中亚热带不同植被恢复阶段林地土壤磷库特征

以湘中丘陵区檵木—南烛—杜鹃灌草丛(LVR)、檵木—杉木—白栎灌木林(LCQ)、马尾松—柯(又名石栎)—檵木针阔混交林(PLL)、柯—红淡比—青冈常绿阔叶林(LAG)4种林地为对象,采用Tiessen和Moir修正后的Hedley磷(P)分级方法,研究不同植被恢复阶段林地土壤P各分级组分含量及其组成比例。结果表明:随着植被恢复,同一土层全磷(TP)、总无机磷(Pi)、总有机磷(Po)含量增加,NaHCO_3-Pi、NaOH-Pi、HCl-Pi和NaHCO_3-Po、NaOH-Po属于快速积累型,Residual-P属于缓慢积累型,Resin-Pi属于稳定型;不同植被恢复阶段林地土壤Pi以NaOH-Pi为主,Po以NaOH-Po为主,土壤P以Residual-P和Po为主;随着植被恢复,同一土层Po含量占TP的百分比增加,Pi先增加后减少,而Residual-P逐渐下降;不同林地土壤TP及P各分级组分含量均随着土壤深度增加而降低;随着植被恢复,群落植物多样性、群落生物量和凋落物层养分含量及质量的变化显著影响着土壤P各分级组分的含量及其组成比例。     

黄土高原石灰性土壤不同形态磷组分分布特征

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。     

转植酸酶玉米大田种植对根际土壤磷含量及组成的影响

转基因作物种植推广中的生态风险是广泛关注的焦点。转植酸酶玉米可以提高动物对玉米籽粒的磷素利用率,但是对土壤磷素的影响尚未见报道。本研究基于2011年开始的田间实验,通过2012年和2013年玉米生长季的动态采样,研究转植酸酶玉米种植对土壤磷含量和组成的影响。结果表明,与亲本相比,转植酸酶玉米对土壤磷的影响强烈依赖于采样时间和磷形态,2012年玉米播种前和2013年抽穗期土壤水溶态磷(H2O-Pi)、氢氧化钠提取态无机磷(NaOH-Pi)和氢氧化钠提取态有机磷(NaOH-Po)含量均显著低于对照;碳酸氢钠提取态有机磷(NaHCO3-Po)在2012年播种前和2013年成熟期显著低于对照,而微生物生物量磷(MBP)只在2013年成熟期有显著差异。种植转植酸酶玉米没有影响土壤全磷(TP)、稀盐酸提取态无机磷(Dil.HCl-Pi)、浓盐酸提取态无机磷(Conc.HCl-Pi)、浓盐酸提取态有机磷(Conc.HCl-Po)和残留态磷(Residual-P)含量。总之,连续3年种植转植酸酶玉米仅在某些采样期对土壤高活性和中等活性磷产生影响。转植酸酶玉米种植对土壤磷素影响的评价和影响机制研究需要结合植物和土壤,并在不同地点开展长期监测。     

不同磷效率油菜根际土壤磷活化机理研究

筛选和培育耐低磷植物是缓解磷矿资源缺乏和提高磷肥利用效率的有效途径之一。本研究在前期材料筛选的基础上,通过根箱试验研究不同磷效率油菜根际土壤磷活化机理,其结果如下:在施磷和不施磷处理条件下,磷高效油菜品种B56（HG）的吸磷量和生物量均高于磷低效品种B10（LG）;两油菜品种根际土壤中的NaHCO3-Pi, NaHCO3-Po和 NaOH-Pi,NaOH-Po四种磷素形态均有显著的亏缺现象;磷高效品种（HG）根际土壤上述四种磷素形态亏缺程度大于磷低效品种（LG）,但Resin-P则出现富集,并且HG的富集程度大于LG,这可能与HG具有较高吸磷能力有关。两油菜品种根际土壤HCl-Pi 和 残渣态磷（Residual-P）没有发生明显的亏缺现象。相比较而言,HG能分泌更多的酸性磷酸酶,该酶活性与NaHCO3-Po含量呈显著的负相关,说明酸性磷酸酶对有机磷矿化起着非常重要的作用。     

