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1.
黄土高原石灰性土壤不同形态磷组分分布特征   总被引:9,自引:0,他引:9  
以黄土高原自北向南采集的12个0~20 cm耕层土壤为供试土样,采用Tiessen和Moir修正的Hedley土壤有机无机磷分级方法研究了黄土高原石灰性土壤中不同形态磷组分的分布特征。结果表明:供试土壤各形态P总体分布特征为:HCl-P>Residual-P>NaHCO3-Po>NaHCO3-Pi>NaOH-Po>NaOH-Pi>H2O-P,以HCl-P和Residual-P为主,分别占土壤全磷的54.00%~88.96%和0~39.11%。黄土高原土壤磷含量总体分布表现为南高北低。在各土壤类型间,NaOH-Po、Residual-P和全磷平均含量表现为干润砂质新成土<黄土正常新成土<简育干润均腐土<土垫旱耕人为土,自北向南依次增加;H2O-P和HCl-P表现为简育干润均腐土<黄土正常新成土<干润砂质新成土<土垫旱耕人为土,自北向南先降后升,且上升幅度较大。黄土高原土壤全氮与全磷及各形态磷含量相关性均达显著水平,其中与NaOH-Pi、NaOH-Po、HCl-P及全磷含量达到极显著水平。C/N、pH及砂粒与全磷及各形态磷含量呈负相关关系,其中pH与NaHCO3-Po呈显著负相关,与H2O-P、NaHCO3-Pi、NaOH-Pi及HCl-P呈极显著负相关;砂粒与NaHCO3-Pi、Residual-P及全磷呈显著负相关。除NaHCO3-Po、NaOH-Po及Residual-P,CaCO3与其他各形态磷含量具有一定程度负相关。除NaOH-Pi和NaOH-Po外黏粒与其他各形态磷及全磷也具有一定程度负相关。土壤各形态磷组分和有效磷的多元回归分析发现,各形态磷中对有效磷贡献最大的是H2O-P,其次为NaOH-Pi和NaHCO3-Po;土壤各形态磷组分和有效磷逐步回归分析结果,进一步说明H2O-P的有效性最高。  相似文献   

2.
石灰性土壤中无机磷形态和有效性的研究   总被引:11,自引:0,他引:11  
  相似文献   

3.
^32P示踪试验表明,加入石灰性土壤中的水溶性磷最初主要转化成Ca2-P,Ca8-P次之,随着时间的推移,Ca2-P不断减少,Ca8-P和Fe-P有所增加,Al-P在一周前后已达到平衡,从比活度看,Ca2-P有效性最高,是石灰性土壤中的速效磷源,Ca8-P,Al-P,Fe-P的有效性接近,是土壤中的缓效磷源。  相似文献   

4.
石灰性土壤中铁的生物有效性及其影响因素   总被引:7,自引:0,他引:7  
施卫明 《土壤》1990,22(2):75-77,82
本文分析了我国华北地区和西北地区主要石灰性土壤的铁素状况。结果表明,黄绵土、灰钙土和棕钙土的有效铁含量较低;(土娄)土和粘质黄潮土的有效铁较高;而黑垆土和轻质地黄潮土居中。根际土壤的有效铁和无定形铁含量均显著地高于非根际土壤。  相似文献   

5.
施肥对石灰性土壤磷素形态的影响   总被引:5,自引:0,他引:5  
张漱茗  于淑芳  刘毅志 《土壤》1992,24(2):68-70
用石灰性土壤无机磷分级方法,研究了施肥对土壤无机磷形态变化的影响。  相似文献   

6.
旱作农田石灰性土壤磷素形态,转化与施肥   总被引:3,自引:0,他引:3  
本文针对近年来人们十分关注的石灰性土壤磷的固定问题,对石灰性土壤磷素形态转化、有效性及其与施肥的关系进行了研究。结果表明,石灰性土壤中Ca2-P是最为有效的磷源,其次分别为Ca8-P、AL-P和Fe-P,为缓效磷源,Ca10-P和闭蓄态磷则为无效态磷;磷肥施入石灰性土壤后,绝大部分转化为缓效态Ca8-P,同时有一定量的Al-P和Fe-P生成,而Ca-P体系中,基本不存在Ca8-P进一步向无效态Ca  相似文献   

