FR2658810A1 - COMPOSITION CONTAINING TRACE ELEMENTS AND METHODS USING THE SAME. - Google Patents

Abstract

Composition for the supply of trace elements such as iron, zinc, manganese or copper to a soil, in particular to a basic soil. The composition provides the trace element in a form which is either a suspension or a complex with humic acids derived from carbon, in an aqueous medium, or in a form trapped by or in an oxidized carbon, or a mixture of these forms. .

Description

COMPOSITION CONTAINING TRACE ELEMENTS

  1 O AND METHODS USING THIS COMPOSITION

  The subject of the present invention is the supply of trace elements or micronutrient elements, as they are also called, such as Fe, Zn, Mn and Cu, to plants in soils where

  problems regarding the absorption of these elements.

  It is well known that the availability of several trace elements, in particular Fe and Zn, decreases at high p H, causing

  nutritional problems under these conditions.

  In order to avoid these problems, synthetic chelates are often used to amend the soil, which are generally both expensive and ineffective. Alternatively, one can

  apply to the leaves.

  According to the present invention, there is provided a composition intended for application to the soil, in particular to a basic soil, comprising a trace element such as Fe, Zn, Mn or Cu, in one of the following forms or in the form of two: I in suspension or in the form of a complex with humic acids derived from carbon, in an aqueous medium;

  It trapped by or in an oxidized carbon.

  According to the invention, a method is also provided for supplying a trace element to a basic soil, comprising the step

  of application to this soil of a composition as described above.

  According to the invention, there is also provided a method for improving the absorption of a trace element by a plant from basic soil, comprising the step of applying to the soil a

  composition as described above, in the vicinity of the plant.

  The oxidized charcoal is preferably an oxidized charcoal of lower to medium class. Examples of charcoal of this type are subbituminous and bituminous coals The oxidized charcoal is preferably produced by the wet oxidation process described in US Pat. No. 4,912,256 According to this process, an oxidized carbon is produced which contains humic acids The oxidized carbon has an acid p H, for example a p H in the range of 2 to 3 The 1 i O trace elements are trapped by this oxidized carbon, by setting

  contact of the latter with an aqueous solution of the trace element.

  Generally, the aqueous solution is a sulfate solution.

  The trace element is trapped by oxidized carbon and it is then put

  available to the plant grown in alkaline soil.

  During the production of an oxidized carbon by a wet oxidation process, some water-soluble fulvic acids are also formed. Fulvic acids can be eliminated with this oxidized carbon (by filtration) before treatment with the solution containing the trace element. However, it is not necessary

  to remove fulvic acids from oxidized carbon.

  The humic acids which can be used in the implementation of the invention are preferably obtained from an oxidized carbon,

  in particular of an oxidized coal of class lower than average.

  The humic acids are mixed with an aqueous solution of the trace element The trace element will either be complexed by humic acids, or suspended with humic acids, in both cases in an aqueous medium The trace element is used under this

form for application to a floor.

  Humic acids derived from coal and oxidized charcoal generally present an elemental analysis (calculated with respect to the substance air-dried) such as: Element Range (%) Carbon 45 70 Hydrogen 2 6 Oxygen 20 40 Humic acids derived from charcoal and oxidized charcoal generally also present an analysis of functional groups such as: Range functional group (meq / g) Total acidity 3 13 Carboxylic groups 0.5 12 Phenolic groups 0.5 9 Trace elements, in particular iron and zinc, are not easily absorbed by a plant from a basic soil, since the trace element or part of it is found in these soils in an insoluble form The trace elements contained in the composition according to invention are in a form that allows them to be absorbed by a plant from these basic soils, in a way that makes them easily accessible for the metabolism of

the plant.

  The invention will be better understood using the example

below.

  Bituminous coal (200 g) and water (400 ml) are mixed so as to form a suspension in a stirred reactor with a capacity of 2 liters The reactor is placed under a pressure of 8.0 M Pa, at l Using oxygen, it is heated to 200 ° C using external bar-shaped heating elements. Oxygen is passed through the suspension with a flow rate of 4 liters / minute. hour, the passage of oxygen is stopped, the reactor is cooled to room temperature and the pressure is reduced

  its content at atmospheric pressure.

  The suspension contains oxidized charcoal (insoluble in water and designated below by "oxycharbon") and an aqueous solution of fulvic acids The oxycharbon is separated by filtration from the aqueous solution of fulvic acids The concentration of fulvic acids in water is determined to be 8.45% (by mass by volume) The oxycharbon has the elemental analysis (based on the substance air-dried) and the analysis of the following functional groups: Elemental analysis Element Percent Carbon 51.3 Hydrogen 2.3 Oxygen 28.7 Analysis of functional groups Functional group Quantity (meq / g) Total acidity 6.25 Carboxylic groups 2.16 Phenolic groups 4.09 Humic acids are obtained by subjecting the suspension of oxycharbon at boiling under reflux with aqueous sodium hydroxide for 5 hours The insoluble residue is removed by centrifugation and the humic acids (80% yield) are recovered by precip itation in acidic medium, from the supernatant liquid This product will be designated

hereinafter by "oxyhumic acids".

  The oxyhumic acids present the elementary analysis (related to the air-dried substance) and the analysis of the following functional groups: Elementary analysis Element Percent Carbon 55.5 Hydrogen 2.7 Oxygen 32.1 Analysis of functional groups Functional group Quantity (meq / g) Total acidity 7.45 Carboxylic groups 3.38 Phenolic groups 4.07 The oxyhumic acids are mixed with 0.1 M solutions of Fe and Zn sulfates, to obtain the concentrations in the formulations respectively, 7.21 and

8.44 meq / ml of Fe and Zn.

  The oxycharbon is mixed with 0.1 M solutions of sulfates of Fe and Zn The oxycharbons thus formulated are filtered

1 5 and dried.

  The formulated oxycharbons are subjected to analysis and

  contain 10.4% Fe and 0.37% Zn.

  A test of culture in sand is carried out, using

  4 kg of quartz sand in Mitscherlich culture vessels.

  A Hoagland nutrient solution, containing nitrogen in the form of both NH 4 and NO 3, but containing neither Fe nor Zn, is supplied initially and added during the Iron growth period, at a rate of 0, 5 mg / dm 3, or zinc, at a rate of 0.05 mg / dm 3, is introduced into the containers by appropriate treatments, according to the different sources: control (0), sulfate, EDTA, acids

oxyhumic and oxycharbon.

  Two degrees of liming are used: the equivalent of 10 t and 20 t / ha at 300 mm depth of calcium carbonate (AR),

  which is incorporated intimately before the start of the test.

  Corn (Zea mays cv TX 24) is used as the test plant, with five plants per pot, and each treatment is repeated three times. Plant growth is monitored and photographs are taken at

appropriate growth stage.

  Both the upper parts and the roots of the plants are harvested after about 14 weeks, and the dry mass (650 C) Fe and Zn are also determined in both the upper parts of the plant. and in the roots, according to the method of Barnard, RO and Fôlscher, WJ 1988, Growth of Legumes at Different Levels of Liming, Trop Agric (Trinidad)

(2): 113-116.

  For the standard statistical analysis, the two aspects of the test, Fe and Zn, were treated separately, and the respective data were thus presented. The Tukey test for a degree of significance of 5% is carried out according to Steel, RGD and Torrie, JH, 1980, "Principles and

  Procedures of Statistics "McGraw-Hill Book Corporation, New York.

RESULTS

  The results are collated in Tables 1 and 2 for the

  iron and in Tables 3 and 4 for zinc.

TABLE 1

  Yield and Fe content of the upper parts of the maize, with different Fe treatments Yield in parts Fe content of the upper upper parts Treatment (T) (g / pot) (mg x 100 / pot) t 20 t T 10 t 20 t T

  Ca C 03 Ca mid CO 3 Ca C 03 Ca mid CO 3

  nes nes Witness Fe 58.05 59.24 58.64 357 397 375 Sulfate 57.08 56.89 56.98 227 340 283

EDTA 71.55 64.29 67.92 214 225 219

  Oxyhumic acids 66.85 68.50 67.68 267 380 324 Oxycharbon 64.19 61.41 62.80 369 338 353 Average liming degree (L) 64.69 63.83 296 343 LSDT (5%) for Treatment ( T) 9.62 168 Degree of liming (L) 3.69 64

C.V% 8.3 29.0

TABLE 2

  Yield and Fe content of the roots of maize, with different treatments with Fe Yield of roots Fe content of the roots (g / pot) (mg x 100 / pot) Treatment (T) 10 t 20 t T 10 t 20 t T

  Ca CO 3Ca CO 3 medium Ca CO 3Ca C 03 medium-

  nes nes Witness Fe 22.70 22.25 22.47 736 990 863 Sulfate 21.50 25.67 23.58 943 659 801

EDTA 28.11 21.58 24.85 1,277 661,969

  Oxyhumic acids 25.28 27.55 26.42 519 1,624 1,071 Oxycharbon 26.58 24.92 25.75 1,099 670,885 Average liming degree (L) 24.93 25.86 923 1,175 LSDT (5%) for Treatment ( T) 6.15 1208 Degree of liming (L) 2.35 462

C.V% 13.0 62.0

TABLE 3

  Yield and Zn content of the upper parts of the corn, with different Zn treatments Yield in parts Zn content of the upper upper parts Treatment (T) (g / jar) (mg x 100 / jar) t 20 t T 10 t 20 t T

  Ca CO 3 Ca mid CO 3 Ca CO 3 Ca mid CO 3

  nes nes Witness Zn 74.94 68.15 71.55 180 82 131 Sulfate 67.95 75.28 71.62 74 84 79

  EDTA 82.03 78.40 80.22 (no 78 (no

  det) det) Oxyhumic acids 78.89 93.19 86.04 308 323 315 Oxycharbon 80, 23 88.71 84.47 453 470 461 Average liming degree (L) 77.72 82.69 (293) 236 LSDT ( 5%) for Treatment (T) 7.72 101 Degree of liming (L) 2, 96 72

C.V% 5.0 14.0

TABLE 4

  Yield and Zn content of corn roots, with different Zn treatments Root yield Zn content of roots (g / jar) (mg x 100 / jar) Treatment (T) 10 t 20 t T 10 t 20 t T

  Ca CO 3 Ca CO 3 medium Ca CO 3 Ca CO 3 medium

  nes nes Witness Zn 19.62 27.67 23.67 35 33 34 Sulfate 27.99 21.31 24.67 68 24 46

EDTA 29.16 28.21 28.69 40 36 38

  Oxyhumic acids 23.92 22.97 23.45 229 174 201 Oxycharbon 25.61 25.57 26.59 253 263 258 Average liming degree (L) 25.80 25.70 149 134 LSDT (5%) for Treatment ( T) 6.31 49 Degree of liming (L) 2.93 19

C.V% 14.0 19.0

  The results collated in Tables 1 to 4 show that very often, excellent absorption of iron and zinc is obtained from soils having a high p H level, both with oxyhumic acids and with oxycharbon However, it should be noted that the quantity of iron and zinc absorbed by the plant is not always an exact reflection of the quality of iron and zinc which is offered to the plant Oxycharbon as well as the oxyhumic acids provide to the plant excellent metabolites consisting of iron and zinc, which is evident in the appearance of the plant. For example, corn treated with oxycharbon and oxyhumic acids containing iron and zinc has a much better quality than corn treated with iron and zinc supplied by EDTA or by iron and zinc sulphate The plants have a healthier appearance, the leaves are brighter and have a deeper green color, indicating that the iron and zinc abs orbited from products derived from oxidized carbon constitute for the plant a more accessible source of iron and zinc for the 1 O metabolic processes of the plant There is also an important economic advantage, that is to say that the use of iron and zinc from oxycharbon is at least ten times more economical

  than iron and zinc from EDTA.

Claims (9)

  1 Composition intended for application to a soil, characterized in that it comprises a trace element in one of the forms chosen from: (i) a suspension or a complex formed with humic acids derived from carbon in an aqueous medium; (ii) a form trapped by, or in an oxidized carbon;   (iii) mixtures of (i) and (ii).   2 Composition according to Claim 1, characterized in that the trace element is chosen from iron, zinc, copper, manganese and their mixtures.   3 Composition according to claim 1, characterized in that   that the trace element is chosen from iron, zinc and their mixtures.   4 Composition according to any one of   Claims 1 to 3, characterized in that the carbon of which   come from humic acids is a class oxidized carbon below average.   Composition according to any one of   Claims 1 to 3, characterized in that the oxidized carbon is   an oxidized coal of lower to medium class.   6 Composition according to any one of   Claims 1 to 5, characterized in that the humic acids and   3 O the oxidized carbon presents an elementary analysis (related to the air-dried substance) such as: Range element (%) Carbon 45 70 Hydrogen 2 6 Oxygen 20 40 1 2 7 Composition according to any one of the   Claims 1 to 6, characterized in that the humic acids and   the oxidized carbon present an analysis of the functional groups such as: Functional group Range (meq / g) Total acidity 3 13 Carboxylic groups 0.5 12 1 O Phenolic groups 0.5 9 8 Composition according to any one of the   Claims 1 to 7, characterized in that the oxidized carbon has an acid p H.   9 Composition according to claim 8, characterized in that   that the oxidized carbon has a p H in the range of 2 to 3.   Method for applying a trace element to a basic soil, characterized in that it comprises the step of applying to   sol of a composition according to any one of claims 1 to 9.   11 Process for improving the absorption of a trace element by a plant from a basic soil, characterized in that it comprises the steps of applying to the soil a composition according to   any one of claims 1 to 9, in the vicinity of the plant.