Waterlogging effects on elemental composition of wheat genotypes in sodic soils

Waterlogging + sodicity proved more harmful than sodic or waterlogging stress individually. Wheat genotypes were evaluated for waterlogging tolerance in neutral (pH 7.8) and sodic (pH 9.3) soils. There was 50% greater reduction in overall grain yield when genotypes were waterlogged for 15 days in sodic soil than in neutral soil. This was associated with proportional reductions in biomass and productive tillers. Severe effects of waterlogging were observed on grain yield in sodic soil and the extent of damage depends heavily on the stage of development, duration, and temperature. Waterlogging reduced the concentration of macro elements (K, Ca, and Mg), whereas effects on microelements concentration were mixed, with some elements increasing (Fe, Al, Mn, and Na) and others decreasing (Cu and Zn). Significant genotypic variation was observed for grain yield and biomass under the stress treatments and KRL 3–4, KRL 99, KRL 210, and Kharchia 65 were the top performers.     

The influence op soil treatments on elemental composition of corn and on zinc soil tests on two Missouri soils

Abstract

Corn (Zea mays L) was grown at three locations on soil treated with Zn at two levels of soil fertility. Corn leaves were sampled at 2 stages of growth and analyzed for several elements. Yields were measured and soils were analyzed for O.lN HCl and DTPA extractable Zn and by standard testing methods for other components.

Zinc at 10 and 20 lb/A did not affect corn grain yields. The Zn treatments significantly increased leaf Zn concentrations. The influence of leaf sampling time differed between locations. The DTPA and O.lN HCl extractable soil Zn both reflected the Zn soil treatments. The DTPA appeared to extract a more soluble component of soil Zn which became more un‐extractable with time. In general, the extractable soil Zn was poorly correlated with Zn concentrations in the corn leaves. Under the conditions of the experiment the soil Zn levels as measured by the 2 extractants were a poor predictor of plant Zn when soil Zn levels were adequate.     

Effects of previous elemental sulfur applications on oxidation of additional applied elemental sulfur in soils

Oxidation of elemental sulfur (S⁰) in 20 Chinese agricultural soils was tested and the effects of previous S⁰ applications on the oxidation of additional applied S⁰ in selected soils were investigated using laboratory, greenhouse, and field experiments. Results showed that sulfur oxidative capacities presented great variability among 20 tested soils, with a coefficient of variation of 92.4%. There were no significant relationships between S⁰ oxidation and physical and chemical properties of the selected soil. Previous S⁰ amendment significantly increased the oxidation rate of additional applied S⁰. These stimulatory effects after the first applications of S⁰ were greater than those after two applications. The percent increase in S⁰ oxidation rate due to S⁰ pretreatment was negatively correlated with the oxidation capacities of soils before S⁰ pretreatments. The significant reduction of sulfur oxidation in autoclaved soils and significant increase in S⁰ oxidation after inoculation with S⁰-treated soil suspension demonstrated that microbial oxidation was mainly responsible for the enhancement of soil oxidation ability after previous S⁰ amendments.     

The elemental composition and amphiphilic properties of humic acids in southern taiga soils

This paper gives the characteristics of the elemental composition and amphiphilic properties of humic acids (HAs) extracted from different horizons of the most typical soils in the Central Forest Biosphere Reserve (CFBR, the Tver Oblast). An attempt at characterizing some properties of the structure of HAs is made based on the data of the elemental composition. The data on amphiphilic properties enable one to reveal whether components that are capable of migration are present.     

Effects of foliar fertilization on yield,protein, oil and elemental composition of two soybean varieties

Abstract

The effects of foliar fertilization on the yield and seed composition of two soybean (Glycine max L. Merrill) varieties were investigated under mid‐Missouri conditions over a 2‐year period. The foliar fertilizer treatments consisted of (i) 80–8–24–4 (NPKS) kg/ha, (ii) 40–4–12–2 (NPKS) kg/ha, and (in) control (no foliar treatment) with the optimum proportion of N:P:K:S in the solution 10:1:3:0.5 respectively. Nutrient sources were urea, potassium polyphosphate, and potassium sulfate. Water solutions of fertilizers (pH 6.9) containing 0.1% Tween 80 (v/v) were sprayed on the plants using a CO₂ ‐ pressurized back‐pack sprayer. Foliar fertilizer was split between four equal applications during the seed filling period. The variety Mitchell at the higher rate and the variety Williams at the lower fertilizer application rate produced slight, though statistically insignificant, yield increases. At the higher rate of application, the seed protein contents of both varieties increased, while the oil contents decreased. The concentrations of P and K in the seeds were not affected by foliar fertilization, but at the higher rate, there was a small decrease in S content of Williams variety.     

Spatial and temporal variation in the elemental composition of soil solution from gleyic peaty-podzolic soils

The behavior of different elements in solutions from gleyic peaty-podzolic soils was described by four types of fluctuations (from weak to strong ones). With account for the spatial and temporal variation, chemical elements were divided into groups with stable (Si, Al, Na, and C_wso) and variable (Co, Mo, Ni, Sb, and Pb) concentration levels. The spatial variation component of the solution composition was lower than its time dynamics. The intratype variability of the composition of the solutions was insignificant within a season, but it was significantly affected by the contrasting climatic conditions of different years. The solutions from the upper soil horizons had different specific features. The F, H, and AE horizons were similar in their solution composition, and the solutions from the E horizon and litter differed in the concentrations of most macro-and microelements and their pH values.     

Effect of bentonite characteristics on the elemental composition of wine

Physical, chemical, and mineralogical characteristics of six bentonites were assessed and related to their elemental release to wine. Extraction essays of bentonites in wine at three pH levels were carried out. The multielemental analysis of bentonites and wines was performed by atomic absorption spectrometry (AAS) and inductively coupled plasma mass spectrometry (ICP-MS). Bentonite addition resulted in significantly higher concentrations of Li, Be, Na, Mg, Al, Ca, Sc, V, Mn, Fe, Co, Ni, Ga, Ge, As, Sr, Y, Zr, Nb, Mo, Cd, Sn, Sb, Ba, W, Tl, Bi, and W. In contrast, the concentrations of B, K, Cu, Zn, and Rb significantly decreased. A strong correlation between Na concentrations of treated wines and its content in bentonite exchange complex was observed. Al and Fe contents reflected bentonite extractable aluminous and ferruginous constituents, while Be, Mg, Ca, V, Mn, Ni, Ge, Zr, Nb, Mo, Sn, Sb, Tl, Pb, and U concentrations reflected the elemental composition of bentonites. Several nonconformances with OIV specifications demonstrated the need for an effective control.     

Changes in the elemental composition of lignin during humification

Lignin was extracted with aqueous dioxane in the genetic series of humification: dead nonhumified plants → plant residues at the initial stage of humification (during the first 1–3 annual cycles) → weakly decomposed peat → highly decomposed peat. In the course of the humification and peat formation, the lignin was subjected to profound redox transformation; therefore, the elemental composition of the dioxane lignin in the humified peat-forming plants differed from that in the original plants by the higher contents of hydrogen and nitrogen and the lower contents of oxygen and carbon. As a result of the redox reactions, the lignin was partly oxidized and converted to humic substances during the humification of the dead plants. Therefore, it could not be extracted with aqueous dioxane. The reduced part of the lignin remained in the humified materials. The proportion of aromatic fragments in the molecules of the remaining lignin was smaller and that of aliphatic fragments larger than in the lignin of the original plants.     

不同土壤与海拔高度对谷子(粟)蛋白质氨基酸组成的影响

用红土、黄土和红黄土3种土壤在不同海拔高度进行谷子优质栽培试验.结果表明,与红黄土相比,红土和黄土地种植的谷子籽粒蛋白质质量较高,主要氨基酸含量分别高25.4%和21.4%;必需氨基酸含量高23.2%和21.6%;除赖氨酸外其余氨基酸含量基本接近人体的需求量;氨基酸指数高21.5%和21.9%.在较高海拔高度种植的谷子蛋白质品质较优,1100～1200m比900～1100m海拔高度种植的谷子主要氨基酸含量高8.7%,氨基酸指数高7.8%.因此,谷子优质栽培适于在1100～1200m海拔高度的红土或黄土地种植为宜.     

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。     

Selective determination and formation of elemental selenium in soils

A selective method for the determination of elemental selenium in soil was developed and was applied to the study of elemental selenium in soil. (1) Elemental selenium extracted with carbon disulfide from soil was selectively transformed into selenocyanate ion by reacting with potassium cyanide in carbon disulfide. The selenocyanate ion formed was recovered into an aqueous solution and the amount of selenium in the aqueous solution was determined. This method was specific to elemental selenium and did not interfere with the other selenium compounds and soil components. The method was also highly sensitive and enable to determine more than 0.1 μg kg^-1 of elemental selenium in soil. (2) The formation of elemental selenium was confirmed, when a soil was submerged and the redox potential of the soil decreased. The amount of elemental selenium formed was proportional to the selenite content of the soil, indicating that elemental selenium is transformed from selenite upon its reduction.     

Effect of water composition on phosphorus concentration in runoff and water-soluble phosphate in two grassland soils

Many irrigation experiments determine phosphorus (P) losses from soil. Often, these studies cannot be compared, because the irrigation water was not characterized. We used calcium‐rich tap water and deionized water to investigate the influence of water composition on P concentrations in induced runoff. We irrigated two grassland sites: one acid and one calcareous. Less P was measured in runoff from tap water irrigation than from deionized water, especially for the acid soil. Batch experiments confirmed the findings of the field experiments. Tap water decreased water‐soluble phosphate and increased calcium in the solid phase. This interaction increased with decreasing soil:water ratio. Water of low ionic strength gave results comparable to rainwater. Our findings demonstrate that solution chemistry and the soil:water ratio can strongly influence the availability of P for transport. We recommend that P tests or irrigation experiments should use water resembling that of the system of interest. Irrigation experiments aiming to simulate P losses by surface runoff should be carried out with water having a composition comparable to rainwater.     

Effects of vegetation regime on denitrification potential in two tropical volcanic soils

Effects of vegetation and nutrient availability on potentail denitrification rates were studied in two volcanic, alluvial-terrace soils in lowland Costa Rica that differ greatly in weathering stage and thus in availability of P and base cations. Potential denitrification rates were significantly higher in plots where vegetation had been left undisturbed than in plots where all vegetation had been removed continuously, and were higher on the less fertile of the two soils. The potential denitrification rates were correlated strongly with respiration rates, levels of mineralizable N, microbial biomass, and moisture content, and moderately well with concentrations of extractable NH _inf4 ^sup+ , Kjeldahl N, and total C. In all plots, denitrification rates were stimulated by the removal of O₂ and by the addition of glucose but not by the addition of water or NO _inf3 ^sup- .This is Paper 2772 of the Forest Research Laboratory, Oregon State University     

生物炭对两种植烟土壤活性有机碳的影响

为调查烟秆生物炭对典型植烟土壤根际与非根际活性有机碳组分的影响及其在不同土壤类型中是否具有一致性,选取我国烟草主产区贵州省毕节市黄壤区(东部的黔西林泉科技示范园)和黄棕壤区(西部的威宁黑石科技示范园)两个土壤类型,研究施用不同量烟秆生物炭(0、5、20、40 t·hm-2,分别记为B0、B5、B20、B40)后根际与非根际土壤总有机碳(TOC)、易氧化有机碳(ROOC)、可溶性有机碳(DOC)和微生物量碳(MBC)含量的变化情况。施用生物炭后,根际土壤TOC、ROOC以及非根际土壤DOC在两个土壤中的表现基本一致,而其余则在两种土壤中表现不同。但整体表现为TOC、ROOC及DOC含量在B5处理中没有显著变化,而在B20和B40处理中显著增加,3种有机碳含量与B0相比,增幅最高分别可达305.63%、630.41%及768.48%;不同有机碳及土壤类型的峰值出现在B20或B40处理中。而对MBC来说,非根际土壤中MBC含量在黄壤B5处理中显著降低了20%,在黄棕壤B20和B40处理中分别显著增加了53.98%和145.80%,其余处理与B0之间没有显著差异;而在根际土壤中仅在黄壤B20处理中MBC含量显著增加42.17%,其余处理与B0之间均无显著差异。说明短期施用生物炭对植烟土壤活性有机碳组分(尤其是MBC)的影响与土壤类型、生物炭施用量、根际环境等有关。     

土施有机添加剂和硫磺对小白菜生长和养分吸收的影响

通过盆栽试验,研究了土施粗氨基酸、风化煤、L-TRP、L-PHE和硫磺对小白菜干物质积累、叶绿素含量、硝酸盐含量、硝酸还原酶活性(NRA)以及N、P、K、Fe吸收的影响。结果表明,土施风化煤、硫磺以及L-TRP和L-PHE混施可以显著提高小白菜生物量。当风化煤的用量为20g/kg干土时,能显著提高小白菜的叶绿素含量和N的吸收量,改善氮素营养状况。当硫磺的施用量为0.2g/kg干土和0.4g/kg干土时,可使小白菜体内的硝酸盐含量分别比对照降低41.6%和47.4%。供试条件下,硫磺可以提高小白菜对P、K、Fe的吸收,而粗氨基酸、风化煤、L-TRP、L-PHE以及L-TRP和L-PHE混施处理抑制了P、K、Fe的吸收或促进作用不明显。研究结果还表明,土施有机添加剂和硫磺与对照相比,能显著提高小白菜体内的NRA,但是各处理硝酸盐含量与NRA之间不存在显著的相关关系,NRA提高可能是由于植物激素或有机酸和硝酸盐共同作用的结果。     

Effects of two grass species on the composition of soil fungal communities

Many studies have shown effects of plants species on fungal communities, but these are often confounded with soil effects. Thus, the specific role of plant species in structuring rhizospheric and soil fungal communities is poorly described. Our study used microcosms in which plants were grown under artificial conditions to bridge this gap. Two perennial grasses dominating subalpine grasslands, Festuca paniculata and Dactylis glomerata, were grown at two levels of fertilization on standard soil. Fungal communities were determined by 454 pyrosequencing of the internal transcribed spacer 1 region. Among the fungal communities characterized by the primers used, original communities were associated to each plant species and also diverged between rhizosphere and bulk soils within each plant species, though there were no significant fertilization effects. Differences regarded global composition of the fungal communities and abundant molecular operational taxonomic units (MOTUs). Both plant species and location effects were reflected more in the abundance than in the composition of MOTUs. The observed differences in fungal communities coincide with differing strategies of plant root growth, with D. glomerata having greater root mass, length, and area than F. paniculata. Our study, by dissociating soil effects from plant effects, demonstrated that plant species exert a key control on soil fungi. We suggest that such effects may be linked to inter-specific differences in root traits and their consequences on nitrogen uptake.     

Effects of dissolved organic carbon on phosphate retention on two calcareous soils

To evaluate the effects of dissolved organic carbon (DOC) on phosphate retention (including both sorption and/or precipitation reactions) on soils, experiments were performed by using two typical calcareous soils from southeastern Spain (Calcic Regosol and Luvic Xerosol) and two different types of DOC: (1) extracts from a commercial peat (DOC-PE) and (2) high-purity tannic acid (DOC-TA). The experiments were carried out from a 0.01 M CaCl2 aqueous medium at 25 degrees C. The results obtained show that the presence of both DOC-PE and DOC-TA, over a concentration range of 15 (DOC-15) to 100 (DOC-100) mg L(-1), produces in all cases a decreasing amount of phosphate retained in the soils studied, the decrease observed being higher when DOC-PE is used as source of DOC. The values of the decrease observed when DOC-PE was added ranged between 19.9% (DOC-15) and 15.6% (DOC-100) for the Calcic Regosol and between 17.3% (DOC-70, DOC-100) and 14.6% (DOC-15) for the Luvic Xerosol. The variation observed when DOC-TA was added ranged between 8.5% (DOC-100) and 0.5% (DOC-35) for the Calcic Regosol and between 7.0% (DOC-100) and 1.0% (DOC-15) for the Luvic Xerosol.     

Effects of nitrogen fertilizer on the acidification of two typical acid soils in South China

Purpose

A laboratory incubation under constant temperature and humidity was conducted to estimate the impacts of nitrogen (N) fertilizers on the acidification of two acid soils (Plinthudult and Paleudalfs) in south China.

Materials and methods

The experiment had three treatments, i.e., control (CK), addition of urea (U), and addition of ammonium sulfate (AS). We measured soil pH, nitrate (NO₃ ^?), ammonium (NH₄ ⁺), exchangeable hydrogen ion (H⁺), and aluminum ion (Al³⁺) concentrations at various intervals during the 90 days of incubation. Soil buffering capacity (pHBC) was also measured at the end of the experiment.

Results and discussion

The application of N fertilizers resulted in soil acidification. The U treatment caused greater acidification of the Plinthudult soil than the AS treatment, while there were no differences between U and AS treatments on the acidification of the Paleudalfs. At the end of the trial, the pHBC of Plinthudult in AS treatment was greater than that in CK and U treatments, which may be due to the buffering system of NH₄ ⁺ and NH₄OH. However, the pHBC of Paleudalfs was unchanged between treatments. The dynamics of exchangeable H⁺ and Al³⁺ corresponded to that of soil pH. Correlation analysis showed that both soil exchangeable H⁺ and soil exchangeable Al³⁺ were significantly related to soil pH.

Conclusions

Application of urea and ammonium sulfate caused acidification in both soils and increased soil exchangeable Al³⁺ and H⁺ concentrations in the Paleudalfs. The application of urea increased exchangeable Al³⁺, and ammonium sulfate increased pHBC in the Plinthudult.     

Total elemental analysis digestion method evaluation on soils and clays

Abstract

The standard digestion method for total elemental analysis of soil material by the Soil Survey Laboratory (USDA Natural Resources Conservation Service) uses a 2‐mL clay suspension with hydrofluoric acid (HF) in a closed Teflon digestion vessel (method HF‐SUS). The accuracy and efficiency of elemental recovery by method HF‐SUS was compared to: (a) modification of HF‐SUS by use of a dried sample (method HF‐DRI); (b) modification of HF‐SUS by use of a dried sample and HF+aqua regia (method HF+AR); (c) sample digestion by Li metaborate fusion (method FUS); and (d) microwave digestion of samples with HF+aqua regia in Teflon bombs (method MICRO). Three replications of three standard reference materials (SRMs), fine‐earth (<2 mm) from 12 soils, and the clay (<2 urn) from 10 of those soils were analyzed. Method HF+AR shows the most consistent statistical agreement with the certified SRM values. Analysis of variance (ANOVA) indicates significant effects (α=0.05) for method of digestion, nonsignificant effects for method times SRM and method times clay, but significant effects for method times fine‐earth. Composition and/or variability of material are significant factors in the method of digestion. Method HF+AR yields significantly higher experimental means of A1₂O₃, Fe₂O₃, and K₂O contents and oxide recovery (summation of experimental means for oxides of all reported elements) than all other methods.     

pH Influenced by the elemental composition of nutrient solutions

Nutrient solutions can be considered as aqueous solutions of inorganic ions. The pH of a nutrient solution is a property that is inherent to its composition. If another pH is aimed at, this can only be reached by changing the elemental composition. The pH of an aqueous solution is determined by the initial concentration of acids and bases. In the case of nutrient solutions, this is dihydrogen phosphate (H₂PO₄ ^‐), bicarbonate (HCO₃ ^‐) and/or ammonium (NH₄ ⁺). In this study, formulas are derived to calculate the pH of a nutrient solution as a function of the concentration of H₂PO₄ ^‐, NH₄ ⁺, and/or HCO₃ ^‐. The pH of a nutrient solution affects the dissociation, complexation, and precipitation reactions occurring in nutrient solutions. These chemical reactions significantly impact elemental speciation and bioavailability, and therefore, have to be taken into account in hydroponic plant nutritional research. The term “speciation”; indicates the distribution of elements among their various chemical and physical forms like: free ions, soluble complexes, chelates, ion pairs, solid and gaseous phases, and different oxidation states, all of which influences their reactivity, mobility and bioavailability. A good knowledge of the chemical reactions occurring in nutrient solutions is the first prerequisite in hydroponic plant nutritional research. The pH of a nutrient solution is determined by its initial concentration of H₂PO₄ ^‐, NH₄ ⁺, and HCO₃ ^‐.