Subject: Effects of Boron of Grasses

From: "Neil R. Terry" <[email-masked]>
Date: Wed, 06 Mar 1996 21:29:49 -0700

I'm looking for some information about the toxic effects of 
excess boron on grass.

Neil Terry
[email-masked]

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From: [email-masked] (Jim Mumm)
Date: Sun, 17 Mar 1996 01:41:49 GMT

>[email-masked]

I would also be interested. We use borax as a boron source for our
alfalfa seed fields, and we seem to have less trouble with quackgrass
(agrypon repens) since we started this practice. I assumed that the
boron was making the alfalfa more competitive, but possibly there is
some toxic effect on the grass. We are applying about 2kg/ha of actual
B every few years.

Jim Mumm
--
[email-masked]
Jim Mumm
Hazelridge Farm
Box 268, Shellbrook, SK, Canada
S0J 2E0

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From: Oz <[email-masked]>
Date: Sun, 17 Mar 1996 22:29:31 +0000

In article <[email-masked]>, Jim Mumm
<[email-masked]> writes
>some toxic effect on the grass. We are applying about 2kg/ha of actual

Do you have any information on the Boron req. of Alfalfa. Is it
particularly sensitive to deficiency? What plant levels are considered
satisfactory, and what levels deficient?

I am interested because I have a small plot, and I am trying to keep it
going as long as possible.

------------------------------- 
'Oz     "When I knew little, all was certain. The more I learnt,
        the less sure I was. Is this the uncertainty principle?"

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From: jonesv.wave.co.nz (Vaughan Jones)
Date: Tue, 19 Mar 1996 11:48:51 +1200

In article <[email-masked]>, [email-masked] (Jim

> some toxic effect on the grass. We are applying about 2kg/ha of actual

The following is what I've collected on B over the years. I'm writing a
book on farming and will include chapters on each element. Comments would
be appreciated. 

Vaughan Jones

Boron (B)

Not enough attention is given to this very important element, which is
sometimes required in only small amounts of as little as one kg/ha, but
when it and calcium are deficient, soil, pasture and animal health can
suffer. Considerable research has been done on B use in some countries,
but not always in conjunction with correcting calcium levels and observing
animal health improvements in deficient areas. When farmers, after
fertilising with B, report improved animal health with fewer bone
problems, some people ignore the evidence. It was identified as an
essential nutrient in 1920, but some researchers still seem unable to
recognise its benefits in pasture. 
Pasture may remove as little as 100 grams/ha (1.4 oz/acre) per annum which
some soils can replace naturally, while other soils may need regular
applications. After applying as little as 10 kg/ha (9 lbs/acre) of Borax
(fertiliser boron which contains 11% B) to deficient soils, clover yields
have doubled and pasture drought tolerance has improved. Trials have shown
that frost damage is lessened when B is applied to soils growing apples,
grapes, eucalyptus and Pinus Radiata trees. In some soil types and areas,
frost, disease and fungi resistance in plants are improved. Do your own
comparative trial and compare clover damage after prolonged frosts. 
B differs from trace minerals in that it is not a metal, however it is
important in aiding  the uptake of moisture, sugars and cations,
especially calcium. Lucerne, clovers, maize and brassicas show marked
improvement when B is applied to deficient soils, in fact some of these
plants can fail without it. Ten kg/ha (9 lbs/acre) of borax can increase
the yield of maize grain in B deficient soils, while 20 kg (18 lbs/acre)
on the same soils can decrease yields, so avoid excesses. 
B slows excess moisture uptake by plant roots, so reduces the "thin soup"
sappy pasture problem. B hastens maturity, which encourages the clover to
flower, and some say that you get less bloat when clover is flowering.
Applying as little as 8 kg/ha (7 lbs/acre) of Borax to deficient soils in
Eastern Waikato made the latest clover species (Kopu and Tahora) grow
leaves and stems four times bigger than previously. The new higher
producing more vigorous clovers are more likely to respond than old low
producing resident clovers. 
B can increase the availability of some amino acids which are the bases of
protein. 
 After applying B to a paddock, clover leaves increased in size
dramamtically and after a year the farmer noticed fewer weeds in the
paddock because clovers grew better and covered the bare patches. 
B also helps pasture take up sugars (energy), calcium and magnesium, and
helps keep pasture potassium levels down. The following UK clover figures
show this. 

