陇中黄土高原不同耕作措施下土壤磷动态研究

依托陇中黄土高原旱作农田已实施13 a的保护性耕作试验,研究传统耕作、免耕、传统耕作秸秆还田、免耕秸秆覆盖、传统耕作地膜覆盖和免耕地膜覆盖6种耕作措施下土壤全磷及磷组分动态变化特征。结果表明:试验期各处理土壤全磷和总无机磷均逐年增长;两个秸秆还田处理总有机磷逐年增长,免耕地膜覆盖和免耕处理总体增长,传统耕作和传统耕作地膜覆盖处理相对稳定;各无机磷组分均总体增长,其中氢氧化钠提取态无机磷、水溶态无机磷和碳酸氢钠提取态无机磷涨幅较大,平均涨幅分别为253.6%、128.6%和66.9%;保护性耕作可不同程度地提高水溶态无机磷、碳酸氢钠提取态无机磷和氢氧化钠提取态无机磷含量,相同覆盖条件下免耕较传统耕作效果明显,尤其免耕秸秆覆盖处理最明显;耕作方式对浓盐酸提取态无机磷和残留磷的影响不明显;保护性耕作可提高碳酸氢钠提取态有机磷和氢氧化钠提取态有机磷含量,两个秸秆还田处理最明显,两处理也可提高浓盐酸提取态有机磷含量,但免耕、传统耕作地膜覆盖和免耕地膜覆盖处理下该组分含量降低。综上,采取保护性耕作可适当减少磷肥用量,保护性耕作尤其是免耕秸秆覆盖方式值得在该区推广。     

Soil and Compost Type Affect Phosphorus Leaching from Inceptisol,Ultisol, and Andisol in a Column Experiment

A column leaching experiment using three soils (Inceptisol, Ultisol, and Andisol) and seven livestock manure composts that had different characteristics was conducted for 19 weeks to investigate the interactive effects of composts and soils on the phosphorus (P) leaching potential of compost-amended soils and to identify the principal variables that affect P leaching. Cumulative total P leaching (TP_cum) tended to increase with increasing total and available P concentration in the soils. Among various compost properties, total P concentration was positively correlated with TP_cum from the compost-amended soils, except for the Andisol, which has a high P-sorption capacity. There was no significant relationship between TP_cum and water-extractable P concentration of the composts, suggesting that total P rather than inorganic P concentration of composts may be successfully used in predicting P leaching potential from compost-amended soils except for soils that have a high P-sorption capacity, as in Andisol.     

Use of Industrial By-products to Sorb and Retain Phosphorus

The potential of six industrial by-products for use as phosphorus-sorbing materials (PSMs) in solutions was evaluated. These included two different acid mine drainage treatment residuals (AMDR1 and AMDR2), water treatment residual (WTR), fly ash, bauxite mining residual, and flue gas desulfurization product (FGD). Characterization of the by-products and their mechanisms for sorption and retention of inorganic phosphorus (P) from solution identified those PSMs that sorbed primarily by an iron and aluminum (Fe/Al) mechanism, those that sorbed primarily by a calcium and magnesium (Ca/Mg) mechanism, and those that sorbed by both mechanisms. Degree of P sorption and associated mechanisms were strongly influenced by the pH, buffer capacity, ionic strength, and common ion effects.     

Soil Phosphorus Fractions in a Sandy Typic Hapludaft as Affected by Phosphorus Fertilization and Grapevine Cultivation Period

The purpose of this study was to quantify the phosphorus (P) fractions in phosphate-fertilized sandy soils under grapevines. Soil was sampled from a grassland site and two vineyards (13 and 31 years old) in the State Rio Grande do Sul, Brazil, from the layers 0–5, 5–10, 10–15, 15–20, and 20–40 cm deep. The samples were prepared and P fractions were assessed by chemical fractionation. Phosphate fertilization of the vineyard soils increased P contents to a depth of 40 cm, especially in the more recalcitrant fractions but detectable in the more labile fractions as well, which are plant available and may increase the risk of environmental contamination. Phosphate fertilizers and the period of grapevine cultivation had little effect on the levels of organic P forms, whereas cover crops in vineyards could be an appropriate strategy to increase or maintain the levels of soil organic matter and the levels of organic P over the years.     

