Bemestingsnavorsing & grond kenmerke as riglyne vir ...overberglandbou.yolasite.com/resources/Voorsaai_2014...© Western Cape Government 2012 | 22 1. Soil microbial status ( 2011,

J Labuschagne & W Langenhoven

27 Februarie 2014

Bemestingsnavorsing & grond kenmerke as riglyne vir

volhoubare gewas-produksie.

© Western Cape Government 2012 | 2

Projects in progress at Tygerhoek

1. Nitrogen management (wheat) in crop rotation

2. Long term soil quality programme – Yield and quality and soil quality

3. Strategic use of tillage under conservation farming practices.

Crop response to a once-off strategic tillage operation

Effect of once-off strategic tillage operation on selected soil

properties

1. N management study

© Western Cape Government 2012 |

Increased stubble retention + less soil disturbance: ↑ soil C

4

Current practices

increase OM and the

ability of soil to

increase N

mineralisation potential

Less N ?


Rooting depth of wheat crop

5

500 mm

Sampling depth

0-300 mm


Rooting depth of wheat crop

500 mm

600 mm


Rooting depth of wheat crop (700-800 mm)


Rooting depth of canola


N at

plant

Topdress

30 days

Topdress

60 days

Total N

Fallow Fallow Fallow Fallow

0 0 0 0

0 30 30 60

0 30 60 90

0 60 0 60

0 60 30 90

30 0 0 30

30 30 0 60

30 30 30 90

30 30 60 120

30 60 0 90

30 60 30 120


Systems included

11

• Wheat monoculture (WWWW)

• Wheat after lucerne (first year) (LW)

• Wheat after lucerne (second year) (LWW)

• Wheat after canola in a wheat-canola-wheat-lupin

system

• Wheat after lupins in a wheat-canola-wheat-lupin

system


Tygerhoek mineralisation 2013

12

6-8 Aug 65mm

After canola



13



14

Topdress (13/6) Topdress (17/7)


Grain yield


Wheat after lucerne year 1 grain yield (kg ha-1)

16


Wheat after lucerne year 2 grain yield (kg ha-1)


Wheat after canola grain yield (kg ha-1)

2. Soil quality indicators


Zero-till No-till

Minimum-till Conventional-till


Crop rotation systems

21

Wheat monoculture

Wheat-canola-wheat-lupin

Wheat-medic-wheat


1. Soil microbial status ( 2011, 2012, 2013 and 2014)

2. Nematode status (2011, 2012, 2013 and 2014)

3. Aggregate stability (2011, 2012, 2013 and 2014)

4. Weed seed bank status (2011, 2012, 2013 and 2014)

5. Active carbon status (2011, 2012 , 2013 and 2014)

6. Chemical properties

7. Water balance (Abie Vorster)

8. Soil cover

9. Lime movement (0-5; 5-10; 10-15 and 15-20 cm)

10.Strategic tillage

Current activities on tillage/crop rotation trials


Tygerhoek Wheat Grain Yield (kg ha-1)

After 7 years of treatment applications

23


Tygerhoek canola seed yield (kg ha-1)

24

a

ab b

ab


Tygerhoek Lupin seed yield (kg ha-1)

25

Sprayed with broad spectrum herbicide to control

weeds

Water balance


Evapotranspiration

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Aggregate stability


Soil aggregation

Aggregate stability

29

http://faculty.yc.edu/ycfaculty/ags105/week05/

soil_physical_properties/soil_physical_properties_print.html

http://faculty.yc.edu/ycfaculty/ags105/week05/http://faculty.yc.edu/ycfaculty/ags105/week05/http://faculty.yc.edu/ycfaculty/ags105/week05/https://www.google.co.za/url?q=http://www.hoskin.ca/catalog/index.php?main_page%3Dproduct_info%26products_id%3D278&sa=U&ei=gbQNU8PdBam57AbhioGYAg&ved=0CC4Q9QEwAA&usg=AFQjCNHqsdT4SGCgsK9kAUKCxvHXlWlY9Q


Tygerhoek aggregate stability (%)

30

Glomalin content


Mycorrhiza

32 Go to Insert > Header & Footer > Enter presentation name into footer field


Glomalin content

33

Active C content


Tygerhoek HWEC (mg kg-1)

36

Mean= 1328.8 mg kg-1

Changes in C content 2007-2011

© Western Cape Government 2012 | 39 Go to Insert > Header & Footer > Enter presentation name into footer field No-, Min- and Conventional Zero

Biomass production lower in zero-till


Tygerhoek increase/decrease in C between 07 and 11

40

2007 org C = 2.06 and 2011= 2.08

No removal of crop residue

Biomass low on ZT


Tygerhoek increase/decrease in C between 07 and 11

Thank you

Tel: Fax:

www.elsenburg.com

Contact Us

Dr Johan Labuschagne

Plant Science

+27 (0)21 808 5209 +27 (0)21 808 5331

[email protected]

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Bemestingsnavorsing & grond kenmerke as riglyne vir ...overberglandbou.yolasite.com/resources/Voorsaai_2014...© Western Cape Government 2012 | 22 1. Soil microbial status ( 2011,