Application Of Phosphogypsum Research Articles

Effects of phosphogypsum and water treatment residual application on key chemical and biological properties of clay soil and maize yield

AbstractThe reuse of phosphogypsum (PG) and water treatment residual (WTR) waste for agricultural purposes is a possible option to improve the soil properties and increase the crop yield. The present study was conducted during the 2014 growing season in order to determine the impacts ofPGandWTRapplied to the heavy clay soils (which contain more than 50% clay particles) at rates of 5 and 10 t ha−1with the recommended nitrogen fertilizer (NF) on the key soil properties and maize yield. A field experiment was conducted as a randomized complete block design with five treatments and three replications. The treatments were as follows: recommended nitrogen fertilizer (NF);NF+PGat 5.0 t ha−1(NF+PG5);NF+PGat 10.0 t ha−1(NF+PG10);NF+WTRat 5.0 t ha−1(NF+WTR5); andNF+WTRat 10.0 t ha−1(NF+WTR10). The results revealed that the soil microbial biomass carbon (MBC),CO2evolution and dehydrogenase activity (DHA) increased significantly with the addition ofPGorWTR. The application ofPGwithNFat the rate of 10 t ha−1recorded the highest microbial activity, soil available nutrients, grain yield and yield component of maize plants compared to the other treatments. Additions ofNF+PGat the rates of 10 and 5 t ha−1and F+WTRat 10 and 5 t ha−1increasedDHAby 1.70, 1.60, 1.40 and 1.20 times, respectively, compared to theNFtreatment. It can be concluded that application ofPGandWTRwith the recommended application rates would help in improving the properties of heavy clay soils.

Influence of the adoption of phosphogips and seros-containing fertilizers on the microbial population of south chernozem

The following field experiences were performed on the Chernozem southern carbonate: 1.Control, 2. Sulphoammophos – 150 kg/ha, 3. Sulphoammophos – 250 kg/ha, 4.Phosphogypsum – 3 t/ha, 5.Phosphogypsum – 6 t/ha, 6.Phosphogypsum – 12 t/ha, 7. Phosphogypsum – 3 t/ha ammophos –70 kg/ha ammonium nitrate, 100 kg/ha 8. Phosphogypsum – 6 t/ha ammophos -70 kg/ha ammonium nitrate, 100 kg/ha 9. Phosphogypsum – 12 t/ha ammophos–70 kg/ha ammonium nitrate, 100 kg/ha. 10. ammophos-70 kg/ha + ammonium nitrate 100 kg/ha. The determination of the number of microorganisms produced in the phase of milky-wax ripeness of winter wheat on the selective nutrient medium: meat-peptone agar – number of ammonifiers; on starch and ammonia agar – microorganisms that assimilate mineral forms of nitrogen on the Hutchinson medium – calculatorsreal the number of microorganisms on the Czapek-Dox medium – the number of micromycetes on the Ashby medium – the number of aerobic nitrogen-fixing bacteria of the genus Azotobacter. Introduction phosphogypsum, sulphoammophos, ammophos and ammonium nitrate contributes to the increase in the numbers of various physiological groups of microorganisms. The highest values of the studied indicators in comparison with the control was achieved through the joint application of phosphogypsum – 12 t/ha ammophos-70kg/ha and ammonium nitrate-100kg/ha: ammonifiers on 123.4 million CFU/g (or 2.5 times); nitrifiers at 138 million CFU/g (3.3 times), microscopic fungi on 90,0 thousand CFU/g (1.7 times); cellulose-fermenting microorganisms on 250.6 thousand CFU/g (more than 2 times); aerobic nitrogen-fixing bacteria of the genus Azotobacter by 30.7 thousand CFU/g (1.5 times). Thus, the most responsive to the introduction of phosphogypsum and fertilizers microorganisms that convert mineral and organic nitrogen compounds.

