Residual effects of growing mungbean and uridbean on the yield and nitrogen uptake of a succeeding wheat crop

A two year field experiment was carried out at the Indian Agricutural Research Institute, New Delhi - 110012, India to assess the effect of mungbean (Vigna radiata L.) and uridbean (Vigna mungo L.) residues on the yield and N uptake of a succeeding wheat crop as compared to sorghum fodder. Sorghum produced 3.5–7.5 times more dry matter and removed 2–3 times more nitrogen than mungbean or uridbean during same duration (80 ± 10 days) of their growth. Without N application the grain yield of wheat following mungbean and uridbean (without residue incorporation) was 0.45 and 0.48 t ha^–1 more than the yield of wheat following sorghum fodder. These yields were equivalent to that predicted when 36 and 38 kg urea-N ha^–1, respectively, was directly applied to wheat. The residual effects of these grain legumes were higher when succeeding wheat was fertilized with 60 kg urea-N ha^–1; at this level mungbean and uridbean spared 52 and 43 kg urea-N ha^–1, respectively, in succeeding wheat. The residual effect of mungbean and uridbean further increased when their residue was incorporated in soil; with this practice they spared 94 and 115 kg urea-N ha^–1, respectively, without N application to wheat and 74 and 82 kg urea-N ha^–1, respectively, with an application of 60 kg urea-N ha^–1 to wheat.Mungbean and uridbean, without residue incorporation, increased aboveground plant-N uptake of succeeding wheat by 11.5–34.9 and 10.8–34.0 kg N ha^–1, respectively; whereas with residue incorporation, they increased aboveground plant-N content of succeeding wheat by 26.1–45.8 and 32.7–47.7 kg N ha^–1, respectively.The results of the present study indicate that there is both an indirect sparing effect and a direct residual effect of mungbean and uridbean on the nitrogen needs of succeeding wheat, more so when their residues are incorporated in soil.     

Wacker type and π-allyl type oxidations of propylene controlled by fuel cell system in the gas phase

Oxidation of propylene applying the (C₃H₆, Pd/H₃PO₄/Pt, O₂) fuel cell system in the gas phase produced acrolein and acrylic acid, the -allyl type oxidation products. However, addition of H₂PdCl₄ or HCl to the electrolyte reduced the -allyl oxidation, but enhanced Wacker type oxidation producing acetone. Direction to either Wacker type or -allyl type oxidation can easily be controlled electrochemically by applying the fuel cell system in the gas phase.     

Catalytic properties of new Cu based catalysts containing Zr and/or V for methanol synthesis from a carbon dioxide and hydrogen mixture

Pure unsupported copper is a poor catalyst for CH₃OH synthesis from CO₂+H₂ when it is compared to Cu coprecipitated with Zr or Zr+V in which case its selectivity and yield in methanol are strongly enhanced. The two Zr and V components added to pure Cu are shown to be textural promoters towards zerovalent Cu which participate to the building of the active sites. Methanol formation on these catalysts is a structure insensitive reaction with respect to the metallic Cu dosed by N₂O surface decomposition.     

Developing alternatives to phosphate fertilizers of high water solubility

Superphosphate applied to annual pastures growing on the acidic, sandy-surfaced soils of the coastal plain areas of south-western Australia is the major cause of eutrophication of waterbodies. Watersoluble phosphate, both from freshly applied and previously applied fertilizer, is leached from the profile from deep sandy soils or moved by lateral water flow on shallow sands. As part of an integrated catchment management program for the eutrophic waterbodies, an intensive research program was conducted to develop alternatives to highly water soluble phosphatic fertilizers which were argonomically and economically effective. Field, glasshouse and laboratory work identified several sources of phosphate with low initial water solubility which were at least as effective as superphosphate, and which could be formulated and commercially produced as a practical alternative to superphosphate. On the deep sandy soils, these slow release sources - the most useful of which was found to be sulphurfortified, partially-acidulated rock phosphates - had lower phosphorus leaching losses associated with their use than superphosphate on the basis of equal production of dry matter. The experimental work also investigated some of the factors controlling the agronomic effectiveness of these fertilizers, to enable identification of specific soils on which they are likely to be effective substitutes for superphosphate.     