连续施用解磷菌肥对复垦土壤磷酸酶和Hedley磷形态的影响

为了研究增施解磷菌肥对土壤供磷状况的改善和土壤中磷有效性的提高状况,通过田间小区试验研究了连续施用解磷菌肥对复垦5年土壤碱性磷酸酶活性及Hedley磷形态的影响。结果表明:施用无机肥+有机肥+解磷菌肥处理的土壤碱性磷酸酶活性最高,为30.65μg/(g·h),比对照提高了83.86%。本试验年与第3年复垦土壤相比,土壤中Hedley磷形态的含量都有不同程度的增加,H_2O-Po含量以无机肥+有机肥+解磷菌肥处理为最高,比对照提高了93.90%;NaOH-Pi、HCl-Pi、HCl-Po含量以无机肥+解磷菌肥处理最大,分别比对照提高了194.2%、61.87%、105.8%;残渣态磷含量以无机肥处理影响最大,比对照提高了22.87%;H_2O-Pi、NaHCO_3-Po含量以有机肥处理最大,比对照提高了129.2%、85.89%;NaHCO_3-Pi、NaOH-Po含量以有机肥+解磷菌肥处理提高最大,分别提高了176.9%、114.4%。可以得出:施用解磷菌肥的处理增加复垦土壤中H_2O-Po、NaHCO_3-Pi、NaOH-Pi、NaOH-Po、HCl-Pi、HCl-Po含量的效果较好。H_2O-Pi、H_2O-Po、NaHCO_3-Pi、NaHCO_3-Po、NaOH-Pi、NaOH-Po、HCl-Pi与碱性磷酸酶均呈极显著相关。解磷菌肥在一定程度上增强了复垦土壤碱性磷酸酶活性,影响土壤中Hedley磷分级的各形态磷素含量,从而提高磷的有效性。     

不同开垦年限白浆土土壤磷库特征

以我国三江平原地区不同开垦年限的白浆土为研究对象,采用Hedley等首次提出经Agbenin J.O.Tiessen H改进的方法对土壤磷库组成成分进行研究,即连续浸提法对土壤中不同形态磷素变化特征进行研究,结果表明:长期开垦施肥可显著增加土壤中活性无机磷(Resin-Pi和NaHCO3-Pi)和有机磷(NaHCO3-Po)的含量,NaOH-Pi随开垦年限增加含量升高,且其占总无机磷的比例随开垦年限增加而增加,开垦0 a最低(3.89%),开垦30 a后比例达到最高值(41.98%)。难溶性无机磷(1M HCl-Pi和Conc-HCl-Pi)占总无机磷的比例随开垦年限增加而降低(65.98%³0.98%),NaOH-Po是有机磷库的主要组成部分(57.91%30.98%),NaOH-Po是有机磷库的主要组成部分(57.91%⁸4.41%),开垦0 a比例最高(84.41%),开垦30 a后比例最低(57.91%)。在开垦前20 a有机磷是该地区白浆土土壤磷库的主要组成部分。     

低分子量有机酸对土壤磷活化影响的研究

研究两种低分子量有机酸（柠檬酸和苹果酸）对土壤磷活化影响,并用修正的Hedley法测定土壤磷活化前后磷组分的变化。结果表明,低分子量有机酸能持续活化土壤磷,活化强度随低分子量有机酸浓度的增大而增强,并且柠檬酸活化土壤磷的能力强于苹果酸。低分子量有机酸能促进作物有效态无机磷组分（H2O-P和NaHCO3-Pi）的释放;同时还促进有机磷组分（NaHCO3-Po和NaOH-Po）的矿化。在低分子量有机酸浓度达到0.5 mmol/L以上时,其对土壤磷组分的活化量的顺序为:NaOH-Pi HCl-P NaHCO3-Pi H2O-P,即铁铝结合态磷 钙结合态磷 作物有效态磷。低分子量有机酸活化土壤磷的过程中伴有大量铁、铝释放,且铁或铝的释放量与磷活化量之间显著正相关（P0.05）。说明铁、铝结合态磷是低分子量有机酸活化土壤磷的主要磷源,并且其活化机制可能与铁、铝结合态磷的螯合溶解有关。     