Effect of phosphogypsum and poultry manure on aggregate-associated alkaline characteristics in bauxite residue

Bauxite residue is a highly alkaline solid waste with poor physical structure which ultimately limits plant growth. Ecological reconstruction is an effective strategy to improve its environmental management, although soil formation process still requires further investigation. Here, an incubation experiment was used to investigate the effects of phosphogypsum and poultry manure, on aggregate size distribution and aggregate-associated exchangeable bases of bauxite residue. Phosphogypsum and poultry manure additions significantly increased the proportion of 2–1 mm residue aggregates and enhanced mean weight diameter (MWD) of residues in the 0–20 cm and 20–40 cm layers, although little effect was evident in the 40–60 cm layer. Phosphogypsum addition reduced pH and EC values to approximately 8.5 and 200 mS/cm in different size aggregates at 0–20 cm. Exchangeable Ca2+ concentration was improved, especially in 0.25–0.05 mm and <0.05 mm aggregates, following amendment additions. The relative contents of katoite and cancrinite in >0.25 mm aggregate fractions were relatively higher, which was consistent with changes in pH. Phosphogypsum and poultry manure changed the microstructure and surrounding pores of residue aggregates, whilst the concentration of Ca on microaggregate surfaces was higher than that on macroaggregates. These findings reveal that application of phosphogypsum and poultry manure directly alter the distribution of exchangeable bases and alkaline indicators within residue aggregates, resulting in aggregate size distribution and microstructure variations.

Efficiency of Various Reagents on Ammonia Reduction in Litter Removal From Belt Conveyors for Battery Cages

With the development of technogenic civilization, various anthropogenic factors (ionizing radiation, toxic substances, etc.) affect virtually all living organisms, and often this effect is negative. The current state of affairs on many poultry farms is that they have a negative impact on the surrounding biosphere due to harmful emissions. This is due to the accumulation of litter. The purpose of the study was to investigate the microclimate parameters in the poultry house with the addition of various reagents and zeolite in the belt conveyors of cage batteries. It was proposed to add adsorbents (zeolite) and chemical reagents (phosphogypsum, superphosphate, and aluminium chloride and iron sulphate) directly onto the litter removal belt conveyors of cage batteries. It was found that application of zeolite onto the conveyor belt in an amount of 600 g/m2 reduces the content of ammonia in the premises by 1.6 times on the first day of accumulation of litter, and by 1.25 times on the seventh day, not exceeding during all seven days of maximum allowable concentrations. However, within all seven days of litter accumulation, a difference in this indicator with control was statistically significant (P=0.001). The reduction of ammonia emissions was less significant when applying a dose of zeolite of 300 g/m2 conveyor belt: by 1.6 times on the first day of accumulation of litter, and from the fifth day the difference with control was statistically significant. The application of phosphogypsum onto the conveyor belt in the amount of 600 g/m2 provided a reduction of ammonia emission by 2.1-1.1 times, 300 g/m2-by 1.8 times on the first day of accumulation of litter. Since the fifth the day, the difference in control was statistically significant. The application of superphosphate onto the litter removal conveyor belts reduced the ammonia content in the poultry house in almost the same extent as when applying phosphogypsum. The effective time of this reagent was also close in importance. Aluminium chloride and ferrous sulphate were used in smaller doses than other absorbents and reagents, but on the initial five days of litter accumulation, they provided a relatively significant reduction in the ammonia content of the air in the poultry house: ferrous sulphate at a dose of 200 g/m2 of the conveyor belt area - by 2.0-1.2 times, aluminium chloride - by 4.0-1.5 times. Anyway, the efficacy of these reagents in the last days of litter accumulation was considerably decreased. The use of aluminium chloride and ferrous sulphate in doze of 100 g/m2 for the conveyor belt provided a proper reduction of indoor ammonia content only for the initial tree-four days.

Investigation on the hydration of hemihydrate phosphogypsum after post treatment

Pretreatment is very important for the application of phosphogypsum (PG), but it is seldom adopted in practise due to high investment and costs. In order to promote the application of PG, post treatment of hemihydrate phosphogypsum (HPG) by addition of slaked lime (SL) was investigated. As an alkaline additive, SL can neutralize HPG. In addition, the interaction of HPG and SL can not possibly be avoided, because SL is generally presented in composite binder and it is also the hydration product of cement based materials which are widely used. Therefore, the hydration process, setting and hardening characters of HPG with different SL contents at a constant water/powder ratio were studied in detail. It was found that small amounts of SL can neutralize HPG but lead to super retardation and strength degradation due to the formation of calcium phosphate which would hinder the dissolution of HPG and alter the morphology of gypsum from needle-like to tiny crystal with little interlocking. Surprisingly, the addition of excessive SL regardless of pH would promote the rehydration of HPG and eliminate the influence of calcium phosphate contributing to the comparable strength and normal setting possibly due to the preferential precipitation mechanism of calcium phosphate. This important finding could be translated into specific design guidelines for post treatment.

