WO2009030796A2

WO2009030796A2 - Use of a mixture of compost and vivianite in the prevention and control of iron chlorosis in plants

Info

Publication number: WO2009030796A2
Application number: PCT/ES2008/000577
Authority: WO
Inventors: Ana DE SANTIAGO ROLDÁN; Eusebio Carmona Chiara; José Manuel QUINTERO ARIZA; Antonio DELGADO GARCÍA; María del Carmen DEL CAMPILLO GARCÍA; Vidal BARRÓN LOPE DE TORRE; José TORRENT CASTELLET
Original assignee: Universidad De Sevilla
Priority date: 2007-09-06
Filing date: 2008-09-04
Publication date: 2009-03-12
Also published as: WO2009030796A3

Abstract

The invention relates to the use of compost obtained from agorindustrial waste for the prevention and control of iron [Fe (II)] deficiency in plants, whereby a mixture of compost and an iron [Fe (II)] salt is applied to the soil either directly or using irrigation water. The invention can be used as a fertiliser in the agricultural sector.

Description

Title

Use of mixture of compost and vivianite in the prevention and control of iron chlorosis in plants

Object of the invention

The object of the present invention is the use of compost, obtained from agro-industrial waste, for the prevention and control of iron deficiency [Fe (II)] in plants, by means of the joint application of a mixture of compost with a iron salt [Fe (II)] to the soil directly or through irrigation water. This invention can be used as a fertilizer product in the agricultural sector.

State of the art

Iron chlorosis is a deficiency of iron (Fe) in plants induced by soil properties when plants grow in soils with basic pH. It is a common problem in calcareous soils, which are frequent in arid and semi-arid areas of the planet. The typical symptomatology is an internervial chlorosis in the areas closest to the apex, and there is a clear negative effect on growth and crop production. The correction of iron chlorosis implies the application to the soil or the plant of an iron source. Traditionally, various inorganic products have been used for soil application, such as ferrous iron salts, pyrites and various iron oxides. The required doses were high due to the reduced solubility of some, or, because the iron applied in the case of soluble compounds quickly passed into insoluble forms and, therefore, little assimilable by the plants. The most efficient sources are chelates (in conditions of calcareous soils Fe-EDDHA) that have become common in the last thirty years. They are effective but very expensive products, which can condition the economic viability of certain crops sensitive to such deficiency in calcareous soils. Another limitation of chelates is their reduced persistence and the susceptibility of being washed, which forces several treatments throughout a crop cycle.

Schwetmann and Fitzpatrick (1992) consider that the preservation of oxides of low crystallinity in the soil (especially ferrihydrite) is essential to maintain iron available for microorganisms and plants, so that those factors that contribute to a low crystallinity in the oxide formed from Faith ²⁺ released by the sources of Faith applied will contribute to the iron present in these oxides it is more bioavailable (usable by plants and microorganisms). This fact explains the efficiency of ferrous phosphate (vivanite) over other Fe salts such as ferrous sulfate, since the phosphate present in vivianite favors the formation of oxides of low crystallinity (Barrón et al., 1997; Galvez et al. , 1999). The presence of certain ions and organic compounds can act as inhibitors of crystallization, such as Delgado et al. (2002a, 2002b) have been checked for other minerals that are formed in edaphic environments. This may contribute to a greater efficiency of the iron applied as inorganic salts in the correction of iron chlorosis. It has been observed that the organic matter in the growth medium increases the availability of iron for the plants (Wilkinson, 1972). This seems to be due to two processes: (i) the complexation of the Faith that protects it from precipitation, keeping it more available and contributing to the dissolution of iron oxides of low crystallinity, and (ii) the increase in the diffusion of the Faith towards the roots. The complexation of metal cations by soil organic matter can make them more available to plants (Datta et al., 2001; Greman et al., 2001; Pandeya et al. 1998). Pintón et al. (1999) found that the recovery of iron-deficient plants was faster when iron was applied together with humic substances than if it was applied alone or with other organic complexing agents such as EDTA or citrate. These evidences lead us to believe that the supply of iron in the form of inorganic salts such as vivianite or ferrous sulfate together with an organic source can increase the efficiency of said sources as correctors of iron chlorosis.

From organic waste, composted materials ("compost") can be obtained that can be interesting organic sources for application to agricultural soils or culture media. The application of compost together with sources of Fe can be interesting, for everything I commented previously, in the prevention and correction of the iron chlorosis of the plants.

References

Barrón, V., Gálvez N., Hochela MF and Torrent J. 1997. Epitaxial overgrowth of goethite on hematite synthesized in phosphate media: a scanning force and transmission electron microscopy study. American mineralogist 82: 1091-1100. Datta A., Sanyal SK, and Saha S. 2001. A study on natural and synthetic humic acids and their complexing ability towards cadmium. Plant and Soil 235: 115-125.

Delgado A., Madrid A., Kassem S., Andreu L. And del Campillo M. C. 2002a.

Phosphorus fertilizer recoven / from calcareous soils amended with humic and fulvic acids. Plant and Soil, 245: 277-286.

Eynard, A., del Campillo, M. C ₁ Barrón, V. and Torrent, J. (1992). Use of vivianite

(Fe ₃ (PO ₄ ) ₂ 8H ₂ O) to prevent rum chlorosis in calcareous soils. Fertilizer Research

31: 61-67.

Gálvez N., Barrón V. and Torrent J. 1999 Effect of phosphate on the crystallization of hematite, goethite, and lepidocrocite from ferrihydrite. Clays & Clay Minerals 47:

304-311.

Greman H., Velikonja S., Vodnik D., Kos B. and Lestan D. 2001. EDATA enhanced heavy metal phytoextraction: metal accumulation, leaching and toxicity. Plant and

Soil 235: 105-114. Lindsay W. L. and Norwell W.A. 1978. Development of DTPA test for zinc, iron, manganese and copper. Soil Sci. Soc. Am. J. 42, 215-221.

Loeppert R. H. and Inskeep W.P. 1996. Iron. In: Sparks D.L (Ed.) Methods of soils analysis. Part 3, Chemical Methods. Soil Science Society of America. Madison, Wl

Rosado R., from Campillo M. C, Martínez M. A., Barrón V. and Torrent J. 2002. Long-term effectiveness of vivianite in reducing iron chlorosis in olive trees. Plant and Soil

241: 139-144.

Pandeya S. B., Singh A.K. and Dhar P. 1998. Influence of fulvic acid on transport of iron in soils and uptake by paddy seedlings. Plant and Soil, 198: 117-125.

Pintón R., Cesco S., Santi S., Agnolon F. and Varanini Z. 1999. Water-extractable ble humic substances enhance iron deficiency responses by Fe-deficient cucumber plants. Plant and Soil 210: 145-157.

Schwertmann U. and Fitzpatrick R.W. 1992. Iron minerals in surface environments.

In Skinner H. CW. and Fitspatrick R.W. (eds) Biomineralization. Processes of iron and manganese -modern and ancient environments-. Catena supplement 21. Catena Verlag, Cremlingen-Desdedt, Germany.

Description of the invention

The present invention aims at the application to agricultural soils or compost culture media together with sources of Fe, in the prevention and control of ferric chlorosis in plants. The most efficient solution to iron chlorosis is the application of Fe chelates (particularly Fe-EDDHA in calcareous soils). However, the high price of these products only makes their application possible in highly profitable crops. Sources of Faith such as vivianite (ferrous phosphate), has been very effective in correcting and preventing the problem, increasing its effectiveness when applied together with an organic source, compost obtained from agroindustrial waste. The mixture of vivianite and compost is performed by preparing a suspension of compost to which a solution of ferrous sulfate and subsequently diammonium phosphate is added. When the pH of the compost is greater than 6, the precipitation of the vivianite formed from the two added salts occurs. The resulting product is mixed with the culture medium at a rate that provides 0.3 g of Fe per kg of culture medium or soil, or 0.3 kg per tree in the case of woody crops.

For the realization of the mixtures, any compost obtained by composting process can be used (aerobic fermentation in open batteries with flip, batteries with aeration ...) that allows to obtain a microbiologically stable product, free of phytotoxic substances and pathogen residues, plants or weeds. Anaerobic fermentation by-products are not recommended. The product must have a high humic fraction, which according to previous works contributes to raising the efficiency of the Fe sources added to the plant. Compost is not the source of Faith for the plant. Its action is to favor a lower crystallinity in oxides formed from said sources and also the complexation of Fe by organic compounds present in the compost. The complexes between Fe and organic compounds present in the compost have been revealed as an effective source of Fe for plants. The presence of humic substances in the compost can favor the development of the plant by direct effect on its metabolism (effect similar to auxins, effect on proton pumps and root reducing capacity) that can also increase the assimilation of Fe by Ia plant.

It is recommended that the mixture of compost and vivianite be made wet and that the synthesis of vivianite be performed in a medium where the compost is in suspension. The method of production of the mixture will be: 1. Suspend a given amount of compost in a solution containing 7.5% (w / v) FeSO ₄ -7H ₂ O.

2. Add 25 kg of (NH ₄ ) ₂ HPO ₄ to each suspension per m ³ .

3. Stir and homogenize for 10 minutes. If the pH of the suspension does not exceed 6, it must be elevated with the addition of K (OH).

Embodiment of the invention

As an example of embodiment of the invention, a compost obtained from industrial cork waste has been used. The compost was obtained using the open trapezoid battery method with a base of 2.5 to 3.5 m. The frequency of flips was established according to composting evolution parameters. The time required to obtain a stable product was about six months. After composting, the pH of the product obtained was basic (depending on the battery between 7.5 and 8.5). The mixing was carried out as described in the previous section, using a suspension with 30% (w / v) of compost in a solution of ferrous sulfate. Two mixtures were made, which differed in the time elapsed until the addition of the diammonium phosphate. It was not necessary to adjust the pH after the addition of this last product, since it was basic, so it is assumed that all the vivianite that could be formed from the two salts precipitated. The resulting suspension should have 0.5% vivianite (w / v).

To verify the efficiency of the product, two trials were carried out with 6 repetitions using the following treatments:

1. Witness with the addition of Fe-EDDHA (which is an effective source of Fe in basic media) in nutritive solution (10 μM)

2. Vivianita without compost.

3. Compost + vivianite (type 1)

4. Compost + vivianite (type 2).

The mixture of compost and vivianite type 1 was prepared by dissolving 15 g of FeSO ₄ heptahydrate in about 40 ml of water, to which immediately afterwards 30 g of cork compost were added. The mixture was homogenized and allowed to stand for 18 hours. After the time elapsed, 5 g of diammonium phosphate were dissolved. Subsequently, the pH of the mixture was brought to 6 with 5N KOH. The type 2 mixture was prepared by dissolving 15 g of FeSO ₄ heptahydrate in about 40 ml of water. Subsequently, 5 g of diammonium phosphate were dissolved and the pH was brought to 6 using 5N KOH. The volume was brought to 50 ml with water. Finally, 30 g of compost were added.

In treatments 2, 3 and 4, the amount of Fe applied was 0.3 g per Kg of culture medium (1 g of vivianite). The Fe / compost ratio was 1: 10 by weight in the treatments with vivianite and compost mixture, that is, 3 g of compost applied per Kg of culture medium, which was calcareous sand with 99% calcium carbonate as constituent principal.

10 Variables related to plant Fe nutrition were studied. In the first culture, only the chlorophyll content measured with SPAD meter. In the second one, the Fe content of the aerial part, the extractable Fe with DTPA in the medium after cultivation and the root reducing capacity were also analyzed. The results are indicated in Table 1.

fifteen

It can be seen that the treatments did not give significant differences in chlorophyll in the first culture. In the second, all treatments with vivianite gave significantly more chlorophyll in the plant than chelate. It can be seen that in the compost mixtures with vivianite, the Fe in the culture medium and the root reducing capacity was significantly greater than in the rest of the treatments. The compost mixed with vivianite type 1 was also the one that most increased the concentration of Fe in the aerial part.

Based on these results, it can be concluded that the mixture of compost and vivianite is an effective source of Fe for plants. Type 1 was especially effective by increasing Fe in the plant and in the culture medium. Regarding vivianite without mixing, the type 1 mixture increased twice the assimilable reserve of Fe in the medium (estimated by extraction with DTPA) and 60% the Fe in plant and the root reducing capacity.

Claims

1. Use of a mixture of compost and vivianite in the prevention and control of iron chlorosis in plants characterized by the application to the growth medium, soil or substrate, of a mixture of organic products obtained by composting and vivianite processes as a fertilizer product.

2. Use of mixture of compost and vivianite in the prevention and control of iron chlorosis in plants according to claim 1, characterized in that the application comprises a mixture of compost and vivianite, the recommended dose being 1g of vivianite and 3 g of compost per Every gram of vivianite.