锌肥对不同基因型大麦吸收积累镉的影响

对土壤添加不同Zn、Cd条件下两种基因型(Sahara和Clipper)大麦对Zn、Cd的吸收积累研究表明,在本实验条件下土壤添加Zn、Cd对植物地上部生物量没有显著影响,但土壤添加Zn抑制植物根系生长,在土壤不缺Zn情况下添加Zn<20mg·kg^-1时并没有对大麦体内Cd浓度产生显著影响;当土壤Zn添加量达到40mg·kg^-1时,植物体内Cd浓度明显降低,植物吸收Cd的总量随着土壤添加Zn的增加而显著下降,这主要是由于根系生物量的下降所致,两个基因型大麦品种Zn效率存在显著差异,但这一差异对植物吸收Cd的总量没有影响,Zn高效品种Sahara根部Cd浓度显著低于Clipper。     

不同老化时间对土壤中外源Zn的形态转化及生态毒性阈值(ECx)的影响

选取了6种不同性质土壤,添加7个浓度水平的Zn,研究了不同老化时间(14、90、180、360和540 d)对土壤中外源性Zn有效形态及毒性阈值(ECx)的影响,并对Zn老化过程的主要影响因子进行分析.结果表明:土壤中0.01 mol·L-1 CaCl2提取态Zn含量随着老化时间的增加先快速下降,随后变化减缓,到540 d时基本达到平衡.随着老化时间的增加,土壤中Zn对小白菜生长的毒性阈值(ECx,x=10、50)逐渐增加,毒性显著降低(P＜0.05).Zn老化因子(AF) AF10和AF50分别为1.077～1.743和1.174～1.441,老化因子随老化时间增加而增大.土壤中Zn的平衡浓度(C∞)与土壤pH、阳离子交换量(CEC)、有机碳含量呈显著负相关关系,其中pH是决定Zn老化速率最重要的因素,其次是CEC和有机碳含量,高pH下土壤中Zn达到平衡所需的时间较短.基于土壤老化因子与主控因子建立土壤中Zn的毒性阈值预测模型,所得预测值与实测值之间有较好的相关性.研究结果将为不同土壤中外源性Zn毒性阈值的归一化处理及生态风险基准值的制定提供理论依据.     

不同老化时间对土壤中外源Zn的形态转化及生态毒性阈值(ECx)的影响

选取了6种不同性质土壤, 添加7个浓度水平的Zn, 研究了不同老化时间(14、90、180、360和540 d)对土壤中外源性Zn有效形态及毒性阈值(EC_x)的影响, 并对Zn老化过程的主要影响因子进行分析. 结果表明: 土壤中0.01 mol·L^-1CaCl₂提取态Zn含量随着老化时间的增加先快速下降, 随后变化减缓, 到540 d时基本达到平衡.随着老化时间的增加, 土壤中Zn对小白菜生长的毒性阈值(EC_x, x=10、50)逐渐增加,毒性显著降低(P<0.05).Zn老化因子(AF)AF₁₀和AF₅₀分别为1.077~1.743和1.174~1.441, 老化因子随老化时间增加而增大.土壤中Zn的平衡浓度(C_∞)与土壤pH、阳离子交换量(CEC)、有机碳含量呈显著负相关关系, 其中pH是决定Zn老化速率最重要的因素, 其次是CEC和有机碳含量,高pH下土壤中Zn达到平衡所需的时间较短. 基于土壤老化因子与主控因子建立土壤中Zn的毒性阈值预测模型,所得预测值与实测值之间有较好的相关性.研究结果将为不同土壤中外源性Zn毒性阈值的归一化处理及生态风险基准值的制定提供理论依据.     