30年轮作施肥对棕壤磷库时间变异特征的影响

采用Hedley修正体系分级法对轮作30年的长期定位土壤进行测定,结果表明,不同施肥条件下各形态磷的基本表现为:有机肥区>化肥区>CK,而有机肥和化肥配施能明显增加土壤中各形态磷的含量,从而有效的扩大了土壤磷库。从30年轮作的动态变化来看,CK和单施氮肥处理的NaHCO3-P和NaOH-P含量的变化幅度不大;施磷化肥区NaHCO3-P和NaOH-P的含量随着种植年限的增加而缓慢的上升;有机肥区的NaHCO3-Pi和NaOH-Pi含量不断增加,而NaHCO3-Po和NaOH-Po的含量呈先升高再降低再显著升高的动态变化趋势。棕壤中无机磷主要以NaOH-Pi和HCl-Pi的形态存在,有机磷主要以NaOH-Po的形态存在;不同施肥对NaHCO3-Pi和Res-P所占总浸提磷比例影响较大,施入磷肥和有机肥能提高土壤中NaH-CO3-P的比例;有机肥能促进Res-P的转化并减少Res-P的固定,从而降低了Res-P在土壤中的比例。     

冬小麦–夏休闲体系作物产量和土壤磷形态对长期施肥的响应

【目的】 研究土壤无机磷和有机磷组分变化,有助于选择和优化特定作物体系下不同肥料管理措施,提高磷资源效率。 【方法】 基于20年土冬小麦/夏休闲体系长期肥料定位试验,利用Tiessen-Moir磷素分级法,测定土壤无机磷和有机磷组分,并分析其与小麦磷吸收量、土壤磷表现平衡之间的关系。试验设7个处理:不施肥 (CK)、单施化学氮肥 (N)、氮钾化肥配施 (NK)、磷钾化肥配施 (PK)、氮磷化肥配施 (NP)、氮磷钾化肥配施 (NPK) 和氮磷钾化肥配施有机肥 (MNPK)。 【结果】 旱作条件下,20年长期NP、NPK和MNPK处理较CK、N、NK、PK处理显著提高了小麦籽粒产量,年平均增产在205～265 kg/hm2之间,以MNPK增幅最高。NP、NPK和MNPK处理较CK处理显著提高了小麦籽粒和秸秆吸磷量。PK、NP、NPK、MNPK处理较CK处理显著提高了树脂磷 (Resin-P)、碳酸氢钠提取无机磷 (NaHCO₃-Pi)、氢氧化钠提取无机磷 (NaOH-Pi)、浓盐酸提取无机磷 (C.HCl-Pi) 和残余磷 (Residual-P) 含量,显著降低了碳酸氢钠提取有机磷 (NaHCO₃-Po) 和氢氧化钠提取有机磷 (NaOH-Po) 含量。PK、NP、NPK与CK相比,对稀盐酸提取无机磷 (D.HCl-Pi)、浓盐酸提取有机磷 (C. HCl-Po) 含量影响不大,而MNPK显著提高了D. HCl-Pi和C. HCl-Po含量。N、NK处理较CK显著增加了Residual-P和C. HCl-Po,显著降低了NaHCO₃-Po和NaOH-Po,对Resin-P、NaHCO₃-Pi、NaOH-Pi、C.HCl-Pi和D.HCl-Pi含量没有影响。与试验初始时相比,长期施用化学磷肥和有机肥主要增加了土壤中可利用态无机磷的比例,降低了残余态磷和有机磷的比例。土壤中Resin-P、NaHCO₃-Pi和C. HCl-Pi与小麦磷吸收量之间呈显著正相关关系。磷素盈余显著增加了D. HCl-Pi、Resin-P和NaHCO₃-Pi的含量。 【结论】 供试土壤条件下,NP、NPK和MNPK三种平衡施肥措施都不仅有利于作物增产,而且有利于保持高比例的土壤有效磷库。      

