CA1099984A - Liquid nutrient composition for agricultural use - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE
The invention provides a liquid nutrient composition for agricultural purposes incorporates urea, calcium chloride, and water, to 100% and a proportion of urea lying in the range 38%-60% CO(NH2) in which for any particular percentage x of urea lying in said range, the percentage of calcium chloride contained is defined by the equation:- Percentage CaCl2 - 42.27 - 0.455 x, the percentage x being treated as a simple numeral. The composition is useful as an additive to animal feedstuffs so that the feedstuff will contain an adequate quantity of nitrogen while remaining palatable. The composition has the operational advantage that it remains completely liquid while containing less water than known urea solutions thus reducing its bulk for a given quantity of urea. It is already known to provide strong solutions of urea. These contain more than 50%/50% urea/water but must be stored at an elevated temperature to avoid precipitation. The presence of CaCl2 and urea in the proportions stated provide the inventive effect over the prior art.

Description

The subjec-t o~ this invention is a liquid nu-trien-t composi-tion ~or agricul-tural use, par-ticularly as an addi-tive to animal ~eed s-tu~`fs and as a ~er-tilizer for applica-tion -to crops and/or soil.

Ruminan-t animals are usually given die-ts generally con-taining grass, ha~, silage, straw, roo~t crops and various cereals. The diet may also contain was-te by-produc-ts from breweries and dis-tilleries and products made ~rom sugar beet.
~uch a diet is almos-t always deficient in subs-tances such as n1trogen, calcium, phosphorus and trace elemen-ts and vitamins.
Because of -this i-t has been the cus-tom -to feed animals with supplemen-tary ma-terials. ~o provide additional ni-trogen they have been given ~or example ground nu-t, cottonseed, soya bean, linseed and fish and bone meals but -these substances are expensive and have largel~ to be imported into Europe. An alternative source of nitrogen found -to be suitable for giving to ruminant animals is urea. T~is subs-tance has the advantage - that is is a highly concentrated source o~ ni-trogen and thus only a small proportion in the feed is required but it has the serious disadvantage that if consumed in excessive amoun-ts it may be fatally toxic to the animal consuming it.

: .
The principal additives generally required in basal diets given to ruminant animals are compounds containing nitrogen, calcium and phosphorus. ~odium chloride and magnesium addi-tions are less generally needed but are nevertheless desirable. Various elements including copper, cobalt, manganese, iron, zinc, selenium and iodine are required in ' special circums-tances ln -trace amoun-ts. Calcium is normally provided as calcium carbona-te and phosphorus as dicalcium phospha-te or s-teamed bone ~`lour (bo-th o~ which additionally contain calcium). These ma-terials are almost insoluble in wa-ter. Magnesium is normally provided as magnesium oxide which is also insoluble. Trace elemen-ts are normally providea as their sulphates, and iodine as potassium iodide.

Vitamins A, D and E are generally required, especially when cat-tle are housed durin~ -the winter.

Here-tofore it has been the cus-tom of farmers to buy supplementary ma-terials separa-tely and mix them with -the animal feed. Sometimes the ma-terials are given -to -the animals separately i.e. apar-t ~rom the feed. This has been recen-t practice and in fact the tendency has been to place a quantity f -the supplementary material on free offer to the animals leaving them -to help themselves on -the assumption tha-t each animal will -take what it needs. However, all the farmer can control by this method of providing supplementary feed is the total amount required by a group of animals. The applican-ts have discovered by experiment tha-t the intake of such products is very variable on a day -to day basis by each animal.
Consumption is thus not properly controlled. There is also the added disadvantage -that urea o-therwise so sui-table tends to be unpalatable and the animal is thus not induced to eat its requiremen-t. If the substance is made to be palatable e.g.
by the addition of molasses the animal may take too much.
_ A-ttempts have been made to con-trol the voluntary in-take by providing -the supplemen-tary material in such a form -that -the animal must lick it ra-ther than drink it.

Urea mix-tures in -themselves are unpala-table. Known urea mixtures in liquid form con-tain abou-t 10% - 15~ urea and -to overcome the problem of lack of pala-tibility the urea solution is usually mixed with several -times i-ts own weigh-t of molasses. This raises its own problems because it has no-t been found possible to ircorporate an appropriate amount of calcium because of precipita-tion problems.

It is now the custom to adminis-ter -the requirea amoun-t of calcium, common salt and trace elemen-ts as a separate substance or separate substances to avoid interaction with other substance.

