Predicting plant sulfur deficiency in soils: results from Ohio

We developed a model for plant available sulfur (S) in Ohio soils to predict potential crop plant S deficiency. The model includes inputs of plant available S due to atmospheric deposition and mineralization of soil organic S and output due to leaching. A leaching index was computed using data on annual precipitation; soil pH and clay content that influence sulfate adsorption; and pore water velocity based upon percent sand, silt, and clay. There are five categories of S status ranging from highly deficient to highly sufficient, and the categories are defined based on whether the crop S requirement was 15 or 30kg S ha⁻¹ year⁻¹. The final database derived from the model includes 1,473 soil samples representing 443 of the 475 soil series in Ohio. For a crop requiring 15kg S ha⁻¹ year⁻¹, most soils (68.6%) were classified as variably deficient, which implies that the response to S fertilization will be variable but often positive depending on specific crop conditions. For a crop requiring 30kg S ha⁻¹ year⁻¹, 43.2% of soils were classified as variably deficient, but 49.7% were classified as moderately or highly deficient, implying that a response to S fertilization will usually or always occur. The model predicts crop S status for a single state in the USA, but with proper inputs, it should be applicable to other areas.     

Mineralization of organic sulfur and its importance as a reservoir of plant-available sulfur in upland soils of north China

 An open incubation technique was used to measure S mineralization in a range of upland soils of north China. Six mineralization patterns were examined, and a soil S-exhaustion experiment with ryegrass (Lolium multiflorum L.) was conducted to investigate the availability of various organic S pools to plants. For all of the 12 soils tested, the release of S as SO₄ ^2– was curvilinear with time, and during a 28-week incubation at 30  °C the amount of S mineralized ranged from 14.0 mg S kg^–1 soil to 37.4 mg S kg^–1 soil. A first-order model and Gompertz model appeared to best describe S mineralization. Examination of the soils after incubation revealed the bulk of the mineralized S was mainly derived from the C-bonded S pool, while the majority of mineralized S under soil S exhaustion by ryegrass was derived from the HI-reducible S pool. Received: 9 July 1998     

四川省土壤有效硫状况及硫肥效应研究

通过对四川省 6类 32 9个土壤样品的有效硫的分析 ,结果表明缺硫及潜在性缺硫土样占总样本的 2 3 1 % .但结合田间试验 ,在四川盆地特定环境条件下 ,即使土壤耕层有效硫处于缺乏范围 ,增施硫肥对玉米、小麦、油菜产量无明显增加 ,并就产生的原因作了初步分析 .通过对土壤硫素平衡的测算 ,预测在近期内 ,四川盆地主要农耕地不会发生大面积缺硫问题     

Estimation of sulfur mineralization and relationships with nitrogen and carbon in soils

A 25-week laboratory study was carried out to determine sulfur, carbon, and nitrogen mineralization rates in soil samples obtained from representative soils in France. Their relationship with some of the soil properties was investigated to find a predictor of mineralized S in soils. At 20°C and 80% water-holding capacity, the S mineralization rate ranged from 0.02 to 0.16 mg kg⁻¹ day⁻¹. It was significantly positively related to soil organic C and N and to C and N mineralization rates. It was weakly related to total soil S. The results suggest that the S mineralization is predominantly driven by heterotrophic microbial activity. A predictive equation for S mineralization based on soil C content, soil pH, and clay content is proposed.     

江西省农田土壤有效硫现状研究

采集了江西 1 6个县市 9种主要母质的 6 0 9个农田耕层土样进行了土壤有效硫含量测定 .统计结果表明 :平均值为 2 6 7mg/kg ,缺硫和潜在缺硫样点占 39 1 % .按地区分 ,以赣南、赣东北山区缺硫最严重 ,有效硫小于 1 2mg/kg的样点占 2 6 6 %～ 4 4 7% ,其次是丘陵地区 ,有效硫小于 1 2mg/kg的样点占1 0 0 %～ 1 9 0 % .按母质分 ,以石英岩、花岗岩发育的土壤最缺 ,约占 50 %～ 6 0 % ,其次是红砂岩、泥质岩 ,缺硫为 30 %～ 4 0 % ,这些是江西省急需施用硫肥的土壤 .水稻土以黄砂泥田、麻砂泥田、红砂泥田、鳝泥田等土属有效硫缺乏面积最大 ,全省水稻土有效硫缺乏的面积约为 1 0 3 8万hm2 ,约占水稻土面积的 34 % .     

Effects of seed-placed sulfur fertilizers on canola,wheat, and pea yield; sulfur uptake; and soil sulfate concentrations over time in three prairie soils

The form of sulfur fertilizer can influence its behavior and crop response. A growth chamber study was conducted to evaluate five sulfur fertilizer forms (ammonium sulfate, ammonium thiosulfate, gypsum, potassium sulfate, and elemental sulfur) applied in seed row at 20 kg S ha^?1 alone, and in combination with 20 kg phosphorus pentoxide (P₂O₅) ha^?1, to three contrasting Saskatchewan soils. Wheat, canola, and pea were grown in each soil for 8 weeks and aboveground biomass yields determined. The fate of fertilizer was evaluated by measuring crop sulfur and phosphorus concentration and uptake, and supply rates and concentrations of available sulfate and phosphate in the seed row. Canola was most responsive in biomass yield to the sulfur fertilizers. Sulfate and thiosulfate forms were effective in enhancing soil-available sulfate supplies in the seed row, crop sulfur uptake, and yield compared to the elemental sulfur fertilizer. Combination of sulfur fertilizer with monoammonium phosphate may provide some enhancement of phosphate availability, but effects were often minor.     

耕作方式对紫色水稻土全硫及有效硫的影响

以位于西南大学农业部重庆紫色土生态环境重点野外科学观测试验站 1990 年设立的长期免耕试验田为研究对象,通过采集 0 ~ 60 cm 土壤,应用等质量计算方法,探讨了冬水田平作（DP）、水旱轮作（SH）、垄作免耕（LM）和垄作翻耕（LF）等不同耕作方式对土壤全硫和有效硫的影响。结果表明,在 0 ~ 60 cm 深度内,土壤全硫和有效硫含量呈现出明显的垂直递减规律,即随着土壤深度的增加,含量逐渐降低;不同耕作方式下,土壤全硫含量及储量为 LM＞SH＞DP＞LF,有效硫含量及储量为 LM＞DP＞LF＞SH。长期垄作免耕提高了土壤全硫及有效硫的含量和储量,与对照 DP 处理相比,LM 处理全硫与有效硫含量分别增加了 20.80% 和 1.31%,储量分别增加了 19.54% 和 5.36%。耕作层（0 ~ 20 cm）,DP、SH、LM、LF 处理土壤有效硫平均含量分别为 27.15、13.45、31.43 和 24.01 mg/kg,DP、LF 以及 LM 处理为硫不缺或硫丰足,而 SH 处理为缺硫土壤（土壤有效硫含量＜16 mg/kg）。对缺硫土壤,应重视硫肥的施用,以促进农作物产量和品质的提高。     

Stimulative effects of elemental sulfur in the presence of ammonium on chile and broccoli growth in calcareous soils

The chile pepper plant seldom responds to N and P fertilizers on fertile soils. Surplus industrial H₂SO₄ and elemental S have created interest in “mining”; calcareous soils for additional supplies of P, Ca, Mg and micronutrients. The effect of variable S, on the growth of chile and broccoli was evaluated holding other nutrients constant. Growth of chile and broccoli plants was significantly increased in the greenhouse and chile yield increased in the field. Incremental S additions increased the water extractable and desorbable Ca + Mg and P contents of soil. The total N and K content of chile plant grown in the greenhouse increased, and then decreased, P decreased, as S rates increased. Yield of dry red chile with constant N peaked at 16.5 g S m^‐2 and then decreased with increasing S in the field. Rroccoli responded more to S application than to directly applied foliar micronutrient solutions (Fe and 7n), and responded much better to (NH₄)₂SO₄ + S than to Ca(NO₃)₂ at equivalent N rates. Increased soluble Ca + Mg content of the soil in the presence of S was thought to influence plant absorption of NH₄ and/or K.     

