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1.
不同形态磷肥的径流流失特征及其效应   总被引：4，自引：0，他引：4  
采用野外径流小区方法研究不同形态磷肥的流失特征、流失量以及对氮钾元素的影响。结果表明,在磷的流失途径中,颗粒态磷(PP)占总磷(TP)流失量的61.6%～83.1%,是磷流失的主要途径;施用磷肥可以促进土壤对氮钾元素的保持能力,减少氮钾元素的流失;磷肥的施用提高了小油菜的产量,并促进了小油菜对氮钾元素的吸收;微晶化磷矿粉可以有效减少磷的流失,在等磷量下,微晶化磷矿粉中的磷流失量分别是过磷酸钙和钙镁磷肥的54.2%和69.4%。在一定范围内,随微晶化磷矿粉施用量的增加,磷的流失量增加,但流失率减小,对促进土壤保持氮钾能力及小油菜对氮磷钾元素的吸收越明显。  相似文献   

2.
ABSTRACT

Experiments were carried out with the objectives to reduce the yield gap of plant and subsequent ratoon crops, evaluate juice quality, as well as soil properties. A 3-year field experiment was utilized to assess the use of organic materials and inorganic fertilizers on plant and subsequent ratoon crops. The organic materials included press mud, farmyard manure (FYM), and green manure (GM) of Sunhemp (Crotalaria juncea); the fertilizers were urea, triple superphosphate (TSP), muriate of potash (MOP), gypsum, and zinc sulphate. Farm yard manure was applied at a rate of 15 t ha?1 accompanied with a chemical fertilizer (N178P53K54S26Zn2.6kg ha?1), which produced yield of 108.4, 96.8, and 73.5 t ha?1 in plant cane, first, and second ratoon crops, respectively. Cane yields in the first were recorded in plant cane first and second ratoon crops, respectively. Cane yields in the first and second ratoon crops were 89.3 and 67.8% of plant crop, respectively. Juice quality parameters viz., Brix, pol and purity percent progressively increased in ratoons crops as compared to corresponding plant cane. The organic carbon, total N, and available P, K, &; S contents of soils increased slightly due to incorporation of organic materials. The result of the study revealed that 25% reduction of inorganic fertilizer with FYM or press mud at 15 t ha?1 in plant cane and addition of 50% more N with same amount of fertilizer suggested for plant cane showed better yield and improved juice quality in first and second ratoon crops of sugarcane.  相似文献   

3.
A greenhouse experiment was conducted to investigate the immediate effect of application of mono‐ammonium phosphate (MAP), single superphosphate (SSP), and triple superphosphate (TSP) fertilizers containing varying concentrations of Cd on (1) chemical speciation of Cd and Zn in soil solution by chemical‐equilibrium calculations (MINEQL+4.6 model), (2) growth of barley plants, (3) concentrations of Cd, P, and Zn in soil solution and plant tissue, as well as total plant accumulation of Cd, P, and Zn, and (4) monitoring pH and element changes during incubation periods following phosphate application. Results show that, in general, the pH of soil solution increased during the first 40 d of incubation, then declined. Also, at the end of incubation period, pH of soil solution was affected by fertilization source and fertilization rate. The concentration of Cd in soil solution changed with time. Phosphate fertilization (p < 0.05) or fertilizer source (p < 0.05) showed consistent effects. Also, the application of phosphate fertilizers with three rates significantly increased Zn concentrations in soil solution during the first half (0–30 d) of incubation period and then decreased but still more than in the control. In general, application of different sources of phosphate at 100 g kg–1 did not change the dominant forms of Cd in soil solution during all incubation time intervals. Speciation of Zn in the control after 30 d of incubation had changed, in comparison to 10 d of incubation, and the dominant forms were Zn2+, ZnOH+, ZnHCO3, ZnCO3(aq), and Zn(OH)2(aq). Adding phosphate fertilizer significantly increased both shoot and root dry weight compared to control, indicating P was a growth‐limiting factor in the control plants. The Zn concentrations in shoot and root were lower in the TSP‐ and SSP‐fertilizers treatment than those in the MAP and fertilizer treatments at all rates of fertilization. Adding phosphate increased the Cd : Zn and P : Zn ratios in the shoot and root tissue, with the effect being greater with increasing fertilization rate. Phosphate fertilization greatly increased the total accumulation of Cd of barley compared with the control plants (p < 0.001), with the effect being greater with increasing fertilization rate. Source and rate of fertilizers, and their interactions had significant effect (p < 0.05) on Cd accumulation in the whole plant.  相似文献   

