be deficient in P. The use of fertilizers and manures as a source of P can be costly, limited in supply in some regions of the world and ecologically unfavourable. Nutrient‐enriched biochar has been suggested as a relatively cost‐effective and eco‐friendly P source. This study investigated P availability from Douglas fir biochar modified with magnesium chloride and potassium hydroxide solutions only (B), and modified P‐enriched Douglas fir biochar B50, B100 and B150 corresponding to B treated with 50, 100 and 150 mg P L−1 solutions of potassium phosphate monobasic. Triple super phosphate fertilizer (FC) and a control treatment without phosphate added (C) used as a reference treatment. Treatments were added to soil in varied amounts to obtain the same P rate of 30 kg P ha−1. Aboveground biomass dry weight yield (R2 = .7) and plant height (R2 = .86) improved with P contents. After harvest, residual soil P for the FC treatment was significantly greater than all other treatments (p‐value = 1.7848 E‐6, R2 = .8). Plant height and aboveground dry weight biomass were greater with B150 compared to B50 at the same total P loading, suggesting that the greater P concentration of the biochar (B150) resulted in less tightly bound P and was therefore more available for plant uptake. This study showed promise of utilizing P‐enriched Douglas fir biochar as a slow‐release P fertilizer.

​Effect of Irrigation Regimes and Phosphorus Fertilization on Water-use Efficiency, Phosphorus-agronomic Efficiency and Yield of Grass Pea (Lathyrus sativus L.) Ecotypes

Background: Grass pea (Lathyrus sativus L.) is a crop of immense economic significance. It is one of the most resilient to climate changes and to be survival food during drought-triggered famines. Methods: In a field study split factorial experiment based on a randomized complete block design with 3 replications were used, effects of irrigation regimes (50, 75 and 100% evaporation of Pan class A) and different rates of phosphorous fertilizer (triple superphosphate 0, 60 and 120 kg/ha) on growth and yield of two grass pea ecotypes (Lalehzar and Sharekord) in Lalezar area (Kerman province, Iran) was carried out during 2018 and 2019. Result: The results showed that drought stress reduced grass pea seed yield (401 kg/ha-1) and biological yield (863 kg/ha-1) and this reduction was depended on the severity of stress. In the other side, application of phosphorous fertilizer (60 kg/ha-1) increased grass pea yield (2401 kg/ha-1). This means that phosphorus fertilizer could partiaiiy offset the effect of drought stress and had a significant effect on the water use efficiency and phosphorus agronomic efficiency. Finally, drought stress, either no-application phosphorus fertilizer, could decrease yield. Overally, Shahrekord ecotype showed the higher and most desirable grain yield (2401 kg/ha-1), biological yield (5612 kg/ha-1), grain water use efficiency and biological water use efficiency, respectively, with (0.74 and 1.72 m3 water/ha-1) and phosphorus agronomic efficiency (18.76 kg yield/kg P) to the applied treatments (75% irrigation+ triple superphosphate fertilizer 60 kg/ha).

Legacy effect of green manure crops fertilized with calcium phosphite on maize production and soil properties

Recycling phosphorus (P) is crucial to meet future P demand for crop production. We investigated the possibility to use calcium phosphite (Ca-Phi) waste, an industrial by-product, as P fertilizer following the oxidation of phosphite (Phi) to phosphate (Pi) during green manure (GM) cropping in order to target P nutrition of subsequent maize crop. In a greenhouse experiment, four GM crops were fertilized (38 kg P ha−1) with Ca-Phi, triple super phosphate (TSP) or without P (Control) in sandy and clay soils. The harvested GM biomass (containing Phi after Ca-Phi fertilization) was incorporated into the soil before maize sowing. Incorporation of GM residues containing Phi slowed down organic carbon mineralization in clay soil and mass loss of GM residues in sandy soil. Microbial enzymatic activities were affected by Ca-Phi and TSP fertilization at the end of maize crop whereas microbial biomass was similarly influenced by TSP and Ca-Phi in both soils. Compared to Control, Ca-Phi and TSP increased similarly the available P (up to 5 mg P kg−1) in sandy soil, whereas in clay soil available P increased only with Ca-Phi (up to 6 mg P kg−1), indicating that Phi oxidation occurred during GM crops. Accordingly, no Phi was found in maize biomass. However, P fertilization did not enhance aboveground maize productivity and P export, likely because soil available P was not limiting. Overall, our results indicate that Ca-Phi might be used as P source for a subsequent crop since Phi undergoes oxidation during the preliminary GM growth.

