IE46053B1 - Compositions for use as fertilizers and their production - Google Patents

Abstract

Procedure for the preparation of fertilizer compositions based on nitrogen and phosphorus, suitable for the subscriber located in the juvenile state and which mainly contain the aforementioned nitrogen and phosphorus elements, characterized in that an intimate mixture, possibly ground, of salts or oxides of the compounds is incorporated trace elements copper and zinc to ammonium phosphate in the course of a stage of its preparation, stage chosen between the introduction of a phosphoric acid solution, preferably concentrated and hot, the treatment with ammonia of this solution up to an N / P ratio close to 2, the decrease of the water content of the ammonia solution and its placing in the form of granules, and granules of practically homogeneous composition are collected.

Description

The juvenile stage of the life of a plant is that period which corresponds to the implantation of the root system and during -which nutrition is ensured hy the first roots, which only extend into a very limited space. Further development of the roots is dependent on their finding the indispensable mineral elements in-situ. It is particularly important for the plantlet to he constantly enriched with pho.sphate ions. The roots then extend out into a wader area, where the possibilities of finding mineral elements are increased, A normally fertile soil, if necessary treated with a well distributed basic fertiliser, is sufficient for an already developed root system, but the first period is critical from the standpoint of mineral nutrients. Moreover the risks can he further increased hy unfavourable physical conditions such as temperature, ventilation and moisture. Thus, for example, the assimilation of phosphorus is slowed down and even completely stopped hy a low temperature. Thus, the juvenile stage is a critical period due to the possible interaction of three factors, viz, insufficient roots, poor soil and poor physical conditions.

Fertilizers that are applied locally in the juvenile stage are known: these supply phosphate and ammonium ions as nutrient elements. The technique of applying such fertilizers, which are also known as starter fertilizers, has been used in France since the 1950s following research carried out hy Purdue University, U.S.A, on applying fertilizers to maize (cf, Ohlrogge A, and Kinch D.M. Progress on Agricultural Research, p, 21, Purdue Experiment Station, Lafayette, Indiana 1950), At the time these scientists defined the conditions of effectiveness of nitrogenous phosphate fertilizers and their assimilation by maize roots (Ohlrogge A,J. Some soil-root-plant relationships, Soil Science T. 93, I, 30-38, 1962). This type of fertilizer is applied by means of equipment permitting its location within reach of the first rootlets.

It is applied at tho earliest after tho first cultural dressing and at tho latest cn the first rootlets sprouting.

The results, which are visible on harvesting and particularly when climatic conditions are difficult, are shown by the crop being more forward and often by an increase in the harvested weight. Thus, nitrogenous phosphate fertilisers are applied in particulate or liquid form, examples of these fertilisers being monoanmonium phosphate, diammonium phosphate (d.a.p.), ammonium magnesium phosphate and ammonium polyphosphates, as well as mixtures thereof, and in general manner complex compositions containing nitrogen and phosphorus salts.

It is known that the root must overcome competition relative to colloids, clays and humus in the soil, notably with respect to the phosphate ion, and the function of the ammonium ion is to accelerate the absorption of the phosphate ion by the plantlet.

We have carried out research that confirms the importance of supplying ammonium and phosphate ions in the juvenile stage, particularly in complementary form with respect to normal N Ρ K- fertilisers, with which it is often combined. This research also demonstrated the function of the magnesium ion in certain cases (cf. article Influence de la fertilisation starter localioee sur la teneur en elements mineraux de la Xeuille de mais et la recoltc (Influence of local starter fertilization on the content of mineral elements of the maize leaf and the crop yield) by P. Gautier and A. Langlet, Academie d’Agriculture de Prance, Meeting on 7.1.1970, paper presented by M, Coic).

Moreover, recent research has revealed that soil-plant competition also exists with respect to other ionsj particularly those ions that are generally little available at root level in the soil. The result of this research has been to determine the compositions able to supply all the elements necessaiy during the juvenile stage.