4.
Soybean is an important grain crop for Brazil, and phosphorus (P) plays an important role in improving yield of this crop in Brazilian Oxisols. Data are limited on influence of P sources and rate on soybean yield, yield components, and P-use efficiency. A field experiment was conducted for 3 consecutive years to determine response of soybean to three fertilizers (single superphosphate, Yoorin, and Arad) with 0, 17.5, 35, and 52.5 kg P ha?1 (0, 40, 80 and 120 kg P2O5 ha?1). Grain yield was significantly influenced by phosphorus fertilization. Overall, maximum grain yield was produced by application of single superphosphate, followed by Yoorin and Arad. Number of grains per pod and 100-grain weights were also influenced significantly by P fertilization. Shoot dry weight, number of pods per plant, and grain harvest index had a significant positive association with grain yield. Phosphorus uptake in grain was about six times more than uptake in shoots, and P uptake in grain had a significant positive association with grain yield. Phosphorus-use efficiency (kg grain/kg P applied or uptake) decreased with increasing P rate, and it was greater for single superphosphate than for Yoorin and Arad sources of P fertilization. However, P-utilization efficiency (kg grain plus straw yield / P uptake in grain plus straw) was greater under Yoorin treatment compared to the two other sources of P.  相似文献   

5.
The effects of six phosphate (P) fertilizers in mobilizing and immobilizing water-soluble lead (Pb) were determined in a contaminated soil (Alfisol from Shaoxing) from China and four Australian soils (an Oxisol from Twonsville Queensland and three South Australian soils from Cooke Plains (Typic Palexeralf)), Inman Valley (Vertisol), and Two Wells (Natric Palexeralf). The fertilizers tested were single superphosphate (SSP), triple superphosphate (TSP), monoammonium phosphate (MAP), diammonium phosphate (DAP), monocalcium phosphate (MCP), and dicalcium phosphate (DCP) to produce an initial P concentration of 1,000 mg/L. The Chinese soil contained 16,397 mg/kg total Pb, but the Australian soils were uncontaminated. The four Australian soils were each spiked with 1,000 mg Pb/kg soil (as Pb(NO3)2) and incubated for a month. Single superphosphate treatments decreased total soluble Pb in soil solution to 2–14 % of those of the nil-P (0P) treatment in the four Pb-spiked soils and to 48 % in the Chinese Pb-contaminated soil. The DAP treatment followed by the MAP treatment greatly increased the total soluble Pb in soil solution up to 135–500 % of the 0P treatment, except in the Two Wells soil. MCP could decrease the total soluble Pb in Cooke Plains, Inman Valley, Shaoxing, and Two Wells soils while increase it in the Queensland soil; DCP decreased the total soluble Pb in Cooke Plains and Queensland soils while increased it in the Shaoxing and Inman Valley soils. There were close relationships between the total soluble Pb, total soluble Al, and total soluble Fe in the water extracts of each. Soluble Al and Fe ions in soil solution increased soluble Pb concentrations. We conclude that not all phosphate fertilizers immobilize Pb in soils equally well. SSP and TSP are excellent Pb-immobilizing fertilizers, while MAP and DAP are strong Pb-mobilizing fertilizers. MCP and DCP are either Pb-immobilizing fertilizers or Pb-mobilizing fertilizers depending on their reactions with individual soils.  相似文献   