Gypsum application, soil fertility and cotton root growth

ABSTRACT Since there is no consensus on phosphogypsum (PG) rates to be used in agriculture, a better understanding of its effects on the soil solution is needed. Cotton root growth was evaluated as related to Al and Ca activity in soil solution affected by PG. The experiment was carried out in rhizotrons filled with30∙dm–3 of soil. PG rates were estimated by multiplying the soil clay content by 0.0, 1.5, 3.0, 6.0 and 12.0, and it was mixed to the sub-soil.In the upper soil layer, limestone was applied. After 90 days, samples were taken for analysis, and cotton was planted. After27 days, plants were harvested. PG increased soil pH and decreased Al content and activity. Without PG, dissolved organic carbon concentration was high in the soil solution, which explains the predominance of carbon Al-complexed with PG application. From 1,680 kg∙ha–1 of PG (corresponding to 6 × clay content), sulphur and calcium had the highest concentrations, increasing the SO4 Al-complexed. Cotton root length decreased in the upper layer and increased in the subsoil up to 2,324 kg∙ha–1 (corresponding to 8.3 × clay content) of PG. Cotton root growth is better related with soil properties than with soil solution attributes, and the present recommendations for PG use based on soil clay content underestimate the rate to be applied.

ЭФФЕКТИВНОСТЬ ПРИМЕНЕНИЯ ФОСФОГИПСА НА ДЕРНОВО-ПОДЗОЛИСТОЙ ПОЧВЕ В СЕВООБОРОТЕ С КАРТОФЕЛЕМ

The research is aimed to improve the agrochemical properties of sod-podzolic soil and increase the productivity of crop rotation with potatoes. The decrease in the mineral and organic fertilizers use in Non-Chernozem zone of Russia leads to low yields of potato tubers and worse agrochemical properties of sod-podzolic soils. Agronomical positive and ecologically safe effects of phosphogypsum on physical and chemical properties of sod-podzolic sandy soil and formation of productivity and quality of potato and spring barley was revealed. With the introduction of phosphogypsum, on average for 3 years, the soil received (kg S/ha per year): with a dose of 0.5 t/ha +35.1, with a dose of &#x0D; 1.0 t/ha +57.6, with a dose of 1.5 t/ha +79.8 and against a background of 3.0 t/ha +105.6, which led to an increase in the content of salpho in the soil, respectively, introduced doses of meliorant – by 9.7, 17.5, 26.5 and 32.9 mg S/kg compared to the initial level. A single application of phosphogypsum to sod-podzolic soil provided an increase in the content of labile phosphorus by 72 and 40 mg/kg against the background of doses of 1.5 and 3.0 t/ha. The As-sessment of the possible toxicity of phosphogypsum showed that the ratio of Ca/Sr in the soil is at a safe level and amounted to 97 in the control variant, against the background of doses of phosphogypsum 0.5, 1.0 and 1.5 t/ha – 104-117. In total, for three years of research, the use of meliorant provided an increase in the productivity of potato – barley – potato crop rotation by 30-38 kg of grains units/ha or 19-24% in comparison with the option where only NPK fertilizers were used.

Utilisation of Water-Washing Pre-Treated Phosphogypsum for Cemented Paste Backfill

Recycling phosphogypsum (PG) for cemented paste backfill (CPB) has been widely used at phosphate mines in China. However, the impurities in PG prolong the setting time and reduce the uniaxial compressive strength (UCS), limiting the engineering application of PG. This paper aims to investigate the feasibility of treated PG (TPG) washed repeatedly using deionised water (DW) for CPB. A water-washing pre-experiment was first conducted to find the proportion with the least DW demand and the effects of water-washing on ordinary PG (OPG). Then, based on the PG:DW ratio obtained from the pre-experiment, the properties of the OPG-based CPB (OCPB) and TPG-based CPB (TCPB) were tested using slump tests, UCS tests, and microstructural analysis. The results show that (1) after 11 water-washings at the PG:DW ratio of 1:1.75, the pH of the supernatant (pH = 6.328) meets the requirements of Chinese standard GB 8978-1996. (2) Water-washing improves the particle gradation quality of PG and removes the soluble impurities adsorbed at the surface of PG crystals. (3) The initial slump values of TCPB are 0.19–1.15 cm higher than that of OCPB, furthermore, the diffusivity values of TCPB are better than the performance of OCPB, with 0.61–1.68 cm of superiority. (4) The UCS values of TCPB are up to 0.838 MPa, 1.953 MPa, and 2.531 MPa, after curing for 7, 14, and 28 days. These are 0.283 MPa, 0.823 MPa, and 0.881 MPa higher than that of OCPB, respectively. It can be concluded that water-washing pre-treatment greatly improves the workability and mechanical property of PG-based CPB. These results are of great value for creating a reliable and environmentally superior alternative for the recycling of PG and for safer mining production.

