Glasshouse Trials 1970 - Digital Library

(1)

Digital Library Digital Library

Experimental Summaries - Plant Research Agriculture

1970

Glasshouse Trials 1970 Glasshouse Trials 1970

M G. Mason

Follow this and additional works at: https://library.dpird.wa.gov.au/rqmsplant Part of the Agronomy and Crop Sciences Commons

Recommended Citation Recommended Citation

Mason, M G. (1970), Glasshouse Trials 1970. Department of Primary Industries and Regional Development, Western Australia, Perth. Report.

This report is brought to you for free and open access by the Agriculture at Digital Library. It has been accepted for inclusion in Experimental Summaries - Plant Research by an authorized administrator of Digital Library. For more information, please contact [email protected].

(2)

GLASSHOUSE TRI.ALS:11 1970.

M.G. iMASON1 RESEARCH OFFICER

Two glass.house trials were carried ^out~-

( 1) Ef'fect of Placement of' Urea and Soi.l Moisture Le-Vel on Germination. of Wheat.

(2) Effect of Placement of Urea on Germination of Wheatg Oats, Barley, Linseed and Rapeo

·j • Germj.nation of wheat was adversely aff'ected by drilling

UI'ea in contact with the wheat seed and also by high rates b:r'>oa.dcasto Rates used were the equivalent of 50, 100, 150,

300 and 450 lb urea/acre. Generally the eff'ects were not as severe (at least .. at the lower rates) as have been observed- in :field ·trials.. This may be mainly due to the greater

intensity of water appli~ation in the pots compared with the field situation, even though both si.tuations received the.

same total amount of rain.

The harmful ef'f'ects were of' three types:- ( a) Delayed ger•minat ion ..

(b) Reduction in the maximum number of plants germ~nating.

(c) Dea~h of plants alrea~y emerged.

The effect of broadcast applications was mainly on the death of' emerged plantso Drilled urea had an effect at all three stages o These effects could have been due to a number of caui?es and all could have been operating in this cas<?•, . Delayed · germination c:ould have been due to high osmotic pressure of' t;he soil solution due to large amounts of' fertiliser .. - The main ef:t'ect would have been due to the presence of high-levels of' f'ree ammonia which is formed duri.ng .hydr•olysis of' the urea.. Free ammonia is

toxic to plantso A third f'actor could have been due to a build up in the level of' n:i.trite nitrogen du,r;i.ng the later stages.. This nitrite nitrogen is also toxic to_plants and could have been the cause of some of the later plant deat~s. Nitrite nitrogen is an inte.rmediate product of the process of' ni trif'ication f'rom

ammonium nitrogen to nitrate nitrogene

. (_nitrosomonasJ (nitrobacter)

Ammonium _-. -. -···.,...--.--- " nitrite nitrate

High levels of' free ammonia tend to af'fect the ni trobacter more than ni trosomonas ^~ SD that the -Second part of'. thf'l process is slowed down more than the first part., This.results in a build up in the level of' nitrite ^nitrogen~which is normally converted to nitrate nitrogen as quickly as it is formed.,

As would be expected the harm:tu.l ef'f'ects on- germinatiOn were more mark~~ as.the rate of upea was increasedG However, the degree of' harm caused. ^W?.S a:;Lso i.nf'luenc:ed '°bY pre-and post seeding moisture levels.. If' the pots were watered to simulate rain

immediately af'ter seedi.ng, the harmful e1~f'ects o:f drilled urea were reduced considerably. If' no rain was received after seeding the harmf'ul ef'f'ects were greater in initially moi.s t soil than in dry soil. This la·tter ef':f'ept is due ·to the fact that there is just enough moisture tO start the seeds germinating and hydrolysis of' urea· al130 commences ^P resulting in the f'ormation of f'ree

ammonia. However s there i.s not ~nough moisture to dissolve and remove much of' this ammonia f'rom the immediate vicinity of' the · germinating seeds.

e>e•eeeee/2.

7D

(3)

Page - 2 -

Therefore the germinating seeds ·would be exposed to high concentration.'IB of' f'ree ammonia.,

Maximum harm to germination in the field ^·~ouldbe ^e~ected when the crop is sown into mqist soil and there is a rainless period f'ollow'ing planting ..