6.
磷是作物和畜禽生长必需的营养元素,同时也是不可再生资源。为了提高农牧业生产力,80%左右的磷矿石用于生产磷肥与磷饲料添加剂,因此提高磷肥和磷饲料添加剂生产效率至关重要。然而关于磷肥和磷饲料添加剂"采矿—选矿—磷酸—磷肥/磷饲料添加剂"整个链条的磷流动特征和各个环节效率的定量研究却很少。本研究通过企业实地调研,建立企业流动数据库,利用物质流分析的方法扩展了NUFER(NUtrient flows in Food chains,Environment and Resources use)模型的磷肥和饲料磷添加剂生产模块。以我国某大型磷化工企业为例,定量揭示磷化工企业"采矿—选矿—磷酸—磷肥/磷饲料添加剂"整个链条磷流动特征、损失和利用效率;分析各种磷肥和饲料添加剂产品生产磷流动、利用效率和磷足迹;并利用情景分析提出提高磷利用效率的策略和优化潜力。结果表明:2015年该企业利用含3.902?106 t P2O5的自然矿石,生产了2.426?106 t(折纯P2O5,下同)磷复肥和磷饲料添加剂,其中磷酸二铵和磷酸一铵是最主要的产品,分别为156万t和54万t。磷酸二铵、磷酸一铵、重过磷酸钙、磷酸一二钙、普通过磷酸钙、复合肥、硫肥和磷酸二氢钾产品的生产效率分别为98%、98%、93%、95%、91%、99%、98%和91%,整个生产链条的生产效率为80%。大多数的磷资源在矿石加工部门损失掉,占磷损失量的51%;其次是矿石开采部门(25%)和磷酸生产部门(14%)。通过提高生产效率和废弃物利用率,磷资源损失预计可以减少42%。研究企业的磷利用效率在国内已达先进水平,但仍有提升潜力。  相似文献   

7.
Abstract

The quality of phosphate rock (PR) is declining and the use of lower quality PR results In lower water‐soluble and higher citrate‐soluble P in the fertilizer product. A greenhouse study was conducted to evaluate the plant availability of P in commercial superphosphate fertilizers having various levels of water‐soluble P. Seven commercial fertilizers, Including 6 granular concentrated superphosphates and one normal superphosphate, were evaluated. Reagent grade monocalcium phosphate served as a control. The fertilizers were manufactured from PR deposits located in the United States (Florida, Idaho and North Carolina) and Morocco. Water‐soluble P ranged from 77 to 92 X of the total fertilizer P. Citrate‐soluble, water‐insoluble P ranged from 7 to 20 % of the total fertilizer P. Four of the 5 American fertilizers had a lower percentage of water‐soluble P as compared to the concentrated superphosphate from Morocco. Fertilizers manufactured from U.S. phosphate deposits contained an average of 6 times more Fe and 4 times more Al than the Moroccan concentrated superphosphate.

Each source was added to a Mountvlew slit loam soil (pH = 6.5) at rates to supply 0, 10, 20, 30, 40 and 50 mg P kg‐1soil (0, 22.9, 45.8, 68.7, 91.6, and 114.5 ppm P2O5, respectively). Sorghum‐sudangrass (Sorghum bicolor) was harvested at 28 and 56 days after planting in the treated soil. Herbage yields and the P concentration in harvested forage were not affected by the source of added P. The effect of the rate of added P on forage yield and P concentration was described by polynomial regression. The granular concentrated superphosphate fertilizers used in this study contained ≥ 80 % of their plant available P in a water‐soluble form and were as effective as reagent grade monocalcium phosphate. Thus the level of water‐soluble P that will be required to reduce the performance of a fertilizer is lower than the levels currently found in American commercial concentrated superphosphates  相似文献   