磷石膏的发展及其在石膏板中的应用

磷石膏的发展及其在石膏板中的应用

Evaluation of raw and chemically treated waste phosphogypsum and its potential applications

A million tons of Phosphogypsum (PG) is stacked in the environment every year and is progressively considered an asset. South African construction industry is expanding as a result of infrastructural developments in the country, the reuse of PG in this industry is considered for recycling and reducing the stacks in landfills. Phosphogypsum is known for its limited ability to use in cement industry due to its phosphorus and radionuclides impurities. This study was conducted to reduce these impurities and investigate the probability of PG application in building and construction. Leaching of PG with citric acid was conducted whereby a relative proportion of P2O5 and radionuclides was reduced in the material, constituents which contributes to strengths reduction. Optimum moisture Contents and maximum dry densities were determined for various PG content mix designs in which Lime and Fly Ash were added to stabilise PG material. The composites were compacted at various moisture contents and cured at low and elevated temperatures of at 40 °C and 80 °C for 4 days. The results obtained shows that for unconfined compressive strengths; the composites produced from PG, and cured at high temperature qualified for the use in construction industry.

Effect of neutralization on the setting and hardening characters of hemihydrate phosphogypsum plaster

Phosphogypsum (PG) which is a waste byproduct of fertilizer production is the promising source of the gypsum industry. In order to explore the application of hemihydrate PG (HPG) as a substitute of hemihydrate gypsum, the setting and hardening characters of HPG plaster at different pH after neutralization were examined and contrasted with hemihydrate flue gas desulfurization gypsum (HFGD) plaster. Results showed that HPG plaster sets slow with a fall in strength and this effect was more pronounced after retarders were added when pH increased from 5.85 to 11.08. By contrast, HFGD plaster sets fast and without strength variation in the similar alkaline range. Microscopic studies including chemically combined water and temperature evolution curves of HPG plaster revealed that with the increase of the pH, the hydration reaction mechanism of hemihydrate and the gypsum crystal morphology were radically changed due to the fact of interaction between impurities and alkali. Consequently, HPG plaster is very different from HFGD plaster and its application in thealkaline condition was restricted.

Preparation of Calcium Fluoride using Phosphogypsum by Orthogonal Experiment

AbstractThe resource utilization of phosphogypsum is confronted with great challenge. Of all the different methods for phosphogypsum resource utilization, using phosphocypsum to fabricate calcium fluoride (CaF2) is an effective resource utilization method. In this work, high-quality nano-calcium fluoride was successfully prepared in aqueous solution using calcined phosphogypsum by direct precipitation method. A series of orthogonal experiments were carried out in study. Here, the calcined phosphogypsum powder was mixed with NH4F to react at 40°C for 70 min according to the optimum molar ratio (Ca/ F=0.4). Meanwhile, the residue obtained by separating the mixture reacted was dried at 120°C for 90min. After preparation, the nano-calcium fluoride was analyzed by X-ray diffraction and scanning electron microscope, results found that the average particle diameter of calcium fluoride was around 70 nm. This work could increase the industrial chain of phosphogypsum application and apply a method to solve the fluorite resource shortage.

A Novel Phosphogypsum Application Recommendation Method under Continuous No‐Till Management in Brazil

Core Ideas Phosphogypsum application increases grain yield, particularly in acidic subsoils. Phosphogypsum rates can be based on Ca2+ saturation in the ECEC of the subsoil. We show a new method for phosphogypsum recommendation based on M5‐Rules. Phosphogypsum (PG) is used in tropical and subtropical agriculture when subsoil acidity is an important yield‐limiting factor. However, the conditions that increase crop yield under PG application in continuous no‐till systems remain unclear. In addition, the methods used in Brazil to estimate the PG requirements are sometimes imprecise. Thus, to develop an accurate method for establishing PG recommendation, a dataset from experiments performed in southern Brazil and selected published papers involving PG application on various Oxisols under continuous no‐till was analyzed by computational techniques of data mining using the M5‐Rules algorithm to create regression models. Experimental areas consisted of annual crops managed under a long‐term (≥10 yr) no‐till system. These included maize (Zea mays L.), soybean [Glycine max (L.) Merr.], wheat (Triticum aestivum L.), and barley (Hordeum distichum L.). Results allowed the proposal of a new method for establishing the PG requirement to increase Ca2+ saturation to 60% in the effective cation exchange capacity (ECEC) at the 20‐ to 40‐cm soil layer when this is lower than 54% using the following equation: PG (Mg ha−1) = (0.6 × ECEC – exchangeable Ca2+ content in cmolc dm−3) × 6.4. The PG rates indicated by this method agreed with those leading to the maximum economic yields obtained in most studies conducted on continuous no‐till soils in Brazil. The proposed method might be efficiently used when subsoil acidity is an important growth‐limiting factor.

Phosphogypsum stabilization of bauxite residue: Conversion of its alkaline characteristics.

Reduction of the high alkalinity of bauxite residue is a key problem to solve to make it suitable for plant growth and comprehensive utilization. In this study, phosphogypsum, a waste product from the phosphate fertilizer industry, was used to drive the alkaline transformation of the bauxite residue. Under optimal water washing conditions (liquid/solid ratio of 2 mL/g, 30°C, 24 hr), the impact of quantity added, reaction time and reaction mechanism during phosphogypsum application were investigated. Phosphogypsum addition effectively lowered pH levels and reduced the soluble alkalinity by 92.2%. It was found that the concentration of soluble Na and Ca ions in the supernatant increased gradually, whilst the exchangeable Na+ and Ca2+ in solid phase changed 112 mg/kg and 259 mg/kg, respectively. Ca2+ became the dominant element in the solid phase (phosphogypsum addition of 2%, liquid/solid ratio of 2 mL/g, 30°C, 12 hr). X-ray diffraction data indicated that cancrinite and hydrogarnet were the primary alkaline minerals. SEM images suggested that phosphogypsum could promote the formation of stable macro-aggregates, whilst the content of Ca2+ increased from 5.6% to 18.2% and Na reduced from 6.8% to 2.4%. Treatment with phosphogypsum could significantly promote the transformation of alkalinity cations by neutralization, precipitation and replacement reactions. This research provided a feasible method to promote soil formation of bauxite residue by phosphogypsum amendment.

Mechanical Activation on Phosphogypsum: Hydrosodalite System

The application of phosphogypsum in the production of binding materials is problematic because of phosphate, fluorine and other soluble impurities. These impurities influence the strength development of binding materials and during operating time can be released (efflorescence) from binding materials’ products. For these reasons, it is important to neutralize the above-mentioned impurities. The objective of the work was to investigate the neutralization process of the acid impurities of hemihydrate phosphogypsum (obtained from Kovdor apatite mine) with zeolite hydrosodalite. Mechanical activation together with the neutralizing zeolite additive was used in this research. Mechanical activation was carried out in a ball mill. Two types of samples were formed: one type with non-milled mixtures and the second type with milled mixtures. The additive of 0, 3, 5, and 10% of hydrosodalite was chosen. This paper describes the process of adsorbing of hazardous phosphate impurities by hydrosodalite. The compressive strength of phosphogypsum specimens with hydrosodalite additives subjected to mechanical treatment was higher as compared to the specimens without mechanical activation and additive of hydrosodalite. In this case pH values of milled mixture with hydrosodalite become neutral for these samples. It was determined that the mixture of phosphogypsum with hydrosodalite under mechanical treatment is an effective additive for neutralizing the acidic phosphogypsum medium.

&lt;b&gt;Application of lime, phosphogypsum and fertilization rates affect soil fertility and common bean development in no-tillage system in a Cerrado Oxisol

There is a lack of information about the effects of interactions among lime, phosphogypsum (PG) and fertilization on soil fertility and their effects on common bean yields in the tropics. This study aimed to determine the effects of annual application of PG and limestone and rates of fertilization on the chemical attributes of soil, fertilization efficiency, yield components and the grain yield of the common bean. The study was performed for three growing seasons in an acidic Oxisol. The experimental design was randomized blocks in a 4x4 factorial scheme. The treatments consisted of lime, lime + PG, PG, and control (without corrective application) with four fertilization rates. In an acidic and low-fertility Cerrado soil, limestone or limestone + PG applied annually at 1/3 of the total rate in a no tillage system increased the common bean yield and the efficiency of the fertilization, although the improvement of the soil acidity indicators did not reach the desired levels. The application of soluble fertilizers to provide adequate and balanced amounts of nutrients provided greater yield gains and improved soil fertility compared to surface liming without fertilization, but the combination of the two practices resulted in the greatest benefits to both plant and soil fertility.