   No Boron Applied
   B  K  Ca Mg
   11 ppm   2.1%  0.7%  0.4%

Boron Applied
   B  K  Ca Mg 
   50 ppm   1.6%  1.1%  0.7%

All the above changes are beneficial to livestock health. 

Photo #  Clover (anywhere in boron section)
Caption: Kopu white clover, prolific after getting 10 kg/ha (9 lbs/acre)
of Borax with balanced fertiliser on deficient soil. 

Animal Deficiencies
Symptoms include - 
€  Slightly reduced digestion. US trials have shown lucerne low in B has
higher levels of lignin which is fibre. 
€  Rumen bacteria growth is slower. 
€  Bone development is poorer.
€  Cows are slightly more prone to milk fever and grass tetany, due to
their inability to retain calcium and magnesium, and their lower blood
sugars. The treatment for milk fever is calcium boroglucenate (the boro is
short for boron).  Calcium on its own can adversely affect a cow. 
€  Calving when B is deficient can cause pelvic bones to crack and bones
can be heard rasping against each other when affected cows walk. Cows cast
after calving are sometimes diagnosed as being affected by nerve damage.
It could be that bones have cracked. Ask someone who has cracked a rib or
other bone about the pain. In the high rainfall areas of the South
Island¹s West Coast where up to 3 metres (120²) fall per annum), low B has
caused dairy cows to suffer these problems and even die. After applying B
with fertiliser, problems ceased. 
€  Low B can adversely affect bone development in animals, sometimes
causing slow growth and hunch backs. 
€  In humans, painful distorted joints, arthritis and osteoporosis have
been associated with low B. Animals may suffer the same, but how would we
know?

Animal Excesses
Symptoms include - 
€  Diarrhoea. 

Soil & Plant Deficiencies
Symptoms include -
€  Clovers don¹t grow as well. Seedling root depth is poor. B reduces
aluminium toxicity so clover roots go deeper in high aluminium soils
reducing drought effects. 
€  Clover leaves become reddened and edges become hard almost like steel
and brittle to the touch. New leaves can remain a healthy green. High B
levels and low potassium and drought effects can look similar, so use a
herbage test to be certain. 
€  Lucerne is very sensitive to deficiencies. Its leaves go yellow,
flowers fail to form, and buds appears as white or light brown dead
tissue. It has higher levels of lignin. 
€  Turnips and swedes can have rotten centres (Brown Heart).
€  Maize can have up to 25% fewer cobs which have irregular distribution
of kernels, shrivelled on the side adjacent to the stem, with fewer on the
tips. The leaves of young deficient plants don't unroll. Wide white
stripes can develop between the leaf veins. High lysine maize needs even
more B. In deficient soils 2 kg of pure B/ha has increased maize yields by
15% in Florida. 
€  Grass growing tips die. 
€  Citrus can be sour. Applying B, where deficient, can make citrus fruit
taste sweeter. 
€  Pine trees have browning and die back of their growing tips. 
€  Uneven grazing by stock can be another symptom. Lignin (fibre) levels
are higher in low boron plants, so could be a cause. High potassium can
accentuate the problem. 
B is less available in low and high pH soils. Between 6 and 7 is best. 
Deficiencies are more prevalent in sandy low organic matter soils in high
rainfall areas after long dry periods when B is not taken up by the plant
because low soil moisture decreases root growth and the movement of
elements towards roots, and after prolonged wet periods because of
leaching. Cold weather can slow organic matter decomposition which then
slows B release. Symptoms may disappear under normal conditions, however,
clover growth can be retarded in both cases. 
Clovers can sometimes show adequate levels in an analysis because the leaf
has grown with B, but then show B deficiency symptoms in dry conditions
when roots are not growing to new areas in the soil. 
Plants vary in their requirement for B. Levels of 22 ppm in pasture
herbage (80% perennial ryegrass and 20% clover) are considered adequate.
This means that a yield of 3 tonnes/ha (2,700 lbs/acre) of hay uses only
66 grams/ha (0.9 oz/acre), but, without it, clover in particular, and
grasses subsequently, will yield less dry matter. 
Lucerne herbage should contain about 40 ppm. If below 30 ppm B should be
applied. 
Excess lime and/or potash can lower B, so one should analyse pastures at
least annually, and if below 15 ppm apply Borax or equivalent where
necessary at about 10 kg/ha (9 lb/acre). This equates to about one kg/ha
(1 lb/a) of pure boron. 
Analyse pasture again six months later and apply as required. As with many
elements, B leaches faster out of sandy soils. 
Crops such as brassicas need more B, so up to double the above rates may
be necessary in deficient soils, especially where sown more than once.
Maize also needs 
Pasture tissue levels can double within a month of applying boron, then
return to previous levels in about  a year, or faster in light low organic
matter soils and high rainfall. 
Spreading must be even over the whole paddock. Because such small
quantities are required, thorough mixing is imperative and other fine
material such as rock phosphate must be included to hold it, or shake down
(settling in transport) will occur resulting in uneven spreading.
Granulated fertilizers are a problem in this respect, whereas rock
phosphates are not. 

