Chemical characterization and bioavailability of phosphorus in water-insoluble fractions of three mono-ammonium phosphate fertilizers

Elemental impurities in mono-ammonium phosphate (MAP) fertilizers, such as Fe, Al, Ca, Mg, and F, result in compounds other than NH4H2PO4. The phosphorus availability of the impurity compounds was determined in 3 commercial MAP fertilizers produced from North Carolina, Florida, and Idaho phosphate rocks. Soluble compounds, including NH4H2PO4, were washed out of the fertilizers, and the water-insoluble fraction was collected. The North Carolina, Florida, and Idaho MAP fertilizers contained 13, 16, and 17% water-insoluble fractions, respectively. Availability of phosphorus in each MAP fertilizer and water-insoluble fraction was determined in a greenhouse pot study using sorghum-sudangrass (Sorghum bicolor) as the test crop. There were no differences in dry matter weights or phosphorus uptake between reagent grade MAP and each MAP fertilizer. Lower dry matter weights and phosphorus uptake were produced from the water-insoluble North Carolina, Florida, and Idaho fractions (NC greater than FL greater than ID). Chemical analysis and characterization with optical microscopy, infrared spectroscopy, and X-ray diffractometry indicated 77.3, 73.8, and 73.6% NH4H2PO4 in the North Carolina, Florida, and Idaho MAP fertilizers, respectively. MgAl(NH4)2H(PO4)2F2, AlNH4HPO4F2, and FeNH4(HPO4)2 were identified as water-insoluble phosphorus compounds. There was a significant negative correlation between the percent phosphorus present as MgAl(NH4)2H(PO4)2F2 and the phosphorus availability. Increased crystallinity of the various water-insoluble compounds also contributed to reduced phosphorus availability.     

水磷一体化对磷素有效性与磷肥利用率的影响

水肥一体化是发挥水肥耦合效应提高养分效率的重要途径,然水磷一体化研究较少。本文在模拟滴灌条件下研究了液体磷肥和固体颗粒磷肥(TSP)及其不同施用方法对土壤磷移动性、各形态无机磷含量动态变化的影响,比较了玉米磷素营养与磷肥利用率对不同磷源及其施用方式的响应,旨在提出滴灌条件下磷肥高效利用的最优策略。研究结果表明:1)与TSP肥料分次施用相比,液体磷肥分次施用更能提高土壤磷素有效性,在各土层Ca2-P与树脂磷(resin-P)平均含量分别提高12.4%与21.6%,且可显著提高磷在土壤中的移动性(P0.05),resin-P含量的垂直下降幅度降低56.5%;2)与TSP分次施用相比,液体磷肥分次施用的土壤中高活性无机磷含量(Ca2-P、resin-P及Na HCO3-P之和)占无机磷总量的比例提高21.0%,而低活性无机磷含量(Ca10-P与residue-P之和)占无机磷总量的比例则下降10.1%,说明液体磷肥分次施用可减小磷肥在土壤中的固定转化;3)玉米地上部干物质、叶片吸磷量和植株磷素累积吸收量均对不同磷源与施用方式有明显响应(P0.05),液体磷肥分次处理的玉米生物量、吸磷量及肥料利用率分别比TSP肥料分次处理提高27.1%、34.6%及61.4%。水磷一体化施用可提高磷在土壤中的移动性和有效性,减少磷的固定转化,显著改善玉米磷素营养,并明显提高磷肥利用率。     

An examination of potential extraction methods to assess plant-available organic phosphorus in soil

The role of soil organic phosphorus (P) in plant nutrition was assessed using data from a glasshouse pot experiment carried out on seven soil types using two contrasting plant species (Lolium perenne, Pinus radiata) and 12 different extractants (five salts (0.025 M ethylenediaminetetraacetic acid (EDTA), 0.025 M EDTA pH 7, Olsen, Mehlich-III, and 6% NaOCl pH 7.5) and seven exchange resins (Hampton chelating resin, Bio-Rad Chelex-100, Dow MAC-3, Amberlite IRC76, Diaion WT01S, Lewatit MP500A, Diaion WA30)). The contribution from mineralization of soil organic P was inferred by consistent increases in correlation coefficients between extractable P and plant P uptake when organic P was considered in addition to inorganic P. The best correlated extractants for combined inorganic and organic P were NaOCl (r = 0.84), Hampton chelating resin (r = 0.78), and MP500A resin (r = 0.73), which compared favorably with Olsen P (r = 0.66) and EDTA (r = 0.72). ³¹P nuclear magnetic resonance analysis of selected extracts from two soils confirmed that the Hampton-chelating-resin-extractable P was mainly monoester and diester forms of organic P, while there was no monoester or diester organic P in the IRC76 resin extract—poorly correlated with plant uptake. The findings of this study suggest that readily extractable forms of organic P in soil contribute to short-term plant P uptake, and this P should be considered for inclusion in routine tests for soil P availability.     

Effects of companion crops and tillage on soil phosphorus in a Brazilian oxisol: a chemical and 31P NMR spectroscopy study

Journal of Soils and Sediments - Phosphorus (P) is often the main limiting factor for plant growth in highly weathered tropical soils. Phosphate use efficiency and crop yields could be increased in...     

Biosolubilization of phosphorus from rock phosphate and other P fertilizers in response to phosphate solubilizing bacteria and poultry manure in a silt loam calcareous soil

‘Phosphate solubilizing bacteria' (PSBs) are able to release unavailable P from native and applied P sources into plant‐available soil pool through their solubilizing and acidifying effects. The effects of three indigenous and one exotic PSBs on P solubilization from different P sources, plant biomass production, and P‐uptake efficiency of maize (Zea mays L.) were examined in an incubation and greenhouse study. For incubation study, surface (0–15 cm) soil was collected from an arable field (Inceptisols) and amended with rock phosphate (RP), single superphosphate (SSP), poultry manure (PM), and RP+PM with and without PSBs. The amended soil was incubated in the control environment at 25 ± 2°C for a total of a 100‐d period to establish relative potential rate of P solubilization of added P sources. A complementary greenhouse experiment was conducted in pots by growing maize as a test crop. Growth characteristics, P‐uptake, and P‐utilization efficiency (PUE) were determined. Phosphate solubilizing bacteria generated a solubilization effect on different P sources by releasing more P into plant‐available soil pool, i.e., 14.0–18.3 µg g^?1 in RP, 5.0–9.9 µg g^?1 in SSP, 1.4–4.4 µg g^?1 in PM, and 4.5–7.8 µg g^?1 in RP+PM compared to their sole application without PSBs. The available P from inorganic SSP declined continuously from the mineral pool (after day 30) and at the end 40% of applied P was unaccounted for. However, P losses were reduced to 28 and 27% when PSBs (PSB₁ and PSB₃) were applied with superphosphate treatments. In the absence of PSBs, the recoveries of applied P (in soil) from RP, SSP, PM and RP+PM were 4, 25, 9, and 12%, respectively, those had been increased to 14, 30, 12 and 15% in the presence of PSBs. Similarly, the plant biomass in RP+PSBs treatments compared to the RP without PSBs increased between 12–30% in first sampling (30 DAG) and 13–30% in the second sampling (60 DAG). The P utilization efficiency (PUE) in plants supplemented with PSBs was 20–73% higher compared to those without PSBs. The detection of oxalic and gluconic acids in culture medium treated with PSBs (7.8–25.0 and 25–90 mg L^?1, respectively) confirmed the production of organic acids by the indigenous bacterial isolates. This study indicate that low P recovery both in plant and soil can likely be improved by using indigenous PSBs and organic amendment poultry manure, which allowed a more efficient capture of P released due to P solubilization.     

Identification of soil organic phosphorus by 31P nuclear magnetic resonance spectroscopy

Abstract

Soil samples from different land use systems were collected before cropping (in spring) and after harvest (in fall) for organic phosphorus (P) extractions by 0.4M sodium hydroxide (NaOH) and characterization by ³¹P nuclear magnetic resonance spectroscopy. To prevent hydrolysis of organic P compounds prior to sample concentration, NaOH was removed from the NaOH soil extracts using a G‐25 Sephadex column. The ³¹P NMR spectra in the NaOH soil extracts showed the presence of glucose‐6 phosphate (up to 64%), glycerophosphate (up to 45%), nucleoside monophosphates (up to 91%), and polynucleotides (up to 58%) as the major forms of organic P in soils. The relative concentration of nucleoside monophosphates and polynucleotides decreased in some of the soils after harvest. The ³¹P NMR spectra of the extracts also revealed the presence of phosphoenolpyruvates, a previously unreported form of soil organic P.     

锌与磷肥混合方式对土壤中磷、锌有效性的影响

[目的]研究了锌与磷肥分别以物理混合和反应混合的方式结合后施用对土壤中锌、磷有效性的影响,为磷肥与锌肥的科学配施及高效利用提供科学依据.[方法]将锌肥(ZnSO4·7H2O)分别按0.5％和5％的质量比与磷酸氢二钾进行物理混合(P+Zn)和反应混合(PZn)后,制备含锌磷肥分别为P+Zn0.5、P+Zn5、PZn0.5...     

Characterization of phosphorus fractions in mountain soils of the Bavarian Alps by 31P NMR spectroscopy

NaOH-extracts from different soils of the alpine and shrub zones at the Schneibstein (Nationalpark Berchtesgaden) between 1790–2275 m were studied using ³¹P NMR spectroscopy. NaOH (0.5 M) dissolved 29–49% of P_t. Orthophosphate monoesters were the dominant fraction (41–79%). Orthophosphate diesters comprised 10–20%. A higher diester content (36%) was found in a hydromorphic soil. Inorganic phosphate comprised 5–27%, depending on soil pH. So, in acid horizons (pH 4.45 and 5.05) 27 and 23% were detected, whereas in horizons with higher pH (> 6) only small amounts (5–8%) were found. Pyrophosphate and polyphosphates were found in traces. Phosphonates (ca. 6%) occurred mainly in acid soils.     

Ability of various water‐insoluble fertilizers to supply available phosphorus in hydroponics to plant species with diverse phosphorus‐acquisition efficiency: Involvement of organic acid accumulation in plant tissues and root exudates

Previous studies describe the suitability of a new type of phosphorus (P) fertilizer, called “rhizosphere‐controlled fertilizer” (RCF), to supply available P to plants while reducing soil phosphorus fixation. In order to explore the involvement of organic acid root exudation in P uptake from RCF, we investigated the relationship between shoot and root P concentrations, and the concentration of the main polycarboxylic organic acids in roots, shoots, and plant exudates. Plant species with different P‐acquisition efficiency (low: maize; medium: chickpea; high: lupin) were grown in hydroponics with three different P fertilizers: The water‐insoluble P fraction of RCF (RCF); Phospal, a slow‐release source of phosphate composed of calcium and aluminum phosphates (PH); monopotassiumphosphate (KP), and a control treatment without P (P–). RCF was as efficient as KP in supplying P to plants in the case of chickpea and lupin, and slightly less efficient than KP in maize. However, P from PH was not available for maize and less available compared to KP and RCF in chickpea and lupin. This variation reflects the different efficiencies in P acquisition for the three plant species. Except in the case of maize, plants receiving KP presented the lowest concentration of organic acids in roots and exudates, while those plants suffering severe P deficiency (P– and PH) showed the highest organic acid concentration. However, RCF had a high concentration of organic acids in roots and exudates, as well as a high P concentration in the shoot indicating that P uptake from RCF is enhanced due to root release and action of specific organic acids.     

