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
Outly of presenttion Bckground Mterils nd methods Results nd conclusion Generl conclusions Acknowledgements Western Cpe Government 212 2
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
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
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
Rinfll (mm) Rinfll (mm) Rinfll (mm) Rinfll (mm) Rinfll : Riversdle nd Tygerhoek Riversdle 216 Riversdle 217 12 1 8 6 4 2 Apr My Jun Jul Aug Sep Month 216 Long-term 12 1 8 6 4 2 Apr My Jun Jul Aug Sep Oct Month 217 Longterm 12 1 8 6 4 2 Tygerhoek 216 Apr My Jun Jul Aug Sep Okt Month 216 Longterm 12 1 8 6 4 2 Tygerhoek 217 My Jun Jul Aug Sep Oct Month 217 Longterm Western Cpe Government 212 6
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 T1 25 25 T2 5 25 T3 75 25 T4 15 25 T5 135 25 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
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 B1 4 3 2 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 5 6 7 12 11 1 C + F2 C + F1 Spu puitstrook T4 + F2 T4 + F1 13 14 15 B12 2 19 18 B13 UREA+I T3 + F2 LAN C + F2 21 B18 28 B19 UREA+I T2 + F2 T3 + F1 C + F1 T2 + F1 Spu puitstrook 22 23 27 26 T4 + F2 T4 + F1 T3 + F2 Spu puitstrook AMS T1 + F2 T1 + F1 T5 + F2 T5 + F1 T6 + F2 29 3 31 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 4 17 24 25 T + F1 T6 + F1 C + F2 C + F1 32 Western Cpe Government 212 8
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
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 48 48 Kysn (LAN + S) Lnggewens whet fter cnol 24% N; 3% S 75 75 Ure Porterville whet fter medics 46% N 35 35 Ure + urese inhibitor 46% N Porterville whet fter cnol 63 63 Drling whet fter medics 35 35 Drling whet fter cnol 65 65 Western Cpe Government 212
Results : Averge yields for 216 & 217 5 4759 Yield 216 Yield kg h -1 4 3 2 1 476 1341 395 3353 3516 385 2471 3368 25 3545 135 2659 594 Yield 217 239 1927 946 734 Western Cpe Government 212 11
Western Cpe Government 212 Results Study 1 Topdressed N rtes
Yield (kg h Yield (kg -1 ) h -1 ) Results : Riversdle whet fter cnol 6 2 18 5 16 14 4 12 LSD: 671.8 LSD: P < 26.9.5 P < CV:.58.1% CV %: 1.2 bc c c b bc Yield 216 Yield 217 bc bc b c bc bc 1 3 8 6 2 4 1 2 d 1175 1417 1298 3639 1517 482 1454 4359 1561 4752 12 4624 1262 489 1314 4849 C 25 5 75 15 135 165 C 25 5 75 15 135 165 Topdress N rte (kg h Topdress N rte (kg h ) -1 ) Western Cpe Government 212 13
Yield (kg h -1 ) Yield (kg h -1 ) Results : Tygerhoek whet fter cnol 5 45 4 4 35 35 3 3 25 25 2 2 15 15 1 1 5 5 LSD: 877. LSD: 458.4 P <.5 P <.5 CV%: 15.1 CV%: 9. Yield 216 217 b 2462 3126 3729 3382 384 3318 4211 3324 4458 354 4243 3111 4524 3498 4132 3527 C C 25 25 5 5 75 75 15 15 135 135 165 165 Topdress N rte (kg h -1 ) Topdress N rte (kg h -1 ) Western Cpe Government 212 14
Yield (kg (kg h h -1 ) -1 ) Results : Cledon whet fter lucerne 5 45 45 4 4 35 35 3 3 LSD: 855.5 LSD: P <.5 457.6 P CV <.5 %: 16.5 CV %: 1.1 Yield 216 217 25 25 2 2 15 1 5 35 3377 3284 3778 392 3532 3119 3819 3245 3342 2961 326 346 3523 2929 3555 C 25 5 75 15 135 165 Topdress N N rte (kg (kg h h -1-1 ) ) Western Cpe Government 212 15
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 5 55 25 55 25 8 78 3 35 Western Cpe Government 212 16
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 212 17
Results Study 1 Lte-seson folir UAN ppliction Western Cpe Government 212
Protien Protein content (%) (%) Results : Riversdle whet fter cnol 14 17 13 16 15 12 14 11 13 1 12 11 9 1 8 9 7 8 LSD:.8 1.4 CV CV %: %: 3.7 6.2 217 216 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 25 5 75 15 135 165 C 25 5 75 15 135 165 Top-dress Topdress N N rte rte (kg (kg h ¹) h ¹) Western Cpe Government 212
Protein Yield content (kg h ¹) (%) Results : Tygerhoek whet fter cnol 14 15 13 14 12 13 11 12 1 11 1 9 89 LSD: 1. LSD:.5 CV %: 5.5 CV %: 3. de g h f def e h de e fge 216 217 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 25 25 5 5 75 75 15 15 135 135 165 165 Topdress N rte N rte (kg (kg h ¹) h ¹) Western Cpe Government 212