Effect of the naturally occurring salt ‘Kanwa’ as a fertilizer on the productivity ofStylosanthes in the subhumid zone of Nigeria

Soil nutrient deficiencies pose a serious limitation to higher crop and forage yields in the Nigerian subhumid zone. Some of the deficiencies may be alleviated by using as a fertilizer a salt mined locally called Kanwa which is traditionally used as a cattle lick. Yields ofStylosanthes hamata cv Verano andS. guianensis cv Cook seed and dry matter increased with Kanwa application at different locations. The effect of Kanwa was enhanced when phosphorus was adequately supplied. Improvements to soil physical properties were proportional to the yield of the legume. The implications of good quality fodder and improved soil conditions in Agro-pastoral Systems in the Nigerian SHZ are discussed.     

Nutrient transformation in soil due to addition of organic manure and growing crops

Maintaining organic pools of nitrogen (N) in soil is important for providing a steady flux of N in soil solution. Bioslurry, which is the product obtained from anaerobically digested (methanised) farm yard manure (FYM), is an efficient source of organic manure with capability to supply nutrients, particularly N to crops. A study was conducted to see the equilibrium relationship between the inorganic and organic N fractions as affected by application of bioslurry and fertilizer N in a maize (Zea mays L.) — mustard (Brassica campestris) crop sequence. Results obtained revealed that 75.7 percent of the total soil N was in the hydrolyzable N fraction. Among the hydrolyzable fractions, aminoacid N, unidentified N and hydrolyzable NH ₄ ⁺ constituted 25.8, 25.7 and 18.6 percent of the total N, respectively. Ammonium fixed in clay lattice constituted 19.1 percent of the total N. Application of bioslurry @ 13.32 t ha^–1 under N-unfertilized conditions increased NO₃-N, fixed NH ₄ ⁺ , aminoacid N, hexosamine N and hydrolyzable NH ₄ ⁺ . The magnitude of increase in total hydrolyzable and inorganic N fractions was 31.4 and 15.2 percent, respectively. Growing crops decreased N in the inorganic fractions. Transformation reaction of organic N to inorganic N was evident after second crop in the sequence. Fertilizer N application encouraged build-up of N in organic fractions, particularly in aminoacid, hydrolyzable NH ₄ ⁺ and unidentified N fractions. Application of bioslurry maintained higher status of N in both organic and inorganic N fractions. Linear regression relationship between N content in different fractions and bioslurry applied both under fertilized and unfertilized conditions assisted in developing prediction models on the rate of bioslurry to be applied to arrive at the desired N content in different fractions. Significant intercorrelation coefficients (r²) between different fractions indicated free mobility between the N fractions under limited N conditions suggesting a dynamic equilibrium between them. Path coefficient analysis showed that exchangeable NH ₄ ⁺ and NO₃-N had substantial direct positive effect on N uptake by mustard with bioslurry application. Under untreated conditions exchangeable NH ₄ ⁺ , hexosamine and hydrolyzable NH ₄ ⁺ fractions had higher direct contribution to meet mustard N requirement. Most of the hydrolyzable N fractions contributed to N uptake by mustard by first transforming to exchangeable NH ₄ ⁺ and NO₃—N and thus setting an equilibrium condition for maintaining the steady flux of N to plants.Part of Ph.D. Thesis of the senior author     

Partial oxidation of methane to synthesis gas

Partial oxidation of methane to synthesis gas has been carried out over a number of transition metal catalysts under a range of conditions. It is found that the metals Ni, Ru, Rh, Pd, Ir and Pt, either supported on alumina or present in mixed metal oxide precursors, will bring the system to equilibrium. The yield of CO and H2 improves with increasing temperature in the range 650–1050 K, and decreases with increasing pressure between 1 and 20 atm. An excellent yield (92%) is obtained with a 421 N₂CH₄O₂ ratio at 1050 K and atmospheric pressure, with a space velocity of 4×10⁴ hour^–1.     