Effect of Chemical Amelioration on the Physicochemical Properties of Chernozem Soils in Irrigated Fruit Nurseries

This paper presents the results of a study on the effects of long-term use of drip irrigation with mineralized or, in other words, saline waters on the physicochemical properties of black chernozem soils in a fruit nursery. Irrigation induced local accumulation of water-soluble salts in the main wetted zone, alkalinization of the soil, and saturation of the soil-absorbing complex with Na+ and Mg2+ cations and Ca2+ depletion. The introduction of phosphogypsum in a dose of 2 t/ha for chemical reclamation reduced high alkalinity of the soil and increased the content of exchangeable calcium in the soil-absorbing complex. The application of phosphogypsum seems to be an effective method to restore the fertility of chernozem soils under conditions of long-term use of drip irrigation with mineralized waters.

Effect of phosphogypsum application and bacteria co-inoculation on biochemical properties and nutrient availability to maize plants in a saline soil

ABSTRACTPhosphogypsum (PG), which contains Ca, P and S and has an acidic effect, may be applied to manage soil constraints such as alkalinity and salinity. For increasing nutrients bioavailability, biofertilizers are commonly applied. Therefore, the aim of this study was to assess PG effect either alone or in combination with the mixed co-inoculation of plant growth promoting rhizobacteria on a saline soil. In a greenhouse pot experiment with maize (Zea mays L.), the inoculated and non-inoculated saline soils were treated with PG at 10 g kg−1 (PG10), 30 g kg−1 (PG30), and 50 g kg−1 (PG50). The soil pH, electrical conductivity (ECe), and macro-(NPK) and micronutrients (Fe, Mn, Zn, and Cu) availability to mays were examined. Applying PG reduced soil pH and co-inoculation induced significant decreases in soil ECe. Applying PG increased significantly soil available P. Applying PG combined with co-inoculation effectively increased the soil available K. The soil available micronutrients decreased significantly with PG. However, the inoculated maize treated with PG showed significant higher dry weight (82.1–127.4%) and nutrients uptake than the control. It could be concluded that PG along with co-inoculation may be an important approach for alleviating negative effects of salinity on plant growth.

Preparation and thermal insulation performance of cast-in-situ phosphogypsum wall.

The mass accumulation of phosphogypsum has caused serious environmental pollution, which has become a worldwide problem. Gypsum is a kind of green building material, which is lighter, has better heat and sound insulation performance, and is easier to recycle compared to cement. The application of cast-in-situ phosphogypsum wall could consume a large amount of pollutant, and improve the efficiency of building construction. The preparation and thermal insulation performance of cast-in-situ phosphogypsum wall were investigated. The property of phosphogypsum-fly ash-lime (PFL) triad cementing materials, the adaptability of retarders and superplasticizers, and the influences of vitrified microsphere as aggregates were explored. Thus, the optimum mix was proposed. Thermal insulation performance tests and ANSYS simulation of this material was carried out. Optimal structures based on heat channels and the method of calculation determining related parameters were proposed, which achieved a 12.3% reduction in the heat transfer coefficient of the wall. With good performance, phosphogypsum could be used in cast-in-situ walls. This paper provides the theoretical basis for the preparation and energy-saving application of phosphogypsum in the walls of buildings.

A practice to mitigate greenhouse gases from a wheat-grown soil by the phosphogypsum waste

A large amount of industrial phosphogypsum (Pg) waste pollutes the environment. The reuse of these waste resources in agriculture not only amended the soil and stimulated the crop growth but also decreased the soil greenhouse gas (GHG) emissions. A continuous two-year-field-experiment of the phosphogypsum application in winter wheat was conducted to investigate whether and how phosphogypsum affects soil N2O and CO2 emissions. A two-month lab incubation was also performed to explore the possible mechanism of Pg reducing GHGs. The results indicated that the soil CO2 and N2O was mitigated by the phosphogypsum. Compared to the control (Pg0), the soil N2O emissions in the treatment phosphogypsum decreased by 5.8%-29.9% and the CO2 emission decreased by 2.5%-6.6% in the winter wheat growing season of 2013-2014, while the N2O emission decreased by 20.6%-30.4% and the CO2 emission decreased by 6.2%-9.6% in 2014-2015. The N2O emission declined by 18.9%-28.5% and the CO2 emission declined by 33.5%-50.1% in the lab incubation. The unit weight grain/biomass CO2 and N2O emissions equivalents were reduced by the phosphogypsum. This result suggested that mitigating agricultural GHGs, stimulating crop growth and protecting the environment could be achieved simultaneously by the phosphogypsum.