Protein Protein content content (%) (%) Results : Cledon whet fter lucerne 15 17 15 16 14 14 15 13 14 13 12 13 12 11 11 11 1 LSD: LSD: 1.2.6 CV %: 5.7 CV %: 3.3 217 216 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 25 5 75 15 135 165 Topdress N rte rte (kg (kg h h -1-1 )) Western Cpe Government 212
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
Western Cpe Government 212 Results Study 2 N sources
Yield (kg h -1 ) Results : Tygerhoek whet fter cnol 5 45 5 4 35 4 3 3 25 2 2 15 1 5 LSD: LSD: 323.1 521.5 CV CV %: %: 6.68.2 216 217 324 42 3154 4273 333 422 3164 4152 3147 3919 Ure Ure + I AMS LAN LAN Kysn + S N source Western Cpe Government 212
b Riversdle C/W b b 4675 488 4331 4663 4859 LAN + S Ure Ure + I AMS LAN Kysn Other 216 results Cledon L/W Study 2 3949 3941 4175 3929 3695 Ure Ure + I AMS LAN LAN + S Western Cpe Government 212
bc c Riversdle C/W b bc 143 1251 1591 1539 1372 Other 217 results Cledon Study L/W2 Ure Ure + I AMS LAN LAN + S 3217 326 3332 3126 3346 Ure Ure + I AMS LAN LAN + S Western Cpe Government 212
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
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
Cnol N tril E du Toit, J Lbuschgne, P Swnepoel Africn Combined Congress Cpe Town 18 Jnury 218
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
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 216 12 LSD = 33.43 CV = 3.28 1 8 LSD = 18.95 CV = 26.6 bcd bc b 6 LSD = 1.72 CV = 4.51 LSD = 5.89 CV = 24.82 4 2 d cd cd cd b b b b b b b Pre-plnt Pre-topdress Post-topdress Post-hrvest Smpling time Western Cpe Government 212 31
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 217 12 1 8 LSD = 14.12 CV = 2.46 LSD = 18.56 CV = 3.84 LSD = 11.6 CV = 37.98 6 4 2 bc c c b bc bc bc Pre-plnt Pre-topdress Post-topdress Post-hrvest Smpling time Western Cpe Government 212 32
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 216 12 LSD = 26.32 CV = 22.66 1 8 LSD = 1.27 CV = 16.29 LSD = 15.93 CV = 19.25 bc b 6 4 b b b b b b c c c c c LSD = 1.2 CV = 4.65 2 Pre-plnt Pre-topdress Post-topdress Post-hrvest Smpling time Western Cpe Government 212 33
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 24 29 Soil minerl N content (mg kg -1 ) 34 32 Tygerhoek: Soil minerl N content 217 12 1 8 LSD = 13.15 CV = 25.81 LSD = 14.17 CV = 34.45 LSD = 7.18 CV = 24.42 6 4 2 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 212 34
Yield (kg h -1 ) Yield (kg h -1 ) Riversdle yield 216 nd 217 25 2 bc Riversdle 216 c b bc b 15 d d 1 5 25 2 15 1 5 b C 25 5 75 15 135 165 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 25 5 75 15 135 165 Topdress N rte (kg h -1 ) Western Cpe Government 212 35
Yield (kg h -1 ) Yield kg h -1 ) Tygerhoek yield 216 nd 217 Tygerhoek 216 3 25 2 b b b b b b 15 c 1 5 3 25 2 15 1 5 C 25 5 75 15 135 165 Topdress N (kg h -1 ) Tygerhoek 217 b b b b b b A A A A b A A A A c 25 5 75 15 135 165 Topdress N rte (kg h -1 ) yield yield+f Western Cpe Government 212 36
Reltiv yield (%) Riversdle: Reltive Yield 11 1 9 8 7 6 5 4 3 2 1 C 25 5 75 15 135 165 Topdresed N rte (kg N h -1 ) Western Cpe Government 212 37
Reltive yield (%) Tygerhoek: Reltive Yield 12 1 8 6 4 2 c 25 5 75 15 135 165 Top dress N rte (kg N h -1 ) Western Cpe Government 212 38
Results Study 2 ) N sources yield Western Cpe Government 212 39
Yield (kg h -1 ) Yield (kg h -1 ) N source yield: Tygerhoek nd Riversdle 217 3 25 2 15 1 5 Tygerhoek LSD = 539.2 CV = 14.28 UREA UREA+I AMS LAN KYSAN N Source 2 15 Riversdle LSD = 477.37 CV = 18.33 b b b b 1 5 UREA UREA+I AMS LAN KYSAN N source Western Cpe Government 212 4
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 212 41
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 212 42
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