7.
石灰性土壤难溶态磷的微生物转化和利用   总被引:22,自引:2,他引:22  
目前农业生产中大多通过施用可溶性磷肥为植物提供有效磷。磷酸根化学性质活泼,施入土壤后能很快与土壤中的其它成分发生反应,使植物对其利用的有效度随时间延长而降低,最终以难溶性磷酸盐或吸附态形式滞留于土壤中,难以被植物直接吸收。据估计,在石灰性土壤中约有80% 的磷肥以难溶性磷酸盐存在。为此人们采用了许多方法提高磷肥的利用率,其中利用植物根际与磷循环相关的生物学系统来调节植物根际磷的有效性是重要的途径之一。这个生物学系统包括植物本身对土壤难溶态磷的吸收与利用以及土壤中某些微生物参与的难溶态磷的释放与利用。本文论述了微生物( 细菌和真菌) 转化和利用石灰性土壤中难溶态磷的研究进展。  相似文献   

8.
为研究水溶性磷肥在石灰性土壤中的转化,采用室内土壤培养的方法,在土壤中分别添加过磷酸钙0、6.25、12.5、25、50和100 mg/kg干土(即P0、P6.25、P12.5、P25、P50和P100处理),保持土壤湿度为田间持水量的70%~80%,在25℃恒温培养箱中培养120 d。培养期间在第1、3、7、15、30、60和120 d连续采样,测定土壤Olsen-P、CaCl2-P和各无机磷组分的含量。结果表明,在石灰性土壤中施用过磷酸钙能显著增加土壤Olsen-P和CaCl2-P含量,在一定的培养时间内,过磷酸钙转化为土壤Olsen-P和CaCl2-P的比例不随施肥量的变化而变化。随着培养时间的延长,土壤有效磷含量逐渐下降,尤其是培养前期(前7 d)土壤有效磷含量显著下降,之后下降速率减缓。施入土壤中的过磷酸钙主要转化为Ca2-P和Ca8-P(两者之和约占90%),其次是Al-P和Fe-P(两者之和约占10%),在短期内O-P和Ca10-P相对较为稳定。随着培养时间延长,Ca2-P逐渐向Ca8-P转化,在培养的前30 d转化速率较快,之后速率减缓。随着磷肥施用量的增加,Ca2-P转化为Ca8-P所需的时间逐渐延长。Olsen-P和CaCl2-P含量均与土壤无机磷组分中的Ca2-P、Ca8-P和Al-P含量呈显著正相关,通过逐步回归分析表明,其中Ca2-P是土壤Olsen-P和CaCl2-P的主要来源。  相似文献   

9.
新疆石灰性土壤锌有效性及其影响因素   总被引:2,自引:1,他引:2  
为探讨新疆石灰性土壤锌的组分分布特征及锌有效性的影响因素,对南北疆3种最主要土壤类型农田土壤锌及其组分含量进行研究。结果表明:新疆石灰性土壤有效锌平均含量为潮土(0.69mg/kg)>棕漠土(0.57mg/kg)>灰漠土(0.51mg/kg),变异系数为灰漠土>潮土>棕漠土。在土壤锌组分中,松结有机态锌(WBO)、碳酸盐结合态锌(CARB)、氧化锰结合态锌(OxMn)、紧结有机态锌(SBO)、无定形铁结合态锌(AOFe)平均含量均为潮土>棕壤土>灰漠土。南北疆土壤锌背景值不同,南疆土壤全锌含量高于北疆土壤,而北疆土壤全锌变异较大。土壤碳酸钙含量和物理性粘粒含量与松结有机态、碳酸盐结合态、紧结有机态锌分配率高度相关。松结有机态锌、碳酸盐结合态锌及松结有机态锌分配率与土壤物理性粘粒含量呈(极)显著正相关。交换态锌与松结有机态锌呈显著正相关。松结有机态锌与碳酸盐结合态锌呈显著正相关。石灰性土壤有效锌含量与松结有机态锌、碳酸盐结合态锌含量呈显著正相关,可用方程Y=0.306+0.123WBO+0.116CARB(F=20.095,r2=0.801**)预测。  相似文献   

