IMPACT OF CONSERVATION AGRICULTURE UNDER CHALLENGING CLIMATIC CONDITIONS. Soil Health Day Joostenberg 22 March 2018

Transcription

1 IMPACT OF CONSERVATION AGRICULTURE UNDER CHALLENGING CLIMATIC CONDITIONS Soil Health Day Joostenberg 22 March 2018 Dr JA Strauss

2 Presentation Layout Background CA trials Case study: Langgewens Other successes Closing remarks 2

3 Background Two main production areas 3

4 Background Mediterranean Hot dry summers 4

5 Background West to East Lucerne 5

6 Background Two main production areas Rainfall distribution 6

7 mm 250 Rainfall: Swartland Mrt Apr May Jun Jul Aug Sep Okt Langgewens Swartland avg 2007 Long term

8 mm Rainfall: Southern Cape Mrt Apr May Jun Jul Aug Sep Okt Tygerhoek Rietpoel Boontjieskr. Riversdal Tygerhoek long term

9 Background Two main production areas Rainfall distribution Soil & OM 9

10 Background Composition shallow clay/loam (10 tot 20%) (shale's Malmesbury and Bokkeveld) well drained sand Average depth 200 to 400mm in the shale's could have more than 70% rock large part ha more than 30% rock 10

11 CA trials Langgewens Old trial 8 systems Minimum till 1996 to 2001 No-till 2002 to 2015 Zero-till 2016 to. New trial Zero-till systems based on diversity Low inputs Tygerhoek 5 main systems Multiple subsystems No-till 2002 to 2016 Zero-till 2017 to 11

12 CA trials Napky 3 x 5 year cash crop phases 6 crop sequenes No-till New focus 2018 onwards Riversdale 2002 to x 5 year cash crop phases 6 systems 2012 to.. Pure cash crop systems Cover crops Hopefield New trial in sand 12

13 Case study: Langgewens 13

14 Langgewens CA systems more resilient over time Minimal soil disturbance Improved soil structure = better moisture retention going longer on less Crop rotation Improved weed management = less competition for available moisture Soil cover Lower evaporation and better moisture infiltration maximizing available moisture for production 14

15 Langgewens - Carbon sequestration Carbon content increase WWWW MgC.ha-1 WMc+S MgC.ha-1 Tillage practices and carbon WMWM CT MgC.ha-1 NT MgC.ha-1 WCWL CT MgC.ha-1 NT MgC.ha-1 15

16 Langgewens - Carbon sequestration %C increase from 2000 to A B C D E F G H 2 16

17 kg/ha Langgewens - Average yields Average wheat yield within systems 2002 to Cropping systems 17

18 kg/ha Langgewens - Wheat yield per crop sequence 3800 Average wheat yield following different crops wwww cw cww cwww lw mw cmw Crop sequence 18

19 Langgewens - Improvement in production under drought conditions Apr May Jun Jul Aug Sep Total Ave Yield 0,51 / ,01 2,1 3,45 2,33 19

20 KG/HA Wheat Yield SYSTEMS 20

21 Langgewens - Yield and effectivity with reduced N inputs Crop sequence Yield 2017 Tot N kg/kgn Canola WBC WWC Barley WWB Oats WWO Wheat WCW WFaW WCocW WWW WLinW WColW WVetW Go to Insert > Header & Footer > Enter presentation name into footer field 21

22 Reduced fertiliser inputs Example of systems working for the producer Wheat following medic legume pasture within systems trial 22 nd production year Planted on good and poor soil Half of camp received 12kg of total nitrogen (1ha) Half of camp received 32kg of total nitrogen (1ha) Good soil - yield 40kg/ha higher on 12 kg N total than with 32 kg N Yield 2.82 t/ha vs 2.78 t/ha Poor soil - yield 150kg/ha higher on 12 kg N total than with 32kg N Yield 1.61 t/ha vs 1.46 t/ha 22

23 Other succeses 23

24 Tygerhoek yield kg / mm Wheat 18, Barley 21, Canola 6, Oats 22, Triticale mm Apr to Sep

25 kg/ha Cover crop effects on wheat 6000 Wheat yield following different crops in W after L W after W W after C W after S Ave 25

26 kg/ha Cover crop effects on canola Canola Yield following different preceding crops in C after W 2791 C after legume cover 1856 C after barley 2275 AVE 26

27 Cover crop project effects on barley and wheat following winter covers Barley Wheat Mixture Riversdale kg/ha Tygerhoek kg/ha Riversdale kg/ha Tygerhoek kg/ha Caledon kg/ha Average

28 Cover crop project summer covers 28

29 29

30 Conservation Agriculture Western Cape 30

31 Contact Us Johann Strauss Directorate Plant Sciences Tel: Fax: