A study of tillage mechanisms in relation to soil properties and crop growth : a thesis presented in partial fulfillment of the requirements for the degree of Master of Agricultural Science in Agricultural Mechanisation at Massey University

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A STUDY 0!1' TILl..t.G:S HSC::A.:HSl·~S

rn

P.i:LA'.I'Imi ':'O SOIL PROPERTIES AND CROP GROW?'n.

Mechanisation at f'ilissey university.

Keith .Andrew Eughes

1975

Three tillaqe systems ·•:2-c:e co:npareci ov2r the 1973-74 sprir,g-s"Jr.trner se~son on two trial sites.

was tilled a:-:d left to falbw over the ·::inter, while the ether v.·2s left in ?asture.

studied were:-

The three ti 11 age sys terr:.S

1. t!·adi ticnal plough/Jisc/harrow 2. C:ircct-d::-iliing er d 1-:sical ".:illage 3. rotary-cultivation.

There v;ere ;-io sig!"1i ficant di -:'ferences betv:eer. tre:;.t:lierfS in ~he subsequent est3.blishr::en-'c and yield of d:::-y matte:::· cf a ere? of chou moellier on the trial site which h':1d teen 1 eft

to

fall ow.

On

the non-fa::'..lowed d ir·ect-d:cil l fog ^.

.

,

res¹J1 :.ec in a significar,tly lc:;ier number ci plants comparsc.! to -:he

yields '.Vere h:.gi:est C'.1 the cirect-dr:i..lled plots 2f:Ci ~.C\'i2St

in the rutavateci treat~ent.

Soil which 'r,ac !:>een direct-d:-illeo re!r:;:;.ineo tLe r.io~t

stable as determi~ed by wet-sieving of soil s3moies.

·decrease

te>

a r~1rs2te:- extent t!-:c.n under :oloug:b.ing 2E

tr. e

length of t:.r::e o:..1t of pas tur-= increased.

samples sho~eci the same effect. Lhe :rctc.:~::y cultivaticn treatment resulted in the grec.test pro;xJrticn d soil in the srr.aller 2gT-egate si:::2 fractiori (less thc.n dia:::et2r l .676m.';1).

o~served in scil :resistance as measurc:d by a ;:::e112t:!:'1.T.ns·:er, -:and resistance to Nheel co!npaction between the nor:-tilled

and the ·°'-wo mechanically tilled treatments. In g~nei·al

the

ploughed and rota=y-cultivated soil required a lo~er

penetrometar force than the undisturbed direc-c-drilled

·profile. Or. the tracked areas,

.

increase in t:Jer.etru-ti.:ig ^. force of

tr,e

twc nechanicall y "'.:::!.lled olots was on ave.rage

12 times the increase on the direct-drilled ?lots.

It is probable that soil moisture levels w'?re not affected by cultivation treatment. Differer.ces which occurred, particularly in the non-fal lciwed trial, were thought to have been an effect of diff e~ences in plant density- soil water loss increasing with ?lant density.

Data frcm the two trials showed that total fuel consurr:ption for direct-drilled and rotc.ry cultivated treatments to be 9.7 and 1.9 tiTies respectively, less than the trad2.tional ploug!ling treatment. This did not include the fuel requhem2nts of weed ^contro~ which varied between treatments.

Throughout the whole of this work Yer C.J.

Bc....~er

and

Mr·

D.G. Bowler of the Agrcno!!!y and Soil Department at Massey University gave

consider

abls amounts of their time

to

offer constructive advice and criticism. Their

contri~u-

tion

s are ffiuch appreciated

.

I also wish to thank Mr R. 3iru;ns

of

the Agronomy Depart;nent :or his i:iterest and suggestions

.

Various

members

of the

Ae_;::·cnomy Departm

ent

¹

s technical staff also shm .. -ed considerable interest

in

this prcj

act

a..'ld

often

gave valuable practice.l !-lelp

.

T

he

ir contribution i

s also

much

appreciated,

especially that

of Vir VL.