In addition, basic fertilizers are known which contain various elements that can he added to the basic elements N, Ρ, K, for example sodium, magnesium, calcium, coppci’ and iron, which Iona the subject matter of French 053 Patent Application No. 2,057,086, as well as annonium molybdenatevhich forms the subject matter of French Patent Application No. 2,253,001. Such compositions are generally intended to correct by curative doses- an satiating or foreseeable soil insufficiency. ' .

No complete fertilizer cxmpcsitions exist that can be locally applied to the plant, thereby ensuring an optimum development thereof while causing no -risk of toxicity during the juvenile stage. ®ie invention provides complete compositions suitable for-placement, i.e. local fertilizer application, during the juvenile stage containing mainly the elanants nitrogen and phosphorus and also the micro-nutrients Cu and Zn in the following quantities: 0.02 to 0.06% of copper; by weight and 0.07 to 0.2% of zinc by weight, based on the total composition. Preferably the nitrogen and phosphorus are in the form of annonium phosphate. Preferably also, the relative quantities of the elansnts Cu and Zn are such that the CU:Zn weight ratio is from 0.1:1 to 0.8:1.

The invention also provides such compositions containing also at least one of the following micro-nutrients: boron, manganese, molybdenum, iron and cobalt. In this case the preferred quantity by weight of each of the micro-nutrients just mentioned is from 0.001 to 2% of the total composition.

The compositions may also contain magnesium in a quantity not exceeding 12% by weight of the total composition.

In general, the elansnts are chosen in the form of ceddes or salts such as sulphate, phosphate, nolybdate, or borate or in chelate form, Micro-nutrients are preferably chosen in the chelate form. The magnesium is advantageously chosen in the form of a salt such as magnesium sulphate, potassium magnesium double sulphate, annonium magnesium phosphate or magnesium hydroxide.

Die invention compositions may also contain, in addition to the abovementioned elements, at least one of the potassium or sulphate ions in a quantity not exceeding 15% by weight of the total composition. - 4 46033 In general the nitrogen and phosphorus elements are chosen in a random conventional form, -whereby ammonium phosphate is preferably chosen in the form of an ortho-phosphnto in which the N:P ratio is approximately 2:1.

It is advantageous to choose part of the nitrogen and phosphorus g elements in the form of ammonium magnesium phosphate.

Thus, four types of compositions according to the invention are given hereinafter in exemplified form in a table.

For each example the first column gives the minimum and maximum quantities of the various elements expressed in conventional units $ by weight of the total. The quantities of micro-nutrients are expressed byweight in pure metal or in sene cases as specific oxides, e.g. B2 O3 or Ito Oy. figures in parentheses indicate the preferred quantity expressed in the sane way.

EXAMPLE 1 EXAMPLE 2 First type Second type Third type N lo 17 - 19 12 - 14 9-11P2 °5 68 48 - 51 42 - 44 32 - 34 Mg 0 - 10 - 12 8-9 K2 0 ' - 12 - 15 SC4 1 - 2 1-2 12 - 15 b20„ 0.06 - 0.18 (0.115) 0.06 - 0.18 (0.115) 0,06 - 0.1S (0,075) Mo 0.008 - 0.016 (0.012) 0:008 - 0.016 (0.012) 0.008 - 0.016 (0.008,: Mn 0.04 - 0.1 (θ.θό) 0.04 - 0.1 (θ.θό) 0.04 - 0.1 (0.04) Cu 0,06 0.02 - 0.06 (0.04) 0.02 - 0.06 (0.04) 0.02 - 0.06 (0.03) Zn 0.2 0.07 - 0.2 (0.12) 0.07 - 0.2 (0,12) 0,07 - 0.2 (0.08) Co 0.001 - 0.005 (0.002) O.noi - 0.005 (0.002) 0.001 - 0,005 ie 0,'i - 1.2 0,5 - 1.2 0.3 - 0,8 430 53 Also in accordance with the present invention, the novel compositions are prepared by intimately mixing the compounds (e.g. salts or oxides) of the micro-nutrients chosen in the indicated proportions and incorporating the optionally ground mixture into the airmonium phosphate during one of the stages of its preparation famed by a knew, method. Thus, the mixture of the chosen salts may be incorporated into the anmonium phosphate (e.g. dianmonium phosphate) during the wat granulation stage. Alternatively, the chosen salts may be incorporated into a phosphoric acid solution, after which the solution obtained undergoes anunriaticn up to an N:P ratio of approximately 2:1 and a substantially hanogeneous canpcsition product is collected. Preference is given to concentrated phosphoric acid and it is advantageous to incorporate the salts into the acid which at the end of concentration has a tenperature of approximately 50°C and a P20g content between 40 and 52%. The acid is optionally clarified by a known method. Preferably a wet route phosphoric acid is used.. In general such an acid has a non-negligible content of iron in phosphate farm and account is taken of the presence of this iron when calculating the expositions containing said element.