长期轮作施肥对棕壤磷素形态及转化的影响

对沈阳地区棕壤定位试验地各施肥处理土壤按Hed ley等建议的分级方法进行测定。结果表明,棕壤磷中残留态含量最高,无机磷主要以NaOH-P i和HC l-P i形态存在,有机磷主要以NaOH-Po形态存在,NaHCO3-Po在各组分中所占比例最小。施用有机肥能明显增加潜在活性有机磷(NaOH-Po)的数量。1.0mol L-1HC l浸提的Ca-P i存在着缓慢的动态转化过程,是棕壤中的潜在磷源。     

调控措施对滨海盐渍土磷素形态及作物磷素吸收的影响

滨海盐渍化土壤存在磷素有效性低的问题。本试验采用根袋法盆栽试验,共设不施磷肥、常规磷肥、磷肥+生物质炭、磷肥+腐殖酸、磷肥+商品有机肥5个处理,分析不同调控措施对非盐渍土、轻度盐渍土和中度盐渍土有效磷含量、磷素形态以及大麦磷素吸收利用的影响。结果表明:①盐碱障碍降低根区内外土壤有效磷含量,表现为非盐渍土>轻度盐渍土>中度盐渍土。添加生物质炭能显著提高轻度、中度盐渍土根区内外土壤有效磷含量,较常规磷肥对照处理分别提高40.72%、84.80%。②盐碱障碍降低大麦产量,抑制地上部对磷素的吸收,不同调控措施均能促进盐渍土上大麦对磷素的吸收,提高磷肥利用率。轻度盐渍土上不同调控措施的增产效果不显著,中度盐渍土上添加生物质炭处理显著提高大麦产量,较常规磷肥对照处理提高63.20%。③盐碱障碍降低土壤活性无机磷、NaOH-Pi、NaHCO₃-Po、NaOH-Po比例,增加HCl-Pi比例。添加生物质炭处理能显著提高盐渍土活性无机磷比例,提高土壤磷的有效性。添加生物质炭和商品有机肥处理对中度盐渍土上HCl-Pi比例的降低效果优于轻度盐渍土。     

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。     

东北平原14个地点杨树防护林和农田土壤全磷及其组分差异研究

土壤磷素差异是科学评价农田防护林土壤养分管理的基础之一。本研究在富裕、兰陵、明水、肇州、宋站、杜蒙、赤峰、通辽、奈曼、四平、长岭、白城、德惠和泰来14个地点采集杨树防护林和配对农田表层(0～40 cm)土壤样品共84个,使用Tiessen和Sui修正的Hedley磷素分级法测定土壤9种磷组分,使用配对样本T检验法研究农田、杨树防护林土壤全磷及磷组分含量差异。结果表明：(1)东北平原14地点土壤全磷范围在122～594 mg·kg^-1,均值为266 mg·kg^-1;9种组分中,稀盐酸无机磷(HCl-Pi)占全磷(TP)含量的52.7%,其次是氢氧化钠有机磷(NaOH-Po)占14.8%、浓盐酸有机磷(conc.HCl-Po)占11.2%,闭蓄态磷(Re-P)、浓盐酸无机磷(conc.HCl-Pi)、氢氧化钠无机磷(NaOH-Pi)占比在5%～6%之间,而水溶性磷(H₂O-Pi)、碳酸氢钠无机磷(NaHCO₃-Pi)、碳酸氢钠有机磷(NaHCO₃-Po)占比在0.5%～3%之间。(...     