不同类型污染土壤中赤子爱胜蚓对伴矿景天重金属吸收的影响初报

伴矿景天Sedum plumbizincicola是我国发现和报道的镉/锌(Cd/Zn)超积累植物,在土壤Cd污染修复方面已开展实际应用。由于超积累植物伴矿景天在不同类型土壤下的生长能力以及对镉锌的去除效果存在较大差异,因此需引入强化修复技术为植物修复提供辅助作用。作为大型土壤动物,蚯蚓对植物生长的促进作用已有较多研究,但其对伴矿景天生长和重金属吸取效率的影响则鲜有报道,为探究赤子爱胜蚓对不同类型土壤种植下的伴矿景天是否具有强化修复效应,以及不同类型土壤下的强化修复效应差异,设计以下盆栽试验。通过在常湿淋溶土(Perudic Luvisols)、水耕人为土(Stagnic Anthrosols)、湿润雏形土(Udic Cambisols)3种土壤上种植伴矿景天、引入赤子爱胜蚓Eisenia foetida,探究赤子爱胜蚓对伴矿景天生长及Cd/Zn吸收性的影响。选取Cd有效性较高、修复潜力较大的水耕人为土(Stagnic Anthrosols)进行第二季盆栽修复试验。第一季修复结果显示,在酸性的常湿淋溶土中,添加赤子爱胜蚓使伴矿景天地上部生物量较对照处理增加了106%,Cd和Zn吸收量分别提高了72.0%和36.0%,且蚯蚓结合伴矿景天的处理修复后土壤Cd有效性进一步降低,其余两种土壤仅添加蚯蚓无强化修复效应;第二季结果显示,同时添加秸秆和蚯蚓,可强化中性的水耕人为土上种植的伴矿景天生长,增大植物地上部生物量和Cd/Zn吸收量。结果表明,添加蚯蚓可增强伴矿景天在常湿淋溶土中的养分吸收,提高生物量,以此强化其修复效应。在水耕人为土中,外加秸秆可作为蚯蚓强化伴矿景天修复的配套技术。     

紫色土Zn、Cd复合污染生态效应研究

通过盆栽生物试验结合野外典型污染调查,研究紫色土Zn、Cd复合污染对莴笋、蕃茄、甘兰、小麦等的作物效应.结果表明,Zn、Cd复合污染对Zn表现为加和作用,低浓度Cd促进Zn吸收,加重Zn对养分吸收的抑制,加剧Zn的毒害作用;复合效应对Cd表现为竞争作用,高浓度Zn抑制Cd吸收,减轻Cd对养分吸收的抑制,缓解Cd毒性,向土壤添加Zn 500mg·kg^-1为供试盆栽条件下拮抗效应的临界值.     

紫色土Zn,Cd复合污染生态效应研究

通过盆栽生物试验结合野外典型污染调查 ,研究紫色土Zn、Cd复合污染对莴笋、蕃茄、甘兰、小麦等的作物效应 .结果表明 ,Zn、Cd复合污染对Zn表现为加和作用 ,低浓度Cd促进Zn吸收 ,加重Zn对养分吸收的抑制 ,加剧Zn的毒害作用 ;复合效应对Cd表现为竞争作用 ,高浓度Zn抑制Cd吸收 ,减轻Cd对养分吸收的抑制 ,缓解Cd毒性 ,向土壤添加Zn 50 0mg·kg- 1 为供试盆栽条件下拮抗效应的临界值 .     

三种苦苣苔对石灰土和红壤的适应性分析

为探讨苦苣苔科植物对其岩溶生境的适应性,该研究选取黄花牛耳朵(Primulina lutea)、紫花报春苣苔(Pri.purpurea)和桂林蛛毛苣苔(Paraboea guilinensis)三种苦苣苔科植物,将其栽种在石灰土及红壤两种不同类型的土壤中,观测记录其生长性状并对其叶片元素含量进行测定和比较。植株采集过程中,同时采集自然生境中三种苦苣苔科植物叶片及取样植物基部土壤,并对叶片及土壤元素的含量进行测定,作为今后苗圃试验的参照。结果表明:三种苦苣苔科植物在两种土壤上的生长状况及适应性具有差异,其在石灰土上生长良好,在红壤上生长较差;在两种不同土壤中,除N外,桂林蛛毛苣苔的叶片其他元素(P、K、Mn、Mg、Ca、Zn、Cu)差异极显著(P0.01);除P外,紫花报春苣苔的叶片其他元素(N、K、Mn、Mg、Ca、Zn、Cu)差异极显著(P0.01);除N、Cu、Ca外,黄花牛耳朵的叶片元素(P、K、Mn、Mg、Zn)差异极显著(P0.01);三种植物的叶片元素比值,除少数值没有差异外,大部分指标差异都极显著;对叶片元素与栽培土壤元素的相关性分析,发现植物叶片Mn元素与土壤中N、Ca、Mg、Zn、Mn、有机质含量等呈正相关,土壤P元素与叶片中N、P元素呈正相关,而与叶片中Zn元素呈负相关关系。在其他栽培条件一致的条件下,土壤因素及物种差别是造成黄花牛耳朵、紫花报春苣苔和桂林蛛毛苣苔适应性产生差异的主要原因。     