A liquid nu-trient composition for adding -to ruminant feed or as a fertilizer should for convenience have -the following characteristics as far as possible.

a) It should be concen-trated to reduce the quantity to be handled and keep to a minimum -the resulting wetness of the actual feed to which the liquid is added.
b) It should have no sediment.
c) I-t should be free flowing and should be capable - of being stored for long periods in fluctuating temperature conditions wi-thout forming a precipi-ta-te and i-t should be possible to store it in normal containers and pass it through ~ pumps of normal construc-tion.
d) I-t should contain as much non-protein nitrogen .
, as possible.
e) It shoul~ con-tain calcium and phosp~o~s f) Include sodium chloride, magnesiu~9 -trace elements and vi-tamins if desired.
g) As an animal feed supplement it should be palatable when mixed with the other feed or feeds to be given to the animal.
h) The ingredien-ts should be readily avallable and not unduly costly.

These requirements make the use o~ the urea as the source of nitrogen vir-tually a necessi-ty The main alterna-tives to urea are -the ammonium sal-ts but -there are unsuitable ~or several reasons. Firs-tly, i-t is not legally possible a-t - -the moment to equa-te nitrogen in -the form of ammonia with crude protein. Secondly, most organic ammonium sal-ts such as -the lactate, acetate and propionate, contain only about lO~o ~ and are expensive. Thirdly, ammonium sulphate (21~o ~) cannot be used as i-t forms a massive precipitate with calcium salts in solution. Fourthly, many ammonium salts are unpalatable and are more po-tentially toxic than urea. Ammonium :
phospha-tes and polyphosphates and other polyphosphates which are water soluble cannot be used because of precipitation in -the presence of calcium salts which are an essential constituen-t o~ any really effec-tive liquid fee~ additive.

I-t will be noted that -the firs-t characteristic ; mentioned is that -the substance should be concentrated~
; ~ Heretofore this has presented an apparen-tly insuperable , .. ...... . ... ~, :

9~4 di~ficul-ty -to the use o~` urea in -that previously urea could not be made to form an aqueous solu-tion con-taining more -than about-50~0 urea -to wa-ter.

The resul-t of -this difficulty is that when the known liquids are used as an additive to animal feed in the quan-ti-ty necessary to provide the desired intake of urea they cause -the feed -to beco~le undeslrable we-t. Whether for use as an animal ~eed or as a fertilizer the high propor-tion of water presen-t maximizes -the bulk -to be transpor-ted and -this keeps -transpor-t costs high as well as causing handling difficulties. Another difficulty of the known liquids has been -the tendency ~or precipi-tation to occur as a result of in-terac-tion of the various ingredients.

Phosphoric acid is the mos-t concentrated and suitable form of phosphorus. I-t is already in liquid form and available at a suitable price. I-ts acidic nature is importan-t. It has been discovered -that urea in the presence of phosphoric acid is less potentially toxic to animals than urea alone or in admixture with dicalcium phosphate. The acidity also enables the calcium and any added trace elements to be kept in solution.

Calcium chloride is the preferred calcium source on the grounds of solubility and cost. Calcium nitrate (ano-ther soluble calcium salt~ is -toxic to ruminants. Calcium carbonate and calcium sulphate are insoluble. Sodium chloride of the common sodium salts is the preferred source of sodium, as .
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... .. . .

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sodium ni-trate is toxic and sodium sulpha-te vvould form a precipi-tate wi-th soluble calcium sal-ts.

I-t may also be desirable -to provide some or all of the following subs-tances:-(a) Molasses (of a -type known -to form no preeipi-ta-te with a calcium chloride solution). Molasses is no-t necessary in a fertilizer.
(b) Magnesium, coppe:r, eobalt, zinc, iron, se~enium and manganese in the form of -the ehlorides, also potassium iodide (for animal use only).
(c) Vi-tamins A7 D3 and E in liquid form. (~ot neeessary in a fer-tilizer).

, ~he purpose of -the presen-t invention is to provide a single liquid composition suitable for use as a feed addi-tive or as a soil fertilizer whieh as a feed additive eontains all the substanees required to supplement the normal feea eonstituents of ruminants and ~hieh ean be in-termixed wi-th or sprayed on -to the feed material so that the animal will be foreed to consume it along with its principal foods, hay straw, silage, fodder, roots, eereals ete. and whieh as a soil fertillzer eontains all the substances required in the fer-tlllzation of soil.