8.
ABSTRACT

Direct application of phosphate rocks (PRs) with low/medium in reactivity has shown to be low in agronomic effectiveness for cereal crops. Presence of water-soluble P (WSP) in the vicinity of PR can significantly enhance the rooting system at the early stage of plant growth. This, in turn, can enable the plant to utilize the associated PR more effectively than the use of PR alone at planting. This report presents the results of several greenhouse experiments that show the granulated (WSP+PR) products by dry compaction process using different low-reactive PR sources were as effective as WSP fertilizers viz triple superphosphate (TSP) and monoammonium phosphate (MAP). The test plants were maize (30 days) and soybean and upland rice were grown to maturity on acid or neutral soils. Based on the results obtained a P ratio of 50:50 between WSP and PR is recommended for the granulated (WSP+PR) products that can achieve crop yields at the same levels as that with the WSP fertilizers.

Abbreviations: phosphate rock, PR; water-soluble P, WSP; dry-matter yield, DMY  相似文献   

9.
Summary The influence of vesicular-arbuscular mycorrhizae on the efficiency of triple superphosphate and rock phosphate fertilizers was compared in two tropical, acid, P-fixing soils (Ivory Coast) in which the available P was labelled with 32PO inf4 sup3- . Both soils were planted with micropropagated oil palms. The growth reponses to the fertilizer applications were low unless accompanied by VAM inoculation, but both fertilizers were equally available to plants. Isotopic-dilution kinetics analyses indicated that the rock phosphate was solubilized in both soils and there was an enrichment of the labile pool of plant-available P, similar to that with superphosphate. The specific activity and the fraction of P derived from either fertilizer was similar in both mycorrhizal and non-mycorrhizal plants, showing that both absorbed P from the same labile pool of P in the fertilized soils. However, VAM inoculation increased the fertilizer utilization coefficient of plants 2.7- to 5.6-fold, depending on the soil and fertilizer. We conclude that VAM inoculation increases fertilizer efficiency, as much of rock phosphate as of superphosphate, for plants growing in acid, P-fixing soils, and the processes involved are not different for the two fertilizers.  相似文献   

10.
The high cost of conventional, water‐soluble phosphorus (P) fertilizers limits their use by resource‐poor farmers in sub‐Saharan Africa. Phosphate rocks are a low‐cost alternative. We evaluated the effectiveness and residual effects of Egyptian phosphate rock (EPR) and Togo phosphate rock (TPR) relative to triple superphosphate (TSP) applied at 0, 20, 40, 80, and 160 kg P ha‐1 to annual Trifolium species grown in a P‐deficient Vertisol. The fertilizers were applied once and their effects were followed on seven consecutive annual clover crops. Clover responded to P at all the rates used. Significant (P<0.05) responses to P at the low 20–40 kg P ha‐1 rates were registered up to the fifth crop after application of P, and responses to higher rates of 80–160 kg P ha‐1 were significant up to the seventh crop. Critical evaluation of residual effects by comparing the response of clover to these fertilizers with response to fresh applications of TSP in the second and third crops confirmed these observations. Over all the seven crops, EPR was 82% as effective as TSP in increasing clover DM and 83% as effective in increasing P uptake. Its substitution rates were 67% for DM yields and 69% for P uptake. For TPR, the relative responses were 54% and 52% for DM yield and P uptake, respectively, and the corresponding substitution rates were 29% and 27%. In separate experiments, the effects of mixing these phosphate rocks with triple superphosphate (TSP) in various proportions (at 60 kg P ha‐1) were also investigated. The highest response of clover was observed with TSP applied alone, but the phosphate rocks applied alone also significantly increased yields compared with the controls without applied P. Mixtures of TPR and TSP increased yields only slightly over pure TPR, and mixtures of EPR and TSP had no effect on yields compared with pure EPR, presumably because EPR is more reactive than TPR. It was concluded that EPR is highly effective in these soils, but the effectiveness of TPR is low. The highly reactive EPR could be used to elevate the P status of the P‐deficient Vertisols and increase feed availability and livestock productivity in the Ethiopian highlands. Mixing of these phosphate rocks with TSP cannot be recommended.  相似文献   