宁夏荒漠草原蒙古冰草功能性状和根际效应对土壤性状的响应

植物功能性状组合的权衡是植物适应土壤环境的重要机制,它也通过对根际效应的调控进而影响着根际过程和生态系统功能。以位于宁夏盐池县的典型荒漠草原为研究区域,通过对灰钙土、黑垆土和风沙土中蒙古冰草功能性状和根际效应的对比分析,探究不同土壤对蒙古冰草功能性状和根际效应的影响以及它们之间的关系。结果表明：(1)不同土壤中蒙古冰草根际和非根际土壤理化性质存在显著差异,根际土壤理化性质的变化与非根际土壤性质有关。(2)不同土壤中的根际效应大小存在差异,不同因子的根际效应大小因土壤而异,总体表现为风沙土最大,灰钙土最小;土壤理化性质是影响蒙古冰草根际效应的主要因素,可解释根际效应变异的69.5%。(3)土壤理化性质与蒙古冰草功能性状密切相关,其对根长和根冠比的影响最大;蒙古冰草功能性状与根际效应大小密切相关,根长和根冠比是影响根际效应的主要因子。研究表明蒙古冰草通过根际效应改善了土壤性质,进而提高土壤质量,这种作用受土壤理化性质和植物功能性状等因子的共同影响。     

西土寒宪蚓和三叉苦植物对大叶相思人工林土壤CO2通量的短期效应

西土寒宪蚓(Ocnerodrilus occidentalis)为广东人工林和撂荒地内广泛分布的外来种蚯蚓, 因其对水热、pH值及土壤有机质等的变化不敏感, 其分布范围有逐渐扩大的趋势。研究西土寒宪蚓对人工林碳循环的影响过程, 可以为如何减少外来蚯蚓影响下的人工林土壤碳排放提供思路。在广东鹤山大叶相思(Acacia auriculaeformis)人工林内设置外来蚯蚓和乡土植物野外控制实验, 利用静态箱-气相色谱法对土壤CO₂通量进行15天的原位测定。结果发现, 单独添加西土寒宪蚓及单独种植三叉苦(Evodia lepta), 对土壤CO₂通量的效应都不明显。植物物理过程(如遮阴作用等)、植物生物过程(如根际化学物质分泌过程等)及植物在未添加蚯蚓样方和添加蚯蚓样方中对土壤CO₂通量的效应分别为-32.1%、40.9%、8.8%和-7.2%、30.7%、23.5%。植物的物理过程抑制了土壤CO₂排放, 但提高了蚯蚓对土壤CO₂排放的促进作用(提高了39.3%)。植物的生物过程促进了土壤CO₂排放, 但减弱了蚯蚓对土壤CO₂排放的促进作用(降低了23.5%)。试验期间蚯蚓对多数土壤理化性质的影响并不明显, 但是蚯蚓的存在有增强土壤细菌活性的趋势, 而且使土壤CO₂通量与土壤理化性质的相关性更加密切了; 同时, 蚯蚓的存在也使土壤CO₂通量与土壤水热因子的关系发生了变化。可见, 森林土壤CO₂通量不仅与水热条件有关, 还受地上和地下生物过程的调控。如果只关注森林土壤CO₂通量的大小, 而忽略影响土壤CO₂产生及释放的生物学过程, 将无法找到减少森林土壤CO₂排放的有效途径。减缓人工林中土壤碳的排放, 必须综合考虑植物物理过程、植物生物过程以及蚯蚓对土壤CO₂排放过程的独立效应和交互效应。     

重金属在土壤生态系统中的富集及毒性效应

对清水塘重金属污染区土壤生态系统重金属的富集及毒性效应的研究结果表明,土壤中 主要富集的重金属元素为生物毒性较强的Cd、Hg、As以及具有一定毒性的Zn、Pb、Cu,平均综 合污染指数为640.大型土壤动物重金属含量的分析结果表明,重金属富集量随污染程度的 增加而增加,尤其某些巨蚓科种类对Cd表现高富集,富集系数为1196.通过染毒试验进一 步证明,土壤动物种类和数量随Cd浓度的增加而减少.同工酶分析表明,Cd对蚯蚓同工酶活性 有明显的毒性效应.污染区主要种植蔬菜作物,而重金属在蔬菜体内的富集量也随污染 程度的增加而增加,其中蔬菜对Cd的富集有明显的品种间差异.     

Influence of potassium fertilization and foliar application of zinc and phosphorus on growth,yield components,yield and fiber properties of Egyptian cotton (Gossypium barbadense L.)

Aims Supplying optimal quantities of mineral nutrients to growing crop plants is one way to improve crop yields. Nutrients need to be used rationally in order to avoid a negative ecological impact and undesirable effects on the sustainability of agricultural production systems. Excessive application of nutrients also affects the farmer's economy. In order to calculate the amount of fertilizer to be applied to crops, it is necessary to develop recommendation programmers that adjust nutrient rates to crop requirements.Methods Experiments in two successive seasons were conducted to investigate the effect of K fertilization and foliar application of Zn and P on yield and fiber properties of cotton cv. Giza 86. Potassium (0.0 and 47.4 kg of K ha^-1) was soil applied, while chelated zinc (0.0 and 57.6 g of Zn ha^-1, applied twice at 70 and 85 days after sowing 'DAS') and phosphorus (0.0, 576, 1?152 and 1?728 g of P ha^-1, applied twice at 80 and 95 DAS) were applied to the foliage.Important findings Dry matter yield, total chlorophyll concentration, K, Zn and P uptake per plant, number of opened bolls per plant, boll weight, seed index, lint index, seed cotton yield per plant, seed cotton and lint yield ha^-1 and earliness of harvest increased with the application of K, Zn and P. Treatments generally had no significant effect on lint percentage and fiber properties, with exceptions, for micronaire reading and flat bundle strength, and uniformity ratio, where the mean values of these characters were significantly increased over the untreated control by applying K, and for the micronaire reading in the first season, when applying P at 1?728 g ha^-1, and uniformity ratio in the second season, when applying P at 1?152 and 1?728 g ha^-1, where the mean values of these characters were significantly increased over the untreated control by applying P. Under the conditions of this study, applying K fertilization at 47.4 kg ha^-1 combined with spraying cotton plants with zinc at 57.6 g ha^-1 and also with P at 1?728 g ha^-1 improved growth and yield of Egyptian cotton.     

Accumulating behaviour of Lupinus albus L. growing in a normal and a decalcified calcic luvisol polluted with Zn

Lupinus albus L. is a leguminous plant that is starting to generate interest for the phytoremediation soils showing intermediate metal pollution. Among these metals, Zn causes major phytotoxicity problems and is common in polluted soils of central Spain. The purpose of this study was to explore the nutritional behaviour of this plant species towards increasing Zn concentrations in two calcic luvisol soils: a normal basic soil and a decalcified acid soil. For this purpose the effects of different Zn concentrations on mineral nutrition, growth, nodulation and nitrogenase activity of nodulated Lupinus albus cv. Multolupa plants has been investigated. A 12-week trial was performed in pots under greenhouse conditions. In each soil, four replicate pots were set up per treatment (100, 150, 300, 500 and 700 ppm Zn). Seeds were inoculated with a Bradyrhizobium sp. (Lupinus) strain ISLU-16.

Statistical analysis of data revealed significant effects of soil Zn on grown, plant mineral composition and nodulation. Lupin growth was better in acid soil than in basic soil with the low dose of Zn applied, although plant growth in acid soil was severely affected from 300 ppm Zn, where the pH of the soil was 4.7. Zn application produce nutritional imbalances, especially with the higher dose added. Most of Zn accumulation occurred in the roots in both types of soils. In acid soil, lupin absorbs high amounts of Zn in both root (4650 ppm) and aerial part (3605 ppm), when the doses of Zn applied was 300 ppm. This feature permits Lupinus albus cv. Multolupa to be considered as potential phytoremediator and also for the revegetation of degraded landfill areas with slightly acid or neutral soils polluted with Zn.     

Zinc hyperaccumulation and uptake by Potentilla griffithii Hook

The ability of Potentilla griffithii Hook var. velutina Cardot to hypaeraccumulate zinc (Zn) was identified through field survey and hydroponic experiments. Our results showed that P. griffithii could be classified as a new Zn hyperaccumulator. Zn concentrations in the shoots of P. griffithii averaged 6250 mg kg(-1) (3870-8530 mg kg(-1)) growing in Zn-rich soils. The highest Zn concentration was observed in the leaves of P. griffithii at 22,990 mg kg(-1). The fact that P. griffithii was able to grow in a mining soil with a Zn concentration of 193,000 mg kg(-1) without showing a major sign of phytotoxicity demonstrated its high tolerance to Zn. When growing in hydroponic systems, P. griffithii accumulated a maximum 26700 mg kg(-1) zinc concentration in the shoots, indicating the ability of this species to effectively take up and translocate Zn. Translocation factors (the ratio of Zn concentration in shoot to root) of 1.1 to 1.6 were obtained. Compared to the control, dry biomass of P. griffithii in 160 mg L(-1) Zn treatment increased 66.6% (P < 0.05). The time-course experiment showed that the maximum Zn concentration at 100 mg L(-1) Zn treatment was found at 16 d, much later than that of the 10 mg L(-1) Zn treatment, which might be an attribution of a accumulating mechanism or detoxification of a plant. The report of a new Zn hyperaccumulator provides a new plant species for the phytoremediation of contaminated soil and for the research on mechanisms of Zn hyperaccumulation in plants.     