Soil & Plant Excesses
Symptoms are similar to those of B and potassium deficiency, i.e., the
tips of clover and lucerne leaves turn yellow then brown and appear
scorched, but with high B leaves can fall off. 
Borax has been used as a weed and grass killer. It can adversely affect
seed germination, so fertilisers with B should not be mixed with seeds.
Excesses in irrigation water can injure plants. 

Sources
Borax (11% B). One kg (2.2 lbs) of Borax provides 110 grams (3.8 oz) of
pure B. There are other sources such as the highly soluble Solubor fast
release for foliar spray application which must not exceed 0.5 kg/ha (0.5
lb/a) of B per application. 
Ulexite (13% B) slow release chips are used in forestry to reduce frost
damage to saplings. 
B should not be applied unless a herbage test shows that a deficiency
exists. As with other elements, visual deficiency symptoms can also
indicate high levels. 
Although animal manure and compost contains B, there is insufficient to
increase low levels.
Some irrigation water can be high in B. It should be below 0.5 ppm. Above
0.5 ppm can kill some plants. 

Further Information
US Borax, 6250 River Rd, Suite 7020, Rosemont, Illinois, 60018-4288, USA.
Borax Holdings Ltd, Borax House, Carlisle Place, London SW1P1HT, UK. 
Both supply excellent info on B, backed by photos. 

Good luck,
Vaughan Jones

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From: [email-masked] (Ronald Florence)
Date: Thu, 21 Mar 1996 13:57:11 GMT

Vaughan Jones writes:

I'm sorry to take newsgroup bandwidth for this, but the return address
in Mr. Jones' posted note is not valid.  I'd like to use a portion of
this material in the Pasture FAQ at http://www.connix.com/~mlfarm/,
and would appreciate if Mr. Jones would write me directly with
permission and his email address and location for a proper credit.

An ascii-digest version of the Pasture FAQ is posted every 60 days to
newsgroups misc.rural, misc.answers, and news.answers.

Thanks.
-- 

				Ronald Florence

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From: [email-masked] (Jim Mumm)
Date: Sun, 24 Mar 1996 13:50:42 GMT

>going as long as possible.

Alfalfa is one of the most sensitive crops to boron deficiency.

See the long reply by Vaughan Jones. Lucerne is alfalfa. Unless you
are in a high Boron area, you could probably apply 10lbs/acre of Borax
safely. You could even use the 20 Mule Team laundry variety on a small
plot. Just be very careful to apply the right amount, and evenly.

Jim Mumm