10.
石灰性土壤无机磷的形态分布及其有效性   总被引:66,自引:1,他引:66  
本文应用蒋柏藩和顾益初(1989)提出的石灰性土壤无机磷的分级方法,对我国北方主要的石灰性土类进行了无机磷形态分级的研究,并对其有效性作出了初步评价。供试的甘肃、陕西和河南的16种土壤的无机磷形态的分布情况为:Ca2-P平均占无机磷总量的1.34%,Ca-P占9.91%,Al-P占4.27%,Fe-P占4.40%,O-P占10.9%,Ca10-P占69.1%。生物试验的结果表明:Ca2-P型的磷酸盐是最有效的,也是作物磷素营养的主要来源;Ca8-P、Al-P和Fe-P可以作为缓效磷源;Ca10-P和O-P只是一种潜在磷源。本研究为石灰性土壤无机磷的研究和磷肥的合理施用提供了理论依据。  相似文献   

11.
Journal of Soils and Sediments - The difference in copper (Cu) availability between soils can be a result of different distribution of Cu forms in various size fractions of aggregates. This study...  相似文献   

12.
Organic amendments considerably affect nutrient balance and interfraction mobility of nutrients by influencing the chemical, physical, and biological environment in soils. In this study, the effects of five amendments including: two composts, farmyard manure, packaging‐industry by‐product, and olive‐mill waste on time‐dependent interfraction mobility of P among mineral P fractions in two semiarid‐region soils differing in carbonate content and texture were investigated. Organic materials were applied at the rate of 0, 25, 50, and 100 g (kg soil)–1 soil thoroughly mixed and incubated at 27°C ± 2°C for 110 d. Phosphorus fractions were sequentially extracted by 0.1 M NaOH + 1 M NaCl (NaOH‐P), citrate‐bicarbonate‐dithionite (CBD‐P), and 0.5 M HCl (Ca‐P). Results showed that organic amendments especially farmyard manure significantly influenced NaOH‐P, CBD‐P, and Ca‐P. In addition, higher application rates of organic residues increased NaOH‐P fraction. NaOH‐P and CBD‐P fractions were increased after addition of organic residues and then converted to Ca‐P fraction within the end of incubation period. Increasing application rate of organic residues allowed P to be retained in more labile fractions for a longer period. The amount of Ca‐P was found to be related with carbonate content of soils. It can be concluded that organic residues applied to calcareous soils may enhance P nutrition of agricultural plants.  相似文献   

13.
华北某些旱地硫库的组成   总被引:1,自引:0,他引:1  
Soil sulfur fractions,including monocalcium phosphate-extractable S,slowly soluble inorganic S,C-O-S,C-bonded S and unidentified organic S,were analyzed for 48 soils,as representatives of 6 major groups of upland soils,fluvisol,cinnamon soil,loessial soil,chestnut soil,black soil and brown soil,in North china,The contents of total S and monocalcium phosphate-extractalble S in the above 48 soils ranged from 234 to 860 and 5.1to 220.3mg kg^-1,respectively and each of 6 soil groups contained the samples with a low level of phosphate-extractable S.Great differences in the average contents of each fraction of S were observed among the above 6 soil groups.Expressed as average percentage of the total S in soils,fluvisols,cinnamon soils,loessial soils,chestnut soils,black soils and brown soils contained 6.1%,9.5%,5.7%,13.2%,3.5%and 6.8% monocalcium phosphate-extractable S,5.7%,3.0%,9.3%,10.4%,3.2%and 3.1% slowly soluble inorganic S,51.6%,26.7%,17.4%,31.2%,28.9%and 22.7% C-O-S,11.0%,9.1%,6.6%,6.8%,9.7%and 9.4% in C-bonded S,and 25.6%,51.7%,60.8%,38.4%,54.7%and 53.0% unidentifed organic S,respectively,FOr the above 6 groups of soils,the mean C/N ratios were remarkably similar,ranging from 9.7 to 10.7,while the mean N/S ratios ranged from 1.16 to 3.12,The highest ratios of C/N,C/C-O-S and C/C-bonded S were found in black soils.averaging 30.4,104.9and 314.7,respectively,while the lowest ratios arose in chestnut soil,averaging 12.4,39.7 and 183.3,respectively.  相似文献   