Iron,zinc and manganese nutrition of wetland rice (Oryza sativa L.) on a gypsum amended sodic soil

A field experiment was conducted to evaluate the effect of three levels of Fe and two levels of Zn, and their combinations, on the growth, yield and Fe, Zn, and Mn nutrition of rice on a zinc deficient sodic soil amended with gypsum. Iron and zinc were supplied as sulphates. Application of Zn significantly enhanced the yield of rice and available soil and plant Zn irrespective of Fe application. Maximum response of rice to Zn was obtained when Fe was applied at the highest rate. While Fe application brought about a significant improvement in available soil and plant Fe and Mn, it decreased significantly Zn content of the crop. After crop harvest, recovery of added Fe was 20% and Zn 12%. Results suggest that benefits of Fe application to rice in sodic soils can only be realised if it is applied along with Zn.     

Animal models in the study of vomiting

The emetic responses to various pharmacological agents, cytotoxins, and radiation are compared among animal species. The species included for comparison are the human, nonhuman primate, dog, cat, and ferret. The categories of pharmacologic compounds include both those compounds that act on identified membrane receptors (e.g., cholinergic agonists, catecholamines, and neuroactive peptides) and those that act on unidentified receptors (e.g., cardiac glycosides and Veratrum alkaloids, among others). Emphasis is placed on emetic dose-response relations and threshold ED50 and ED100 values calculated from these relations, as indices of species sensitivity to emetic stimuli. For the more noxious emetics, the cytotoxins and radiation, the latency to the first emetic episode and duration of emesis are also compared across species. The effect that peripheral and central nerve lesions have on species differences in emetic responses to stimuli is also discussed.     

Asymmetric effects of grazing intensity on macroelements and microelements in grassland soil and plants in Inner Mongolia Grazing alters nutrient dynamics of grasslands

Grazing is a traditional grassland management technique and greatly alters ecosystem nutrient cycling. The effects of grazing intensity on the nutrient dynamics of soil and plants in grassland ecosystems remain uncertain, especially among microelements. A 2‐year field grazing experiment was conducted in a typical grassland with four grazing intensities (ungrazed control, light, moderate, and heavy grazing) in Inner Mongolia, China. Nutrient concentration was assessed in soil and three dominant plant species (Stipa krylovii, Leymus chinensis, and Cleistogenes squarrosa). Assessed quantities included four macroelements (carbon (C), nitrogen (N), phosphorus (P), and magnesium (Mg)) and four microelements (copper (Cu), iron (Fe), manganese (Mn), and zinc (Zn)). Soil total C, total N, total P, available N, and available P concentrations significantly increased with grazing intensity but soil Mg, Cu, Fe, Mn, Zn concentrations had no significant response. Plant C concentration decreased but plant N, P, Mg, Cu, Fe, Mn, and Zn concentrations significantly increased with grazing intensity. In soil, macroelement dynamics (i.e., C, N, and P) exhibited higher sensitivity with grazing intensity, conversely in plants, microelements were more sensitive. This result indicates macroelements and microelements in soil and plants had asymmetric responses with grazing intensity. The slopes of nutrient linear regression in C. squarrosa were higher than that of S. krylovii and L. chinensis, indicating that C. squarrosa had higher nutrient acquisition capacity and responded more rapidly to heavy grazing. These findings indicate that short‐term heavy grazing accelerates nutrient cycling of the soil–plant system in grassland ecosystems, elucidate the multiple nutrient dynamics of soil and plants with grazing intensity, and emphasize the important function of microelements in plant adaptation in grazing management.     

陶瓷工业污染区污染元素在8种树种中的积累与分布

选取8种抗性较强的1年生树苗栽植于广东省佛山市陶瓷工业污染区,1.5年后对它们的生长参数、干物质量和污染元素含量进行测量,评价不同树种和器官对污染元素的积累能力.结果表明,试验地的S、Cu和Pb污染风险较大,Ni、Zn、Mn和Cr污染风险较小.单株干物质量的种间差异较大,约为198 ～3248 g,平均为1187 g;...     

Quantifying the Effect of Rhizosphere Processes on the Availability of Soil Cadmium and Zinc

Our purpose was to quantify the effect of rhizosphere processes on the availability of soil cadmium and zinc to various plant species. E values for Cd and Zn were measured on two contaminated soils differing mainly in their pH (6.2 and 8.1). L values were measured for six plant species with contrasting metal uptakes. The difference between E and L values quantifies the mobilization of the element which was non-phyto-available prior to cultivation. For Zn, L values were 1.2 to 5.6 times greater than the E values, depending on the plant species. The increase in Zn availability was greater in the basic soil. For Cd, L values in the basic soil were 1.1 to 2 times greater than the E value. In the slightly acid soil, plants did not enhance the cadmium availability. The mobilization of non-labile metal could be due to exudates from roots or microflora, phytosiderophores being responsible for the highest mobilization. The lower availability of Fe or Zn could explain the greater mobilization in the basic soil.     

Application of a 15N tracer to simulate and track the fate of atmospherically deposited N in the coastal forests of the Waquoit Bay Watershed, Cape Cod, Massachusetts

The central grassland region of the United States encompasses major gradients in temperature and precipitation that determine the distribution of plant life forms, which in turn may influence key ecosystem processes such as nutrient cycling and soil organic matter dynamics. One such gradient is the threefold increase in precipitation from the eastern Colorado shortgrass-steppe, in the rain shadow of the Rocky Mountains, to the tallgrass prairie in eastern Kansas. We investigated the relative roles of plant species and plant cover in influencing soil C and N cycling in three sites along this gradient. Plant cover (i.e., the presence or absence of an individual plant) was relatively more important than plant species in explaining variability in soil properties at the dry site, the Central Plains Experimental Range in␣northeastern Colorado. However, plant species explained relatively more of the variability in soil properties than did plant cover at the two wetter sites, Hays and Konza, in central and eastern Kansas. The wetter sites had more continuous plant cover, resulting in less plant-cover-induced variation in soil C and N, than did the dry site, which had distinct patches of bare ground. Plant species at the wetter sites had higher and more variable levels of tissue C:N than plant species at the dry site, due to both within species changes and changes in species composition. Aboveground tissue C:N was better correlated with net nitrogen mineralization rates at the wet sites than the dry site. Thus, tissue chemistry appears to exert more control on nitrogen dynamics at the wet than the dry sites. The results suggest that plant species traits that are relevant to nutrient cycling (e.g., tissue C:N ratios, spatial patterns, productivity) reflect environmental limitations as well as species' physiological potentials. Furthermore, a dominant environmental driver such as precipitation may ameliorate or exaggerate the importance of individual species traits for nutrient cycling. Received: 11 July 1996 / Accepted: 5 December 1996     

The role of plant–soil feedbacks and land-use legacies in restoration of a temperate steppe in northern China

Plant–soil feedbacks affect plant performance and plant community dynamics; however, little is known about their role in ecological restoration. Here, we studied plant–soil feedbacks in restoration of steppe vegetation after agricultural disturbance in northern China. First, we analyzed abiotic and biotic soil properties under mono-dominant plant patches in an old-field restoration site and in a ‘target’ steppe site. Second, we tested plant–soil feedbacks by growing plant species from these two sites on soils from con- and heterospecific origin. Soil properties generally did not differ between the old-field site and steppe site, but there were significant differences among mono-dominant plant patches within the sites. While soil species origin (i.e., the plant species beneath which the soil was collected) affected biomass of individual plant species in the feedback experiment, species-level plant–soil feedbacks were ‘neutral’. Soil site origin (old-field, steppe) significantly affected biomass of old-field and steppe species. For example, old-field species had higher biomass in old-field soils than in steppe soils, indicating a positive land-use legacy. However, soil site origin effects depended on the plant species beneath which the soils were collected. The predictive value of abiotic and biotic soil properties in explaining plant biomass differed between and within groups of old-field and steppe species. We conclude that the occurrence of positive land-use legacies for old-field species may retard successional replacement of old-field species by steppe species. However, high levels of idiosyncrasy in responses of old-field and steppe plant species to con- and heterospecific soils indicate interspecific variation in the extent to which soil legacies and plant–soil feedbacks control successional species replacements in Chinese steppe ecosystems.