~he present applicants after extensive experiments, have produeed a liquid composi-tion whieh contains a eonsiderably higher propor-tion of urea to water than has ; hitherto been believed possible while also con-taining if ~ .
neeessary phosphoric acid and other ingredien-ts~ ~hey have .

'" '. ' ' ~ , ~ . ' ' ' . ; ' 9~34 al~o discovere~ a method o:~ makirlg the co~lposi-tion.

liquid nutrien-t eomposition ior agricul-tural purposes according -to -the inven-tion incorpora-tes a-t leas-t urea, calcium chloride and water in propor-tions by weigh-t one -to -the other, irrespective o~`-the presence or absence of .ai~y o-ther substance, which lie in -the ranges 38% ~CO.(NH2)2~ 60~o; 0~CaC12<~25~o ana wa-ter to 100%, : subject to -the condi-tions that for any percentage x of urea in -the range 38% to 6C~o,-the percentage being -treated as a simple numeral 9 the maximum percentage of calcium chloride is de-termined from -the equation:-maximum percen-tage CaC12 = 42.27 - 0.455x ~or any percentage x of urea in the range 38% -to 50% -the r minimum percentage of calcium chloride is de-termined from the equation:-minimum percen-tage CaC12 = 104.15 - 2.083x and for any percentage x of urea in the range 50~O-to 60% the : minimum percentage of calcium chloride is de-termined ~rom the equation:-- 20 minimum percentage CaC12 = 1.50x - 75.00 and that the proportion by weight of urea is greater than the proportion by weigh-t of water.
The basic discovery of -the invention is shown in the accompanying graph which is given for explanatory purposes only and is only accurate within practical drawing llmits.
All the proportions represen~ted by the portion of -the graph lying above the line A-C-B refer to -the proportions by weigh-t of urea, calcium chloride and water which can form a liquid ~ 39~

~ree o~ un~i~solved material. Proportions ]ying wi-thin -the area of -the graph below -the line A-C-B produce a liquid in which undissolved ma-terial is necessarily pre~en-t. I-t will be appreciated of course tha-t the graph includes the kno~n pure urea solutions in water up to -the maxirnum known concen-tration of abou-t 50~o urea to wa-ter and the known pure calcium chloride solutions in wa-ter up to -the maximum knol~n concentration of about 42~o calcium chloride to water, 'rhese compositions are ou-tside the scope of -the present invention.
The highes-t proportion o~ urea for minimum water is represented by the point C a-t which the proportion of urea is Z0%, the proportion o~ calcium chloride is 15% and -the proportion o~ water is 25~o~ In this concen-tra-tion the urea is presen-t in solution in a propor-tion -to water about -two and a .
half times as much as has been heretofore at-tainable. As i-t is the presence of calcium chloride in solution which makes possible the much greater solubility of urea it will be seen that the urea/CaC12/H20 composi-tion of the invention lies only wi-thin the portion of the part of the graph which is contained within -the area boundea by -the portion AD~.

..
Examples o~ use of the equations are given below~

Urea 60% (upper limi-t of urea) gives maximum CaC12 15.0%: and the equation for minimum CaC12 with 60% urea gives also a percentage of 15.0~ This agree~ with point C
on the graph and shows -that for 60% urea i-t is necessary -to use 15~o CaC12.

38% of urea (lower limi-t) -the maximum CaC12 _9_ '' .
' ,. . .
usable is 25.0~ and -the minimum is a]so 25.0~,. This corresponds wi-th -the poin-t D on -the graph and shows that at t~ë~
lowest limit of 38~o urea i-t is necessary to use 25~ CaC12.

The proportion of CaC12 has a range of ~alues when used wi-th urea a-t intermediate percen-tages e.g. at 45% urea, the maximum percen-tage of CaC12 is 21.8% and the minimum percen-tage is lO.~o i.e. any percentage o~ CaC12 be-tween 10.~% and 21.8~o can be used wi-th 45~o urea to give the effect of the invention.

In all cases there is also presen-t wa-ter -to lOO~o ei-ther as free wa-ter or as free water and combined water.
As is explained later in -the specifica-tion o-ther substances may be added to the mix-ture but -they are added as additions j to the 100% composi-tion containing urea? CaC12 and wa-ter.