施用常规磷水平的80%可实现玉米高产、磷素高效利用和土壤磷平衡

【目的】近年来,黑土有效磷含量呈逐年增加趋势。研究田间条件下,黑土的玉米产量及构成因素、磷素的吸收利用和土壤有效磷含量变化对不同施磷水平的响应,为黑土区的磷肥合理施用和地力培育提供理论依据。【方法】在土壤有效磷初始含量较高（30.15 mg/kg）的吉林公主岭黑土区,进行了3年的田间试验,以不施磷肥为对照（P0）,设置当地磷肥用量的80%（P₂O₅ 60 kg/hm2,P60）和当地施肥量（P₂O₅75 kg/hm2,P75）,研究不同施磷水平对玉米产量及产量性状、磷素吸收分配、磷肥利用效率的影响,并分析了土壤表观磷平衡和有效磷含量的变化。【结果】连续三年（2009~2011年）不同施磷水平下,玉米的产量随施磷水平的提高而增加,到第三年施磷处理的玉米产量显著高于不施磷处理,随施肥年限增加,P60与P75处理的增产效应差距缩小。P75处理吸收的磷素高于P60,但分配到籽粒中的磷素比例逐年下降,说明其吸收的磷素未高效转移到籽粒中,存在磷素奢侈吸收现象。两个施磷处理的磷肥利用率均为P75>P60,磷肥偏生产力均为P60>P75,说明P60处理中土壤基础养分和施入磷肥的综合效应更大。2009~2011年,土壤的表观磷平衡,P0处理一直处于亏缺状态,P60和P75处理均有盈余。P0、P60和P75处理的土壤有效磷的变化量为-15.4、-0.19和3.50 mg/kg。有效磷含量变化与表观磷盈余量呈极显著线性正相关,土壤P盈余每增加100 kg/hm2,有效磷含量增加9.6 mg/kg。【结论】在有效磷含量较高的黑土区,适当减少磷肥用量（60 kg/hm2 P₂O₅,比传统施肥减少20%）能获得与传统施磷相当的产量,维持土壤适宜的有效磷含量和供磷水平,并能保证磷肥的高效利用。可以考虑将P₂O₅ 60 kg/hm2作为黑土区的推荐施磷水平。     

The influence of phosphate fertilizers on Cd solubility in soil

We investigated the influence of monoammonium phosphate (MAP) and diammonium phosphate (DAP) on the adsorption process of Cd by two typic soils. The phosphate induced variations in the pH values of soil-Cd suspensions, drastically influenced the solubility of the heavy metal in the two soils. MAP decreased the amount adsorbed while DAP increased the quantity fixed by the soil. The effect was particularly remarkable in the soil with low content of organic matter (Lamporecchio soil) where the addition of DAP caused the precipitation of the heavy metal. In the organic soil (Orentano soil) the effect of phosphate was less evident because of the high buffering capacity of this soil, rich in colloidal fractions.     

Agronomic evaluation of phosphorus fertilizers developed from sokoto rock phosphate in Nigeria

Abstract

Sokoto rock phosphate (SRP) obtained from Sokoto in the Northern Nigeria was evaluated with some other phosphorus (P) sources viz: Partially acidulated rock phosphate (PARP) and single superphosphate (SSP) in the greenhouse and field studies. These fertilizers were also compared with nitrogen‐phosphorus‐potassium (NPK) 11–12–11–9.7S‐1.4Zn and NPK 10–20–5–6.5S which have 80% of their P as rock phosphate and were formulated through compaction. The fertilizers were applied in the greenhouse at 0–400 mg kg^‐1soil on the Oyo Arenic Haplustalf and Alagba Kandiudult soil. Field trials were carried out at four locations—at Ikenne in the humid, Samara in the subhumid, Gumi and Gusau in the semi‐arid zones of Nigeria. The fertilizers were applied at 0–150 kg P₂O₅ ha^‐1 in the humid zone and 0–100 kg P₂O₅ ha^‐1in the subhumid and semi‐arid zones. Maize was used as test crop in most sites except at Samaru where sorghum was planted. The results of the greenhouse study showed that on the Haplustalf, PARP, and NPK 10–20–5–6.5S gave almost a similar relative agronomic effectiveness (RAE about 70%) as SSP, which was followed by SRP and NPK 11–12–11–9.7S‐1.4Zn (RAE between 50 and 60%). On the Kandiudult, the RAE of the fertilizers increased significantly. The PARP and NPK 10–20–5–6.55S gave high effectiveness (RAE about 90%) relative to SSP. The field trials results indicated that ground SRP was suitable for direct application on slightly acid soil in the humid zone (annual rainfall > 1,200 mm). Its efficiency was fairly moderate in the subhumid and quite low in the semi‐arid zones (annual rainfall <900 mm). The PARP gave higher RAE than SRP and had almost similar efficiency as for NPK 10–20–5–6.5S. The PARP was well comparable to SSP in the humid and subhumid zones and was fairly comparable to the later in the semi‐arid. This suggests that PARP may be suitable for humid and subhumid zones and the physical quality was also superior to SRP and SSP. Application of SRP on soils in the semi‐arid zones of low rainfall gave relatively low yields which could be due to inadequate moisture availability required to enhance P solubilization.     

常见铁肥品种及其使用效果综述

铁是植物正常生长必需的微量营养元素之一。铁虽然在土壤中的丰度很高,但植物可以吸收利用的有效铁很少,导致植物极易缺铁,尤其是在干旱、半干旱的石灰性土壤上,缺铁现象较为严重。利用农艺和生物技术手段解决植物缺铁的效果尚不十分明显,施用铁肥仍是纠正植物缺铁常用的有效方法。国内常用铁肥品种主要有硫酸亚铁为主的无机铁肥和一些有机物与铁复合形成的铁肥(木质素磺酸铁、腐殖酸铁)。乙二胺四乙酸(EDTA)铁肥稳定性相对较低,且EDTA会转化成二酮哌嗪,成为持久性有机污染物。国外推广使用乙二胺二邻羟苯基乙酸(EDDHA)、乙二胺二(2-羟基-4-甲酰-苯基)乙酸(EDDHMA)、乙二胺二(2-羟基-4-磺基-苯基)乙酸(EDDHSA)等新型螯合铁肥,用作土施或叶面喷施。另外市场上也出现了新型缓释铁肥和一些可生物降解螯合铁肥,如亚氨基二琥珀酸铁(IDHA/Fe3+)和乙二胺二琥珀酸铁(EDDS/Fe3+)。本文就常见的铁肥品种及其性质与效果等方面的研究进展进行了综述。     

Corn biomass,uptake and fractionation of soil phosphorus in five soils amended with organic wastes as P fertilizers

Abstract

Sustainable food production includes mitigating environmental pollution and avoiding unnecessary use of non-renewable mineral phosphate resources. Efficient phosphorus (P) utilization from organic wastes is crucial for alternative P sources to be adopted as fertilizers. There must be predictable plant responses in terms of P uptake and plant growth. An 18-week pot experiment was conducted to assess corn (Zea mays L.) plant growth, P uptake, soil test P and P fractionation in response to application of organic P fertilizer versus inorganic P fertilizer in five soils. Fertilizers were applied at a single P rate using: mono-ammonium phosphate, anaerobically digested dairy manure, composted chicken manure, vegetable compost and a no-P control. Five soils used varied in soil texture and pH. Corn biomass and tissue P concentrations were different among P fertilizers in two soils (Warden and Quincy), with greater shoot biomass for composted chicken manure and higher tissue P concentration for MAP. Plant dry biomass ranged from highest to lowest with fertilizer treatment as follows: composted chicken manure?>?AD dairy?=?MAP?=?no-P control?=?vegetable compost. Soil test P was higher in soils with any P fertilizer treatment versus the no-P control. The loosely bound and soluble P (2.7?mg P kg^?1) accounted for the smallest pool of inorganic P fractions, followed by iron bound P (13.7?mg P kg^?1), aluminum bound P (43.4?mg P kg^?1) and reductant soluble P (67.9?mg P kg^?1) while calcium bound P (584.6?mg P kg^?1) represented the largest pool of inorganic P.     

磷肥对甘蓝型春油菜产量、磷肥利用效率及经济效益的影响

利用大田试验研究了不同磷肥用量对甘蓝型春油菜产量、养分积累、磷素利用效率和经济效益的影响。结果表明,在低磷土壤上施用125 kg/hm2N和135 kg/hm2K2O基础上增施磷肥,可显著增加油菜不同部位产量,其中籽粒产量平均提高12.5%,生物量平均提高29.0%。施磷明显提高油菜地上部P素含量,有利于促进油菜K素营养累积,但对N素、K素含量无显著影响。随磷肥施用量的增加,磷肥偏生产力显著下降,施磷后磷肥农学效率、磷肥表观利用率和磷肥生理利用率平均分别为4.6 kg/kg P2O5、13.0%和40.2 kg/kg P2O5,磷肥对籽粒产量的贡献率仅为10.9%。根据经济效益分析结果,青海甘蓝型春油菜生产中磷肥用量以75 kg/hm2为宜。     

增值磷肥对潮土无机磷形态及其变化的影响

在实验室条件下制备了海藻酸磷肥、腐植酸磷肥和氨基酸磷肥3种增值磷肥,利用室内土壤培养试验研究增值磷肥对潮土无机磷组分及其变化的影响。结果表明, 1）培养180 d后,普通磷肥（磷酸一铵,下同）和增值磷肥均显著提高了土壤速效磷含量,并降低了土壤pH; 施用增值磷肥提高土壤速效磷的幅度为34.6～41.92 mg/kg,高于普通磷肥; 施用增值磷肥降低土壤pH的幅度为0.23～0.36个单位,高于普通磷肥。2) 与普通磷肥相比,增值磷肥明显降低土壤对磷的固定,腐植酸、海藻酸和谷氨酸增值磷肥处理的固定率分别比普通磷肥降低7.32%、7.13%和11.99%。3）培养180 d后,与普通磷肥处理相比,增值磷肥均提高土壤Ca2-P、 Ca8-P 和 Al-P含量,减缓Al-P 向 Fe-P 的转化。     

Rapid decomposition of phytate applied to a calcareous soil demonstrated by a solution 31P NMR study

myo‐Inositol hexakisphosphate (phytate) is widely regarded as an abundant form of soil organic phosphorus (P) in many soils. Its abundance is believed to be because of its resistance to microbial degradation. We examined the fate of phytate added to a calcareous soil as a solution at a concentration of 58 mg P kg⁻¹, with and without the addition of wheat straw. The soil was incubated for 13 weeks, with phytate concentrations determined at 0, 1, 4, 7 and 13 weeks using NaOH‐EDTA soil extraction followed by ³¹P nuclear magnetic resonance (NMR) spectroscopy. The phytate concentration declined rapidly, with 18% (phytate + wheat straw) and 12% (phytate) of the initial phytate remaining after 13 weeks. This coincided with an increase in the proportion of orthophosphate relative to total NaOH‐EDTA extractable P (from 65 to 81%) and a small increase in α‐ and β‐glycerophosphate concentration, providing evidence for the microbial degradation of phytate. The decrease in phytate concentration was consistent with a first‐order decay with a half‐life for phytate of 4–5 weeks. This study demonstrates that in the calcareous soil examined, phytate was not highly stable, but a potentially biologically available form of P. In order to quantify the concentration of P species, we developed an improved method of spectral deconvolution. This method accounted for a broad signal (3.5–6.5 ppm) in the monoester region of the spectra that represented up to 23% of the total extractable P. We found that when this broad signal was not included, phytate concentrations were over‐estimated by up to 54%.     

A quantitative study of native soil phosphorus supply to plants

Abstract

Rhodes grass (Chloris gayana Kunth ) plants were grown on various soil types In order to study the relationships between the available and hardly available soil P fractions. Results indicate that when plants are grown intensively in soils for long periods without additional P fertilization, recharge rate of the available fraction of soil P becomes a limiting factor. An approach to determine the recharge rate, using data on plant uptake and changes in sodium bicarbonate extractable soil P content are suggested.     

Response of greenhouse cucumber to mineral fertilizers on a high phosphorus and potassium soil

The response of greenhouse cucumber (Cucumis sativus L. cv. Lolita) to nitrogen (N), phosphorus (P) and potassium (K) fertilizers on a soil high in available P and K was studied during 1986. The greenhouses were located in the Beqa Valley, central Lebanon, and their soil chemical properties before planting were: NO₃‐N = 52 ppm, P(NaHCO₃ ext.) = 100 ppm, K (ammonium acetate ext.) = 650 ppm, ECe = 1.6 dS/m, pH = 7.5. Nitrogen at 200 kg/ha, P at 85 kg/ha and K at 150 kg/ha were applied in the following combinations: N, N+K, N+P+K and an unfertilized control. The rates were split into four equal weekly applications starting on the fourth week after transplanting the seedlings to the greenhouse. The treatments were applied through the drip irrigation system of the greenhouses. Fruit yield over the two months of harvest was highest in plants receiving N alone, which yielded 57 ton/ha. Yields of the plots receiving N+K, N+P+K and the control were 55.0, 54.0 and 39.5 ton/ha, respectively. Yield during the first month of harvest was comparable in all fertilized treatments and was substantially higher than the control.