Influence of source,rate, and method of applicating controlled release fertilizer on nutrient release and growth of ‘Savannah’ holly

An experiment was conducted to determine the effect of rate of fertilizer application and method of application on the rate of nutrient release and growth of Savannah holly (Ilex ×attenuata Ashe) using three controlled release fertilizers. The controlled release fertilizers used were Osmocote 17N—3P—9.9K, Sierrablen 17N—3P—8.3K, and High-N 24N—1.7P—5.8K, all 12 to 14 month formulations. The three fertilizers had different release rates as determined by leachate nitrate—N and electrical conductivity (EC) measurements. Topdressing of fertilizer had the greatest release rate at seven days after treatment compared to fertilizer incorporation which had the lowest EC readings at 120 days after treatment. Fertilizer source had no effect on the shoot growth of Savannah holly. Growth index and shoot dry weight of Savannah holly increased linearly as N rate increased from 0.9 to 2.1 kg N m^–3. A significant linear relationship (R² = 0.97, Nitrate—N = 409 (EC)) between nitrate—N and EC indicates that nitrate—N concentration can be estimated from EC readings when the pour-through method is used with multicoated controlled release fertilizers. The controlled release fertilizers used in this study provided adequate nutrient release rates for up to four months under outdoor nursery conditions during the months of June through October.     

Synthesis and properties of aromatic polyesters and brominated polyesters derived from α,α′-bis(4-hydroxyphenyl)-1,4(or 1,3)-diisopropylbenzene

The interfacial polycondensation technique was used for the preparation of polyarylates and brominated polyarylates. Polyarylates and brominated polyarylates were prepared by mixing a solution of diacid chloride such as terephthaloyl chloride, isophthaloyl chloride, or their mixture in dichloromethane with an aqueous alkaline solution of ,-bis(4-hydroxyphenyl)-1,4(or 1,3)-diisopropylbenzene or ,-bis(4-hydroxy-3,5-dibromophenyl)-1,4(or 1,3)-diisopropylbenzene using triethylbenzylammonium chloride as the phase transfer agent. Moderate to high molecular weight polyarylates with _inh up to 1.27 dL/g were obtained, and most of them could be cast into tough and flexible films depending on the polymer composition. In general, polymers containing more 1,3-isomer or isophthaloyl chloride moieties gave transparent and flexible films and had lower glass transition temperatures and higher solubility. Although these polymers have two isopropylidene linkages in their repeating units, they still exhibit moderately high thermal stability and show no obvious weight loss before 400 °C. The introduction of bromine on the polymer backbone caused a decrease of inherent viscosity, crystallinity, and thermal stability of the polyarylates, while causing an increase in glass transition temperature and a great enhancement of fire retardancy.     

Synergistic interaction between potato glycoalkaloidsα-solanine andα-chaconine in relation to destabilization of cell membranes: Ecological implications

In studies of the lysis of rabbit erythrocytes, red beet cells, andPenicillium notatum protoplasts by the potato glycoalkaloids -solanine and -chaconine, the latter was consistently the more membrane-disruptive compound and erythrocytes the more susceptible cell type. A 11 mixture of solanine and chaconine produced pronounced synergistic effects in all three test systems. In beet cells, such effects were apparent from an early stage of treatment and persisted over a period of several hours. With erythrocytes and fungal protoplasts, the synergism was maximal with mixtures containing approximately 70% chaconine, whereas with beet cells it peaked at approximately 40% chaconine. Synergistic interactions between solanine and chaconine also occurred with regard to cholesterol binding in vitro, with a maximum response corresponding to the 50% mixture. The implications of these findings for the nature and efficacy of chemical defense systems in plants are discussed.     

Steady-state kinetics of the NO-CO reaction on Rh(111): extrapolation from 10−10 to 1 bar

Ultrahigh vacuum studies indicate that the mechanism of the NO-CO reaction on Rh(111) involves reversible adsorption of NO and CO, NO decomposition, nitrogen desorption, and a Langmuir-Hinshelwood reaction between CO and oxygen. Employing available experimental data for the rate constants of these steps, we have calculated the steady-state reaction kinetics in a wide range of pressures and temperatures. At relatively high pressures (P _NOP _CO0.01 bar), the results of simulations are in marginal agreement with the experimental data. Analyzing the difference between the theory and experiment makes it possible to understand the type of changes which might be introduced into the model in order to improve the agreement with the experiment.     

Crystal Orientation Dependence of Macropore Formation in n-Si With Backside-Illumination in HF-Electrolyte

The formation of macropores on anodically biased n-type silicon with backside-illumination was investigated as a function of crystal orientation and bias voltage. Specimens were cut from bulk crystals with various orientations from {100} to {111}, polished and subjected to anodic etching in HF. The resulting pores were investigated on cleaved samples by SEM. All pores were found to grow in either a 100 direction or a 113 direction, depending on the misorientation angle. This finding applies also to the branching of a single pore. The results can be understood if the valence for the dissolution reaction is approximately 2.6 in 100 and approximately 4 in the 113 direction, and if all other directions are not allowed for the growth of pores in Si.     

Organic-Inorganic Hybrid Materials Based on the Incorporation of Polysilicic Acid Nanoparticle (PN) with Organic Polymers. 3. Shrinkage Characteristics in the Cure of Unsaturated Polyester Resin in the Presence of a Modified PN

The polysilicic acid nanoparticle (PN) was modified by the reaction of silanol group on its surface with silyl group (–Si(OR)₃) containing modifiers such as phenyltrimethoxylsilane (PTS), 2-(p-styryl)ethyltrimethoxylsilane (SETS), and 3-(trimethoxylsilyl)propyl methacrylate (TPMA), respectively, to afford modified PNs (M-PNs) including P-PN, S-PN, and T-PN. P-PN, S-PN and T-PN were mixed, respectively, with unsaturated polyester resin (UP) in styrene, UP/St, and then let homogeneous solutions cure at 150°C to produce transparent hybrid materials, UP/St/P-PN, UP/St/S-PN, and UP/St/T-PN. It was found that the M-PNs could not only act as low-profile additives (LPAs) to reduce the shrinkage of the hybrids during curing but also enhance their dynamic mechanical properties. The shrinking mechanism of the hybrids during curing and the interfacial force between M-PNs and UP/St matrix, which plays an important role in shrinking control and properties of hybrid, were studied in detail.     

Model of Air Gasification of a Solid Fuel in a Filtration Regime

A twotemperature mathematical model of steady filtration combustion is proposed. The model takes into account the finite length of the reactor and the dependence of heat capacities of the phases on temperature and composition. The model describes the process of gasification of a solid fuel in a filtration regime. Calculation results for the gasification reaction of a carbon–nert component mixture are presented. The range of fractions of the fuel component is determined in which neither a purely normal nor a purely inverse wave is formed (an approach of a transitional wave is proposed for this interval). It is shown that the combustion temperature is finite within the entire interval of fractions of the fuel component.     

Hydroformylation of functional alkenes with heterodonor phosphine rhodium catalysts: substrate or ligand directed regioselectivity?

The catalytic activity and selectivity of heterodonor phosphine rhodium catalysts prepared in situ were tested in the hydroformylation of functional alkenes (ethyl acrylate, methyl methacrylate, styrene, 4-vinyl-1-cyclohexene, dicyclopentadiene and cis-1,2,3,6-tetrahydrophthalic anhydride). Systematic variation of the heterodonor atom in the ortho position of the ligand showed that the heterodonor atom has a significant influence on the activities and selectivities of the reaction. However, the activity seems to depend mainly on the modifying ligand, and the regioselectivity mainly on the substrate (i.e., the structure and functionality of the alkene). Nevertheless, regioselective control is only obtained through synergy between the substrate and the catalyst. Clear regiocontrol was observed in the hydroformylation of ,-unsaturated esters and styrene with an in situ formed o-(thiomethylphenyl)diphenylphosphine rhodium catalyst.     

Transport of phosphorus forms and of nitrate through a clay soil under grass and cereal production

Many nutrients are lost from soil to water viatile drains. However, there are very few reliable studies of such phosphorus(P)losses under Swedish agriculture practices, especially in connection tofertiliser and slurry applications and related to nutrient balances. Tile drainlosses were measured from nine experimental plots in south-west Sweden; fourplots were measured for 7 years and five plots for 2–3 years. Cereals,mainly spring barley (Hordeum vulgare, L.) and oats(Avena sativa, L.), were grown in six plots, while oneplotwas cultivated with grass, timothy (Phleum pratense L.)andmeadow fescue (Festuca pratensis, L.), one with lucerne(Medicago sativa, L.) and meadow fescue (F.pratensis, L.), and the last one was a set-aside withgrass (Lolium perenne, L. and Trifoliumrepens, L.) that was neither fertilised nor used for crop removal.Attention was paid to the forms in which P was transported to water since thishas important ecological implications. Average losses of particulate P (PP)fromthe set-aside land was significantly lower than from the cerealproduction, but the average losses of soluble reactive P (SRP) and dissolvednonreactive P (DUP) were the same. Average loss of PP from the grass ley during 3years (0.09 kg per ha^–1 y^–1) wassignificantly less than the losses from cereal production. Total P loss of 0.3kg per ha^–1 y^–1 was equal to the averagelossfrom the Swedish monitoring network of observation fields. Compared to theaverage nitrate-nitrogen (NO₃-N) leaching, which was 7 kg perha^–1 y^–1 from cereals, the NO₃-Nleaching was very low from the plots with lucerne-grass and set-aside.After applying and directly ploughing in 80 kg ha^–1 ofsuperphosphate for cereal production in November 1998, 0.6–1.8 kgSRP ha^–1 y^–1 was lost through the drain tiles.Surface application of cattle slurry in spring 1999 to the grass ley alsoresulted in a very pronounced increased base level of SRP. This paper documentsthe importance of applying slurry during dry conditions and of placingfertiliser into the soil according to crop requirements in the time perspectiveof one year.     

Asymmetric structure analysis of active surface-sites by in situ polarized total-reflection fluorescence EXAFS

An in situ polarization-dependent total reflection fluorescence yield EXAFS system has been developed to analyze the asymmetric structures of catalytically active metal sites on single crystal surfaces. This technique separately reveals the bonding feature parallel and perpendicular to the support surface. The systems of Cu ion on -quartz(0001), Co oxide on -alumina(0001), and Pt₄ on -alumina(0001) were investigated as model surfaces of supported catalytic systems. The location of Cu sites on -quartz(0001), the epitaxial growth mode of Co₃O₄ on -alumina(0001), and the Pt raft structure with metal-support interaction in Pt₄ / -alumina(0001) were observed.     

Computational and Theoretical Studies of Mass‐Spectrometric Measurements of the Comet Halley Dust Composition in Vega Experiments

Results of computational and theoretical studies are presented. A formulation of the problem is given and approaches to its solution are described. Brief information is given on the models, difference methods, and software designed or adapted to perform direct numerical modeling of massspectrometric measurements of cometary dust on PUMA instruments. The results of a number of computational experiments are presented.     

Silyl Triflate-Initiated Ring-Opening Polymerizations of Cyclosiloxanes

Polymer yields between 70 and 85% form in ring-opening polymerizations of trimeric cyclosiloxanes initiated with trimethylsilyl triflate in the presence of a selective scavenger for protic acids, 2,6-di-t-butylpyridine. Examples include the polymerization of 1,3,5-trimethyl-1,3,5-tris(3,3,3-trifluoropropyl)cyclotrisiloxane (F₃) and hexamethylcyclotrisiloxane (D₃). Siloxane bond redistribution is essentially absent and data are presented establishing a nonterminating polymerization giving an average of roughly one trimethylsilyl group per chain. The present observations contrast with other work that suggests that the presence of free triflic acid is required for initiation with trimethylsilyl triflate.