The liquid nutrient composi-tion according -to the invention may also contain phosphoric acid. The amount o~
phosphoric acid which can be present without formation o~ a precipitate has been found to be dependent on the amount of calcium chloride in the urea/CaC12/H20 composition and also -the amount of urea in the urea/CaC12/H20 composition. On a parts by weight basis the maximum amoun-t of phosphoric acid which can be present without precipi-tation in any specific urea/CaC12/H20 composition lying within the scope o~ -the invention is given by the following equa-tion.
` p = 9z0 antilog (2.63 - 0.1353 (uc)0'5) . . . (i) where p represents the maximum number o~ parts by weight to an accuracy of ~ 5~0 of l3P04 which can be added ~ 9~

-to 1 part by weigh-t of a urea/CaC12/H20 composition o~ speci~ic propor-tions.
c is -the percen-tage o~ CaC12 (w/w) contained in -the same specific composi-tion inser-ted in -the equa-tion as a simple numeral, e.g. 12.5% is in~erted as 12.5.
u is the percen-tage urea (w/w) contained in -the same speci~ic composi-tion also inser-ted as a numeral.
z is a fac-tor representing the percentage phosphoric acid by weight in -the additive expressed as a simple numeral. ~his factor -takes account o~ the ~ac-t -that phosphoric acid almos-t invariably contains some wa-ter.

~rom a practical point o~ view the ~ormula is applied particularly to urea/CaC12/H20 compositions in which the CaC12 is present in the proportion w/w 5%~caal2~ 21~o~

This is because with propor-tions o~ aaC12 between 21% and 25~o -the amount o~ H3P04 which can be added ceases to have any practical use~ulness and with proportions o~
CaC12 less -than 5% the graph of the equatlon becomes asymp-totic showing proportions of H3P04 approaching infinity.
' On a percen-tage by weight basis the maximum amount of phosphoric acid which may be present in a H3P04jurea/Caal2/H20 composi-tion is given by -the following ~ormula:-q = 9z antilog (1.8782 - 1.5652 ulcl x 10-3) .~ . (ii) where q represents -the maximum percen-tage to an accuracy of ~ 5~ o~ H3P04 which can be present in a given weight o~

.

.

.. . . , :

a H3P04/urea/CaC12/H20 composi-tion o~ speci~ic propor-tions.
ul and cl are the percentages by weight o~ urea and ~aC12 respec-tively in -the H3P04/urea/CaC12/H20 composi-tion.
z is a factor representing the percen-tage phosphoric acid by weight in the additi~e expresse~ as a simple nu~eral. This factor -takes accoun-t of -the :~ac-t -that phosphoric acid almos-t invariably co~tains some wa-ter.

Equation (ii) is useful where i-t is desired -to pro~ide a composition containing given proportions o~ urea, CaC12 and phosphoric acid. By solving equa-tion (ii) for the particular values of u1 and cl in the given composition it becomes a-t once apparen-t whether the aesired proportion of phosphoric acid can be present without precipitation. If i-t is fou~d from the equation (ii) that the amount of phosphoric acid proposed is too grea-t it may be possible -to accommodate that proportion of phosphoric acid by aajusting the amoun-t o~ urea and CaC12 wi-thin the limits of the present invention.

The phosphoric acid may be adaed subsequent -to -the forma-tion o~ the urea/CaC12/H20 composition or may be aaded during the formation of the urea/CaC12/E20 composit1on.

Exam~le I
_________ -A comple-tely liquid s-table urea/CaC12/H20 composition was made containing lO~o calcium chloride 55~o urea and 35r~0 wa-ter b~ weight. The propor-tion of urea to wa-ter is thus 55/35 i.e.
higher than the maximum 50/50 propor-tion which has been here-to-fore ob-tainable with urea and water alone.

~xample II
_~________ ~ composition was made con-taining CaC12, urea and water in -the same rela-tive proportions as in Example I, i.e.
10/55/35 and there was added 0.2~ par-t oE 90% phosphoric acid -to each part oE the said composi-tion. There was obtained a completely stable composi-tion free of precipitation and con-taining by weight 19.7~o phosphoric acid (anhydrous), 7.8~o calcium chloride, ~3.0% urea a-nd the remainder water.
In -this composition -the propor-tion of urea to wa-ter is ~3.0/29.5.

The graph actually shows the conditions prevailing a-t a tempera-ture o:E 15C. ~here are sli~h-t varia-tions a-t other temperatures normally experienced bu-t the ranges of propor-tions quoted for -the cons-ti-tuents of the composition of -the i-nvention remàin tru~ wi-thin the usual slight varia-tions which inevitably occur when making up such composi-tions under normal manufacturing conditions~ for all temperatures normally experienced.