14.
The organic matter of five low-moor peat soils and one eutrophic raised-bog peat soil was chemically characterized by C fractionation and ion-exchange chromatography of amino acids and carbohydrates. C fractions were related to potential denitrification, Dpot, as a measure of microbial activity and C availability, determined by the acetylene inhibition technique. Chemical and physical properties vary distinctively between different kinds of peat, and show increasing C/N ratio and decreasing bulk density and ash content within the profile. Generally, the carbon composition reflects the geobotanical origin of the peat. In most samples more than 65% of organic C consists of non-hydrolysable C. Readily hydrolysable neutral sugar C represents up to about 12% of organic C, usually decreasing with depth. The recalcitrant fraction of neutral sugar C is much smaller (1 to 4.2% of organic C) and does not vary with depth. The content of readily hydrolysable glucose exhibits a strong profile differentiation that decreases with depth, whereas the higher contents of recalcitrant glucose carbon (12/0.5 M H2SO4) in the lower peat horizons reflect their cellulose character. Regression analysis between Dpot and single C components explains up to 51.5% of the variability. Combining fractions which point to C availability (readily hydrolysable glucose) and microbial metabolism (amino acids), it is possible to estimate Dpot with a certainty of more than 80%.  相似文献   

15.
The release of non-exchangeable potassium from 24 calcareous soils of divergent mineralogy, from southern Iran, was examined. Sand, silt and clay particles were fractionated after dispersion with an ultrasonic probe. Samples were extracted with 0.01 M CaCl2 for 30 successive 2-h periods. The clay fraction released the largest amount of K in each soil. Cumulative K released ranged from 175 to 723, 35 to 128, and 71 to 146 mg kg?1 contributing 20–90, 4–39 and 2–54% for clay, silt and sand fractions, respectively. The lower proportion of K released from sand and silt fractions can be explained by the presence of a high content of CaCO3 and quartz in these fractions. The release kinetics for the non-exchangeable K data showed that parabolic diffusion and power function were the best fitting kinetic models. This indicated that slow diffusion of K from the mica interlayer positions is the main rate-controlling process. Cumulative K released and constant b values of parabolic diffusion model correlated significantly with the mica content of the clay fraction.  相似文献   

16.
The effect of elemental sulphur (S) and S containing waste applications on soil pH treated with 0–2,000 kg ha‐l elemental S, and 0–100 tons ha‐1 of waste was determined in the field and the pots. Sorghum (Sorghum bicolor L.) was grown in a Lithic Xerorthent soil which was taken from where the field experiment was conducted in pots receiving 5 kg soil. Plants were harvested 20 weeks after planting or 30 weeks after the applications for determination of dry matter yield and phosphorus (P), iron (Fe), zinc (Zn), manganese (Mn), and copper (Cu) uptake by shoots. EC, NaHCO3‐extractable P, and DTPA‐extractable Fe, Zn, Mn, Cu also were measured in pot soil at the 5th, 10th, and 30th weeks. All treatments led to a decrease in soil pH though pH tended to increase again during course of time in both field and pot experiments. The both elemental S and waste applications in pot experiment caused an increase in dry matter yield and P, Fe, zinc (Zn), Mn and Cu uptake (mg pot‐1) by shoots in sorghum plant. There was also an increase in EC of soil due to both applications of S. The concentration of available P extracted by NaHCO3 in the pot soil, though not significantly different, was slightly higher compared with the control. Waste applications increased DTPA‐extractable Fe content of the soil, DTPA‐extractable Mn and DTPA‐extractable Cu. DTPA‐extractable Zn content, however, was reduced by the same applications.  相似文献   

17.
Shen  Yan  Duan  Yinghua  McLaughlin  Neil  Huang  Shaomin  Guo  Doudou  Xu  Minggang 《Journal of Soils and Sediments》2019,19(7):2997-3007
Purpose

Calcareous soils are characterized by high pH and phosphorus (P) fixation capacity. Increasing application of P fertilizer recently has significantly improved soil P concentration, especially available P (Olsen-P) and inorganic phosphate (Pi) fractions. However, there are few data available on the ability of soils with different initial Olsen-P levels to continuously supply P (i.e., P desorption capacity) to crops without additional P fertilization and on which Pi fraction exerts the greatest influence on P desorption capacity.