Badger.

I

wish to tha11.c various othe r persons irho offered

suggestions and in some cases gave p:-actica1 helpr and

my

parents

who did the typing

a.rid.

binding of tills t2ieais .

Chapter 1

Chapter 2

2.1.

2.2.

2.

2

.1.

2.2.2.

2.3.

LIST OF CO::I~TTS

Ir..troduction Literature 3.evi er,..r

G-eneral

Tne objects and effects of tillage

T:.~e

objects of t

illage The

effects cf

tillage

lfainte.na

.. 11ce e..nd I:'.lcdification of

scil

str-:lc tu.re.

2 .. 3.1. Soil

aggre;,;a.tes

an.d

their

breakdown

2.4. Tillage

3..L.ri pla...1t g.rm.rth

2.6.

,... n

.:::.. I•

2 .. 7. I.

2,.7.2.

2.7. J .

C

hapter 3

Crop gro:;.;ths an.d

yields

Energy requira:nents of tilla.ge

An introduction to

experiJlental

tec.r..niques The measurer:en t

o: str·uettlre and

stability.

~he use of

penetrowsters

Heasl.:2'ing pmmr

out out

-:1:rough fuel cons·.lmption

Experimer.tal ::net:iods a.rd.

;nateriG.ls 3.1.

Orga.nisat~on

of

trials

J.1.1. E_xper~ental cite J.1.2. Design of trials

J.1.3. Plot layout

J.1. 4. Till age

operations 3.1.5. Sowi:r;.g of ^t~e crops

3.2.

Nee.slli'e:nen.t of energy ;nputs

3.2 .. 1.

Design of

~e~suring

appa!'atus

J.2.2. Accuracy

of fuel m

easuring method

3.2.J. Tractor operation

in

the

e~uerimerrts

Drilling

a.~d

fuel

use

3A2.5. Correction

for i!::lplement

widths

3.3.

Penetrometer measuremen~s

3 ... 3

.1. 'l'h3 pe:1et!'j::;.eter

.Page 1

2 2

4 4

7

16

16

24 26 30 34

38 38

38

38 41

42 42

46

49

50

52 52

Disadvanta.;cs

of t..!.ie u.enetromet0r method 55

3. 3 . 3.

3. 4.

3. 5.

3. 6

3. 6 • .3 . 3. 6. 4.

3. 6. 5.

J . 6. 6.

J . 6. 7.

J . 7.

3. 8 3. 9.

Cha}:'ter

4

!.:,. 1.

4.

1 .1.

4.1. 2.

4. 2.

4. 2.1.

4. 3.

Penetr ometer mesaurei:ents aYi.d data.

Soil

moist

¹

.ll'e measurements

Organic matter deter::i.in&ticns Wet

sieving and

dry

sieving

Dry sier...ng Wet sieving

Preparation of samples

Pra--wetting of tte soil samples Nllihber and size of si eves

Time period o: sievtng

Expressior. of sieving results Harvesting 0f crcps

?~oto5raphs

and -risual assessment of soil

and ·crops

Surface crusting eva.lu.aticns Evaluat ion of the

crust3

Discussio~

of

res~lts

Heasu.re::ient of energy i nputs

Compari son of tne two

till~d

plot3 C o:rmarison o: direct-:iril1ed, nl• JugheQ

and-rotar:;;-c~ltiva~e~ treat~~nts

Results of :pen3tr·o;neter

analy3is

Wheel compactton

Soil

moisture

r es-.U.ts

Page 55 56 57 58 58 60 61 63 64 66 67 70

70 72

75

75 75 75 77

30

83

88

4. 4. Surface cFJ.sting ar:d o!'ga.nic matter

ri:;sl~_,_ ~::: 9L

4 . 4. 1. Surface

^crust~~g

94

4.4.2. Organic rratter rest:lts 97

4. 5.

Dry

sieving results

100

4 . 6. Wet sieving results 106

4.

