The response of whet grown in Andisols nd Oxisols to grnulr nd fluid phosphorus fertilizers Dniel Montlvo, Fien Degryse, nd Mike McLughlin
Introduction Previous studies showed there is more biovilble P in clcreous soils fertilized with fluid P thn with grnulr P (Hollowy et l., 2001; Lombi et l., 2005) Incresed efficiency of fluid fertilizers ws relted to less precipittion of C-phosphtes in nd round the fluid P injection zone MAP flmap Hollowy, et l. 2001 Slide 1
Reserch question Cn fluid P enhnce fertilizer efficiency on cidic strongly P-sorbing soils? Jrmillo, 2011 Jrmillo, 2011 Slide 2
Fte of P in cidic soils Adsorption/precipittion limit P vilbility Adsorption rections: P strongly dsorbed hydrous oxides of Al, Fe Precipittion rections: Few studies hve reported Al-nd Fe phosphte precipittes in soils Slide 3
Lbile P (% of dded P) Behviour P fertilizers: cidic soils Montlvo et l. 2014. Soil Sci. Soc. Am. J:78:214-224 100 80 60 MAP flmap * Andisol Oxisol 40 20 NS * Clcreous 0 Andisol Oxisol Clcreous MAP flmap Greter diffusion but not lbility from fluid P fertilizers in cidic Al/Fe oxides-rich soils Greter diffusion nd lbility in clcreous soil becuse of reduced C-P precipittion Slide 4
Slide 5 Residul MAP composition: cid soils ~ 10% of initil P remined in grnule Al, Fe did not significntly increse in the grnule (no movement) C content incresed in residul grnule incubted in clcreous soil Elementl comp. (mg grnule -1 ) P C Al Fe Unincubted 9.4 0.2b 0.4 0.6ns And. (Chile) 0.9cd 0.2b 0.4 0.7 And. (North) 0.8d 0.2b 0.4 0.5 Ox. (Green.) 1.0bc 0.1c 0.4 0.6 Ox.(Redv.) 0.9cd 0.2b 0.3b 0.6 Clc. (Pt K.) 1.2b 0.7 0.4 0.6 Montlvo et l. 2014. Soil Sci. Soc. Am. J:78:214-224
Hypothesis In cidic nd Al/Fe oxide-rich soils the ppliction of fluid P will provide no gronomic benefit over grnulr P sources Slide 6
Aim of the study To evlute the effectiveness of fluid nd grnulr P fertilizers for whet grown in cidic strongly P-sorbing soils under glsshouse conditions Slide 7
Mterils nd Methods Soils (5): Andisols (Chile nd North, NZ) Oxisols (Greenwood nd Redvle, AUS) Clcreous Inceptisol (Pt Kenny, AUS) Fertilizers (4): Grnulr: TSP (0-20-0), MAP (10-22-0), DAP (18-20-0) Fluid: flmap (12-26-0) Control (nil P) Slide 8
Selected soil properties Soil ph (H 2 O) Al ox Fe ox CCO 3 C DGT C 2+ ---- g kg -1 ---- % µg L -1 cmol c kg -1 Chile 5.3 43 17 b.d.l. 4 1.5 North-NZ 5.7 42 8 b.d.l. 11 6.6 Greenwood 5.9 17 4 b.d.l. 6 4.0 Redvle 6.4 2 2 b.d.l. 2 7.4 Pt Kenny 8.7 0.2 0.1 28 33 26.6 b.d.l.: below detection limit Al ox, Fe ox : oxlte extrctble Al nd Fe C DGT : Diffusive grdient in thin-film concentrtion, criticl conc. 60 μg L -1 (Mson, 2010) C 2+ : NH 4 Cl exchngeble C Slide 9
Mterils nd Methods Bsl mcro & micro nutrients Soils spiked 500 kbq kg -1 33 P Fertilizer rte: 150 mg kg -1 (And. & Ox.) 40 mg kg -1 (Clcreous Incep.) Whet plnts hrvested fter 6 weeks Shoots digested nd nlysed for totl P nd 33 P ctivity Slide 10
Mterils nd Methods Isotopic dilution (indirect lbeling) to determine % P in the plnt tht derived from fertilizer %Pdff = 100 [1 33 P shootf SA Pdfsoil 31 P shootf ] %Pdfseed f SA Pdfsoil = 33 P shootctrl 31 P shootctrl Pdfseed ctrl 33 P 31 P Slide 11
Shoot dry weight (g plnt -1 ) Plnt response: shoot dry weight 1.2 Andisols Oxisols Clc 1.0 0.8 0.6 0.4 0.2 0.0 b b b b b b b b c b b b b c Chile North Greenwood Redvle Pt Kenny TSP DAP MAP flmap CONTROL And. & Ox.: N.S. between flmap nd MAP Clc.: flmap produced 31% more dry mtter thn MAP Slide 12
Plnt response to fertilizers Redvle TSP DAP MAP flmap Ctrl TSP: C nutrition effect Slide 13 TSP: poor performnce likely C-P precipittion
Plnt response to fertilizers Pt Kenny MAP flmap Ctrl Slide 14
Shoot P (mg g-1) Plnt response: shoot P 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0.0 Andisols Oxisols Clc N.S. b bc b c bc b c b d b d Chile North Greenwood Redvle Pt Kenny TSP DAP MAP flmap CONTROL Plnt response to fertilizer ppliction Slide 15
TSP MAP DAP flmap CONTROL TSP MAP DAP flmap CONTROL TSP MAP DAP flmap CONTROL TSP MAP DAP flmap CONTROL TSP MAP DAP flmap CONTROL P Uptke (mg plnt -1 ) Plnt P uptke: Andisols & Oxisols 3.0 2.5 2.0 1.5 1.0 0.5 0.0 Fertilizer Soil Seed Chile North Greenwood Redvle Pt Kenny And. & Ox.: Soil P contribution to the shoots is miniml Clc.: Soil P contribution to the shoots ~58% verge Slide 16
P derived from fertilizer (%) Fertilizer Chile North Greenwood Redvle Pt Kenny TSP 88 80NS 81NS 65b 12c MAP 23c 79 85 79 30b DAP 54b 73 84 88 20c flmap 41bc 78 86 85 49 And. & Ox.: flmap = MAP Clc.: flmap > MAP Slide 17
Summry No gronomic benefits in Andisols nd Oxisols from the ppliction of fluid P fertilizers Clcium phosphte sources (e.g. TSP) should be voided in soils with ner neutrl to bsic ph to void opportunities for C-P precipittion In Andisols nd Oxisols most of crop P derived from fertilizer P, which highlights the importnce of fertilizer ppliction Slide 18
Acknowledgments Collection of soil in Austrli, New Zelnd, nd Chile- Drs Mike Bell, Leo Condron, nd Crlos Michiels Technicl stff- Bogumil Tomczk, Colin Rivers, nd Ashleigh Brodbent Funding Slide 19