Effect of giving triple super phosphate and dolomite fertilizer on mushroom media (baglog) on production of white oyster mushroom (Pleurotus ostreatus)

The effort to increase the growth and production of white oyster mushroom (Pleurotus ostreatus), it is necessary to add nutrients to sawdust which will be used as a growing medium for white oyster mushroom. One of the nutrients that need to be added is minerals including Ca (calcium) and Magnesium (Mg) contained in dolomite (CaMg(CO3)2) and macronutrients such as phosphorus contained in TSP fertilizer. The aim of this research to determine the effect of giving TSP fertilizer and dolomite on mushroom growing media (baglog) on the production of white oyster mushrooms. This research was conducted in September 2019 to March 2020 in the village, of, Lau Bakeri village, Kutalimbaru District, Deli Serdang Regency The research used a factorial randomized block design with two treatment factors, namely TSP fertilizer (control, 1.2%, 2.4%) and dolomite (control, 1%, 2%, 3%. The results showed the application of triple super phosphate fertilizer and dolomite did not significantly affect to all observation parameters of white oyster mushrooms, but the interaction between triple super phosphate fertilizer and dolomite was able to accelerate the age of harvesting, increase the fresh weight of mushrooms in the first and second harvests and the number of mushroom caps at the third harvest.

INTERACTION OF SOIL ORDERS AND LEVELS OF APPLIED PHOSPHORUS ON P-STATUS OF SOIL CALTIVATED WITH WHEAT AT ELONGATION STAGE

A pot experiment was carried out during autumn growing season of 2016-2017 at the Gerdarasha field of College of Agriculture Engineering Sciences, to study the effect of three dominant soil orders (Mollisols (M), Vertisols (V) and Aridisols (A)), five levelsof applied triple super phosphate (TSP) fertilizer (0, 80, 160, 240 and 320 kg TSP ha-1) and combination between them on chemical availability of phosphorus (P) using solubility diagram at elongation stage and wheat yield. The factorial experiment was depended using a completely randomized design (CRD) with three replicates. The results indicated that the soil orders were affected on phosphorus status, it has appeared that the studied soil order was located between TCP and HA for both Aridisols and Vertisols it means the solubility of phosphorus is low. but in Mollisols is slightly more than Vertisols and Aridisols. It is the P-status and availability was very low since shifting towards TCP, it means precipitation of P in a non-available form then decrease in its availability. The application of phosphorus fertilizers caused shifting the points towards a more soluble form of phosphorus. The results indicated that the application of TSP fertilizer increased the solubility of P in the studied dominate soil orders. Then, the treatment combination (M, V, A) TSP0 were the nearest point to TCP falling between TCP and OCP which were the lowest soluble of phosphorus there less available, phosphorus application of phosphorus caused to shifting towards DCP In contrast, for treatment combination (M,V and A) TSP320 kg ha-1 were located between OCP and DCP the nearest point treatment combination for DCP

EFFECT OF DIFFERENT TYPES OF FERTILIZER ON THE GROWTH OF MARINE PHYTOPLANKTON POPULATION Chlorella vulgaris

This research was conducted on October 13-26, 2019 in the Regional Technical Implementation Unit of the Seawater and Brackish Aquaculture Fisheries Office (UPTD BPBALP Teluk Buo), West Sumatra. This study aims to determine the effect of applying different types of fertilizers to the growth of Chlorella vulgaris microalgae populations on laboratory scale culture. The method used in this study was an experimental method in the laboratory using a completely randomized design (CRD) one factor, namely the difference in fertilizer types with 3 (three) replications. Fertilizers used are Walne fertilizer, ZA (Zwavelzure Ammoniak) and TSP (Triple Super Phosphate). The testing organism in this study was phytoplankton C. vulgaris. The container used was a glass jar (3 liter capacity). The parameters measured in this study include absolute growth, relative growth, specific growth, self-doubling time and water quality. The results of this study indicate that the best type of fertilizer for C.vulgaris population growth was TSP fertilizer, followed by ZA fertilizer and the lowest in Walne fertilizer.