7. Cropping ::.·e sul

ts 112

1,..8. Visual appraisals and

general disc11ssion

of

trials

119

C

hapter 5

SU!!!Uary a.~d

concl usions

126

.Bibliogrs.phy

131

LIST OF T_~LES

Page 1.. Mites and Springtail distribution 12 2. Soil changes in 0-10cm tilled horison 17 3. Properties of skins around soil aggregates 18

4. Soil losses as a result of cultivation 21 5. Yield of potatoes on light sandy loam 29 6. Stand densities of (means of wheat barley and oats) 29 7. Fuel consumption during cultivation JO

8.

Machine system and energy input 30

9. Fuel used

by

rotary cultivator 47

10. Mean amount of petrol used

by

tractor

alcne 48

11. Fuel used

in

drilling 50

12. Implement

^~1idth

conversion factors 51 13. Bulk density l!2easured by soil sampler 52 14. Moisture content of random soil samples taken

from

pa

sture

57

15. Computing method for mean-weight-diameter 68

16. Fuel used in cultivation 75

17.

18.

19.

20.

21.

22.

Comparative penetrometer r

eadings

, cultiva·(,ed.

a.nd

uncultivated soil

Soil moisture (wet basis)

Soil organic matter percentages Dry-sieving of cultivated soil

Wet-sieving cf soil under cultivation Results of herbage yield analysis

82

89 97

100 i O'i

116

1.

2.

3.

4.

5 ..

6.

7.

8.

9.

10.

11.

12.

13.

14.

15.

16.

17.

18.

19.

20.

LIST 0:5'

^P~AT~S

Fuel measurement apparatus T'ne penetrometer

Penetr ometer graphs Wet-sieving apparatus

Surface coil sampler

Barley establishment Fallowed plots Barley establishment :fon-fallowed olots

Non-fallowed direct-drilled plant establishment Fallowed direct-drilled nla!:t

est~blishm6nt

Weeds in rotary-cultiva.ted

chem

moellier crop Apparent lo"'vl nu.rnber of nla.nts

in

dir 8ct-drill2d crop

Freedom from weeds

in

plo;igl.:.ed c:;:·llp

Poor establishment of pl&nts on non-fallm.mci direct-drilled plots

Surface of fallowed

C. i ;-ect-d:::-2.~l;3d.

plot Weediness in rotavated fallowed flot Water damage on ploughed fallowed plot Ploughed

a..~d

rotavated plot (Spring 1973) Surface of fallowed rotavateci plot on 5-11-73

Tl II II 11 11

on 28-3-74 Ploughed surface on 23-3-74

Page 44 53 54

60 77

112

113

114 114 115

115

115

115

120 120

123 123

l25

1.

2.

...,

~-

4.

5.

o. /

7.

8.

9.

10.

11.

12.

13.

14.

15.

LIST OF FIG;:.T?2S

?lan of trials

Diagram of fuel ~easuring apparatus

Wet sieviI1g, percents.ge oversize Vs sieving time Total fuel useage by implemer~ts in crop

establishment

Soil resistance to penetrometer probe - fallowed plots

(16-7-73)

Comnarison of soil resistance to penetrometer probe

(4-1-74)

Soil resistance to penetromever probes

(15-11-73)

Soil moisture at

0- 75IlllJ

depth - fallowed plots Soil moisture at

75-125L1ill

depth - fc..llo;.rsd plots Soil moisture - unfallo',;ed plots

Penetrometer force requi:remer ... ts - culti1.rs.ted c_nd

ul^{.J. • -} t d • , ( 29 ^I " j )

unc t..lva e sci..L -";.- /4

Dry sieve analysis - cll.ltive.ted soil Dry sieving 1in.alysi2 - cultiv5."Led. soil

Wet sieving of cul ti va ted and. non- ci.:1 ti va. ted soil Trial 1 (fallowed plots)

Wet sieving of cultivated a..'1d non-cultivated soil Trial 2 (non-fallowed plots)

Page

39

45

65

79

84 85

86

9'1 9..2

9 3

98

l04

105 i10 111