The effect of ferrous sulphate on the yield and manganese uptake of oats on sandy soil fertilized with pyrolusite

Summary In pot experiments with oats on a sandy soil deficient in managanese and with an extremely low content of reducible managanese, the effect of 0.125 g reducible managanese in two pyrolusite fertilizers (-managanese dioxides) made in 1938 and 1955, respectively, was compared with the effect of 0.125 g water-soluble managanese as managanese sulphate.On soil to which no ferrous sulphate was added, the response to manganese added as Pyrolusite 1938 and Pyrolusite 1955 was of the same magnitude, but slightly less than the response to managanese added as managanese sulphate. The difference between the effect of pyrolusite and that of managanese sulphate was not, however, statistically significant.On soil to which ferrous sulphate had been added, a response was obtained to Pyrolusite 1938 twice as high, and to Pyrolusite 1955 three times as high as the response to manganese sulphate. These results support the suggestion² that the manganese effect of ferrous sulphate is due to its ability to reduce higher managanese oxides in the soil.Since soil dressed with ferrous sulphate gave a response to added Pyrolusite 1955 which was about 50 per cent higher than the response to Pyrolusite 1938, and since, furthermore, the same amount of reducible manganese and the same number of manganese atoms on the surface of the two fertilizers were involved, it is probable that the difference between the effects of the two pyrolusite fertilizers found under these circumstances is due to difference in their crystallinity.     

The effect of ferrous sulphate on the yield and manganese uptake of oats on sandy soil fertilized with natural pyrolusite

Summary The effects of soil treatments with ferrous sulphate and an equivalent amount of hydroquinone on the yield of dry matter and the manganese uptake of oats were investigated in pot experiments using a sandy soil deficient in manganese, with and without additions of finely ground, natural pyrolusite containing some manganite.In soil not fertilized with pyrolusite an application of hydroquinone gave a higher yield of dry matter and a considerably higher manganese uptake than an application of the equivalent quantity of ferrous sulphate.In soil fertilized with hydroquinone an increase of 23 per cent in the yield of dry matter and an increase of 50 per cent in the manganese uptake per pot were found when the soil was fertilized with 100 g of natural pyrolusite <50µ per pot. In soil fertilized with a quantity of ferrous sulphate equivalent to hydroquinone, an increase of 21 percent in the yield of dry matter and an increase of about 200 per cent in the manganese uptake per pot were found when the 100 g of pyrolusite was applied.     

The effect of liming a neutral soil on the uptake of manganese by plants

Summary The uptake of manganese by oats in a manganese-deficient soil was increased on raising the pH from 7.0 to 8.0 with Ca(OH)₂. This effect occurred in the absence of added manganese as well as when manganese was added to the soil as -MnO₂. When the soil was initially sterilized the uptake of manganese at pH 7.0 was greatly increased at both pH's, but the uptake at pH 8.0 was now a smaller than at pH 7.0.     

Chemical methods of estimating plant available manganese in soils

Summary Twelve different chemical extraction procedures for extracting soil manganese were used. Soil test values determined for fourteen representative soil samples of Rajasthan State with manganese uptake by six crop species have shown that of the extractants used, 3N ammonium dihydrogen orthophosphate can be best used for estimating plant available soil manganese.     

An effect of conifers on available soil nitrogen

Summary Comparison of the soil and herbaceous vegetation beneath young conifers and adjacent open fields identical in prior treatment shows that conifers increase nitrogen availability above their own net uptake. The effect extends a short distance beyond their crowns. The presumed explanation is greater mineralization of soil nitrogen rather than fixation.     

Effect of soil and foliar application of ferrous sulphate and of acidulation of soil on iron chlorosis of paddy seedlings ingoradu soil nurseries in India

Summary Nursery experiments were conducted to determine the cause for the chronic problem of chlorosis in paddy seedlings raised ongoradu soil nurseries of Anand area of Kheda district of Gujarat State and to find out remedial measures for it. The findings are (i) the chlorosis is due to high bicarbonate content of the soil (ii) application of ferrous sulphate to soil at 40 kg Fe/ha increased the survival period of the seedling but did not quite control the chlorosis (iii) spray of 0.4% ferrous sulphate solution twice a week was helpful in partial recovery of the seedlings from chlorosis (iv) acidulation of soil with sulphuric acid about ten days prior to sowing produced very healthy, vigorous and green seedlings of paddy which did not show any signs of chlorosis at all and (v) total and IN HCl-soluble iron content of the shoots did not at all reflect the degree of chlorosis of the paddy seedlings. These results are discussed in the light of current theories of absorption and translocation of iron in plant system and the iron-chlorosis of paddy seedlings ingoradu soils is attributed to both soil and plant factors.     

Characterization of plant growth-promoting Bacillus edaphicus NBT and its effect on lead uptake by Indian mustard in a lead-amended soil

The plant growth promotion characteristics of a heavy-metal-resistant strain of Bacillus edaphicus NBT was characterized. The strain was also evaluated for promoting plant growth and lead (Pb) uptake of Brassica juncea L. Czern (Indian mustard) in soil artificially contaminated with 0, 400, and 800 mg Pb.kg-1 soil. Atomic absorption spectrometer analysis demonstrated that strain NBT could release water-soluble Pb from lead carbonate in the solution. Strain NBT had the capacity to produce indole acetic acid, siderophores, and 1-aminocyclopropane-1-carboxylate deaminase. Low and high Pb treatments significantly decreased the growth of Indian mustard. Inoculation with strain NBT was found to increase root dry mass (ranging from 16% to 22%) and above-ground tissue dry mass (ranging from 24% to 30%) of Indian mustard in the Pb-amended soil. Strain NBT was able to mobilize Pb efficiently in plants in Pb-amended soil. In the soil treated with 400 and 800 mg Pb.kg-1 soil, the increase in Pb uptake varied from 18% to 46% in live bacterium-inoculated Indian mustard plants compared with dead bacterium-inoculated control. The strain was also able to colonize and develop in the rhizosphere soil of Indian mustard after root inoculation.     

Preferential uptake of soil nitrogen forms by grassland plant species

In this study, we assessed whether a range of temperate grassland species showed preferential uptake for different chemical forms of N, including inorganic N and a range of amino acids that commonly occur in temperate grassland soil. Preferential uptake of dual-labelled (¹³C and ¹⁵N) glycine, serine, arginine and phenylalanine, as compared to inorganic N, was tested using plants growing in pots with natural field soil. We selected five grass species representing a gradient from fertilised, productive pastures to extensive, low productivity pastures (Lolium perenne, Holcus lanatus, Anthoxanthum odoratum, Deschampsia flexuosa, and Nardus stricta). Our data show that all grass species were able to take up directly a diversity of soil amino acids of varying complexity. Moreover, we present evidence of marked inter-species differences in preferential use of chemical forms of N of varying complexity. L. perenne was relatively more effective at using inorganic N and glycine compared to the most complex amino acid phenylalanine, whereas N. stricta showed a significant preference for serine over inorganic N. Total plant N acquisition, measured as root and shoot concentration of labelled compounds, also revealed pronounced inter-species differences which were related to plant growth rate: plants with higher biomass production were found to take up more inorganic N. Our findings indicate that species-specific differences in direct uptake of different N forms combined with total N acquisition could explain changes in competitive dominance of grass species in grasslands of differing fertility.     

土壤有效氮及其相关因素对植物细根的影响

细根(直径≤2mm)作为植物吸收水分和养分的主要器官之一,在陆地生态系统养分循环和能量流动中起重要作用。开展土壤有效氮变化对植物细根影响研究对于了解全球气候变化条件下的陆地生态系统养分循环具有重要意义。本文就相关研究进行了综述:1)土壤有效氮变化对植物细根生长、发育、寿命及呼吸的直接影响;2)土壤质地、温度、大气CO2浓度和氮沉积等相关因素对植物细根的影响。由于研究方法及物种间差异等的影响,研究结果不尽相同。今后,应在不同空间尺度上深入研究土壤有效氮对植物细根的影响,而植物细根-土壤-微生物三者间相互关系变化对土壤氮变化的潜在响应将可能成为今后研究的热点问题之一。     

On the mechanism of anion uptake by plant roots

Summary The effect of the valence of the associated cation on Cl^–-uptake by excised barley roots grown in CaSO₄ has been studied at 26°, 6° and 2°C. The uptake of Cl^– relative to that of the associated cation was found to increase in the order: trivalent > divalent > monovalent. This was explained on the expected effect of the cation on the negative charge and potential of root surfaces. A lyotropic order was observed in case of monovalent cations, whereas divalent cations showed no such order. The order observed in Cl^–-uptake from chloride solutions of monovalent cations is associated with the ability of the absorbed cation to remove Ca and Mg from the roots. Li⁺ behaved similar to divalent cations in affecting the relative Cl^–-uptake from LiCl.As to the effect of temperature on the uptake of Cl^– and associated cation, it appears that Cl^– is not taken up to any great extent at 2°C whereas cations are still adsorbed at this low temperature. This has been explained on the assumption of the presence of negative adsorption spots on the root surface which can hold cations but not anions. It appears that Cl^–-uptake by roots requires the expenditure of energy to overcome repulsion arising from the negative surface.This work is supported by AEC contract AT (11-1) — 34 project 55.     

On the mechanism of nitrate uptake by plant roots

Summary A study has been made on the influx and outflux of nitrogen compounds by the excised roots of barley, wheat and peas. A two way movement of nitrogen compounds was found to occur between root and external medium. Factors such as initial N content in the roots, species of plant and external concentration of N highly affect the extent to which this two-way movement proceeds. Further investigations are needed for more understanding of the nitrogen balance between plant roots and external medium.     

The effect of sodium chloride and sulphate on sulphur oxidation in soil

Summary The effect of sodium chloride on sulphur oxidation in Terra Rossa and Rendzina soils was studied by incubation and perfusion techniques. Sulphur oxidation was observed at concentrations up to 8 per cent NaCl, but was completely arrested at 10 per cent sodium chloride. Sodium chloride caused a delay in the onset of sulphur oxidation, its rate being only slightly affected. A relationship between sulphate appearance and decrease in pH was observed only in sulphur-amended Terra Rossa soil. Under optimal conditions, 53 and 54 per cent of added sulphur (5000 ppm) was recovered as SO₄-S from the Terra Rossa and Rendzina soils, respectively. This maximal level of sulphate production was only slightly affected by the addition of sulphate up to 3000 ppm S.It was concluded that inhibition in further sulphur oxidation was not caused by sulphate accumulation.     

Modelling non-uniform soil water uptake by a single plant root

The assumption of uniform water flow to the root or uniform water potential at the root surface was shown by Hainsworth and Aylmore (1986, 1989) to be erroneous. The present paper demonstrates how the non-uniform uptake of water by a single root can be modeled. Differential equations are numerically solved to describe simultaneous water movement in the plant and in the soil. In the plant, boundary conditions are the water potentials at the root surface (Ψ_s) and in the xylem at the root base (Ψ_b). A set of difference equations describe the flow of water radially through the cortex to the xylem and in the xylem axially upwards to the base. For calculating the water flow in the soil and the values of Ψ_s, i.e. the boundary conditions for flow in the root, the finite element method (FEM) is used, the boundary conditions being the flux of water into the plant root and the zero flow across the wall, bottom and surface of a hypothetical soil cylinder surrounding the root. ei]Section editor: B E Clothier     

Induction of gene conversion and reverse mutation by manganese sulphate and nickel sulphate in Saccharomyces cerevisiae

Manganese sulphate and nickel sulphate were tested for the induction of gene conversion at the trp5 locus and reverse mutation at the ilv1 locus in D7 strain of Saccharomyces cerevisiae. Nickel sulphate was more toxic than manganese sulphate but did not induce any reverse mutation and gave a weak positive response for conversion. Manganese sulphate was also only slightly mutagenic and convertogenic.     

The effect of applications of manganese sulphate to a neutral soil upon the yield of tubers and the incidence of common scab in potatoes

Summary Potatoes grown on a neutral soil with low water-soluble manganese content gave a normal crop with no signs of manganese deficiency. Treatment with manganese sulphate (0.5 cwt per acre) mixed with a compound fertiliser and applied in the drill at planting time, increased the manganese content of leaves and tubers but had no effect on the total yield of tubers. The manganese treatment, however, increased the average weight of tuber and markedly reduced the incidence of scab. The results suggest a possible method of controlling scab in neutral soils.