DEVELOPING NITROGEN FERTILISER MANAGEMENT STRATEGIES FOR WHEAT AND CANOLA UNDER CONSERVATION AGRICULTURE PRACTICES IN THE WESTERN CAPE, SOUTH AFRICA

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1 DEVELOPING NITROGEN FERTILISER MANAGEMENT STRATEGIES FOR WHEAT AND CANOLA UNDER CONSERVATION AGRICULTURE PRACTICES IN THE WESTERN CAPE, SOUTH AFRICA PJ Neethling, E du Toit, J Lbuschgne, P Swnepoel Overberg Agri Voorplnt Inligtingsdg, Rietpoel. 13 Mrch 218

2 Outly of presenttion Bckground Mterils nd methods Results nd conclusion Generl conclusions Acknowledgements Western Cpe Government 212 2

3 Bckground Nitrogen (N) is one of the most limiting plnt nutrients (Provin nd Hossner, 21; Zhu et l., 213) Supplying enough N to growing crops is one of the most criticl fctors influencing whet production Conservtion griculture (CA) prctices will influence the physicl, chemicl nd biologicl properties of soils (Grhmnn et l., 214) These chnges will influence the mount of vilble N It is therefor importnt to estblish optiml nd effective N mngement progrmmes under CA prctices Western Cpe Government 212 3

4 Bckground There hs been strong drive towrds CA in South Afric, especilly within the Western Cpe Province (Bsson et l., 217). N fertiliser mngement needs to be site-specific Differences in climte nd soil chrcteristics Six individul sites were identified within the lrger Western Cpe re Western Cpe Government 212 4

5 1. Uitkyk, Riversdle 2. Tygerhoek Reserch Frm 3. Klipfontein, Cledon 4. Lnggewens Reserch Frm 5. Nuhoop, Porterville 6. Klipklei, Drling South Afric 5 Western Cpe Government 212 5

6 Rinfll (mm) Rinfll (mm) Rinfll (mm) Rinfll (mm) Rinfll : Riversdle nd Tygerhoek Riversdle 216 Riversdle Apr My Jun Jul Aug Sep Month 216 Long-term Apr My Jun Jul Aug Sep Oct Month 217 Longterm Tygerhoek 216 Apr My Jun Jul Aug Sep Okt Month 216 Longterm Tygerhoek 217 My Jun Jul Aug Sep Oct Month 217 Longterm Western Cpe Government 212 6

7 Mterils nd Methods Study 1 (N rtes + Folir) N input t plnt (kg N h -1 ) N topdress tretment (Whole plot) Topdress N rte (kg N h -1 ) Folir N ppliction (split plot) Totl N input (kg N h -1 ) C (control) 25 T 25 T T T T T T6 165 Western Cpe Government 212 -Folir +Folir 1 (yr 1) & 2 (yr 2) -Folir 25 +Folir 35 (yr 1) & 45 (yr 2) -Folir 5 +Folir 6 (yr 1) & 7 (yr 2) -Folir 75 +Folir 85 (yr 1) & 95 (yr 2) -Folir 1 +Folir 11 (yr 1) & 12 (yr 2) -Folir 13 +Folir 14 (yr 1) & 15 (yr 2) -Folir 16 +Folir 17 (yr 1) & 18 (yr 2) -Folir 19 +Folir 2 (yr 1) & 21 (yr 2) 7

8 Mterils nd Methods B3 B2 Experimentl design Two seprte studies; First Kysnstudy: All N UREA+I All N Kysn All N UREA ) Topdressed Nitrogen (N) rtes effect on crop yield AMS b) Lte-seson UREA+I folir UREA N pplictions AMS (UAN) effect AMS on UREA grin protein content. LAN B4 B5 B9 B8 B1 B11 B15 B14 B16 B17 B21 B2 All N Kysn B22 B23 B LAN UREA B6 B7 Kysn Second: The effect of different N sources t topdress on crop yield nd protein. T2 + F2 T2 + F1 T3 + F2 T3 + F1 The first study ws lid out in split-plot design: LAN -Seven T4 + F2 N T topdressing + F2 rte T5 + F2tretments T1 + plus control T6 + F2 (whole T + F2 fctor). -Hlf of the whole plots received folir UAN (sub-plot fctor). T4 + F1 T + F1 T5 + F1 T1 + F1 T6 + F1 T + F1 -Whole plot sizes were 12.6 x 2.1 m nd sub-plot sizes 6.3 x 2.1 m. -Replicted T1 + F2 T6 + F2 in four blocks. T3 + F2 T + F2 T5 + F2 T2 + F2 Spu puitstrook C + F2 C + F1 Spu puitstrook T4 + F2 T4 + F B B13 UREA+I T3 + F2 LAN C + F2 21 B18 28 B19 UREA+I T2 + F2 T3 + F1 C + F1 T2 + F1 Spu puitstrook T4 + F2 T4 + F1 T3 + F2 Spu puitstrook AMS T1 + F2 T1 + F1 T5 + F2 T5 + F1 T6 + F B24 1 T1 + F1 T6 + F1 T3 + F1 T + F1 T5 + F1 T2 + F1 The second study ws lid out in rndomized block design: -Five C + F2 N source T5 + F2 tretments (Ure, T6 Ure + F2 + I, AMS, T4 LAN, + F2 LAN + S). -Plot C + F1 sizes T5 were + F1 9 x 2.1 m. T2 + F1 -Replicted in four blocks. T6 + F1 T4 + F1 T1 + F1 8 9 T3 + F1 T2 + F2 T1 + F2 T + F2 16 REP 1 REP 2 REP 3 REP T + F1 T6 + F1 C + F2 C + F1 32 Western Cpe Government 212 8

9 Mterils nd Methods Cropping rottions Whet fter cnol (All sites except Cledon) Whet fter lucerne (Cledon) Plnting method Discplnter Row spcing 175 mm Stndrd N rte of 25 kg N h -1 t plnt 5 kg N h -1 with seed, 2 kg N h -1 brodcsted Fertiliser mngement Top-dress t 4-5 lef stge t mximum N uptke (±4 dys fter plnting) Folir UAN ppliction t beginning of er emergence Western Cpe Government 212 9

10 Mterils nd Methods Study 2 (N sources) Site Topdress N rte (kg N h -1 ) Yer 1 Yer 2 Riversdle whet fter cnol 3 N nd S elementl 3 Fertiliser source Tygerhoek whet fter cnol 55 composition 55 Limestone mmoinium nitrte (LAN) Cledon whet fter lucerne 28% N 5 1 Ammonium Sulphte (AMS) Lnggewens whet fter medics 21% N; 24% S Kysn (LAN + S) Lnggewens whet fter cnol 24% N; 3% S Ure Porterville whet fter medics 46% N Ure + urese inhibitor 46% N Porterville whet fter cnol Drling whet fter medics Drling whet fter cnol Western Cpe Government 212

11 Results : Averge yields for 216 & Yield 216 Yield kg h Yield Western Cpe Government

12 Western Cpe Government 212 Results Study 1 Topdressed N rtes

13 Yield (kg h Yield (kg -1 ) h -1 ) Results : Riversdle whet fter cnol LSD: LSD: P < P < CV:.58.1% CV %: 1.2 bc c c b bc Yield 216 Yield 217 bc bc b c bc bc d C C Topdress N rte (kg h Topdress N rte (kg h ) -1 ) Western Cpe Government

14 Yield (kg h -1 ) Yield (kg h -1 ) Results : Tygerhoek whet fter cnol LSD: 877. LSD: P <.5 P <.5 CV%: 15.1 CV%: 9. Yield b C C Topdress N rte (kg h -1 ) Topdress N rte (kg h -1 ) Western Cpe Government

15 Yield (kg (kg h h -1 ) -1 ) Results : Cledon whet fter lucerne LSD: LSD: P < P CV <.5 %: 16.5 CV %: 1.1 Yield C Topdress N N rte (kg (kg h h -1-1 ) ) Western Cpe Government

16 Totl N rtes (kg N h Results -1 ), where no further increse (P >.5) in yield ws recorded with incresing N rtes, vs the recommended N rtes (kg N h -1 ) for whet production t ech specific site. Site Riversdle whet fter cnol Tygerhoek whet fter cnol Cledon whet fter lucerne Totl N pplied Yer 1 Yer 2 Totl N recommended Totl N pplied Totl N recommended Western Cpe Government

17 Conclusion Incresing topdress N rtes hd less profound effect on crop yields thn expected Due to the potentil influence of CA, fertiliser N recommendtions might hve to be djusted Western Cpe Government

18 Results Study 1 Lte-seson folir UAN ppliction Western Cpe Government 212

19 Protien Protein content (%) (%) Results : Riversdle whet fter cnol LSD: CV CV %: %: edc bcde cdef fg ef f bcde ghi ef i def fgh fg hi i g b b bc bc cd b b bcd bc de bc bcd ef Protein Protein Protein Protein + folir folir C Top-dress Topdress N N rte rte (kg (kg h ¹) h ¹) Western Cpe Government 212

20 Protein Yield content (kg h ¹) (%) Results : Tygerhoek whet fter cnol LSD: 1. LSD:.5 CV %: 5.5 CV %: 3. de g h f def e h de e fge de de ef bcd b b b b b bc b b bcd efg de cd de Protein Protein Protein Protein + + folir folir 78 C Topdress N rte N rte (kg (kg h ¹) h ¹) Western Cpe Government 212

21 Protein Protein content content (%) (%) Results : Cledon whet fter lucerne LSD: LSD: CV %: 5.7 CV %: b bc bcd b bc b cde bc bcd bc bcd bcd def cdef efg cdef cde cde bcd bcde fgh bcde bcdef cdef def gh ef h f Protein Protein Protein + folir C Topdress N rte rte (kg (kg h h -1-1 )) Western Cpe Government 212

22 Conclusion Study 1 ) Topdressed N rtes: Incresing topdress N rtes hd less profound effect on crop yields thn expected Due to the potentil influence of CA, fertiliser N recommendtions might hve to be djusted b) Lte-seson folir UAN ppliction UAN consistenly incresed protein content t two (Tygerhoek, Lnggewens M/W) of the nine sites during Yer 1. At the other seven sites in Yer 1 nd ll of the sites in Yer 2, UAN filed to consistently increse protein contents. These results indicte tht the ppliction of folir UAN s tool to increse grin protein content of whet might not be fesible (not conclusive). Western Cpe Government 212

23 Western Cpe Government 212 Results Study 2 N sources

24 Yield (kg h -1 ) Results : Tygerhoek whet fter cnol LSD: LSD: CV CV %: %: Ure Ure + I AMS LAN LAN Kysn + S N source Western Cpe Government 212

25 b Riversdle C/W b b LAN + S Ure Ure + I AMS LAN Kysn Other 216 results Cledon L/W Study Ure Ure + I AMS LAN LAN + S Western Cpe Government 212

26 bc c Riversdle C/W b bc Other 217 results Cledon Study L/W2 Ure Ure + I AMS LAN LAN + S Ure Ure + I AMS LAN LAN + S Western Cpe Government 212

27 Conclusion Study 2 Different N sources hd no profound effect on yield. This might indicte tht the optiml N source for whet production might be the chepest nd most ccessible one. Western Cpe Government 212

28 Generl conclusion whet Fertiliser N recommendtions might hve to be djusted. The recommended rtes of N to produce whet led to over-fertilistion in some res, which my, in turn, led to environmentl pollution nd cn led to economic losses. Folir N ppliction t post-nthesis hd limited success in incresing grin protein content of whet. Determining the optiml N source might entil choosing the most cost-effective nd ccessible source. Western Cpe Government 212

29 Cnol N tril E du Toit, J Lbuschgne, P Swnepoel Africn Combined Congress Cpe Town 18 Jnury 218

30 Results Study 1 ) Soil minerl N content b) Topdressed N rtes yield c) Folir N ppliction t stem elongtion yield Western Cpe Government 212 3

31 C N 25 N 5 N 75 N 15 N 135 N 165 N C N 25 N 5 N 75 N 15 N 135 N 165 N C N 25 N 5 N 75 N 15 N 135 N 165 N C N 25 N 5 N 75 N 15 N 135 N 165 N c b bc bc bc bc bc Soil minerl N content (mg kg -1 ) Riversdle: Soil minerl N content LSD = CV = LSD = CV = 26.6 bcd bc b 6 LSD = 1.72 CV = 4.51 LSD = 5.89 CV = d cd cd cd b b b b b b b Pre-plnt Pre-topdress Post-topdress Post-hrvest Smpling time Western Cpe Government