11.
Abstract

The agronomic effectiveness of five partially acidulated phosphate rocks (PAPRs) and an unground phosphate rock (PR) were compared against single superphosphate (SSP) in a glasshouse experiment using a high phosphorus (P) retention soil at a near‐neutral pH (pH 6.5), and corn (Zea mays L.) as the test crop. The PAPRs were prepared by acidulating unground North Carolina PR with either phosphoric or sulphuric acid (expressed as Phos‐PAPR and SA‐PAPR, respectively) and at three levels of acidulation (20, 33, and 50%). The relative agronomic effectiveness (RAE) and substitution value (SV) of the test fertilizers, calculated with respect to SSP using the standard “vertical”; and “horizontal”; comparisons, showed that 50% phosphoric acidulated PAPR performed as effectively as SSP whereas the other fertilizers were less effective. The PR treatment showed a small yield response. The dry matter yield and P uptake were linearly related to water‐soluble P of the fertilizers up to 66% of total P and there was no advantage in acidulating fertilizers above this level of water‐soluble P using reactive PR. Whereas very little of the directly‐applied PR dissolved (3.4% of PR applied), PR applied as a component of PAPRs dissolved up to 22%. The dissolved proportion of added PR component increased with increasing water‐soluble P content of the fertilizer. The results suggest a greater efficiency of PAPR than SSP as a P supplier to plants.  相似文献   

12.
李庆逵  曹翠玉  戎捷 《土壤学报》1964,12(3):330-337
用P32标记的磷肥已在磷素营养的研究中得到广泛的应用,并且已经有了不少的综合性总结[1,2,3]。但是,应用放射性磷矿粉来研究其肥效的报告,则还极为有限。  相似文献   

13.
Liming or adding organic matter may improve productivity of soils receiving phosphorus (P) fertilizers. This study assessed the effectiveness of amendment of acidic soil with limestone and organic matter on growth of tomato (Lycopersicon esculentum Mill.), corn (Zea mays L.), and cucumber (Cucumis sativus L.) with different P fertilizers. These crops were grown in a greenhouse to evaluate superphosphate, bone meal, and rock phosphate as fertilizers and calcitic limestone and peat moss as amendments. Superphosphate was the superior P source to sustain crop growth, limit deficiency symptoms, and enhance P accumulation. Bone meal was less effective than superphosphate but exceeded rock phosphate in these capacities. Rock phosphate was better than adding no P fertilizer. The amendments of limestone or organic matter singly or together had little effect on growth, appearance, or P accumulation. The availability of P in the fertilizers governed the growth responses of the plants.  相似文献   

14.
The geochemical reactivity of single superphosphate (SSP), triple superphosphate (TSP), phosphate rock (PR), partially acidulated phosphate rock (PAPR) and potassium dihydrogen phosphate (KH2PO4) was evaluated in an incubation trial. The soil was Anthrosols, Ap horizon (Sandy loam). Solubility equilibrium of phosphates was calculated by phosphate (PPot = logH2PO4 – pH) and calcium (CaPot = logCa + 2pH) potentials. Next, activity ratio (AR°) and Woodruff potential (ΔF) were considered for estimating phosphate dynamics in the soil. Data showed that phosphate potentials stressed on significant solubility process and varied accordingly to the rates of the fertilizers: ?5.50, ?4.81, ?4.47 and ?4.09 for 0, 50, 100 and 150 kg P ha?1. The values of the Woodruff potential (ΔF) varied widely from ?1929 to 8573 cal mol?1, i.e., from marginal supplying power in the case of the control treatment to very high supplying power for the TSP (Triple superphosphate). These findings are of practical value for the following reasons: TSP and KH2PO4 are recommended for quick and high P supply to plants; SSP and PAPR for moderate supply and finally PR for slow and low supply. Phosphorus efficiency should be treated with priority particularly for areas with intensive cropping and susceptibility to runoffs.  相似文献   

15.
A laboratory experiment was carried out to study the influence of 100 mg phosphorus pentoxide (P2O5) kg–1 soil from various phosphate sources on ammonia losses from soils amended with urea at 200 mg nitrogen (N) kg–1 soil. Irrespective of soil type, ammonia (NH3) loss was significantly greater from untreated soil (control) than from the soil treated with phosphorus (P) sources. A maximum decrease in ammonia loss (56%) was observed by applying phosphoric acid followed by triple and single superphosphate. Ammonia losses were significantly greater from sandy clay loam than from clay. Rate of ammonia volatilization was maximum during the first week of incubation and became undetectable for both soils at 21 days after incubation. The addition of phosphate sources significantly decreased pH in the sandy clay loam, but in the clay a significant decrease was observed only with the phosphoric acid addition. Addition of phosphate fertilizers was beneficial in reducing NH3 losses from urea.  相似文献   

16.
The aim of the study was to appraise various types of phosphate fertilizers (bone meal, superphosphate, triple superphosphate, and potassium orthophosphate) for immobilizing metals and metalloids in mining-impacted soils from Broken Hill, Australia. Soils were rich in metals (Pb, Zn, Cu, and Cd) and metalloids (As and Sb) which were mainly contained in minor to trace amounts of coronadite [PbMn8O16], kintoreite [PbFe3(PO4)2(OH,H2O)6], Pb, and Zn sulfides and sulfates (possibly sphalerite, galena, and anglesite) as well as in unidentified soluble metal-bearing phases. Phosphate stabilization experiments were conducted as kinetic column leaching experiments, and chemical and mineralogical changes were assessed using elemental, sulfur isotope, and XRD analyses as well as electron microprobe phase mapping. The application of phosphate fertilizer to the metal-contaminated topsoils led to mineralogical changes, including the formation of secondary metal-bearing phosphates. The elemental concentrations of leachates were used as a criterion to assess the performance of phosphate treatments. Potassium orthophosphate fertilizer was the most effective amendment for Cd stabilization; superphosphate and triple superphosphate fertilizers were the most effective amendments for Pb stabilization. By contrast, the release of As, Cu, Mn, Sb, and Zn were not significantly suppressed, and in several cases, increased, using bone meal, superphosphate, triple superphosphate, and potassium orthophosphate amendments. This study indicates that in situ phosphate stabilization of mining-impacted soils at Broken Hill would most likely be a complex and impractical undertaking in residential areas due to the risk of substantial metal, metalloid, phosphate, and sulfate release.  相似文献   

17.
The relatively low solubility and availability of phosphorus (P) from indigenous phosphate rock could be enhanced by legumes in the acid soils of humid forest agroecosystems. Crotalaria micans L. was grown in a screenhouse without P or with P from triple superphosphate (TSP) and Malian Tilemsi Rock P. The P response of 20 cover crops was field‐evaluated using TSP and Rock P. In both experiments, the fertilized cover crops were followed by upland rice without mineral N or P application. Mean rice grain yield and agronomic residual P‐use efficiency were similar for both P sources. In the field, 1‐year fallow treatment of Canavalia ensiformis (velvet bean) supplied with Mali Rock P gave the highest rice grain yield of 3.1 Mg ha?1, more than 180% that of 2‐year continuous unfertilized rice (cv. ‘WAB 56‐50’). Among continuous rice plots, ‘NERICA 2’ (interspecific rice) supplied with Rock P produced the highest yield (2.0 Mg ha?1), suggesting that ‘NERICA 2’ might have greater potential to solubilize rock P. Results indicate that when combined with an appropriate legume, indigenous rock‐P can release sufficient P to meet the P requirement of the legume and a following upland rice crop in rotation.  相似文献   

