酸性土壤上缺磷和铝毒对大豆生长的交互作用

以7个磷效率不同的大豆基因型为材料,通过土壤盆栽试验进行石灰和磷肥处理,研究酸性土壤上缺磷和铝毒对大豆生长的交互影响及其基因型差异.结果表明：缺磷和铝毒是酸性土壤上同时存在的影响大豆生长的主要障碍因子,其中铝毒对大豆生长的限制更为严重;缺磷和铝毒对酸性土壤上大豆生长的影响具有显著的交互作用.同时施用石灰（降低铝毒）和磷肥（提高磷有效性）比单施石灰或单施磷肥处理对大豆生长的促进效果更显著;缺磷和铝毒对大豆磷吸收的影响远大于对氮、钾吸收的影响.合理种植大豆对酸性土壤具有较好的改良作用.同时施用石灰［1.103 g Ca(OH)₂·kg^-1土］和磷肥（2.018 g KH₂PO₄·kg^-1土）可使酸性土壤pH值平均提高38.4%,交换性铝含量降低96.3%,有效磷含量提高3223.8％.种植磷高效大豆基因型比磷低效大豆基因型对酸性土壤的改良效果更好.     

不同磷水平配施生物炭对土壤磷有效性

生物炭在提高土壤磷素有效性及促进作物生长方面具有显著作用,但其效果因土壤类型不同存在较大差异。试验以赤红壤(pH 4.91)和褐土(pH 7.24)为供试土壤,设置3种磷肥水平(0、30、90 kg P·hm^-2,分别以不施磷、低磷、高磷表示)配施稻秆生物炭(0、4%)的大豆盆栽试验,研究了不同磷水平下配施生物炭对土壤磷有效性、磷酸单酯酶活性和植株磷吸收的影响。结果表明: 不同磷水平配施生物炭显著提高了两种土壤的速效磷和全磷含量,且低磷水平添加生物炭处理速效磷增幅最大,在赤红壤和褐土的增幅分别为192.6%和237.1%。与低磷相比,赤红壤中低磷配施生物炭处理的碱性磷酸单酯酶活性显著增加78.9%,活性有机磷含量降低39.3%,同时显著促进了植株生长与磷吸收;生物炭添加显著降低了褐土活性有机磷含量,但不同处理对土壤磷酸单酯酶活性和植株生长无显著影响。土壤活性有机磷含量与速效磷含量均呈显著负相关。综上,生物炭对土壤磷有效性的作用因土壤类型和磷肥水平差异而不同,其在赤红壤上对植株生长和磷吸收的促进效应强于褐土,且在低磷条件下效果更佳。本研究为生物炭在减施磷肥和促进大豆磷吸收,特别是在赤红壤上的应用提供了科学依据。     

岩性和土地利用方式对桂西北喀斯特土壤肥力的影响

选取桂西北喀斯特石灰岩和砂页岩典型土地利用方式的土壤为研究对象,揭示土地利用方式和岩性对土壤肥力的影响.选取土壤的11项肥力指标进行因子分析,并对各样地的因子得分进行PCA排序和聚类分析.因子分析将11项指标归纳为土壤的综合肥力、土壤pH和全磷、有效磷和全钾4个因子.PCA排序和聚类分析结果表明:土壤的综合肥力主要受土地利用方式的影响,撂荒有利于土壤综合肥力的提高;土壤pH和全磷主要受母岩性质的影响,沙页岩发育的红壤pH和全磷含量都低于石灰土;有效磷和全钾主要受施肥的影响.与全国总体水平相比,桂西北喀斯特石灰岩和砂页岩土壤均很缺乏有效磷和全钾.石灰土可通过施用铵态氮肥提高磷的有效性,红壤可通过施用石灰提高有效磷含量.另外,喀斯特石灰岩和红壤区都需注重施用钾肥以改善土壤肥力.     

温度和施磷对石灰性潮土小麦苗期生长及磷形态的影响

以石灰性潮土为对象,通过盆栽试验研究温度和磷肥对小麦苗期生长和土壤无机磷形态转化的影响.结果表明: 温度和磷肥是影响小麦生长的重要因子,但二者交互作用影响不显著.温度对小麦生长的影响大于施用磷肥,15 ℃是小麦苗期的适宜生长温度.与不施磷肥(-P)处理相比,5 ℃下,施磷肥(＋P)处理显著促进了小麦生长,小麦地上部、根部生物量分别提高18.2%、33.3%,地上部、根部磷素积累量分别提高30.6%、13.3%,根冠比、株高、分蘖、根系活力分别提高3.5%、10.0%、10.5%、70.3%;15 ℃下,施用磷肥对小麦生物量、分蘖影响不显著,但小麦地上部、根部磷素积累量分别提高32.3%、23.8%,根冠比、株高、根系活力分别提高15.6%、2.5%、32.8%;25 ℃下施用磷肥对小麦生长没有促进作用. 3种温度下,施磷能显著增加各处理土壤有效磷(Olsen-P)、二钙磷(Ca₂-P)、八钙磷(Ca₈-P)、铝磷(Al-P)和铁磷(Fe-P)含量.-P和+P处理下,温度对Ca₂-P含量影响不显著,对Olsen-P、Ca₈-P、Fe-P、Al-P含量影响显著.Ca₈-P、Fe-P含量表现为5 ℃>15 ℃>25 ℃;Al-P含量表现为25 ℃>15 ℃>5 ℃.小麦苗期可以吸收利用根际土壤Ca₂-P、Ca₈-P、Al-P、Fe-P,而Al-P、Fe-P对小麦的有效性明显低于Ca₂-P、Ca₈-P.各处理pH、闭蓄态磷(O-P)和十钙磷(Ca₁₀-P)差异不显著.总之,温度主要通过影响小麦生长来影响磷素吸收,低温下施用磷肥能显著促进小麦生长,高温能加速石灰性土壤有效磷的固定,施磷能缓解这一过程.     

生物黑炭与无机肥料配施对旱作红壤有效磷含量的影响

针对我国南方旱地红壤有效磷含量普遍较低的问题,研究了生物黑炭与无机肥料配施对旱地红壤有效磷、有机碳含量和pH的影响.结果表明:生物黑炭与无机肥料配施后,红壤理化性质得到不同程度的改善;土壤pH值、有机碳和有效磷含量在油菜各生育期均得到不同程度的提高,在抽薹期、开花期、成熟期分别较种植前平均提高了16%、24%、26%,23%、34%、38%及100%、191%、317%.pH、有机碳和有效磷含量随着生物黑炭用量的增多而增加.施用生物黑炭处理的土壤有效磷与pH和有机碳呈显著相关性.研究结果可为改善旱地红壤缺磷状况及其理化性质提供科学依据.     

玉米秸秆还田对石灰性土壤Zn形态及其有效性的影响

采用尼龙网袋田间填埋的方法,研究了玉米秸秆还田对石灰性土壤Zn形态及其生物有效性的影响.结果表明：与施用Zn肥相比,秸秆还田对提高土壤全Zn含量贡献较小;施Zn肥和添加秸秆处理均显著增加土壤有效Zn(DTPA-Zn)含量,且施Zn肥处理增加的幅度更大;高锌秸秆还田后释放的Zn更易转化为土壤DTPA-Zn,转化率达49.0%,秸秆还田后土壤DTPA-Zn转化率呈先减小后增大的趋势,而施Zn肥处理的变化不大.土壤交换态Zn(Ex-Zn)、碳酸盐结合态Zn(Carb-Zn)、氧化锰结合态Zn(OxMn-Zn)、紧结有机态Zn(Sbo-Zn)和残渣态Zn(Min-Zn)含量在各处理中差异不大,施Zn肥处理的土壤松结有机态Zn(Wbo-Zn)含量显著大于对照和只添加秸秆处理.尽管玉米秸秆的含Zn量较低,但秸秆Zn释放后更易转化为DTPA-Zn,秸秆还田同时施用Zn肥是提高石灰性土壤供Zn能力的有效方法.     

平衡施肥对缺磷红壤性水稻土的生态效应

为了研究平衡施肥对缺磷水稻土的生态效应,对长期缺施磷肥水稻土进行了3.5年平衡施肥试验。试验采取盆栽水稻的方式,在长期缺施磷肥的红壤性水稻土上比较不施磷肥（NK）、平衡施用氮磷钾无机肥（NPK）、无机氮磷钾肥配施硅肥（NPKSi）、无机氮磷钾肥配施有机肥（无机肥占3/5）、NPK基础上增施磷肥（NKhP）、NPKM基础上增施磷肥（NKhPM）处理的土壤肥力、土壤微生物特性、土壤磷的渗漏量以及地上部水稻产量、养分利用率、磷肥利用率的变化。试验表明,平衡施肥处理NPK、NPKSi、NPKM、NKhPM显著提高水稻产量,比不施磷肥（NK）平均增产147%,其中NPKM提高152%;能提高土壤肥力,比不施磷肥土壤有机质含量平均提高18.5%,其中NPKM提高30.1%;显著提高土壤微生物生物量,比不施磷肥土壤微生物生物量碳（MBC）平均提高57.2%,其中NPKM提高87.1%;提高氮素、钾素养分利用率,比不施磷肥平均分别提高120.3%、33.6%,其中NPKM分别提高152%、43%。而长期重施无机磷肥处理（NKhP）虽然水稻产量比不施磷肥处理提高125.1%,但因土壤中磷酸根离子含量过高影响土壤微生物正常生长,土壤微生物活度比不施磷处理降低9.4%,土壤微生物量碳（MBC）降低2.4%,稻田土壤微生物生态系统质量劣化。此外,重施磷肥处理（包括NKhP、NKhPM）易导致稻田水体的磷污染。各处理比较,NPKM综合生态效应最佳,以下依次是NKhPM、NPKSi、NPK,NKhP,NKhP对稻田土壤微生物生态系统产生负效应。根据试验结果,平衡施肥是恢复缺磷水稻土的有效措施,其中在平衡施用氮磷钾化肥的基础上增施有机肥或硅肥效果较好。     

长期施肥处理对红壤水稻土微生物群落结构和功能多样性的影响

利用磷脂脂肪酸分析法和微平板测定法研究红壤荒地开垦为水田耕种20年后,不同施肥处理条件下土壤微生物群落结构和功能多样性变化,并分析土壤微生物学指标与土壤养分含量变化的关系。结果表明,与不施磷处理相比,施磷处理的水稻年产量、土壤有机碳、全氮、碱解氮、全磷和速效磷含量平均提高了196.6%、11.4%、19.4%、14.0%、100.6%和300.1%;而与未施有机肥处理相比,施有机肥处理上述各指标平均提高了85.4%、23.8%、25.0%、15.0%、38.6%和86.8%。与对照相比,施用磷肥和施用有机肥处理的微生物总磷脂脂肪酸(PLFA)含量提高了13.6%~68.9%。磷肥和有机肥的施用也提高了各菌群微生物的PLFA含量。不同施肥处理土壤微生物群落平均吸光度(AWCD)值、Shannon指数、Simpson指数和Mc Intosh指数分别为0.17~0.30、2.79~3.03、0.93~0.94和1.46~2.27。磷肥和有机肥的施用提高了微生物群落的AWCD值和功能多样性指数。主成分分析表明,施用磷肥和施用有机肥的处理微生物群落结构和碳源利用方式明显区别于对照、单施氮肥和施用氮钾肥的处理。逐步回归分析显示,有机碳、全磷、全氮和速效磷是影响土壤微生物群落结构和功能多样性的关键因素。磷肥和有机肥的施用有利于促进土壤微生物活性和多样性,提高土壤生物功能和生产力。     

施用污泥对油菜根际养分和不同种类重金属的影响

根际是控制植物养分动态的重要因素,养分动态也影响着根际土壤环境。当土壤被污水污泥改良后,根际土壤中的养分和重金属性质也会发生变化。目前很少有人研究施用污泥的土壤中植物根系对根际重金属有效性和分布的影响。采用根垫—冰冻薄层切片法对施用污泥后土壤中油菜根际的养分和重金属分布情况进行研究,以期探明污泥改良土壤中根际重金属的活化特征。当土壤施用污泥后,根际土壤中DTPA提取态Zn,Cd,Ni,Mn,有效磷,有效钾和铵态氮被显著消耗,而根际土壤中DTPA提取态Cu没有明显的消耗或积累。当土壤中施用大量污泥时,根际土壤的pH值随着离根表面距离的增加而增加。无论土壤是否用污泥处理,油菜根际土壤中可交换态Cu都显著减少。当土壤被50%污泥改良时,在距离根表面0—2 mm处的油菜根际土壤中碳酸盐结合态,铁锰氧化物结合态,有机物结合态,残渣态的Cu和Zn都被消耗较多。污泥的施用对油菜的生长有促进作用。随着污泥施用量的增加,油菜地上部分Cu和Zn的含量没有显著变化。施用污泥量小于25%的土壤中,污泥没有增加重金属的可利用性和移动性。除了Cu,油菜根际土壤中DTPA提取态Zn,Cd,Ni的减少表明施用污泥的土壤中重金属的活化是非常有限的。     

模拟增温对中亚热带杉木人工林土壤磷有效性的影响

气候变暖改变与土壤磷循环相关的生物地球化学过程,对陆地生态系统磷循环产生直接或间接影响。为研究亚热带地区杉木人工林土壤磷有效性对增温的响应,开展了模拟增温实验。实验设置对照组及增温组(5℃),经过1.5a的短期增温,对杉木人工林的土壤全磷、有机磷、微生物量磷、有效磷、酸性磷酸酶活性及相关土壤理化性质进行测定,结果表明:增温处理下,土壤酸性磷酸酶活性提高约1.5倍,土壤全磷、微生物量磷以及有机磷含量分别减少了6%、34%和12%,土壤有效磷含量增加25%。可见,短期增温通过提高土壤磷酸酶活性进而促进土壤有机磷矿化和降低土壤微生物固磷量,从而增加土壤磷有效性,但是增温导致潜在可利用的土壤微生物量磷大幅度的降低,将有可能加剧亚热带杉木人工林土壤磷限制。     

Effect of exchangeable sodium percentage and presubmergence on yield and nutrition of rice under field conditions

Summary The effects of exchangeable sodium percentage (ESP) levels of 82, 72, 65 and 35 and 0, 15 and 30 days of presubmergence (submergence prior to the transplanting of rice) on yield and chemical composition of rice and availability of Fe, Mn, Zn and P in soil were studied factorially in a field experiment. Presubmergence increased rice yields at all ESP levels, the effect being more pronounced at high ESP's. Increasing ESP decreased yields and the contents of Ca, Mg, K, Fe, Mn, Zn and Cu but increased that of P and Na in the crop. Presubmergence enhanced absorption of all the above elements by the crop except P, K, Mg, Zn and Cu in the grain and decreased Na in grain and straw. Growing of rice under submerged conditions also facilitated the improvement of these soils. Effects of submergence and ESP on the availability of Fe, Mn, Zn and P in soil and their role in the nutrition of rice are discussed. The results suggest that 15 to 30 days presubmergence improved rice yields on a calcareous sodic soil of the Indo-Gangetic alluvial plain.     

Mobilization of iron and other micronutrient cations from a calcareous soil by plant-borne,microbial, and synthetic metal chelators

Mobilization of Fe, Zn, Cu, and Mn by various chelators from a calcareous soil was measured using a simple dialysis tube/complexing resin system. Root exudates from Fe-deficient barley increased the concentrations of all four metals in solution by, on average, a factor of 20, and the addition of complexing resin as a sink for heavy metal cations forced steady state solution concentrations to be reached sooner. Root exudates mobilized increasing amounts of the various micronutrients in the following order: Cu<Fe<Zn<Mn. Phytosiderophores isolated from root exudates of Fe-deficient barley mobilized similar amounts of Cu and Zn but somewhat more Fe and considerably more Mn than crude exudate. The synthetic chelators EDDHA and DTPA showed low specificity in micronutrient mobilization, but the microbial siderophore Desferal was relatively more specific, preferentially mobilizing Fe and Mn. The data indicates that phytosiderophores are capable of increasing the amount of complexed cations in solution. Despite their lack of specificity, phytosiderophores were just as effective as Desferal increasing the availability of Fe. Thus, phytosiderophores, as plant-borne chelators, are certainly of significance for the Fe nutrition of cereals grown in calcareous soils.     

北京石灰性草甸土冬小麦营养元素生物循环的特点与锰、锌肥效应

 本文用盆钵试验研究京郊石灰性草甸土冬小麦养分生物循环的结果表明：小麦对不同养分吸收、携出和归还数量的差异很大。根据随籽粒携出和以根茬归还的比例特点,可将养分划分为三种类型：1)低归还高携出型(N、P、K);2)低携出高归还型(Ca、Fe);3)中归还中携出型(Mg、Mn、Cu、Zn)。施锰增加植株对氮和锰的吸收及钾和锰随籽粒的携出;施锌则降低植株对锰的吸收和随籽粒携出的钾、钙、镁、铁、锰量。锰肥和锌肥有拮抗作用。     

Acquisition of Cu, Zn, Mn and Fe by mycorrhizal maize (Zea mays L.) grown in soil at different P and micronutrient levels