不同施肥条件下生物腐植酸对磷的转化效果分析

在实验室利用4个土槽分别施入复合化肥（CF）、普通有机肥（OF）、生物有机肥（BF）和不施肥（CK）来改变土壤中磷的基础含量,另取4个土槽在相应处理中配施相同的生物腐植酸,以15°角放入自制的降雨淋溶装置下进行试验,观测径流液中的全磷含量,以分析研究生物腐植酸对土壤和不同施肥条件下磷的转化效果.结果显示,施用复混肥、普通有机肥和生物有机肥降雨3h后,径流液中磷（P）流出量分别为不施肥处理（CK）的2.90、1.32和9.73倍,而相同处理配施生物腐植酸后,复混肥、普通有机肥、生物有机肥处理的径流液中P含量有增有减,分别为CK的7.09、2.32和5.00倍.表明在施用复混肥、普通有机肥的土样中加入生物腐植酸能够有效释放肥料中的磷素,使之转化为更利于植物吸收的可溶性磷,其转化率分别为0.76％和0.37％;而在施用生物有机肥的土样加入生物腐植酸反而抑制磷的转化,其转化率为-0.85％.不仅如此,加施生物腐植酸还能改变磷的转化进程,使CK和OF处理的磷含量峰值由出现在第3小时变为出现在第2小时,使CF处理的磷含量峰值由出现在第2小时变为出现在第1小时,加速了磷释放.由此可得,生物腐植酸能有效释放肥料中的磷素、使之转化为更利于植物吸收的可溶性磷并加速其转化进程.研究结果可作为推广生物腐植酸的依据和有关作物磷吸收研究的基础.     

Relationship between Soil Phosphorus Availability and Phosphorus Loss Potential in Runoff and Drainage

Abstract

Elevated soil phosphorus (P) content is common in the central coastal valleys of California, the result of decades of the intensive vegetable production. Undesirably high P concentration in surface water in this region stimulated interest in evaluating techniques to rank the potential for soil P loss to the environment. Phosphorus availability of 25 representative soils from fields in vegetable rotations were evaluated by the following techniques: bicarbonate‐extractable P (P_bc)–calcium chloride, extractable P (P_cc), P extractable by iron‐impregnated paper (P_Fe), P extractable by anion exchange resin (P_ae), and the degree of P saturation (P_sat). A column study was conducted in which these soils were evaluated for soluble P concentration in runoff and leachate from two simulated irrigation events. There were strong correlations among all measures of soil P availability (r=0.66–0.90). Runoff soluble P was most strongly correlated with P_cc, P_ae, and P_bc (r=0.98, 0.93, and 0.91, or 0.98, 0.90, and 0.85 in the first and second irrigation, respectively). The relationship of runoff soluble P to P_bc, P_ae, and P_cc was characterized by a change point; runoff soluble P from soils <50 mg kg^?1 P_bc was minimal, whereas at higher P_bc runoff P reached levels of environmental concern. Leachate soluble P was also correlated with P_cc, P_ae, and P_bc (r=0.84–0.99). Across soils, leachate soluble P averaged 1.4 mg L^?1, compared to 0.11 mg L^?1 for runoff P. We conclude that P_cc, P_ae, and P_bc are useful tests to rank the potential for P loss in irrigation runoff or drainage. Given the relative complexity of the P_ae technique, P_bc and P_cc appear to be the most practical soil tests for this purpose.     

有机磷在调节土壤磷素保持与释放过程中的作用

以巢湖沿岸土壤和沉积物为对象,分析了速效磷、藻类可利用性磷、有机磷含量和碱性磷酸酶活性的空间变化格局,并测定了磷吸附参数.结果表明,土壤有机磷含量差异显著,以草地最高,而速效磷和藻类可利用性磷含量无明显差异;酶活性及速效磷含量与有机磷含量呈显著正相关,土壤对正磷酸根的吸附量与土壤中有机磷含量呈正相关;湖泊沉积物中有机磷含量与周边土壤中有机磷含量显著正相关.因此,土壤有机磷及其酶促水解过程是调节沉积物作为磷源或磷汇功能的关键因素之一.     

Phosphorus Availability in Low-P and Acidic Soils as Affected by Liming and P Addition

Acidic soils typically suffer from high phosphorus (P) retention, a problem that can be dealt with using greater P fertilization, soil liming, or both. The aim of this work was to examine which of these practices bears the more beneficial result for Lolium perenne L. growth. In a pot experiment, five acidic soils were treated as follows: L0P0 (unamended control), L1P0 (liming only), L0P1 (P addition only), and L1P1 (both liming and P addition). We found that P amendment alone was sufficient to increase plant P levels when the initial soil P concentrations were low. Liming without P addition increased plant P satisfactorily only in the high-P soil. We conclude that P addition alone is a better practice than liming alone for improved plant growth conditions in acidic, low-P soils, unless there is relatively high P content in soil, in which case liming alone may be sufficient to increase P availability.     

Phosphorus and Carbon Fraction Concentrations in a Cambisol Soil as Affected by Tillage

Abstract: Changes of soil phosphorus parameters (SPP) and soil organic matter (SOM) fractions were investigated in a Cambisol of medium‐heavy texture. Soil sequential samples were taken from a minimum (MT) and conventional (CT) tillage field in Sitzenhof (Germany). For the CT soil, concentrations of available forms phosphorus (P) were stable to ～0.3‐m depth, below which they rapidly decreased to relatively low values. In contrast, the decrease in the MT soil profile was gradual from the surface layer; available forms of P concentrations were higher and sorption index values were lower than in the CT soil in corresponding depths. Concentrations of SOM fractions were higher in the MT than CT treatment soil along the whole soil profile, especially below the 0.3‐m depth. The correlations between SPP and SOM fraction concentrations were closer in the MT than in the CT, particularly below 0.3‐m depths.     

Zinc Tolerance in Wheat Cultivars as Affected by Varying Levels of Phosphorus

Abstract

The effect of zinc–phosphorus (Zn‐P) interaction on Zn efficiency of six wheat cultivars was studied. The higher dry matter yields were observed when Zn was applied at 5 µg g^?1 soil than with no Zn application. Phosphorus applications also increased dry matter yield up to the application of 25 µg P g^?1 soil. The dry matter yield was significantly lower at the P rate of 250 µg g^?1 soil. At the Zn‐deficient level, the Zn‐efficient cultivars had higher Zn concentrations in the shoots. Zinc concentrations in all cultivars increased when the P level in the soil was increased from 0 to 25 µg P g^?1 soil except for the cv. Durati, in which Zn concentrations decreased with increases in P levels. However, when Zn×P interactions were investigated, it was observed that at a Zn‐deficient level, Zn concentrations in the plant shoot decreased with each higher level of P, and more severe Zn deficiency was observed at P level of 250 µg g^?1 soil.     

Phosphorus fractions in Andisol and Ultisol inoculated with Bacillus thuringiensis and phosphorus uptake by wheat

Abstract

Only a small portion of soil phosphorus (P) is available to plants on a short-term basis, and therefore, P taken up by crops in one growing season is small compared to total P (Pt) content of the soil. A group of soil microorganisms capable of transforming insoluble P into soluble and plant accessible forms. The objective of this study was to evaluate the changes in soil P-pools and P uptake by wheat crops as influenced by inoculation with Bacillus thuringiensis in two soils (Andisol and Ultisol), the experiment was conducted in pots under greenhouse conditions using a completely randomized design. Wheat plants were inoculated and re-inoculated at 20 and 46?days after sowing, respectively, with B. thuringiensis; and, plant sampling were performed after 46, 66 and 87 and soil at 87?days based on the Zadoks growth scale, and the soil was submitted by Hedley’s P fractions. The inoculation with B. thuringiensis affected significantly some P organic P (P_o) and inorganic P (P_i) fractions in both soils (Andisol and Ultisol), improved P uptake by wheat crop in (Ultisol) and decreased significantly in (Andisol). The positive effect was more consistent in Ultisol than in Andisol, this strain can be solubilized P fraction extracted with conc. HCl-P_o and HCl 1?mol.     

湿地沉积物磷的吸附与解吸研究

采用恒温培养法研究美国纽约Pelham Bay Park 6种典型淡水湿地沉积物中磷的吸附与解吸行为及其动力学过程。结果表明:湿地沉积物具有强烈吸附溶液中磷的功能,随着溶液中磷浓度的增加,吸附量增大;但是湿地沉积物也有释放磷到溶液中去的功能,释放量为0~41.19 mg/kg,与沉积物吸附磷量的关系不大,沉积物释放磷与沉积物的特性有关。衡量一种淡水湿地沉积物的除磷能力,可根据沉积物最大吸附磷量和吸附解吸附平衡浓度(EPC0)来衡量,6种沉积物中,磷的最大吸附能力强弱依次是:S1>S2>S3>S6>S5>S4;S1沉积物吸附磷的最大量为500 mg/kg。各沉积物的平衡浓度相差很大,S4的吸附与解吸附平衡浓度最高,其值为166.00μg/L,而S2的吸附与解吸附平衡浓度最低,其值为0.36μg/L。低的EPC0值表明,沉积物有很强的吸附磷的能力,故S2湿地生态系统有非常强的除磷能力。     

不同利用方式对潮棕壤比表面影响的研究

对中国科学院沈阳生态实验站潮棕壤水稻田、玉米地、撂荒地和人工林地4种土地利用方式经过14年后在0~150 cm土体10个土层中土壤比表面的剖面分布进行比较研究的结果表明,不同土地利用方式及不同深度土层土壤比表面差异显著,除林地0~5 cm表层外,4种土地利用方式在80 cm以内深度的土层中土壤比表面随剖面深度增加呈渐次增大的趋势,说明林地表层高有机碳积累对土壤比表面增加可能产生了重要影响。150 cm深度土壤比表面平均值为林地>玉米地>撂荒地>水稻田。土壤比表面与土壤风干含水量及交换性盐基总量呈极显著正相关关系:水稻田、玉米地、撂荒地、林地中土壤比表面与风干含水量相关系数分别为0.767、0.911、0.943、0.953(n=30,P<0.001);与土壤交换性盐基总量的相关系数分别为0.877、0.978、0.673、0.780(n=30,P<0.001)。不同利用方式下土壤比表面与土壤有机碳、全氮、碱解氮呈显著负相关关系,与土壤pH、硫、磷之间的关系因土地利用方式不同而具有一定的差异。研究结果表明,土壤比表面可作为指征不同土地利用方式对土壤理化性质影响的可行的土壤物理学指标,测定不同土壤的比表面可以基本反映出土壤交换性能的差异。     

不同磷肥调控措施下红壤磷素有效性和利用率的变化

南方红壤区磷肥当季利用率仅为10%～25%,提高磷肥利用率是亟待解决的问题。通过两年田间试验,分析了不同磷肥品种（过磷酸钙、猪粪、钙镁磷肥、磷酸一铵、磷酸二铵）、磷肥梯度（常规施磷、减磷20%、减磷30%）以及调控措施（石灰、钙镁磷肥配施磷酸二铵、钙镁磷肥配施秸秆）对红壤磷素有效性和作物生长的影响,探索提高磷肥利用率的途径。结果表明,各磷肥品种间,以猪粪处理土壤有效磷、地上部生物量、磷肥累积利用率等指标最高,土壤有效磷较不施磷处理两年分别提高了32%和241%,地上部生物量较不施磷处理两年分别提高了73%和510%,两年的磷肥累积利用率分别为16.4%和26.5%;伴随磷肥用量的减少,土壤有效磷含量显著降低,而对油菜生长、磷肥利用率及磷肥农学效率无显著影响;与单施钙镁磷肥相比,钙镁磷肥配施磷酸二铵能显著提高油菜籽粒产量、土壤有效磷含量、磷肥累积利用率、磷肥农学效率、土壤磷素盈余量等指标。添加石灰可提高作物产量及土壤有效磷含量。油菜产量与土壤有效磷呈极显著正相关关系。上述结果表明,猪粪替代化学磷肥可达到减施增效、促进作物生长的目的,且以减磷30%为宜;钙镁磷肥配施磷酸二铵可推荐为磷肥调控...     

