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1.
取两个池塘底泥和上覆水进行室内模拟水体小环境试验,设对照组及5个处理组,进行4个月培养,采用连续分组法测定底泥中无机磷形态及其含量,分析底泥潜在无机磷变化及其与上覆水体可溶性活性磷(DRP)含量的关系。结果表明,池塘底泥中无机磷各形态含量依次为钙10结合磷(Ca10-P)〉闭蓄态磷(O-P)〉铝结合磷(Al-P)〉铁结合磷(Fe-P)〉钙8结合磷(Ca8-P)〉钙2结合磷(Ca2-P);4个月后两池塘底泥中的Ca2-P和Fe-P增加,Ca10-P、O-P、Al-P减少;上覆水体中DRP含量与O-P、Ca2-P、Ca8-P和Ca10-P之间呈显著正相关;底泥中无机磷各形态对上覆水体中DRP含量的直接影响大小依次为O-P〉Ca8-P〉Ca2-P〉Ca10-P〉Fe-P〉Al-P;5个处理组上覆水体中DRP含量都低于对照组;沸石与芽孢杆菌组合处理的上覆水体中DRP含量最低,表明采用沸石与芽孢杆菌组合进行底泥处理是控制上覆水中DRP含量的有效方法。  相似文献   

2.
以天津市东丽区和西青区2个养殖池塘为对象,采用室内试验方法,研究了底泥中各有机磷组分与上覆水中可溶性磷(DRP)含量、底泥磷酸酶活性与有机磷各组分及上覆水中可溶性磷之间的关系,并采取不同处理对底泥酸性磷酸酶(ACP)和碱性磷酸酶(ALP)活性进行调控。结果表明,底泥中活性有机磷(LOP)、中等活性有机磷(MLOP)、中稳性有机磷(MROP)与上覆水中DRP之间呈显著正相关。底泥中ALP与MLOP、MROP之间相关显著,并对其直接影响较大;ACP与MLOP之间相关显著,对其产生的直接影响也很大。A、B两池塘底泥中ALP与上覆水中DRP随时间变化规律基本一致,二者之间呈显著正相关。在养殖水体中加入酶抑制剂和沸石能抑制ALP和ACP活性,并以酶抑制剂加沸石的处理效果最好。  相似文献   

3.
施磷对滨海盐土无机磷组分的动态影响   总被引:1,自引:0,他引:1  
采用蒋柏藩、顾益初提出的土壤无机磷组分测定方法,在50d的培养过程中对滨海盐土的各无机磷组分进行了跟踪测定。结果表明:施入盐土中的无机磷在短期内主要增加土壤中的Ca2-P和Ca8-P的含量,而对A1-P、Fe-P和O-P的影响较小;施入盐土的无机磷首先转化成Ca2-P,然后再向Ca8-P、Ca10-P、Al-P、Fe-P和O-P转化;培养过程中,水分和温度的有利条件促进了土壤微生物的活动,加强了微生物对无机磷的固定。  相似文献   

4.
长期施肥对砂姜黑土无机磷形态的影响   总被引:4,自引:1,他引:3  
采用顾益初、蒋柏藩的无机磷分级方法,研究了长期施肥下砂姜黑土无机磷组分含量变化、生物有效性及其与土壤有效磷的关系。结果表明,长期耗竭状况下Ca2-P和Ca8-P的植物营养效率最高,其次为Al-P和Fe-P,O-P和Ca10-P也表现出了一定的有效性;Fe-P和Al-P对植物的营养贡献率最高,虽然Ca2-P和Ca8-P活性最高,但由于含量低,对磷素养分的贡献率较低,土壤磷素极度耗竭下,Ca2-P的植物营养贡献率甚至低于Ca10-P和O-P。砂姜黑土对磷的固定严重,土壤中积累的磷主要向Al-P、Fe-P和有效性更低的Ca10-P和O-P转化,Ca2-P、Ca8-P的增量较少。相关分析和通径分析表明,无机磷组分对有效磷的贡献为:Al-P>Ca8-P>Ca2-P>Fe-P>O-P>Ca10-P;建立了Olsen-P与无机磷组分间的回归方程:Y = 3.8751 +0.4674X1 +0.4470X2+ 0.3769X3-0.1166X4-0.07838 X 5 (Y代表有效磷含量,X1、、X2、X3 、X4 、X5分别代表Ca2-P、Ca8-P、Al-P、Fe-P和Ca10-P含量;P<0.01,R2=0.9989)。  相似文献   