According to an advantageous embodiment, the water content of the anmoniated solution is reduced and the product is obtained in the form of granules, which are obtained with a substantially homogeneous exposition.

For example, granules are obtained of which 95% have a diameter between 2 and 4 mm. The ccnpositions according to the invention are locally applied to the. planting hole or furrow or to the sewing line. The quantity applied is generally regulated at 100 to 200 kg/hectare.

A series of tests is carried out in pots and in the open.

For each test a ccnparison is made wwith a control in which the same soil is only given a uniform basic fertilizer and a ccnparison is also made wrilth a fertilizer preferably exposed of a dianmonium phosphate (d.a.p.),which - 6 46053 has the content N:P:K 18:48:0 and which is applied in the juvenile stage.

Example 5 The dry material weight is measured hy harvesting, drying and weighing whole maize plants. Six leaves are removed and the weight in grams for three plants is noted. The test programme is a standard harycentric coordinate programme consisting of four repetitions for each of the treatments. Locally applied fertilizers containing respectively compositions (b) and (c) are compared with a control (a) only containing d.a.p. (h) d.a.p. ammonium molybdate boric acid Mn S04. 4If2 0 Cu SO,. 6IJO 0 4 2 Zn S04. 7Π2 0 Iron sequestrene Mg S04 (kieserite) (c) same composition as (b) monopotassium phosphate ammonium sulphate 100 kg .15 g 154 g 214 g .6 g 107 β woo e 4.5 kg except that kieserite is replaced by: kg 37.6 kg dry material (a) 6.06 (h) 6.70 (c) 6.55 Ernmplp 4 The dry material weight is measured on tomatoes in the same way a;· in the preceding example hut leal-aampling takes place opposite the first i 43053 bunch of tomatoes.

The locally applied fertilizers (a), (d) and (e) respectively contain control (a) d.a.p. only (d) d.a.p. 100 kg ammonium molybdate 15 g boric acid 200 g Mn S04, 4 H20 250 g Cu S04. 5 HgO 150 g Zn S04. 7 UgO 500 g Co S04. 5 DgO 5 g (e) same composition as (d) per 100 kg of d.a.p. except for a supplementary quantity of 50 kg of double sulphate of magnesium and potassium. dry material 1975 (a) 7.54 (Λ) 11.16 (e) 11.14 Example 5 The weight of the first ripe fruit picked from tomatoes growing in Bouches du Rhone, France, in 1975 was determined on hatches which had received fertilizers (d) and (e).

Weight of first tomatoes picked in kg/stem (a) 0.545 (d) 0.587 (e) 0.772 The results are more significant with respect to the first tomatoes picked, which is a sign of the crop being forward.

Example 6 The action on the weight of the tomatoes picked was measured, The weight of the total tomatoes picked in kg/stem was noted on tomatoes grown in the open in 1975 (Example 5), (a), (b), (c) and (e) receiving the same fertilizers as previously.

Weight on picking 1974 1975 10 (a) 1.94 (a) 2.34 (h) 2.10 (a) 2.77 (c) 2.08 (a) 2,41 Example 7 The weight in grams per pot wa3 noted relative to melons cultivated 15 in pots. The fertilizers applied were as previously (a), (b) and (c).

Weight in grams .(a) 440,3 (h) 452.3 (c) 452.5 053

Claims (14)

CLAIMS:

1 A composition mainly containing nitrogen and phosphorus in the form of an ammonium phosphate, the composition being in solid particulate form suitable for placement in the juvenile stage of plants aid also containing the micro-nutrients copper and zinc in quantities by weight 0.02 to 0.06% 5 of copper by weight and 0.07 to 0.2% of zinc by weight, based on the total composition.

2. A composition as claimed in claim 1, in which the ammonium phosphate is such that the atomic ratio N:P is approximately 2:1. ., composition as claimed in claim 1 or 2, in which the jq relative quantities of the elements Cu and Zn are chosen in such a way that the weight ratio Cu;Zn is in the range 0.1:1 to 0.8:1.

3. 4 A composition as claimed in any preceding claim that also contains at least one of the micro-nutrients boron, manganese, molybdenum, iron and cobalt. 15 5 A composition as claimed in claim 4, in which the quantity by weight of each of the micro-nutrients specified in claim 4 is in the range 0.001 to 2%, based on the total composition. 6 A composition as claimed in any preceding claim that contains magnesium in a quantity not exceeding 12% by weight based on the total 20 composition. 46033 7 A composition as claimed in any preceding claim, in which the elements are in the form of oxides or salts or in chelate form. 8 A composition as claimed in claim 7, in which the salts are sulphate, phosphate, molybdate or borate.

4. 5 9 A composition as claimed in any preceding claim that also contains potassium and/or sulphate ions in a quantity by weight below 15%, based on the total composition. ,

5. 10 A composition as claimed in claim 1 containing, as a percentage of the total weight, 17 to 19 of N, 48 to 51 of 1 2 of SO^, 0.06 10 to 0.18 of B 2 O 3 , 0.008 to 0.016 of MoCj, 0.04 to 0.1 of Mn, 0.02 to 0.06 of Cu, 0.07 to 0.2 of Zn, 0.001 to 0.005 of Co and 0.5 to 12 of Pe.

6. 11 A composition as claimed in claim 1 containing, as a percentage of the total weight, 12 to 14 of N, 42 to 44 of P 2 °5> t0 1 to 2 of S0^, 0.06 to 0.18 of Β 2 θ3> to 0.016 of MoO^, 0.04 to 0.1 of 15 Mn, 0.02 to 0.06 of Cu, 0.07 to 0.2 of Zn, 0.001 to 0.005 of Co and 0.5 % to 1.2 of Fe.

7. 12 A composition as claimed in claim 1 containing, as a percentage of the total weight, 9 to 11 of N, 32 to 34 of 8 to 9 of MgO, 12 to

8. 13 of K 2 o, 12 to 15 of SO^, 0.06 to 0.18 of 35^, 0.008 to 0.016 of Uo0$, 20 0.04 to 0.1 of Mn, 0.02 to 0.06 of Cu, 0.07 to 0.2 of Zn, 0.01 to 0.005 of Co and 0.3 to 0.8 of Fe. 13 Λ composition as claimed in any one of the preceding claims in granular iorin.

9. 14 A method of preparing a composition as claimed in any one of claims 1 to 12, comprising intimately mixing the compounds of the chosen micro-nutrients and incorporating the mixture obtained into an ammonium phosphate during a stage in its preparation.

10. 15 A method of preparing a composition as claimed in claim 13 in which j the mixture of micro-nutrients is incorporated in the ammonium phosphate during the granulation stage, while the ammonium phosphate is moist.

11. 16 A method as claimed in claim 14, in which the mixture of the compounds of the micro-nutrients is incorporated into a phosphoric acid solution, the thus obtained solution undergoes ammoniation to an N:P 10 ratio of approximately 2:1 and a substantially homogeneous composition is obtained by removing' the water from the solution.

12. 17 A method as claimed in claim 16, in which the water content of the ammoniated solution is decreased and the product is obtained in the form of granules, which have a substantially homogeneous composition. 1$

13. 18 A method as claimed in claim 17, in which approximately 95% of the granules obtained have a diameter in the range 2 to 4 mm.

14. 19 A composition as claimed in claim 1 substantially as hereinbefore described in Example 1 or 2.