长期施用有机物料对旱地红壤磷组分及磷素有效性的影响

针对中亚热带第四纪红黏土发育的红壤旱地,建立了玉米单作系统等碳量投入有机物料的田间试验,利用不同的磷分级方法研究了不同有机物料施用对土壤磷组分的影响,构建了不同磷组分的含量与土壤全磷及有效磷之间的回归方程,明确了不同磷组分对土壤磷活化系数(PAC)及磷肥(表观和经济)利用率的影响。连续7a的试验结果表明:施用有机物料可以增加土壤PAC和磷肥利用率,并以秸秆猪粪9︰1配施(NPKS/M)处理效果最佳,显著高于常规施肥处理(NPK);施用有机物料显著提升了土壤有机磷含量,且与土壤有效磷含量显著正相关,其对土壤PAC及磷肥(表观和经济)利用率影响显著。施用有机物料通过影响土壤有机碳、全氮、碱解氮、交换性K⁺以及交换性Al³⁺含量影响土壤磷的有效性。     

Reclamation of Alkali Soils: Influence of Amendments and Leaching on Transformation and Availability of Phosphorus

Abstract

Phosphorus (P) availability to plants in reclaimed alkali soils was the main objective of this study, which was also focused on P transformations, decrease in Olsen‐P content, and magnitude of P lost in leachate in course of amendment application and leaching. Liquid sodium bicarbonate (NaHCO₃) was added to nonalkali soils to set up four ESP (exchangeable sodium percentage) levels (viz., 2.9, 25.0, 50.0, and 75.0), but actual ESP levels obtained were 2.9, 24.6, 51.2, and 75.3. Amendments (viz., gypsum and pyrites) and P treatments (viz., 0 and 50 mg P Kg^?1) were mixed with dry, sieved soil before filling into PVC (polyvinyl chloride) drainage columns, which were then compacted to uniform bulk density and leached with deionized water for 30 days. Results indicated that the pH and electrical conductivity (EC) of the soils increased with increase in ESP level of the soil but decreased with amendment application. Phosphorus addition to alkali soils decreased the pH on day 30, but it could not affect the EC of the soils. Successive increase in the ESP level of the soil increased the pH and EC off the leachate. Gypsum‐amended soils exhibited lower pH and EC values than pyrite‐amended soils. The EC of the leachate decreased sharply with time in amended soils, but the pH decreased slowly. Phosphorus addition affected the leachate pH earlier than the soil pH. Cumulative volume of leachate decreased with increasing ESP levels, but it increased with amendment and phosphorus application. Leaching of P increased with increase in ESP levels, and the maximum cumulative loss of P was 11.2 mg Kg^?1 in the 75.3 ESP soil. Cumulative P lost in the pyrite‐amended soils was higher than the gypsum‐amended soils. Phosphorus leaching in the gypsum‐amended soils stopped at day 10 and beyond, but it continued until day 30 in the pyrite‐amended soils. Part of the applied P in alkali soils was also lost along with the native P, whereas it was protected in the nonalkali soils. OlsenP increased with increasing ESP levels, and alkali soils invariably contained higher Olsen P than nonalkali soils. At day 30, alkali soils contained much higher Olsen P (12.6 mg Kg^?1) than nonalkali soils (5.9 mg Kg^?1). In general, there was a decrease in the Olsen P with both of the amendments, but it decreased more with pyrites than with gypsum. Phosphorus added through monopotassium phosphate (KH₂PO₄) remained extractable by Olsen's extractant up to day 30. Results also indicated that percent distribution of ammonium chloride (NH₄Cl)‐P, calcium (Ca)‐P, and unknown P increased with rising ESP levels but iron (Fe)‐aluminum (Al)‐bound P and residual P decreased. Percent distribution of Ca‐P and unknown P exhibited an increase with time also. Unamended alkali soils contained more NH₄Cl‐P than amended ones. Iron and Al‐ bound P and residual P increased more with pyrites, whereas formation of Ca‐P and unknown P was enhanced with gypsum. Applied P tended to convert more into NH₄Cl‐P, Ca‐P, and residual P than to Fe‐Al‐bound P or unknown P fractions. Models developed to estimate Olsen P and P concentration in leachate, through pH or EC, have application value for P management in alkali soils that are leached after application of amendments.     