The calcium chloride may be used in the anhydrous form or in -the hydrated form. It will of course be understood -that if the CaC12 is used in the h~drated form a corresponding reduction in -the quan-ti-ty of wa-ter making up the complete bulk of -~he urea/CaC12/H20 composi-tion will be made so that the total water including -the water of crystallization of the hydra-ted material s-till lies within the propor-tions referred -to as being within the scope of - the invention.

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Trace elemen-ts such as magnesium, manganese, copper, cobal-t, iron a~d zinc for example in the form of chlorides of these subs-tances ma~ be added in amoun-ts pre~erably no-t exceeding l~o by weigh-t. Also potassium iodide may be added in a small propor-tion.

Sodium chloride may also be added.

Molasses in -the propor-tion of l~o to 15% by wei~ht may be included in the composi-tion.

Vi-tamins A, D and E where necessary are preferably added in liquid form.

In prac-tice the liquid composition according -to the inven-tion pro~ides a completely s-table liquid wi-thou-t precipi-ta-te which contains urea in a proportion to the wa-ter content of the composition grea~ter ~than has been here-tofore attainable. When used as a feed addi-tive this ensures -tha-t the feed is wetted to the minimum èxtent. Also, whether as a feed additive or a fertilizer the low wa-ter content con-tributes to lowered transport costs and reduced handling difficulties.
lhis desirable and heretofore unob-tainable effect has been produced by the propor-tions of -the materials used and also by the manner in which -they are mixed. ~Ieretofore all ~
attempts to incorporate calcium in a liquid supplement for ruminant feed have failed because previously the calcium had always precipi-tated and in fact many authori-ties have stated -that calcium should always be added separately to the dry feed. Attempts have been made to incorporate calcium .

, . . . ~ , , in a liquid feed as i-t is mos-t desirable tha-t a liquid supplement should suppl~ everything tha-t i,s needed by a,n animal on a day to day 'basis. The previous attempts to incorpora-te calcium have been aimed at providing calcium in the form of a suspension. Such a -type of produc-t is most undesirable where long s-torage times and varying conditions are likely to be met with because of -the grea-t likelihood of -the sedimentation of calcium compounds. Sedimenta-tion in liquid fertillzers causes serio-us difficulty with blocking of nozzles during spraying of -the fer-tilizer. The cornposi-tion of the invention comple-tely elimina-tes thls difflcul-ty.

Urea adm]nis-tered in an uncon-trolled manner may prove fa-tally toxic -to animals and in addi-tion when given alone it has an unpalatable -tas-te. ~'he liquid composition according to the inven-tion can, however, con-tain a high proportion of urea because i-t has been discovered that urea in the presence of phosphoric acid is less po-tentially toxic to animals. ~lso -the comparatively high concentra-tion , of urea in the composi-tion makes i,t possible -to reduce the quan-ti-ty of the addi-tive put ln-to the animals' main feed so that i-ts comparative unpala-tibility is reduced and in fac-t it has been found -that the taste of the normal main feed of the animals is usually sufficient to elimina-te the lack of palatability of the composition wi-thou-t the addi-tion of 25' expensive molasses.

In the specifica-tion all references -to the various substances forming the composi-tion may be taken as being the commercial quali-ty o:~ -these subs-ta~ces al-t'nough -the inven-tion a.lso applles -to -the use of su.bstances oi greater purity -than co1~lerc:ial quall-ty. In this connect;.o.n it may be remarked -that where phosphoric acid in particular is u.sed a co~mon commercial quality is a 90~o solution of phosphoric acid i.e. -the phosphoric acid ac-tually used consis-ts of 90% H3P04 and lO~o Fl20. O-ther concen-trations of phosphoric acid are, however, obtainable and it is emphasized -tha-t where i-t is in-tended to ~.ake a nu-trien-t composi-tion con-taining phosphoric acid any water conten-t o~
-the phosphoric acid is -to be -taken in-to account in -the calcula-tions relating to -the urea/CaCl2/wa-ter por-tion o~
-the composition.

.D~

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Claims (5)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A liquid nutrient composition for agricultural purposes incorporating urea, calcium chloride and water, to 100%, which contains a minimum proportion of water to urea while remaining completely liquid and without precipitate during indef-inite storage at normal ambient temperatures, and a proportion of urea lying in the range 38%-60% CO(NH2)2 in which for any particular percentage x of urea lying in said range, the percentage of calcium chloride contained is defined by the equation.
Percentage Ca Cl2 = 42.27 - 0.455x, the percentage x being treated as a simple numeral.

2. A liquid nutrient composition for agricultural purposes incorporating urea, calcium chloride, phosphoric acid and water, which contains a maximum proportion of phosphoric acid while remaining liquid and without precipitate or gelling during inde-finite storage at normal ambient temperatures, in which the urea, calcium chloride and water, treated in combination as one compon-ent of the composition are in proportions by weight one to the other lying in the ranges 38% ? CO(NH2)2 ? 60%; 0 < CaCl2 ? 25%
and water to 100%, subject to the conditions that for any percen-tage x of urea in the range 38% to 60%, the percentage being treated as a simple numeral, the maximum percentage of calcium chloride is determined from the equation:
maximum percentage CaCl2 = 42.27 - 0.455x, for any percentage x of urea in the range 38% to 50% the minimum percentage of calcium chloride is determined from the equation;
minimum percentage CaCl2 = 104.15 - 2.083x and for any percentage x of urea in the range 50% to 60% the minimum percentage of calcium chloride is determined from the equation:
minimum percentage CaCl2 = 1.50x - 75.00 and that the proportion by weight of urea is greater than the proportion by weight of water, and the phosphoric acid present in the composition lies in the range 0< p ? ? antilog (2.63 - 0.1353 (uc)0.5) where p represents the maximum number of parts by weight to an accuracy of ? 5% of H3PO4 to 1 part by weight of a urea/
CaCl2/H2O composition of specific proportions, c is the percentage of CaCl2 (w/w) contained in the same specific composition inserted in the equation as a simple numberal, e.g.
12.5% is inserted as 12.5, u is the percentage urea (w/w) con-tained in the same specific composition also inserted as a numeral, z is the percentage pure H3PO4 (w/w) present in the actual phos-phoric acid used expressed as a simple numeral.

3. A liquid nutrient composition for agricultural purposes incorporating urea, calcium chloride, phosphoric acid and water, which contains a maximum proportion of phosphoric acid while remaining liquid and without precipitate or gelling during indefinite storage at normal ambient temperatures, in which the urea, calcium chloride and water, treated in combination as one component of the composition are in proportions by weight one to the other lying in the ranges 38% ? CO.(NH2)2 ? 60%; 0 < CaCl2 ?
25% and water to 100%, subject to the conditions that for any per-centage x of urea in the range 38% to 60%, the percentage being treated as a simple numeral, the maximum percentage of calcium chloride is determined from the equation:
maximum percentage CaCl2 = 42.27 - 0.455x, for any percentage x of urea in the range 38% to 50% the minimum percentage of calcium chloride is determined from the equation:
minimum percentage CaCl2 = 104.15 - 2.083x and for any percentage x of urea in the range 50% to 60% the minimum percentage of calcium chloride is determined from the equation:
minimum percentage CaCl2 = 1.50x - 75.00 and that the proportion by weight of urea is greater than the proportion by weight of water, and the phosphoric acid present in the composition lies in the range 0 > q ? ? antilog (1.8782 - 1.5652 u1c1 x 10-3) where q represents the maximum percentage to an accuracy of ? 5% of H3PO4 in a given weight of a H3PO4/urea/CaCl2/H2O
composition of specific proportions, u1 and C1 are the percentages by weight of urea and CaCl2 respectively in the H3PO4/urea/CaCl2/H2O composition, z is the percentage pure H3PO4 (w/w) present in the actual phorphoric acid used expressed as a simple numeral.

4. A method for preparing the liquid nutrient composition defined in Claim 1, comprising admixing water, urea, and calcium chloride in weight proportions selected to produce an aqueous composition free of precipitate and having lasting solution stability, the water to urea ratio being that which is minimal but effective to produce and maintain the compositon in a liquid state.

5. A method for preparing the liquid nutrient composition defined in Claim 2, comprising admixing water, urea, calcium chloride and phosphoric acid in weight proportions selected to produce an aqueous compositon free of precipitate and having lasting solution stability, the water to urea ratio being that which is minimal but effective to produce and maintain the com-position in a liquid state, the proportion of phosphoric acid being that maximal proportion which will preclude precipitation or gelling in said composition.