18.
Abstract

A greenhouse pot culture study was conducted to evaluate the agronomic efficiency of two rock phosphates from Mussoorie (MRP) and Purulia (PRP) in two acidic soils from Dapoli (Maharashtra) and Aruvanthklu (Karnataka), India, by growing maize (cv. Ganga) as the test crop and using 32phosphorus (P) single superphosphate (32P=SSP) as a tracer (A‐value technique). Dry‐matter yield and P uptake increased significantly with the application of P fertilizers compared to control treatment (without P) in both the soils. There was no significant difference with respect to dry‐matter yield among the P fertilizer treatments. However, P uptake by the shoots was found to be significantly higher in the PRP treatment in only Dapoli soil compared to other P fertilizer treatments. Phosphorus derived from fertilizer decreased in rock phosphate treatments compared to standard 32P‐SSP treatment in both the soils, indicating an excess availability of P from the rock phosphates. A‐values of soil and rock phosphate indicate a relatively higher P availability from Aruvanthklu soil compared to Dapoli soil; A‐values for the rock phosphates were in the order PRP>MRP. The substitution ratio showed that the availability of P from both the rock phosphates were less than SSP in both the soils.  相似文献   

19.
Magnesium (Mg) deficiency can significantly limit crop yield and quality. Separate application of straight Mg fertilizer is unattractive because of additional labor costs. Meanwhile, bulk blending Mg with other macronutrient fertilizers is also a suboptimal solution because bulk blended fertilizers often yield poor nutrient distributions. One rapid and economical alternative to alleviating Mg deficiency is to co-granulate macronutrient fertilizers with Mg. However, few commercial products have implemented this approach. One of the barriers hindering the production of Mg-fortified phosphorus (P) fertilizers is the assumption that precipitation of P with Mg will reduce P solubility. In this study, four Mg compounds, anhydrous magnesium sulfate (MgSO4), magnesium oxide (MgO), anhydrous magnesium chloride (MgCl2), and dolomite (CaMg(CO3)2), were co-granulated with mono-ammonium phosphate (MAP), and their granule strength, Mg and P availabilities, and agronomic effectiveness were evaluated. Results showed that there were no significant differences in P solubility between Mg-fortified MAP and MAP treatments. X-ray diffraction (XRD) indicated that the Mg species after co-granulation were boussingaultite (Mg(NH4)2(SO4)2·6H2O), schertelite (Mg(NH4)2H2(PO4)2·4H2O), magnesium hydrogen phosphate (Mg(H2PO4)2), and dolomite (CaMg(CO3)2). A pot experiment using an acidic soil demonstrated an average 9.6-fold increase in shoot Mg uptake, 3.0-fold increase in shoot P uptake, and 3.2-fold increase in soybean shoot dry matter in Mg-fortified MAP treatments, compared to those in MAP treatment. The current study provides a simple, effective, and low-cost approach for the addition of Mg to macronutrient fertilizers, to minimize Mg deficiency.  相似文献   

20.
Increasing soil phosphorus and organic matter content for crop production while reducing the cost of production are required to facilitate the achievement of green revolution in Africa. Field and pot experiments were laid out during 2012 and 2013 to assess the effects of combined application of Kodjari phosphate rock (PR) and water soluble phosphorus on sorghum yields, P uptake and Lixisol characteristics in the centre west of Burkina Faso. Five P fertilizers treatments (zero P, 100% TSP (triple super phosphate), 100% PR, 50% PR + 50% TSP, 75% PR + 25% TSP) and two cow manure treatments (zero, 5 t ha?1) were tested. In field experiment, 50% PR + 50% TSP was as effective as 100% TSP in increasing sorghum yield above the control by 30% in 2012 and 50% in 2013 and P uptake by 30% in both years. Manure had an additive effect on phosphorus fertilizers in increasing sorghum yields and P uptake. In pot experiment, increases of Ca uptake, soil pH and microbial P were observed with the application of 50% PR + 50% TSP. Our results suggest that formulation of fertilizer combining phosphate rock and mineral P would improve sorghum yields and income of smallholders.  相似文献   

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