The Size of P Pools in Soils is Affected by Soil Properties and Compost Addition

It is well known that compost amendment can improve soil phosphorus (P) availability, but there are few studies comparing the effect of one compost type on soil P pools of soils which differ in properties. The aim of this glasshouse experiment was to determine the effect of compost (derived from garden waste) application on P pools in soils with different properties planted with wheat. Four soils from two sites were used, with a heavier and a lighter textured soil from each site. The compost was applied as a 2.5 cm thick layer on the soil surface and wheat plants were grown for 63 days. The treatments also included soil without compost and plants. All pots were regularly watered. The soils were sampled on day 0 in the unamended soils and on day 63 in soil without compost and with compost, and plants after removal of the compost layer. Without and with compost the concentrations of most P pools were higher in the two heavier textured soils (16% and 35% clay) than in the two lighter textured soils (8% and 13% clay). Principal component analysis (PCA) showed that the concentrations of most P pools were positively correlated with organic matter, clay, and silt content of the soils. Only the concentration of water-soluble P was positively correlated with sand content. Compost addition increased the concentration of microbial P, sodium bicarbonate (NaHCO₃)-Pi, sodium hydroxide (NaOH)-Pi, hydrochloric acid (HCl)-P, and residual P in all soils, whereas the concentration of NaHCO₃-Po was reduced and the concentration of NaOH-Po little affected by compost addition indicating that P was transferred from the compost layer with watering. Compared with the unamended soil on day 0, the concentrations of microbial P, NaHCO₃-Pi, NaOH-Pi, HCl-P, and residual P on day 63 were higher, whereas the concentrations of the two organic pools (NaHCO₃-Po and NaOH-Po) were lower. This suggests mineralization of organic P pools and formation of inorganic P as well as microbial P uptake. These changes occurred in the unamended and compost-amended soils with greater increases over time in the compost-amended soils. It can be concluded that the size of the P pools is predominately affected by soil texture. Compost amendment increases P availability and microbial P uptake but also leads to the formation of less labile P pools such as HCl-P and residual P which could serve as plant P sources in the long term.     

Chemical Fractions of Phosphorus: The Effect of Soil Orders,Soil Properties,and Land Use

Low availability of phosphorus (P) in Turkish soils is a significant problem of agricultural production depending on carbonates in slightly weathered and iron/aluminum oxides in highly weathered soils. Thus, crop-based P fertilization along with inherited nature of P partition can lead to changes in the amounts and geochemical fractions of phosphorus. For this reason, horizon-based surface samples were taken from 16 soil series that belong to four orders with different pedotransfer functions. The geochemical phosphorus fractions were sequentially extracted by sodium bicarbonate (NaHCO₃), sodium hydroxide (NaOH), citrate-dithionite-bicarbonate buffer system (CBD), hydrochloric acid (HCl), and aqua-regia. Results indicated that weathering sequence was inversely related to plant available P fractions. The fertilizer P was possibly converted to HCl-extractable (Ca-Pi) fraction in calcareous soils through NaOH-Po and NaHCO₃-Po fractions whereas it accumulated in the CBD-P fraction in relatively weathered soils. The carbonates and Al/Fe oxides were most significant constituents in P partitioning as consequences of parent material and weathering chronosequence.     

两个水稻基因型根际磷素组分、pH以及磷酸酶活性的动态变化

A rhizobox experiment with two phosphorus （P） treatments, zero-P （0 mg P kg^-1） and plus-P （100 mg P kg^-1） as Ca（H2PO4）2.H2O, was conducted to study the chemical and biochemical properties in the rhizosphere of two rice genotypes （cv. Zhongbu 51 and Pembe） different in P uptake ability and their relationship with the depletion of soil P fractions. Plant P uptake, pH, phosphatase activity, and soil P fractions in the rhizosphere were measured. Both total dry weight and total P uptake of Pembe were significantly （P 〈 0.05） higher than those of Zhongbu 51 in the zero-P and plus-P treatments. Significant depletions of resin-Pi, NaHCO3-Pi, NaHCO3-Po, and NaOH-Pi, where Pi stands for inorganic P and Po for organic P, were observed in the rhizosphere of both Zhongbu 51 and Pembe under both P treatments. Pembe showed a greater ability than Zhongbu 51 in depleting resin-Pi, NaHCO3-Pi, NaHCO3-Po, NaOH-Pi, and NaOH- Po in the rhizosphere. HCl-Pi and residual-P were not depleted in the rhizosphere of both genotypes, regardless of P treatments despite significant acidification in the rhizosphere of Pembe under zero-P treatment. Higher acid phosphatase （AcPME） activity and alkaline phosphatase （AlPME） activity were observed in the rhizosphere of both Zhongbu 51 and Pembe compared to the corresponding controls without plant. AcPME activity was negatively （P 〈 0.01） correlated to NaHCO3-Po concentration in the rhizosphere of both Zhongbu 51 and Pembe, suggesting that AcPME was associated with the mineralization of soil organic P.