Materials and methods

Five soils with different initial Olsen-P levels (0.5, 14.3, 38.4, 55.4, 72.3 mg kg?1, hereafter refer as OP1, OP2, OP3, OP4, and OP5) but similar other soil properties were selected to evaluate the capacity of P desorption and its relationship with Pi fractions. Soil P was sequentially extracted once daily for 16 consecutive days using Olsen solution.

Results and discussion

The content and proportions of dicalcium phosphate fraction (Ca2-P), octacalcium phosphate fraction (Ca8-P), aluminum phosphorus fraction (Al-P), and iron phosphorus fraction (Fe-P) in Pi increased significantly with the increase of initial Olsen-P (P?<?0.01). Applied P fertilizer was mostly stored as Ca8-P in the soil. Soil P desorbed reached an equilibrium after 16 extractions for all soils, and P desorption capacity (12–358 mg kg?1) showed a significant linear relationship with initial Olsen-P (P?<?0.01), with an increase of 4.2 mg kg?1 desorbed P per 1 mg kg?1 increase of initial Olsen-P. Ca2-P exerted the conclusive effect on P desorption in the first four extractions, but Ca8-P played a more important role in the 16 extractions.

Conclusions

Ca8-P was the greatest potential pool for P desorption after Ca2-P was depleted. P desorption capacity was significantly linearly related to initial Olsen-P (P?<?0.01). Different fertilizer use strategies were developed based on P desorption capacity for soils with different initial Olsen-P levels. The present study provided basic data on how to reduce effectively the application amount of chemical P fertilizer.

  相似文献   

18.
Water, Air, & Soil Pollution - The objective of this study was to evaluate the formation of a probable Zn solid phase in soils. Thermodynamic solubility isotherms revealed that ZnFe2O4, Zn2SiO4...  相似文献   

19.
ABSTRACT

Sugarcane is a strategic commodity in Indonesia. It is usually raised in a monoculture system. There is a lack of information about the effects of extended sugarcane monoculture on the soil carbon fraction. The aim of this study was to determine the relative changes in the soil organic C fractions in response to the duration of sugarcane monoculture on Entisols, Inceptisols, and Vertisols. The measured variables were the percentages of sand, silt, and clay, organic matter (OM), total nitrogen (TN), pH (H2O), cation exchange capacity (CEC), NH4 +, NO3 -, labile carbon fraction (soil carbon mineralization (C-Min), soil microbial carbon (C-Mic), and carbon particulate organic matter (C-POM)), and stable carbon fraction (humic and fulvic acids). Soil type with sugarcane monoculture period had significant influences on the percentages of clay, sand, silt, CEC, and pH (H2O). Soil type and sugarcane monoculture period had no apparent significant effect on C-Min or C-POM but did significantly influence C-Mic. The humic and fulvic acid levels in all three soil types were affected by the duration of sugarcane monoculture. To establish the impact of long-term sugarcane monoculture on the physicochemical properties of soils with various textures, it is more appropriate to measure the soil stable carbon fractions such as humic and fulvic acid rather than the soil labile carbon fractions such as C-Min, C-POM, or C-Mic.  相似文献   

20.
Ten agricultural soils were spiked with 100 μg of Cu, Zn, and Pb g?1 of soil. The complexation of Pb by 10?4 M DTPA was determined after 60 days of metal equilibrium. A theoretical stability model of Fe, Mn, Cu, Zn, Ca, and Pb, between pH 1 and 10 was developed. It showed that CuL3? (55.4 to 63%), CuHL2? (0.1 to 9.4%), PbL3? (29.1 to 33.3%), PbHL2? (0.01 to 2.5%) and MnL3? (2.8 to 3.2%) as the predominant species between pH 6 and 9. Other species like CaL3?, CaHL2?, FeL2?, FeHL?, FeL3?, FeHL2?, ZnL3?, ZnHL2? and MnHL2? were less than 0.1% between pH 6 and 9. In the experimental soils, DTPA-Pb complexes accounted for 12.3 to 21.2% of metal complexed after 3 days of DTPA equilibriation. DTPA-Cu complexes were the major complexed species in the soils ranging between 72.5 and 82.2% after 3 days equilibriation with 10?4 M DTPA. The proportion of Zn complexed by DTPA (3.8 to 10.1%) was much greater than predicted by the theoretical model. On the contrary, Mn was not complexed in appreciable amounts by DTPA.  相似文献   

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