5.
熊俊芬  石孝均  毛知耘 《土壤》2000,32(5):262-265
通过六年田间定位试验,结果表明,中性紫色土以无机磷为主占全磷83.7±3.6%,其中Ca10-P 54.2%、O-P 27.0%、Al-P 6.4%、Fe-P 5.7%、Ca8-P 4.2%、Ca2-P 1.5%.每年施用150kg/hm2化学磷肥(P2O5),各级无机磷均有积累,增加:Ca2-P 145.9%、O-P 67.2%、Al-P 49.8%、Fe-P 42.6%、Ca8-P 30.1%、Ca10-P 5%,且以化学磷肥的作用显著.中性紫色土不能仅施氮肥或单施有机肥,必须加施化学磷肥.Ca2-P有效性最高,Ca10-P最低,有效性大小:Ca2-P>Al-P>Fe-P、Ca8-P>0-P>Ca10-P.  相似文献   

6.
不同水分和添加物料对石灰性土壤无机磷形态转化的影响   总被引:7,自引:2,他引:7  
利用轻粘质土壤 ,模拟石灰性土壤中不同的组分因素进行室内培养试验。结果表明 ,水溶性磷肥施入土壤后很快向其它无机磷形态转化 ,主要转化为Fe-P ,其次是Ca2-P、Ca8-P和Al-P ,而很少转化为O-P和Ca10-P。其转化规律受不同培养组分因素的影响。较低的土壤水分含量 (200g/kg)利于Ca8-P、Al-P向Fe P和Ca10-P的转化 ,过高的水分含量 (200g/kg)有利于Ca10-P的活化与Fe-P的大量生成 ;不同量CaCO3加入促进了Fe-P、Al-P以及Ca2-P向Ca8-P、Ca10-P方向转化 ;秸杆、腐植酸的加入增加了各形态无机磷量以及无机磷总量。随培养时间的延长 ,Al-P、Fe-P等形态的磷量减少 ,Ca8-P、Ca10-P形态的量增加。不同量秸杆以及腐植酸的加入不同程度地降低了速效磷下降的幅度 ,提高了土壤速效磷水平。  相似文献   

7.
长期定位施肥对棕壤无机磷形态及剖面分布的影响   总被引:16,自引:0,他引:16  
对棕壤26年长期定位试验的无机磷分级表明:长期施入有机肥或化学磷肥,除了Ca10-P含量在耕层减少外,其它各形态无机磷含量都有所增加;仅施N肥或不施肥,Al-P,Fe-P,O-P,Ca10-P含量均减少,Fe-P,Al-P,Cas-P,Ca2-P占无机磷总量的比例增加,而O-P,Ca10-P则下降了.各形态无机磷的剖面分布相似,均为先下降而后略微上升.相关分析和逐步回归分析表明,Ca2-P,Ca8-P,Al-P,Fe-P,O-P与速效磷之间达到1%的极显著水平,Ca10-P与速效磷之间达到5%的显著水平.Ca2-P,Cas-P对速效磷的贡献最大.  相似文献   

8.
山东石灰性潮土、褐土无机磷的形态、转化和有效性   总被引:2,自引:0,他引:2  
应用蒋柏藩、顾益初提出的“石灰性土壤无机磷分级方法”研究了山东省石灰性潮土、褐土、砂姜黑土的无机磷组成、转化和对作物的有效性。结果表明,石灰性土壤无机磷中以Ca10-P占绝对优势,约占无机磷总量的54.52%,其次为O-P,占21.55%,Al-P、Fe-P,Ca8-P分别占5~10%,Ca2-P只有1.08%;在土壤剖面中各级无机磷皆随剖面深度增加而减少;水溶性磷肥施入土壤后,在作物一个生长季节内主要转化成Ca8-P,占全部转化量的50~70%,其次是Ca2-P,占10~30%,Al-P占11~13%,Fe-P很少,占5%左右;在各级无机磷中对作物有效性顺序是Ca2-P>Al-P、Fe-P>Ca8-P>O-P、Ca10-P。  相似文献   