城市化过程中土壤肥力的时空变化分析

该文研究了郑州市城市化过程中土壤肥力质量时空变化及时空分布,结果表明:20多年来,随着土地利用集约度的不断提高,土壤有机质、全氮、速效钾含量都有所提高,仅有速效磷含量有所降低。土壤的综合肥力系数在东北西南方向较低,大面积处在差的水平,其中有少数零星分布的较高肥力。东南和西北方向的肥力较高,大部分处在良与中的水平。     

藻、菌配合施用对水稻土磷有效性及微生物群落的影响

解磷菌和微藻广泛用作生物肥料,影响土壤养分循环及微生物群落的组成和活性。本研究以巨大芽孢杆菌 (Bacillus megaterium)、小球藻 (Chlorella vulgaris)、句容水稻土为试验材料,通过室内培养实验,设置只施用小球藻 (A)、只施用巨大芽孢杆菌 (B)、小球藻和巨大芽孢杆菌配合施用 (A+B)、对照 (CK) 4个处理,探索巨大芽孢杆菌和小球藻配合施用对水稻土磷有效性和微生物群落的影响。结果表明,培养第30天,巨大芽孢杆菌和小球藻配施的处理土壤有效磷含量 (15.92 mg·kg-1) 显著高于对照和单独施用小球藻的处理 (A: 14.46 mg·kg-1, CK: 14.61 mg·kg-1),比对照土壤 (14.61 mg·kg-1) 提高9.0%。巨大芽孢杆菌和小球藻配施还可以显著提高水稻土的pH、全氮以及总有机碳含量。巨大芽孢杆菌和小球藻配施的处理,土壤中芽孢杆菌属的相对丰度 (1.70%) 比单独施用巨大芽孢杆菌的处理 (1.33%) 提高27.9%,小球藻在绿藻门中的相对丰度 (3.14%) 比单独施用小球藻的处理 (3.04%) 提高3.18%。巨大芽孢杆菌和小球藻配施也显著提高了土壤微生物的代谢活性和增殖速率。综上,本研究表明巨大芽孢杆菌和小球藻配合施用可以显著提高水稻土磷有效性,提高土壤微生物的活性,为藻、菌复合生物肥的开发和利用提供了理论基础,为提高水稻土磷有效性、缓解磷积累及其环境风险提供了新的视角。     

Cover Crops and Soil Phosphorus Availability

Plants affect soil phosphorus (P) solubility through root exudates, but studies are lacking on species used as relay or cover crops in tropical environments. We evaluated the effect of cover crops on soil phosphorus (P) availability in an oxisol. Ruzigrass (Brachiaria ruziziensis), pearl millet (Pennisetum glaucum), peanut (Arachis hypogaea), crambe (Crambe abyssinica), and sorghum (Sorghum bicolor) were grown in pots with soil. Phosphorus uptake, soil inorganic and organic P, maximum P adsorption capacity, and plant root systems were assessed. When root length density is high, the efficiency of P uptake is low due to root competition. Crambe results in greater soil P availability, while peanut and sorghum decrease the soil maximum P adsorption capacity, probably by exuding or stimulating microbial production of organic acids and phenolic compounds. Hence, crambe, peanut, and sorghum are species that may be of interest to increase P use efficiency in cropping systems.     

影响土壤磷有效性变化作用机理

土壤磷有效性对植物生长以及磷的生态系统生物循环过程具有重要意义,一直以来也是国内外磷素研究的重点之一,文章综合介绍了土壤环境中影响磷有效性的一些因子及其作用机理,以期为系统的认识土壤中磷的有效性的变化提供借鉴。