Sustainability of soil-plant systems requires, among other things, good development and function of mycorrhizal symbioses. The effects of P and micronutrient levels on development of an arbuscular mycorrhizal fungus (AMF) and uptake of Zn, Cu, Mn and Fe by maize (Zea mays L.) were studied. A pot experiment with maize either inoculated or not with Glomus intraradices was conducted in a sand:soil (3 :1) mix (pH 6.5) in a greenhouse. Our goal was to evaluate the contribution of mycorrhizae to uptake of Cu, Zn, Mn and Fe by maize as influenced by soil P and micronutrient levels. Two levels of P (10 and 40 mg kg⁻¹ soil) and three levels of a micronutrient mixture: 0, 1X and 2X (1X contained, in mg kg⁻¹ soil, 4.2 Fe, 1.2 Mn, 0.24 Zn, 0.06 Cu, 0.78 B and 0.036 Mo), were applied to pots. There were more extraradical hyphae at the low P level than at the high P level when no micronutrients were added to the soil. Root inoculation with mycorrhiza and application of micronutrients increased shoot biomass. Total Zn content in shoots was higher in mycorrhizal than non-mycorrhizal plants grown in soils with low P and low or no micronutrient addition. Total Cu content in shoots was increased by mycorrhizal colonization when no micronutrients were added. Mycorrhizal plants had lower Mn contents than non-mycorrhizal plants only at the highest soil micronutrient level. AMF increased total shoot Fe content when no micronutrients were added, but decreased shoot Fe when plants were grown at the high level of micronutrient addition. The effects of G. intraradices on Zn, Cu, Mn, and Fe uptake varied with micronutrient and P levels added to soil. Accepted: 27 December 1999     

Trace Element Composition of Selected Fertilizers Used in Chile: Phosphorus Fertilizers as a Source of Long-Term Soil Contamination

Anthropogenic activities like agriculture have resulted in increased concentrations of some trace elements of toxicological and environmental concern in soils. Application of fertilizers has been one of the major inputs of these contaminants to agricultural soils in developing countries. Twenty-two fertilizers, including straight nitrogen (N), phosphorus (P), potassium (K), and NK fertilizers and micronutrient sources, were analyzed by inductively coupled plasma optical emission spectrometry (ICP-OES) for arsenic (As), cadmium (Cd), cobalt (Co), chromium (Cr), copper (Cu), iron (Fe), manganese (Mn), molybdenum (Mo), nickel (Ni), lead (Pb), vanadium (V), and zinc (Zn). As expected, the trace element content of fertilizers was highly variable and related to the origin of the material. Phosphorus fertilizers, especially triple superphosphate, presented the highest As, Cd, Cu, Cr, Ni, V, and Zn concentrations. In some of these fertilizers, the Cr, V, and Zn contents reached values greater than 3475 mg kg^?1 of P, and the Cd content (up to 288 mg kg^?1 of P) was several times higher than the regulatory limits of different countries. Some micronutrient sources presented the highest concentrations of Mn and Pb. In the cases of N, K, and NK fertilizers, the trace element concentration was very low, sometimes below the detection limits. In some agricultural systems the input of trace elements such as As and Cd to the soil through P fertilizers application may be higher than the outputs through plant uptake and leaching; therefore the long-term use of these fertilizers may cause the trace element concentration to increase in the plow layer of agricultural soils.     

Mobilization of iron by phytosiderophores as affected by other micronutrients

It has been shown previously (Treeby et al., 1989) that phytosiderophores, released by roots of iron deficient grasses (Gramineae), mobilize from calcareous soils not only iron (Fe) but also zinc (Zn), manganese (Mn) and copper (Cu). Mobilization of Fe may therefore be impaired by other micronutrient cations. This has been studied in both, model experiments with Fe hydroxide and with a calcareous soil (15% CaCO₃, pH 8.6) amended with micronutrients as sulfate salts.Mobilization of Fe from Fe hydroxide by phytosiderophores (epi-3-hydroxymugineic acid) was not affected by the addition of CaCl₂, MgSO₄ and MnSO₄, slightly inhibited by ZnSO₄ and strongly inhibited by CuSO₄. In a calcareous soil amended with increasing levels of ZnSO₄, MnSO₄ and CuSO₄, mobilization of Fe by phytosiderophores remained uneffected by Zn and Mn amendments but was progressively impaired by increasing levels of Cu amendment, correlated with corresponding enhancement of Cu mobilization.High concentrations of ZnSO₄ and MnSO₄ and relatively high concentrations of CuSO₄ were required for inhibition of Fe mobilization by phytosiderophores. It is therefore concluded that in most calcareous soils phytosiderophores efficiently mobilize Fe, and that phytosiderophores play an important role in Fe acquisition by grasses grown on calcareous soils.     

有机物料与锌肥配施对石灰性土壤锌有效性及形态转化的影响

采用尼龙网袋田间填埋培养法探究了外源施锌条件下石灰性土壤Zn有效性及形态转化对不同有机物料(作物秸秆、生物菌肥、黄腐酸和腐熟鸡粪)的响应.结果表明:与对照相比,Zn肥单施和与有机物料配施均显著提高了土壤全Zn含量(7.2%~13.8%)和DTPA-Zn含量(2.1~2.8倍).在施Zn条件下,有机物料对土壤全Zn和DTPA-Zn的贡献量表现为腐熟鸡粪>生物菌肥>玉米秸秆>黄腐酸,但外源锌的DTPA-Zn转化率以添加秸秆和生物菌肥处理最高.与单施Zn肥相比,有机物料与Zn配施处理显著提高了土壤有机质含量,促进了松结有机态Zn的形成,进而提高了土壤Zn转移因子,降低了Zn分配指数.不同物料与Zn肥配施土壤Zn有效性及形态转化之间存在差异,这可能与有机物料自身性质如腐熟度和含Zn量有关.尽管秸秆与Zn配施对DTPA-Zn含量的提升效果不及生物菌肥或腐熟鸡粪与Zn配施,但综合考虑环境和经济效益,其仍是改善缺锌石灰性土壤Zn有效性的最佳选择.     

木质素锌肥在粤北石灰性土壤上的生物有效性研究

木质素锌肥是利用造纸工业副产品木质素为原料合成的一种有机微肥,通过淋溶与盆栽试验研究了木质素锌肥与无机锌肥在粤北两种石灰性土壤上的生物有效性差异．结果表明。木质素螯合锌被土壤固定、吸附量要明显小于无机锌,对于土壤B,当Zn用量为10mg·kg^-1时,木质素锌肥处理锌溶出量比无机锌高65．2％;施用木质素锌肥的处理玉米长势好,不仅生物量高过无机锌肥,而且更有利于玉米对锌的吸收,在土壤A上,当Zn用量为10mg·kg^-1时,木质素锌肥处理的生物量比无机锌增产16．3％。植株锌含量比无机锌肥高81．2％,木质素锌肥的生物有效性优于无机锌肥。     

Micronutrient availability to cereals from calcareous soils

Summary By contrast of strong phosphorus-zinc antagonism in upland crops, P strongly enhanced Zn uptake in flooded rice on a calcareous soil. Radioisotopic studies indicated increase to occur preferentially from applied Zn fertilizer. Phosphorus appeared to stimulate uptake predominantly by enhancing Zn concentration in soil solution and by increasing metabolic Zn absorption by plant roots. The ‘A’ value was not a reliable measure of labile soil Zn for rice as it markedly changed with levels of P and Zn fertilizers. No. VI in the series: Phosphorus-zinc interaction in rice. No. VI in the series: Phosphorus-zinc interaction in rice.     

Microelement composition of plants grown with low to high levels of sulfur applied to calcareous soil in a glasshouse

Summary PI54619-5-1 soybeans (Glycine max L.), which are very susceptible to Fe deficiency, were grown for 24 days in calcareous (10%) Hacienda loam soil with different levels of S each with and without 2 ppm Fe added as FeEDDHA (ferric ethylenediamine di (o-hydroxyphenylacetic acid). The S application rates ranged from sufficient to neutralize about 15% to more than all of the CaCO₃ present if the S were all oxidized. The soil pH values at harvest time ranged from 7.4 to 6.0. The highest S rate was 10% by weight of soil and it overcame Fe deficiency without FeEDDHA. The S treatments resulted in increased concentrations of Fe and other metals in leaves, but the FeEDDHA treatments increased yields more than did S. At the lower levels of S, the effects of S and FeEDDHA on Fe concentrations in leaves were additive, but not at the highest level of S. The FeEDDHA overcame much of the effect that S had on increasing Mn concentrations in leaves. It had a similar effect, particularly at the low S levels, on Zn, Cu, Al, B, and Ni concentrations in leaves. A level of S sufficient to neutralize only 15% of the CaCO₃ of the soil increased leaf concentrations of Fe, Mn, Zn, Cu, Al, B, Ni, Si, and P. The effect for Zn, Cu, and Al appreared maximum at this level. A combination of the1/2% S and the FeEDDHA resulted in the most favorable micronutrient balance. Bush beans (Phaseolus vulgaris L. var. Improved Tendergreen) grown in calcareous soil with S insufficient to neutralize all the CaCO₃ had increased Mn, Ni, and Mo and decreased Ba levels in leaves. CaSO₄ as a source of S did not have the same effects as elemental S.