Polyphosphate‐fertilizer solution stability with time,temperature, and pH

Ammonium polyphosphate fertilizers are gaining popularity in agricultural industry due to ease of application and yield benefits in calcareous soils. In this study, the effects of temperature, pH, and time on the stability of ammonium polyphosphate–fertilizer solution simulating a range of storage conditions were evaluated. Ion chromatography was used for the speciation of orthophosphate, pyrophosphate, and tripolyphosphate in the polyphosphate‐fertilizer solution over time. Polyphosphate solutions were very stable when the pH was maintained close to neutral (pH 6.4) and the temperature was less than 25°C. In contrast, at the lowest pH (2.3) and highest temperature (50°C) almost all tripolyphosphate and 96% of pyrophosphate was hydrolyzed after 28 d. The hydrolysis rate constant for tripolyphosphate at 50°C was calculated to be 9.2 × 10^–7 s^–1 and the half‐life 20 d. At 25°C, the half‐life of tripolyphosphate was 34 d at pH 2.3 and 174 d at pH 5.4. The activation energy at pH 2.3 was 12.7 kJ mol^–1. The results demonstrate that increasing temperature and decreasing pH have a deleterious effect on the stability of condensed P species in polyphosphate fertilizer. The effect of acidification on polyphosphate‐fertilizer composition requires consideration when formulating mixed ammonium polyphosphate blends with acids and trace elements for application in the field.     

溶磷细菌肥对石灰性土壤磷素转化的影响

通过室内模拟培养和大豆盆栽土培生物模拟试验，研究了磷细菌溶解磷酸钙的能力及在北方石灰性土壤上施用磷细菌肥对土壤磷素转化的影响。试验结果表明：磷细菌菌株具有较强溶解磷酸钙的能力，磷酸钙的溶出率从第1天的2．80％提高到第8天的22．00％。在贫速效磷和富难溶性磷土壤上施用溶磷细菌肥有利于土壤中难溶态的Ca10-P和缓效态Ca8-P含量下降，促使土壤中Ca2-P和Al-P的含量增加，从而使土壤中有效磷含量增加。而对于富速效磷的土壤，无论施菌肥与否对土壤中各种形杰的无机磷绢分基本没有影响．     

采煤塌陷区土壤磷赋存形态及其释放规律

[目的]对采煤塌陷区土壤中磷赋存形态以及释放规律进行研究,了解土壤磷污染特征。[方法]以淮南矿区潘一矿塌陷区为研究对象,应用分级提取的方法对塌陷区土壤中磷的赋存形态进行分析测定,采用室内柱状样模拟实验对土壤中磷释放特征进行研究。[结果](1)潘一杨庄塌陷区土壤TP的含量在103.58~489.89 mg/kg之间,平均值为248.47 mg/kg;(2)活性磷(BAP)的含量在86.94~378.24mg/kg,占TP含量的43.53%~91.12%,平均为71.1%。(3)TP累计释放量大小依次为:pH=12pH=3pH=6pH=8pH=10pH=4。[结论]采煤塌陷区土壤中TP有极高的释磷潜力;不同pH值条件下,磷的释放强度大小为:碱性酸性中性。     

有机肥施用对土壤铜形态的影响研究

选取以猪粪为原料的商品有机肥,通过室内培养试验,采用BCR连续萃取法,研究了不同用量、含不同Cu浓度、不同Zn浓度有机肥的施用对土壤Cu形态变化的影响。选取15,30,45 Mg/hm2 的施肥量进行对比,发现增施有机肥使土壤Cu的氧化物结合态显著减少,有机结合态显著增加,土壤中Cu的活性态含量总体减少。Cu浓度较高的有机肥施入土壤后,使土壤Cu的酸提取态和有机结合态明显增加,增强了土壤Cu的活性。土壤中Cu、Zn的交互作用体现了两种元素对土壤不同组分吸附的竞争优势,相对来说Cu与土壤有机物的亲和力更强,Zn浓度升高能置换出土壤中氧化物结合态Cu。     

Hydrolysis rates of inorganic polyphosphates in aqueous solution as well as in soils and effects on P availability

Applications of polyphosphate‐based fertilizers have been reported to have a positive impact on crop yields as compared to orthophosphate sources. Since plants take up P mainly as orthophosphate, hydrolysis rates of polyphosphates into orthophosphates will determine their fertilizer ability. Laboratory and soil incubation experiments were performed to evaluate hydrolysis rates of pyrophosphate (PP), tripolyphosphate (TP), and trimetaphosphate (TMP) in water as well as in two soils having different P‐fixing capacities. P availability was characterized by measuring the orthophosphate (ortho‐P) and polyphosphate (poly‐P) concentration in soil solution as well as the calcium‐acetate‐lactate (CAL)‐extractable amounts of both forms. In water, PP was completely hydrolyzed within 15 d, whereas TMP was hydrolyzed only to about 30% after 90 d. In the two soils, polyphosphates hydrolyzed during the incubation period increasing ortho‐P concentration in soil solution as well as in CAL extract. At the end of the incubation, no significant differences in ortho‐P concentration in soil solution and CAL extract were found in the sandy soil, whereas in the silty‐loam soil, polyphosphate applications resulted in higher soil‐solution ortho‐P concentration. Although polyphosphate hydrolysis is mainly affected by the soil‐specific enzymatic activity, it seems that polyphosphates and/or hydrolysis products are preferentially adsorbed/precipitated compared to ortho‐P in the silty loam, thereby influencing the P availability from polyphosphate sources.     

模拟深松条件下深施磷肥对旱地冬小麦根系生长和水肥效应的影响

通过模拟深松机具下的深施肥技术,研究了深施磷肥对旱地冬小麦产量、根系生长、水肥效应的影响。研究结果表明,深松条件下深施磷肥平均效果比传统施肥增产38.5%,20 cm和40 cm各施一半的效果最好,但深施到20 cm和深施到40 cm之间差异不显著。深施磷肥促进了小麦根系在土层内的生长发育,提高了小麦根系总量,尤其是深层根系总量明显增加,这对旱地冬小麦吸收深层土壤中的水分和养分是十分有利的。深松条件下,深施磷肥的水分利用系数比传统施磷提高了8.4%。此外,深施磷肥有助于冬小麦在整个生育期内磷素的均衡供应,     

Phosphorus Forms and Availability Assessed by 31P‐NMR in Successively Cropped Soil

Abstract

Soils under no‐tillage gradually increase in organic matter and phosphorus (P) content from the top layer. Because of lack of knowledge about the organic phosphorus fraction contribution to plant nutrition, this research was conducted to estimate the availability of phosphorus fractions to plants. Soil samples of a very clayey Rhodic Hapludox that received 0, 156 and 312 kg P ha^?1 were submitted to 15 successive crops in pots without replacing P extracted by plants. ³¹P nuclear magnetic resonance analysis was performed to detect P fractions before cultivation and after the sixth, ninth and fifteenth crops. Inorganic phosphorus was the unique P fraction acting as P source to plants in soils with previous P addition. Contribution of organic P was observed only when inorganic P content was extremely low, with plants showing severe P stress. Contribution of organic P was not enough to supply the required P for normal plant growth.     

磷在红壤肥际微域中的迁移和转化

采用室内土柱实验研究了磷在红壤肥际微域中的迁移和形态转化。结果表明,相同施量的磷在7天和28天时的迁移距离相同,施用磷酸二氢钙(MCP)0 2g和0 5g时的迁移距离分别为1 4cm和2 0cm。磷在施肥7天内的迁移量较大,然后只发生少量迁移。迁移进入土壤的磷86 3%～94 2%被吸附固定,64 1%～72 2%仍以有效态存在。在迁移距离内,土壤水溶性磷、酸溶性磷和有效磷含量与距施肥点距离呈极显著直线负相关。施肥量对水溶性磷、酸溶性磷和有效磷在肥际微域中的含量分布有显著影响;但培养时间只对水溶性磷含量分布有显著影响。     

磷肥和有机肥对不同磷水平土壤磷渗漏影响研究

采用土柱培养的模拟试验方法研究了在不同磷水平土壤上大量施用磷肥和有机肥对土壤测试磷、土壤磷渗漏的影响及影响机理。结果表明,不同磷水平土壤施用磷肥或有机肥土壤CaCl2-P、Olsen—P和土壤渗漏液中可溶性磷均显著增加;单位量磷肥或有机肥所增加土壤各形态磷量随土壤磷水平的增加而增大;随着磷肥或有机肥用量的增加,单位量磷肥或有机肥所增加各形态磷量也逐渐增大,差异均达到显著和极显著水平。在施用磷肥的基础上增施有机肥可以提高土壤CaCl2-P、Olsen—P含量和土壤渗漏液中可溶性磷的增长幅度。土壤磷的渗漏量与土壤测试磷呈显著正相关;单位量磷肥或有机肥所增加的土壤渗漏磷量随着磷肥或有机肥用量以及土壤磷水平的增加而增加。Olsen—P含量与土壤磷吸持指数（PSI）呈显著负相关关系,与土壤磷的吸附饱和度（DPS）呈显著正相关关系。     

Comparison of Colorimetric and ICP Methods of Phosphorus Determination in Soil Extracts

The traditional method for quantifying phosphorus (P) in Manitoba soil extracts is the molybdate blue–ascorbic acid colorimetric method. The shift from this traditional method to newer and more sophisticated analytical methods such as inductively coupled plasma (ICP) optical emission spectroscopy for P determination in soil extract could have serious implications on agronomic and environmental P management. Thus, the objectives of this study were to compare P determination by colorimetric and ICP methods in four extractants, namely Olsen, Mehlich 3, CaCl₂, and water extraction methods and to evaluate the possibility of developing conversion equations for P determination for the two methods in Manitoba soils. A laboratory experiment was conducted to establish relationships between P determination by colorimetric and ICP methods. Sixty surface soil samples (30 manured and 30 nonmanured) were collected from across Manitoba and extracted with Mehlich 3 reagent, Olsen solution, calcium chloride (CaCl₂) solution, and deionized water. Extractable P in the extract was determined by colorimetric (Col-P) and ICP (ICP-P) methods. The concentrations of P measured by the two methods were statistically analyzed. Mean comparison showed that P amounts determined by ICP in Mehlich 3, water, and CaCl₂ solutions were significantly greater than those determined by colorimetric method (P < 0.05) in the study. The differences between P determinations by the two analytical methods in the extractants were probably due to the presence of organic P, which was included in ICP determination but not in colorimetric determination. The influence of other factors such as the presence of colloidal particles on the P that was determined by the two methods could not be ruled out. However, Olsen P determined by the colorimetric method was not significantly different from the values determined by ICP (P > 0.05) probably because the alkaline nature of this extractant enhanced the hydrolysis of organic P in the extract, thus including organic P in the colorimetric determination of P. There were significant correlations between the two methods of P determination in the various extracting solutions with correlation coefficients ranging between 0.94 and 1.00. The two methods of P determination were linearly related for all the extracting solutions.     

Influence of Residual and Fresh Subsurface Phosphorus Fertilizer Bands on Soil Phosphorus Profile Distribution and Maize Growth and Shoot Phosphorus Uptake

A field study was conducted at Beresford, SD, to examine how residual fertilizer phosphorus (P) bands influenced the distribution of Bray-1 extractable P in the soil profile and maize (Zea mays L.) shoot growth and P uptake in a ridge-till system. Liquid ammonium polyphosphate (10-34-0) was injected each fall for three consecutive years in either one or two concentrated subsurface bands in a 5 × 5 cm configuration with respect to the planted seed at rates to provide either 0, 10, 20, or 40 kg P/ha. Soil samples were removed once in the spring before planting with a rectangular block sampler along a 30 cm transect perpendicular to the ridge row to a depth of 15 cm after the third year of the P application. The large sample was separated into eight 7.5 × 7.5 cm × 7.5 cm block sections. Soil was analyzed for Bray-1-extractable orthophosphate-P in each of the sample blocks, composited for increasingly greater soil volumes, and compared with shoot growth and P uptake at the sixth and twelfth leaf and silking stage of growth. Applied-P rate had a strong effect on Bray-1-P levels, increasing them from 7.5 to 195.1 mg P/kg as P rate increased from 0 to 40 kg P/ha. The locations of the previously applied P bands were highly variable in the sampling profile. Coefficients of variation (c.v.) for Bray-1-P levels varied from 1.9 to 141.4 for sampling-block locations and increased as P rate increased. This result indicated that, within treatment replication, there was little consistency with fertilizer P-band placement with respect to the planted seed, and the variability increased with higher P applications. Applied-P rate influenced shoot dry weight, shoot P concentration, and shoot P uptake in the sixth leaf and twelfth leaf growth stages only. The band number had no influence on these parameters. When increasingly larger volumes were considered to improve the accuracy of sampling position with the predictability of the Bray-1 P levels and shoot parameters, the smallest soil volume and sampling position close to the planted seed was as accurate a predictor of shoot parameter responses as the Bray-1 P levels derived from soil composites of larger sampling volumes.     

紫色土减磷配施有机肥的磷肥效应与磷素动态变化

为探索长江上游稻油轮作系统减少农田磷素流失和有效提高磷肥利用率的最佳施肥模式,降低磷对水体富营养化的影响,采用长期田间定点试验并结合室内试验分析,研究了化肥配施猪粪和水稻秸秆还田对紫色土磷肥效应及磷素迁移的影响。结果表明:在常规作物施肥基础上配合施用有机肥,适当减少化学磷肥施用量,对作物产量没有显著的减产效应,且能在一定程度上减少农田磷素损失,提高磷肥利用率。水稻磷肥利用率总体表现为常规施磷量减20%+猪粪有机肥(MDP)常规施磷量减20%+秸秆还田(SDP)常规施肥+猪粪有机肥(MP)常规施肥+秸秆还田(SP)≈优化施肥(P),各处理利用率在20%~25%之间。油菜磷肥利用率总体表现为SDPMDPMPSPP,各处理利用率在17%~29%之间。在水稻生长前一个月内,田面水总磷含量随着施磷水平的增加而增加,其中常规施肥(P)比不施磷肥(P0)处理总磷含量高4倍左右。各处理中磷含量大小表现为PMPSPMDPSDPP0,配施有机肥可以提高稻田土壤对磷的吸附,降低前期土壤磷向水体中释放,配施秸秆比配施猪粪对减少土壤磷素流失效果更好,磷肥施用后的7~10天内是控制稻田磷素流失的关键时期。油菜蕾苔期的土壤有效磷含量较苗期明显降低,但在油菜开花期和收获后期,土壤有效磷含量明显上升,油菜生长花期以后是土壤有效磷淋失的主要时期。有机无机肥配施可以显著提高土壤有效磷含量。化学磷肥减量并配施有机肥是应对农业面源污染控源节流的较好措施。     

石灰性土壤施用不同磷肥对玉米苗期生长和土壤无机磷组分的影响

研究旨在探讨不同磷肥品种对玉米生长发育和土壤无机磷组分的影响,以期为磷肥高效利用提供参考.采用盆栽试验,设置6个处理:磷酸一铵(MAP)、过磷酸钙(SSP)、聚磷酸铵(APP)、氮磷复合肥硝酸磷肥(NiP)、硫酸铵+过磷酸钙混施(SA+P),试验60天后测定了玉米的生物学指标和玉米植株磷素含量,同时测定了土壤有效磷与土...     

叶面肥中磷含量测定方法的比较研究

采用分光光度法、电感耦合等离子发射光谱法(ICP-AES)和离子色谱法测定叶面肥样品中的全磷和速效磷的含量。通过样品测试数据的比较,分光光度法和ICP-AES测定全磷的结果一致,能很好的吻合,两种方法可以在叶面肥全磷的测定中相互确认,并应用于常规分析;而分光光度法和离子色谱法测定速效磷的结果在部分叶面肥中存在一定的差异,离子色谱法只能作为分光光度法测定叶面肥中速效磷的一种补充方法。本文为磷元素含量影响叶面肥品质的分析提供了选择测定方法的依据。     

氮磷配施对苹果幼苗生长、土壤无机磷形态和磷素利用的影响

以矮化苹果砧木M9T337幼苗为试材,设置4个氮水平(N 0,150,300,450 mg/kg,分别以N0、N1、N2、N3表示)和2个磷水平(P2 O5100,200 mg/kg,分别以P1、P2表示),研究了氮磷配施对苹果砧木幼苗生长、土壤无机磷形态转化和磷素吸收利用的影响,以期为果园磷肥高效利用提供参考依据.结...     

有机肥部分替代氮肥的盐碱土壤改良与水稻增产效应研究

本研究旨在揭示利用有机肥部分替代氮肥实现作物增产和土壤改良的可能性及其机理。以南粳9108为供试水稻品种,设置4个处理:常规施肥(T1),低量自配有机肥部分替代氮肥(T2),高量自配有机肥部分替代氮肥(T3),不施肥(CK),T1、T2和T3采用等氮量设计(315 kg/hm²),开展田间试验。研究结果表明:较常规施肥,有机肥部分替代氮肥能够显著降低土壤pH、提升土壤有效磷和速效钾、增强脲酶和碱性磷酸酶活性、增加土壤有机质和碱解氮;能够显著增加收获时的水稻干物质积累量,一定程度地提升水稻株高,促进水稻分蘖并且增加穗粒数、结实率和千粒重。有机肥部分替代氮肥能够实现土壤改良和水稻增产。     

中高地力水平下谷子N、P、K肥效应研究

为明确夏谷生产中不同地力水平下的施肥效应和最优施肥量,本试验在中高地力水平下开展谷子“3414”氮、磷、钾肥肥料效应研究。结果表明,施用氮、磷、钾肥能显著提高谷子产量,在中高地力水平下平均增幅分别为21.4%和12.7%,其中氮肥增产效率分别为20.2%和7.9%,磷肥增产效率分别为6.6%和12.6%,钾肥增产效率分别为11.3%和13.8%,表明在中地力水平下氮肥增产效率最高,高地力水平下磷钾肥的增产效率显著高于氮肥。氮、磷、钾肥间存在明显的交互作用,在中地力水平下,氮磷间存在抑制作用,氮钾和磷钾间存在促进作用;在高地力水平下则均存在抑制作用。氮、磷、钾肥的平均偏生产力在中高地力水平下分别为42.1、50.4、200.0和56.4、72.4、283.8 kg·kg^-1,表明高地力水平下的氮、磷、钾肥偏生产力均高于中地力水平。氮、磷、钾肥的农学效率在中高地力水平下分别为7.6、2.8、14.6和3.5、7.2、28.3 kg·kg^-1,表明氮肥农学效率以中地力水平下最高,磷钾肥农学效率则以高地力水平下最高。通过建立肥料与产量的三元二次施肥模型得出在中高地力水平下谷子氮、磷、钾肥最佳施肥量分别为N 189.3 kg·hm^-2、P₂O₅ 61.1 kg·hm^-2、K₂O 45.0 kg·hm^-2和N 141.2 kg·hm^-2、P₂O₅ 180.0 kg·hm^-2、K₂O 45.0 kg·hm^-2。综上,在谷子中地力水平下,氮肥增产效果最好,应提高氮肥的用量和比例;在高地力水平下,磷钾肥增产效果较好,应提高磷钾肥的用量和比例。本研究结果为夏谷不同地力水平下施肥效应提供了理论依据和技术支持。     

Effects of Swine Lagoon Effluent and Commercial Fertilizer Applications on Phosphorus Status of an Acid and Alkaline Soil

Abstract

Two separate field experiments were conducted to evaluate the effects of swine lagoon effluent relative to inorganic fertilizer at equivalent rates on phosphorus (P) status of an acidic Vaiden (very fine, montmorillonitic, thermic, Aquic Dystrudert) and an alkaline Okolona (fine, montmorillonitic, therimic, Typic Chromudert) silty clay soil. In each site, a randomized complete block design with a factorial arrangement of treatments was used. Treatments were replicated four times. Cumulative swine lagoon effluent P application rates for the year 1994 through 1996 were 0, 59, 121, and 175 kg P ha^?1 on the Vaiden soil and 0, 72, 148, and 223 kg P ha^?1 on the Okolona soil. In each replication, commercial fertilizer P at rates equivalent to swine effluent P application were also included. For both sites, soil P concentration increased with increasing swine effluent and commercial fertilizer P applications. No significant difference in soil P level was observed between two P sources. At high application rate, desorbed P was 1.20 and 0.59 mg P kg^?1 in the Okolona and Vaiden soil respectively. In the Vaiden soil, P adsorption approached the maximum for equilibrium P concentration greater than 600 mg L^?1. However, Okolona soil displayed a linear adsorption potential with application of swine effluent P. Among P fractions, NH4Cl‐P and HCl‐P concentrations increased the most compared to the check in both Okolona and Vaiden soils. Results indicated that P status differs between the soils, but no significant differences in P concentration were obtained between swine lagoon effluent and commercial fertilizer, suggesting that both P sources had similar effect on soil P after 3 years of application.     

海藻中铬形态和含量的检测分析方法研究

为研究海藻中铬的形态和含量,本试验采用IonPac CG5A(4 mm×50 mm)阳离子色谱柱,考察并优化络合剂的种类和浓度、流动相的种类和浓度、pH值、温度及游离态铬的提取方式等条件对Cr(Ⅲ)和Cr(Ⅵ)分离效果的影响。采用高效液相色谱-电感耦合等离子体质谱(HPLC-ICP-MS)对Cr(Ⅲ)和Cr(Ⅵ)进行分析,并利用电感耦合等离子体质谱(ICP-MS)测定海藻中总铬、结合态铬、游离态铬的含量。结果表明,海藻样品在40℃超声条件下,以5 mmol·L^-1吡啶-2,6-二羧酸(PDCA)的硝酸铵溶液(pH值7.0)为络合剂提取10 min,以50 mmol·L^-1硝酸铵溶液作为流动相,可同时测定海藻中Cr(Ⅲ)和Cr(Ⅵ),该方法操作简单,灵敏度和准确度高。此外,海藻中的铬主要以结合态形式存在,游离态铬的含量较低,且游离态铬以Cr(Ⅲ)形态存在为主。Cr(Ⅵ)形态较少,且含量均低于检出限。本试验通过建立海藻中Cr(Ⅲ)和Cr(Ⅵ)分析方法并对海藻中各种形态铬的含量进行分析检测,为相关标准的制定提供了分析方法和数据支撑。