Band-applied elemental sulfur to enhance the phytoavailability of phosphorus in alkaline calcareous soils

Summary Applications of elemental sulfur (S°) increase the phytoavailability of P in alkaline high-Ca soils through the production of H₂SO₄ which is induced by microbial oxidation of S. Concentrated S bands, allowing time release acidity, may aid in maintaining the phytoavailability of both residual and fertilizer P. Greenhouse and field studies were therefore conducted to determine the effectiveness of band-applied S° for increasing the phytoavailability of residual and fertilizer P for spring wheat (Triticum aestivum L.) and corn (Zea mays L.). We also used inoculation of S° with Thiobacillus thioparus to determine whether it is necessary or helpful in alkaline soils to initiate acidification. Treatments were inoculation, S°, S° + inoculation, triple superphosphate, triple superphosphate + S°, triple superphosphate + inoculation, and triple superphosphate + S° + inoculation applied to three alkaline soils: Typic Argiborolls, Borollic Calciorthids, and Ustollic Haplargids. P availability was determined by plant uptake of P, NaHCO₃-extractable P, dry-matter yield, grain yield and grain-protein production, and on available-P index (NaHCO₃-extractable P, post-harvest, + plant uptake of P). Application of S° with triple superphosphate gave a significantly higher available-P index than triple superphosphate alone on all three soils. Inoculation of S° with T. thioparus increased soil acidity; however, in some cases this treatment eliminated the beneficial effect of S°. Grain yields of wheat increased with S° applications at one of two field sites. These results suggest that applying S° with triple superphosphate may be an effective means of increasing soil P availability and the efficiency of superphosphate fertilizers on alkaline high-Ca soils.     

Aggregate associated carbon, nitrogen and sulfur and their ratios in long-term fertilized soils

Farmyard manure (FYM) and fertilizer applications are important management practices used to improve nutrient status and organic matter in soils and thus to increase crop productivity and carbon (C) sequestration. However, the long-term effects of fertilization on C, nitrogen (N) and sulfur (S) associated with aggregates, especially on S are not fully understood. We investigated the effects of more than 80 years of FYM (medium level of 40 Mg ka⁻¹ and high level of 60 Mg ka⁻¹) and mineral fertilizer (NPKS and NK) on the concentrations and pools of C, N, and S and on their ratios in bulk soil, dry aggregates and water stable aggregates on an Aquic Eutrocryepts soil in South-eastern Norway. A high level of FYM and NPKS application increased the proportion of small dry aggregates (<0.6 mm) by 8%, compared with the control (without fertilizer). However, both medium and high level of FYM application increased the proportion of large water stable aggregates (>2 mm) compared with mineral fertilizer (NPKS and NK). The total C and N pools in bulk soils were also increased in FYM treatments but no such increase was seen with mineral fertilizer treatments. The increased total S pool was only found under high level of FYM application. Water stable macroaggregates (>2 and 1–2 mm) and microaggregates (<0.106 mm) contained higher concentrations of C, N and S than the other aggregate sizes, but due to their abundance, medium size water stable aggregates (0.5–1 mm) contained higher total pools of all three elements. High level of FYM application increased the C concentration in water stable aggregates >2, 0.5–1 and <0.106 mm, and increased the S concentration in most aggregates as compared with unfertilized soils. Higher C/N, C/S and N/S ratios were found both in large dry aggregates (>20 and 6–20 mm) and in the smallest aggregates (<0.6 mm) than in other aggregate sizes. In water stable aggregates, the C/N ratio generally increased with decreasing aggregate size. However, macroaggregates (>2 mm) showed higher N/S ratios than microaggregates (<0.106 mm). We can thus conclude, that long-term application of high amounts of FYM resulted in C, N and S accumulation in bulk soil, and C and S accumulation in most aggregates, but that the accumulation pattern was dependent on aggregate size and the element (C, N and S) considered.     

我国某些土壤中硫素的氧化

The status and activities of boron in soils were studied by the approach of electro-ultrafiltration(EUF).The samples of soils,including brown-red soil and calcareous alluvial soil,were collected from Hubei Province of China.The soil samples were incubated in saturated water and then their nutrients were ultrafiltrated with EUF equipment.Filtration and extraction were conducted in accordance with routine process,but fractions in anode and cathode were all collected.Analyses of B,K^ ,Mg^2 ,Ca^2 ,Cl^- and pH in fractions supposed that boron existed not only in a simple form of borate but also in ion -pair with cations partly in acidic soil,and borate was the primary form existing in the calcareous soil.In studying desorption kinetics with EUF,the boron content of Fractions 2-6 was accumulated.and the accumlative quantities were fit to time factors in three kinetic equations:the zero-order,first-order,and parabolic diffusion equations,Fit degree of the parabolic diffusion equation was the best,followed by the zero-order equation,and the first-order equation was the worst。     

Effect of sulfur additions on soil and the nutrition of wheat

Abstract

A field experiment was conducted for two years to determine the effects of four sulfur (S) sources applied at various rates on the elemental composition of Coker 747³ wheat and on the soil S concentration. The concentration of S in plants increased by all sources of applied S. Increased S in the soil from S application decreased P concentrations in plants regardless of the S source used. Sulfur additions did not significantly affect the concentrations of Cu, Ca, Mg, or N in plants. The concentrations of Mn, Zn, and Fe in plants either increased or decreased depending on S source used. Analysis of the silt loam soil to a depth of 90 cm revealed that applied S moved readily from the surface to the lower depths and that the elemental form of S moved less rapidly than the more soluble forms of applied S.     

The effect of elemental sulfur,gypsum and ammonium thiosulfate as sulfur sources on yield of rapeseed

Abstract

A growth chamber experiment was conducted to compare ammonium thiosulfate, gypsum and elemental sulfur in the form of Agrisul as sources of sulfur for rapeseed (Brassica napus var. Regent). Rapeseed supplied with ammonium thiosulfate or gypsum produced significantly higher yields than treatments supplied with elemental sulfur. Powdering and mixing of elemental sulfur, as opposed to banding granules, significantly increased dry matter yield of rapeseed. While not always significant, there was a trend towards higher dry matter yields where gypsum granules were mixed as opposed to banded and where ammonium thiosulfate was placed in a band as opposed to being mixed throughout the soil.     

Influence of nitrogen and elemental‐sulfur fertilization on sulfur oxidation and mineralization in relation to soil moisture on a calcareous soil of the Inner Mongolia steppe of China

Grassland‐livestock farming is the main agricultural activity in the Inner Mongolia steppe of China. It has been estimated that more than 80% of the grasslands suffer from sulfur (S) deficiency in this region. In an incubation study and a greenhouse experiment with alfalfa, the influence of soil moisture (40% and 70% water‐holding capacity, WHC), nitrogen (0 and 200 mg N (kg soil)^–1 as NH₄NO₃), and elemental sulfur (eS; 0 and 300 mg S (kg soil)^–1) amendments on the apparent eS oxidation, eS‐oxidation rate, net S‐mineralization rate, and S uptake of alfalfa were studied. After 28 d of incubation, the eS‐oxidation rate was four times higher at 70% than at 40% WHC if no N was applied. With N application, soil moisture had only minor effects on eS oxidation during the whole incubation period. In the greenhouse experiment, lower values for eS‐oxidation rate and net S‐mineralization rate were found if no N was applied. Application of N and eS significantly increased alfalfa growth and S uptake. The results of both experiments suggest that combined N and eS applications are the best way to alleviate S deficiency on these calcareous soils.     

供硫水平对花生叶片硫素含量与形态的影响

采用盆栽方法研究了供硫水平对花生不同叶龄叶片的硫酸盐、谷胱甘肽和蛋白态硫含量及其形态的影响。结果表明,叶片谷胱甘肽含量随叶龄增大而减少,硫酸盐含量却相反。当硫素供应充足时,幼叶谷胱甘肽含量占总硫 4.6%,蛋白态硫含量占 91%,其余以硫酸盐形式存在;中龄叶及老叶的硫酸盐含量占总硫的60%~80%,而谷胱甘肽含量不到1%。当硫素供应不足时,幼叶和中龄叶含硫化合物总量减少,尤其是硫酸盐。因此,在缺硫时,谷胱甘肽不是植株硫的主要来源,且低氮加重缺硫症状发生。不同叶龄叶片对缺硫反应不同,幼叶对缺硫反应更为敏感。     

长期施肥下黑土有机肥替代率变化特征

探索长期施肥下黑土有机肥替代率与土壤肥力提升的关系,可为农田土壤培肥和有机替代提供理论依据。对吉林省公主岭黑土32年的长期肥力试验定位观测数据进行系统分析,基于作物氮素吸收量和土壤氮素供需方程探讨高产条件下施用不同量有机肥的黑土有机肥替代率的变化特征。研究表明,作物产量随着有机肥施用年限增加逐渐提高,32年的持续施肥,施用有机肥的作物产量趋同甚至高于NPK化肥处理的作物产量。基于作物氮素吸收量,高产条件下有机肥替代率与施肥年限呈极显著线性正相关(P0.01),高量有机肥处理(M2)的有机肥替代率高于常量有机肥处理(M1);且有机肥施用29年后,高量有机肥处理(M2)的有机肥替代率达到100%,并保持稳定不变。基于土壤氮素供需方程估测的常量和高量有机肥处理(M1和M2)的有机肥替代率与基于作物氮素吸收量得到的有机肥替代率相关系数(R2)达到0.78和0.84(P0.01),相对均方根误差(RMSE)均小于15%(分别为10.4%和14.6%),表明土壤氮素供需方程可以较好地估测土壤有机肥替代率。基于作物氮素吸收量和土壤氮素供需方程能够准确反映长期有机培肥下黑土有机肥替代率的变化规律。本研究结果表明,基于作物氮素吸收量和土壤氮素供需方程两种方法验证,高产条件下有机肥替代率是土壤肥力的函数;随着有机肥施肥年限的增加,土壤肥力提升,有机肥替代率逐渐增加。     

辽宁大豆主产区土壤硫素状况及不同硫肥肥效研究

本文通过对辽宁省大豆主要产区(8个县)土壤全硫及有效硫含量进行测定与分析,阐述了不同类型、不同肥力土壤硫素状况。在不同地区开展的硫肥肥效试验结果表明,在有效硫含量很低的土壤上施用硫肥增产效果都很明显,而有效硫含量较高的土壤上施用硫铵增产效果较好,石膏和硫磺的增产效果不稳。     

福建耕地土壤硫肥效应及其临界指标研究

硫是作物生长发育所需的营养元素。根据多年多点田间试验和土壤有效硫测定,研究福建主要粮经作物的硫肥效应、土壤有效硫临界指标和耕地土壤硫肥力状况。64个田间试验表明,福建主要农作物施用硫肥平均增产10.5%,增产幅度是旱作物>水稻>香蕉;水田土壤和旱地土壤有效硫临界指标分别为23mgkg-1和25mgkg-1。根据全省372个耕层土样有效硫测定结果,土壤有效硫含量平均为27.6mgkg-1,低于土壤有效硫临界值的样品数占57.0%,其中,闽东南地区耕地土壤有效硫缺乏程度比闽西北地区高;在土地不同利用类型中,旱地土壤有效硫总体比水田匮乏,旱地土壤有效硫平均含量是茶果园>菜园>农地,其中,农地土壤有效硫低于临界指标的样品占75.3%;水田中不同土种的土壤有效硫含量以埭田最高,灰沙泥田为最低,旱地则以灰赤土最高而风沙土最低。     

长期施肥对土壤团聚体分布和养分含量的影响

土壤团聚体组成和土壤养分状况是评价土壤肥力的两个重要指标。不同粒级的团聚体在营养元素的保持、供应及转化能力等方面发挥着不同的作用。本文通过比较长期施肥对土壤团聚体的分布和对土壤养分在团聚体分布变化的影响,全面评价长期施肥对改善土壤肥力状况的作用。结果表明：长期施肥减少＞5 mm 的非团粒结构的数量,增加 0.25 ~ 5 mm 团聚体的含量,改善了土壤的物理结构;土壤大团聚体中含有更多的全 C、全 N、全 P,因此大团聚体对养分的保持有重要作用;施肥对速效养分含量影响显著,碱解 N 含量随粒级的减小而增加,有利于作物的吸收;肥料的施加使得小粒级团聚体对土壤养分储量的贡献率越来越突出,更利于养分的供给。此外,研究还发现耕作条件下有机无机肥配施不利于较小粒级团聚体全 N 和全 P 的保持。     

河北省土壤硫含量、形态与分布

对河北省主要土壤类型耕层硫含量进行了分析测定。结果表明 ,河北省土壤全硫平均含量为 250.1mg/kg(50～940mg/kg)。土壤全硫平均含量以沼泽土最高 ,灰色森林土最低 ;土壤有效硫平均含量为 46.1mg/kg ,以沼泽土最高 ,红粘土和栗褐土最低。土壤硫主要以有机态存在 ,占全硫含量的 81.6% ;无机态硫占 18.4%。按土类划分土壤无机硫含量最高的是沼泽土 ,灰色森林土最低 ;土壤有机硫含量也以沼泽土最高 ,灰色森林土最低。土壤全硫含量主要受土壤有机质含量、阳离子代换量和土壤碳酸钙含量的影响。根据土壤硫供应水平计算 ,全省约有20.4%的土壤缺硫 ,北部缺硫面积较大 ,南部缺硫面积较小。根据土壤有效硫含量多寡 ,可把全省土壤硫含量划分为极缺乏区、缺乏区、中等区、丰富区及极丰富区 5类