Bio-Organic Fertilizer: A Green Technology to Reduce Synthetic N and P Fertilizer for Rice Production.

Decomposed organic materials, in combination with plant growth-promoting bacteria (PGPB), are environmentally friendly and reduce synthetic fertilizer use in rice production. A bio-organic fertilizer (BoF) was prepared using kitchen waste (79%), chita-dhan (unfilled rice grain) biochar (15%), rock phosphate (5%), and a consortium of 10 PGPB (1%) to supplement 30% nitrogen and to replace triple superphosphate (TSP) fertilizer in rice production with an improvement of soil health. PGPB were local isolates and identified using 16S ribosomal RNA partial gene sequences as Bacillus mycoides, Proteus sp., Bacillus cereus, Bacillus subtilis, Bacillus pumilus, Paenibacillus polymyxa, and Paenibacillus spp. Isolates could fix N2 by 0.7–1.4 g kg–1, solubilize 0.1–1.2 g kg–1 phosphate, and produce 0.1–40 g kg–1 indoleacetic acid. The performance of BoF was evaluated by 16 field experiments and 18 farmers’ field demonstration trials during the year 2017–2020 in different parts of Bangladesh. Performances of BoF were evaluated based on control (T1), full synthetic fertilizer dose of N, P, and K (T2), BoF (2 t ha–1) + 70% N as urea + 100% K as muriate of potash (T3), 70% N as urea + 100% P as TSP + 100% K as muriate of potash (T4), and 2 t ha–1 BoF (T5) treatments. At the research station, average grain yield improved by 10–13% in T3 compared with T2 treatment. Depending on seasons, higher agronomic N use efficiency (19–30%), physiological N use efficiency (8–18%), partial factor productivity (PFP)N (114–150%), recovery efficiency (RE)N (3–31%), N harvest index (HIN) (14–24%), agronomic P use efficiency (22–25%), partial factor productivity of P (9–12%), AREP (15–23%), and HIP (3–6%) were obtained in T3 compared with T2 treatment. Research results were reflected in farmers’ field, and significant (P < 0.05) higher plant height, tiller, panicle, grain yield, partial factor productivity of N and P were obtained in the same treatment. Application of BoF improved soil organic carbon by 6–13%, along with an increased number of PGPB as compared with full synthetic fertilizer dose. In conclusion, tested BoF can be considered as a green technology to reduce 30% synthetic N and 100% TSP requirements in rice production with improved soil health.

A comparison of microwave and ultrasound routes to prepare nano-hydroxyapatite fertilizer improving morphological and physiological properties of maize (Zea mays L.)

Hydroxyapatite nanoparticles have a remarkable potential to be used as nano-fertilizers with great effects on improving the yield of plants. These nano-compounds were synthesized using microwave and ultrasound methods, which decrease the particle size distribution of the products. To investigate the effects of two types of simple and triple superphosphate fertilizers on some properties of maize plant (Zea mays L.), a factorial experiment was conducted based on a completely randomized block design. The fertilizer treatments included in this study were simple superphosphate, triple superphosphate, microwave nano-hydroxyapatite, and ultrasound nano-hydroxyapatite and examined at five concentration levels. The results showed that the application of nano-hydroxyapatite phosphate fertilizers improved the growth and physiological properties of maize plant. This would raise better results in comparison to the simple and triple superphosphate fertilizers. Considering the positive effects of nano-hydroxyapatite fertilizers and high production levels, the results of this experiment revealed that the synthetic nano-hydroxyapatite methods prevent phosphorus loss; therefore, it is recommended to use nano-phosphate fertilizers in food resource management to achieve a favorable quantitative yield. Moreover, they can be regarded as a favorable solution to deal with the environmental problems.

Valorization of calcium phosphite waste as phosphorus fertilizer: Effects on green manure productivity and soil properties

The potential to use calcium phosphite (Ca-Phi) as phosphorus (P) fertilizer may represent an effective recycling of P-containing by-products. A greenhouse experiment was conducted to investigate the effect of Ca-Phi (38 kg P ha−1) on soil properties and the growth parameters of four green manure species in clay and sandy soils using Ca-Phi, TSP (triple superphosphate) and control (no fertilization) as treatments. Eight weeks after sowing, we measured aboveground biomass yield, phosphite (Phi) concentration in plant biomass, different soil P pools as well as microbial biomass nutrients. Compared to control, the addition of Ca-Phi did not negatively affect green manure yield, except for lupine (Lupinus albus L.) in clay soil. The Phi concentration in plant biomass varied across species and soil type with a maximum concentration of about 400 mg Phi kg−1 for mustard (Brassica juncea L.) in clay soil. Compared to control, TSP and Ca-Phi fertilization had a similar effect on different P pools and microbial biomass nutrients (C, N and P) although the response was soil–type dependent. In the sandy soil, after Ca-Phi addition the amount of available P (PNHCO3) increased to the same extent as in the TSP treatment (i.e. around 6 mg P kg−1) suggesting that Ca-Phi was, at least partly, oxidized. In the clay soil with high P fixing capacity, Ca-Phi promoted higher PNaHCO3 than TSP likely due to different solubility of chemical P forms. Additional studies are however required to better understand soil microbial responses and to quantify the P agronomical efficiency for the following crop under Ca-Phi fertilization.

Use of single superphosphate fertiliser produced using Eppawala rock phosphate as a source of phosphorous for rice cultivation

Sri Lanka is an agricultural country totally depending on imported fertilisers for paddy cultivation. Importation of triple superphosphate fertiliser is a heavy burden on the country’s national economy. Hence, optimum utilisation of the locally available Eppawala phosphate deposit (EPD) will save a significant amount of foreign exchange. The objective of this study was to assess the effectiveness of locally produced Eppawala single superphosphate as a source of phosphate fertiliser for rice in comparison to triple super phosphate. Small tonnage of Eppawala single super phosphate (ESSP) was produced for the purpose of experiments using finely ground Eppawala rock phosphate (ERP: 90%

Effect of Phosphate Fertilizer Type and Nitrogen Application Method on Tuber Yield and Growth Indices of Three Potato (Solanum tuberosum L.) Cultivars

Nitrogen and phosphorus are essential nutrients in growth of plants. In addition, the type and method of fertilizer application play an important role in the efficient absorption of nutrients and reduce fertilizer use. Therefore, an experiment was conducted in a randomized complete block design with three replications in the Bahar city in 2017: phosphorus fertilizer was three levels (no application, triple superphosphate and diammonium phosphate), nitrogen fertilizer with two levels (placement and no-placement) and potato cultivar with three levels (Agria, Banba and Sante). The highest leaf area index (5.27), crop growth rate (13.22 g.m-2) and total dry matter (582.86 g.m-2) were obtained from diammonium phosphate along with nitrogen placement in by using Agria cultivar. The results also showed that under conditions phosphorus deficiency, nitrogen application method did not affect leaf area index, crop growth rate and total dry matter: However, tuber yield of Agria under phosphorus deficiency increased by nitrogen placement treatment. In this study, the use of diammonium phosphate, compared to triple superphosphate, increased leaf area index, crop growth rate, relative growth rate and total dry matter. The effect of nitrogen placement along with triple superphosphate was higher than that of nitrogen with diammonium phosphate. Chlorophyll index was not affected by nitrogen placement when using diammonium phosphate, whereas, nitrogen placement increased chlorophyll index by 6.5% with triple superphosphate. The results also showed that the tuber yield increased by 25.4% when nitrogen used by placement combined with triple superphosphate fertilizer. As a whole, highest tuber yields of all three cultivars, especially in Agria and Banba, were increased under nitrogen placement treatment along with diammonium phosphate.