32 Rep 1 Rep 2 Rep 3 C N 25 N 5 N 75 N 15 N 135 N 165 N C N 25 N 5 N 75 N 15 N 135 N 165 N C N 25 N 5 N 75 N 15 N 135 N 165 N 19 d Soil minerl N content (mg kg -1 ) 26 cd 29 bcd bcd bcd bc b Riversdle: Soil minerl N content LSD = CV = 2.46 LSD = CV = 3.84 LSD = 11.6 CV = bc c c b bc bc bc Pre-plnt Pre-topdress Post-topdress Post-hrvest Smpling time Western Cpe Government

33 C N 25 N 5 N 75 N 15 N 135 N 165 N C N 25 N 5 N 75 N 15 N 135 N 165 N C N 25 N 5 N 75 N 15 N 135 N 165 N C N 25 N 5 N 75 N 15 N 135 N 165 N Soil imerl N content (mg kg -1 ) Tygerhoek: Soil minerl N content LSD = CV = LSD = 1.27 CV = LSD = CV = bc b 6 4 b b b b b b c c c c c LSD = 1.2 CV = Pre-plnt Pre-topdress Post-topdress Post-hrvest Smpling time Western Cpe Government

34 Rep 1 Rep 2 Rep 3 Rep 4 C N 25 N 5 N 75 N 15 N 135 N 165 N C N 25 N 5 N 75 N 15 N 135 N 165 N C N 25 N 5 N 75 N 15 N 135 N 165 N Soil minerl N content (mg kg -1 ) Tygerhoek: Soil minerl N content LSD = CV = LSD = CV = LSD = 7.18 CV = b c bc bc b bc b b b b b b b Pre-plnt Pre-topdress Post-topdress Post-hrvest Smpling time Western Cpe Government

35 Yield (kg h -1 ) Yield (kg h -1 ) Riversdle yield 216 nd bc Riversdle 216 c b bc b 15 d d b C Topdress N rte (kg h -1 ) A b A b Riversdle 217 A A b b b A A A A b yield yield+f C Topdress N rte (kg h -1 ) Western Cpe Government

36 Yield (kg h -1 ) Yield kg h -1 ) Tygerhoek yield 216 nd 217 Tygerhoek b b b b b b 15 c C Topdress N (kg h -1 ) Tygerhoek 217 b b b b b b A A A A b A A A A c Topdress N rte (kg h -1 ) yield yield+f Western Cpe Government

37 Reltiv yield (%) Riversdle: Reltive Yield C Topdresed N rte (kg N h -1 ) Western Cpe Government

38 Reltive yield (%) Tygerhoek: Reltive Yield c Top dress N rte (kg N h -1 ) Western Cpe Government

39 Results Study 2 ) N sources yield Western Cpe Government

40 Yield (kg h -1 ) Yield (kg h -1 ) N source yield: Tygerhoek nd Riversdle Tygerhoek LSD = CV = UREA UREA+I AMS LAN KYSAN N Source 2 15 Riversdle LSD = CV = b b b b 1 5 UREA UREA+I AMS LAN KYSAN N source Western Cpe Government 212 4

41 Conclusion (Cnol) Low soil N response to N fertiliser in dry yer (217) Low yield response to N fertiliser in dry yer (217) Adpt N fertilser rte to climte (dry seson) Finl topdress N rte recommendtions will be formulted fter 4 yers of dt cpturing No significnt increse in yield for dditionl Folir N topdressing Similr yield results between N sources t optiml rtes Western Cpe Government

42 Acknowledgements The following people re responsible for helping to mke this project success: Students (PJ Neethling nd E du Toit) nd study leders (Dr. Lbuschgne nd Dr. Swnepoel) Western Cpe Deprtment of Agriculture s technicl stff Funding Winter Cerel Trust nd Ssol Agriculturl Trusts for funding the studies nd WCT for study bursry (PJ Neethling) PNS for prtil contribution to study bursry (E du Toit) Western Cpe Deprtment of Agriculture Western Cpe Agriculturl Reserch Trust Western Cpe Government

43 Thnk you

44 Contct Us Dr John Lbuschgne Plnt Science Tel: +27 () Fx: +27 ()