9.
岩溶区不同土地利用类型土壤无机磷形态分布特征   总被引:22,自引:0,他引:22  
采用蒋柏藩、顾益初的土壤无机磷分级体系,对桂林毛村岩溶区旱耕地、灌丛、林地、水田土壤的无机磷形态分布特征进行研究。结果表明,岩溶区土壤全磷含量较高,速效磷和无机磷的含量均较低。4种土地利用类型总无机磷含量在49.87~489.80g/kg之间,占全磷的比例在6.08%~56.64%之间。各无机磷形态分布除Fe-P以外,均以水田最高,总无机磷含量水田也为最大。在同一土壤剖面不同发生层次上,Ca2-P、Ca8-P、Al-P、Fe-P、Ca10-P的含量随着深度的增加而减小,O-P含量随着深度增加而升高,对比各无机磷形态含量大小发现:Ca10-PO-PFe-PAl-PCa8-PCa2-P。对各无机磷形态与速效磷相关性分析表明:Ca2-P、Ca8-P、Al-P、O-P与速效磷呈极显著正相关关系;各无机磷形态之间,除Ca2-P与Ca10-P相关性不显著,Ca8-P、Al-P、Fe-P与O-P、Ca10-P相关性不显著,其余各形态无机磷之间均存在极显著的相关性。4种土地利用类型土壤磷素活化系数(PAC)除了水田耕层为2.5%2.0%外,其余土地利用类型的PAC均小于2.0%,说明岩溶区全磷不易转化为速效磷,有效性较低。  相似文献   

10.
通过室内土柱模拟实验,采用顾益初、蒋柏藩的无机磷分级方法,研究了三峡库区消落带早地和水田不同无机磷形态在表层和剖面的分布及其对有效磷的影响.结果表明.消落带旱地和水田不同处理无机磷形态均是以Ca10-P为主.整体上来看,各土层中不同无机磷形态的含量是Ca10-P>O-P,Fe-P>Cas-P,Al-P,Ca2-P.土柱模拟实验后,旱地和水田Ca2-P,Ca8-P,Al-P和Fe-P的含量都是相同水分情况下添加有机质的处理大于未添加有机质的,水分不同有机质相同时为淹水处理的含量大于湿润处理,但有机质相同时,淹水处理更利于Ca10-P和O-P向易溶性磷转化,添加有机质也会增加其含量;土壤剖面变化表现在:Ca2-P,Ca8-P和Al-P 3种形态存在底部累积现象.而Fe-P,Ca10-P和O-P的含量随着土壤深度的增加逐渐降低;Caz-P,Ca8-P是旱地和水田有效磷的主要磷源,与水分显著相关的Fe-P在淹水后含量增加,也成为重要的磷源.  相似文献   

11.
Understanding differences in the phytoavailability of various phosphorus (P) sources should improve matching P additions to plant needs and minimize excessive buildup of bioavailable P, which can degrade aquatic systems. We evaluated relative P phytoavailability (RPP) of different P sources in glasshouse and field studies. Bahiagrass (Paspalum notatum Fluggae), ryegrass (Lolium perenne L.), and a second bahiagrass crop were grown in succession in a P‐deficient soil amended with four sources of P (triple superphosphate (TSP), Boca Raton and Pompano; biosolids, and poultry manure), each applied at two rates in the glasshouse study and to an established bahiagrass pasture in the field. The RPP values estimated from plant P uptake of each organic source of P relative to TSP in the glasshouse were similar for the three croppings and similar to the estimates derived from the field study, but varied for the different P sources. Values ranged from 30% for poultry manure to 85% for Boca Raton biosolids. Boca Raton biosolid P was as readily available as P in TSP and would be classified as a high RPP (>75% RPP) source, but Pompano biosolids and manure would be classified as moderate RPP materials (25–75% RPP). The RPP values observed in manure and Pompano biosolid treatments are consistent with 50% “effectiveness” suggested for biosolid P in U.S. Environmental Protection Agency (USEPA) guidelines, whereas P bioavailability of Boca Raton biosolids is similar to mineral fertilizer.  相似文献   

12.
紫色土磷素流失的环境风险评估-土壤磷的“临界值”   总被引:10,自引:0,他引:10  
李学平  石孝均  刘萍  隋涛 《土壤通报》2011,(5):1153-1158
采用室内培养的方法,研究了3种类型的紫色土旱地和淹水土壤磷素流失的环境阈值。结果表明:无论是淹水土壤或旱地生境,3种紫色土Olsen-P与CaCl2-P之间都存在一个"临界值",酸性、中性和钙质紫色土磷素淋失临界点的Olsen-P含量分别为67.2、85.8和113.8 mg kg-1。淹水土壤磷素环境敏感值在酸性、中性和钙质紫色土上,Olsen-P含量分别为49.2、77.9和92.1 mg kg-1。3种紫色土在淹水还原条件下土壤磷环境敏感临界值比旱地低,淹水还原条件提高了紫色土磷向水体释放的风险。淹水土壤Olsen-P含量与田表水TP、DP浓度之间存在"临界值",酸性、中性和钙质土临界值处土壤Olsen-P含量分别为(65±1.41)mg kg-1(、96.7±2.7)mg kg-1和(105.5±1.1)mg kg-1。土壤0.01 mol L-1 CaCl2-P与田表水TP、DP之间呈极显著的线性关系。可以利用这些指标对紫色土区域土壤磷环境风险进行评价,并确定区域磷肥的最佳管理策略。  相似文献   

13.
Most fertilizer phosphorus (P) rate recommendations for the north-central United States are based on combination of a critical soil-test P value and a mass-balance calculation of fertilizer P required to maintain critical soil-test P. Accurate estimates of grain P removal are an essential component of P mass-balance calculation. Current north-central extension service guidelines recommend that estimates of corn and soybean grain P removal should be calculated using constant grain P concentrations. We reviewed research from the north-central region to determine the extent to which variation in grain P concentration accounts for differences in crop P removal and to determine whether predictions of grain P concentration can be improved through consideration of soil-test P, crop yield, and fertilizer P application. We found that soil-test P, grain yield, and fertilizer P are predictor variables that may significantly improve estimates of grain P concentration for corn and soybeans.  相似文献   

14.
Lime was investigated as a soil amendment to decrease phosphorus (P) loss in runoff from two Delaware sandy loam soils, one high and one low in P. Soils were limed at three rates (control and target pH values of 6 and 6.8, respectively), packed into runoff boxes (2,000?cm2) and received simulated rainfall (80?mm?h?1 for 30?min). Lime showed potential to decrease P loss in runoff, but its effectiveness was soil specific and dependant on other management factors also. Lime decreased dissolved reactive P (DRP) and dissolved organic P (DOP) loss by 20?C25 and 52?C93?%, respectively, for the high-P soil and particulate P (PP) by 13?% for the low-P soil. The majority of P lost in runoff was DOP (3?C29?%) or PP (64?C96?%). Lime increased PP losses from the finer-textured soil following P application, indicating that increased P sorption can lead to increased losses if P is sorbed to more erodable particles. Initial soil P status was more important than liming in determining P loss. While amendments may decrease P losses in the short term, addressing nutrient imbalances at the field scale is clearly necessary in the long term. Losses increased significantly following inorganic P application. Although P was sorbed rapidly, with less than 2?% of added P removed in runoff, mean concentrations in excess of 700???g?l?1 DRP, 2,500???g?l?1 OP and 6,500???g?l?1 PP were recorded for both soils immediately following P application.  相似文献   

15.
为研究溶磷真菌菌群对土壤磷素有效性的影响,首先在室内对3株不同种类溶磷真菌(1株属于被孢霉属Z1,1株为青霉属Z2,1株为黑曲霉Z3)的组合效应进行了研究,确定了最佳的菌株组合Z1+Z2+Z3,试验选用Z1、Z2、Z3组成菌群作为试验菌株;然后通过盆栽油菜试验研究溶磷真菌配施难溶态磷(磷酸三钙和磷矿粉)对土壤磷素有效性的影响。结果表明:溶磷真菌处理土壤有效磷、有机质、碱性磷酸酶、蔗糖酶含量和油菜产量分别比基质处理显著增加了60.00%,20.21%,56.45%,53.81%,14.38%,溶磷真菌配施难溶态磷上述各指标都高于单施溶磷真菌处理;单施溶磷真菌对土壤最大吸磷量的影响与基质无差异,溶磷真菌配施难溶态磷可以显著降低土壤最大吸磷量,溶磷真菌+磷酸三钙和溶磷真菌+磷矿粉处理土壤最大吸磷量比溶磷真菌处理显著减少158.7,47.6 mg/kg,溶磷真菌各处理土壤吸附常数都低于对应的基质处理,溶磷真菌可以降低土壤对磷的吸附。在土壤上溶磷真菌应与难溶态磷配合施用,对提高土壤磷素有效性有积极的作用。  相似文献   

16.
Phosphorus (P) loss from urban areas has been identified as a major contributor to declining surface water quality. The objective of this study was to determine the relationship between extractable soil P, depth of soil sampling, and dissolved reactive P (DP) concentration in runoff from turfgrass areas. At each site, runoff was generated on turfgrass and adjoining areas where turfgrass cover was removed. Across all six locations and the wide range of nutrient management schemes, variation of extractable soil P concentration and saturation ratios of 0–2cm samples accounted for 49–59% (r 2 = 0.49–0.59, n = 92) of variation of DP concentration in runoff from bare soil and soil with turfgrass cover. Despite a high degree of soil P stratification, changing sampling depth generally did not improve the relationship between soil test P and runoff DP concentrations. Across the narrower range of soil P levels common to lawns in New York (0–50mg kg?1 Morgan extractable soil P), none of the soil tests or P saturation levels (for 0–2cm depth) could accurately predict runoff P concentrations from soil with turfgrass cover (r 2 = 0.02 to 0.23, n = 72). For bare soil plots, restricting the analysis to the same range (<50mg kg?1 Morgan extractable P) did not alter the relationship between soil test P and runoff DP concentrations observed for the entire range (0–658mg kg?1) of soil-test P concentrations. These results suggest soil testing will not be an effective tool to predict runoff from turfgrass areas across the range of soil P levels common to New York State.  相似文献   

17.
Phosphorus (P) is both a macronutrient for plants and an effective amendment to reduce lead (Pb) toxicity in soil. Thus, in Pb-polluted soil with low P availability, P will act as a nutrient as well as a Pb-immobilizing agent. However, this has not been fully investigated. A soil with 2.50 mg kg?1 Olsen P was spiked with soluble Pb and then amended with superphosphate to examine the effect of P on soil Pb availability and ryegrass (Lolium perenne L. cv. Aubisque) growth. It was found that P/Pb = 2 increased ryegrass yield by 804% and decreased root Pb concentration and soil diethylenetriaminepentaacetic acid (DTPA)–extractable Pb concentration by 25.6% and 1.0%, respectively. As P amendment increased to P/Pb = 4, both plant yield and root Pb concentration declined compared with P/Pb = 2. Results of the sequential extraction indicated that the proportion of carbonate phase Pb decreased, while that of the manganese oxide phase increased as P was added. The proportion of residual Pb was little affected by the amendment. The results suggest that in soils with low P availability and high Pb availability, availability of soil Pb and root concentration of Pb are less affected, whereas the toxicity of Pb is greatly depressed by the P amendment; P/Pb = 2 is high enough to alleviate the stresses of low P availability.  相似文献   

18.
Water-extractable phosphorus (WEP) in manures can influence the risk of phosphorus (P) losses in runoff when manures are land applied. We evaluated several manure handling and extraction variables to develop an extraction procedure for WEP that will minimize pre-analysis manure-sample-handling effects on WEP measurements. We also related manure WEP determinations to runoff dissolved reactive phosphorus (DRP) concentrations found in previously conducted field simulated rainfall experiments using the same manures to evaluate WEP as a predictor of P runoff losses. Dairy and poultry manure WEP concentrations increased with manure-to-water extraction ratio and shaking time. Relative to fresh manures, drying and grinding dairy manures before analysis usually decreased WEP concentrations, while WEP in poultry manures was often increased. Pre-analysis handling effects on WEP were minimized at the 1:1000 extraction ratio with a 1-h shaking time. Relationships between manure WEP and runoff DRP concentrations were strongly influenced by season of year and WEP extraction procedure. The best prediction of DRP concentration in spring runoff experiments was with manure WEP concentration at the 1:1000 extraction ratio. With fall runoff studies, DRP concentrations were best predicted with WEP application rate rather than concentration. These seasonal differences can be explained by the greater percentage of rainfall that ran off in the fall compared to the spring. For all studies, runoff DRP concentrations were strongly related (r2 = 0.82) to the ratio of runoff to rainfall volumes, confirming that models need to take runoff hydrology into account as well as manure WEP in P-loss risk assessments.  相似文献   

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通过2年盆栽试验,探讨不同磷水平下玉米–大豆间作根际土壤无机磷组分、土壤有效磷含量及作物磷吸收的差异,明确土壤无机磷组分、土壤有效磷与作物磷吸收之间的相互关系。试验设置玉米单作、大豆单作、玉米–大豆间作3种种植方式以及3个P2O5施用水平(0、50、100 mg/kg,分别记作P0、P50、P100),共9个处理。结果表明:与单作相比,2018年和2019年在P0、P50和P100水平下,间作显著提高玉米和大豆的籽粒产量,并显著提高玉米和大豆植株的磷素吸收量。与常规施磷水平(P100)下的单作处理相比,玉米–大豆间作在磷肥减少50%(P50)的条件下,并未降低玉米和大豆的磷吸收量与籽粒产量。3个磷水平下,间作提高了玉米和大豆根际土壤有效磷含量,而降低了根际土壤总无机磷以及Fe-P、Al-P、Ca-P、O-P的含量;同时适当增施磷肥显著提高了玉米和大豆根际土壤总无机磷及各无机磷组分的含量。本试验条件下,间作促进土壤中Fe-P、Al-P、Ca-P和O-P的活化(尤其是Fe-P),是低磷胁迫下间作土壤有效磷含量与作物磷吸收量增加的重要原因。玉米–大豆间作具有节约磷肥、维持作物产量及根际土壤有...  相似文献   

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