2.. The cereals wheatf oats and barley were sown to a depi;h of c;me i.nch, while the linseed and ll?pe were planted ^~inch deep., Rates of urea were 100 and 300 lb/ac drilled or broadcast and the

super rate was e~uivalent to 230 lb/ac ..

Within the ^cereals~barley was relatively unaf'f'ected9 as regards germination, with all treatments" Wheat and oats. were adversely affected to some extent. At the higher rate the oats were affected worse than wheat.

By comparison~ the linseed and rape germination was af'fected a great deal more than any of' the cereals. Both dr1lled and broadcast applications of ure·a had drastic effects on rape and linseedo Ri;i.pe was affE;:icted a li tti.e m9re than linseed. In addition the super drilled with the seed was almost as harmful to germination as was the urea ..

The super reduced emergence of rape and linseed from 86%

to 47%. Emergence of both crops was further reduced to about 14%

by drilling urea at.100 lb/acre with the seed. When the rate ^of'.:

urea was 300 lb/acre only'4% of the plants that were capable of.

germinating, did so. Urea broadcast at either rate had an adverse effect on emergence of rape, whereas linseed was only affected by the high ra·te o:t: urea broadcasto

The effect of super was probably more marked than in the f'i_eld because it was powdered and placed in close contact with

the seedo

11

(4)

-·~

l . •

-·.:--.

.. . ···

.·•·.

fl& (

WHi:.t1 r.

. __ (.J?T5·

o~.· _{·. )}. r.trrRV&k!V

·... . ..' ^:

'·

~

^.411..,

~11/J.0(3,6,../'

11/9 .· 111{1

- - -.-€11-

" ,., .... "•·--.--~·-· . -:------,---.~---,--

A- - --A u.<611 5c.oflt/ac di<MpCAsY

~ - - ~ ull.J<:t? 3wflt/uc ~ROIV>C/IS7""

• =.:

----~

... ··-·· -·-- --·-··· ·-p

-a- - - - - ^~ - -m

-!...,.. - - - -

_.'A- _- _{.- ·-. -} -...,& ^-$

"·

(5)

-· ^·.

/&()

or=

• o J.. 1--t5e4j) - <11;uf'lf~PlloSl'lltfTt; .;J3o_etj<c ])il'll..J..~

----" 1-1AS"~tSJ> - :51.1P-€/?Pllosl'1111n: c2i3o.t&J~ + 1All.ffl I oob/tU .J>Au ..

v .

^.J>

x- - ....,x J...1NSct::J> - suf'.f~PJ/oSl'Ht'lU :>Job~ M11..~I> +

1tr-0A/u

. :· ,'. :·~ :

.a- - - ^-Jlf,.... 0-

iJ/fi

( ^. ^.

'-.. ,··C.0ul"JTIS.i:>

···: .·· ·,.

,_· ... ' ~ ··~· .-.~· '· ·_._ ... ^'

A I/ ^p~ JJ..._-~

~ /1 /le. ^{t!l .}

- - -

-

^~-

J!!l- - - -m_ . _..,..

~~ _, ~ ~ . . . ·_·,..,. .• '

(6)

OF for-1L

I I

I

;< I

I .,

_r

I f;l- - +·-&'

! , I

o~ :.~--"'

•/'i • . .• fl

J-t~S~.s:p

^·_

Su~/$/(/'Ho~fl/,q~ .2?<;;~1~.

J>ifJJ.J..tf:D l(,qPt:. SL{,Ptf!E,t?r'flo.S/U1'J~

o&/qa.c

Sv. l'~I?. f'H OSPll Fl T& ;.;>.10,a;~

~---.-,JI(-- - - -JC-· ... -le- - - ' - ·-·><-

·~ -ic_

-*- -1'- -J(- - - -x--><,.- -><- -X- ^-X- ^- ^-·

"'- - - .- _l(

_,r;/

,,

1i!fl -+---+---~---".~__.. ·-~-----4- - -t---.~---<t--·---....---~ .·-···· -~---_ .. _

l'lfl ,)if/ . . ~ ;'6f1 1/1t> ___ .. ---·· ~ ---n----~----

. "/10

^l,jiO

--.. ^~---^----'-^....:-~^.^···--^{.... ,.}___ ---. --· -·--·---~-·-.. -. -_:_~ ~----·: