Diffusive gradients in thin films(DGT)measurements have been shown to outperform other phosphorus(P)tests in soils with strong P sorption,but this has not been confirmed for moderately weathered European soils.We compared the performance of DGT in predicting wheat grain yield in Swedish long-term fertility experiments with those of standard intensity(water-extractable P(P-H20))and quantity(ammonium lactate-extractable P(P-AL))tests.A Mitscherlich-type model was used to fit wheat yield response to P application rates(0,15,30 or 35,and 45 kg P ha-1 year-1)in each individual trial replicate to estimate the maximum yield.For trials with clear plateau-type yield responses and the goodness of fit(R2)＞0.75,relative yields(RYs)were calculated for each P treatment and plotted against the soil P test results(n=143).The goodness of the Mitscherlich-type fits decreased in the following order:DGT-measured P(P-DGT)(R2=0.35)＞P-H20(R2=0.18)＞P-AL(R2=0.13).When excluding soils with P-AL:P-DGT≥0.1 L g-1,R2 was considerably improved to 0.55 for P-AL,0.46 for P-H2O,and 0.65 for P-DGT(n=61).At 95％of maximum yield,the upper limit of P deficiency for P-DGT was 44.8(the soils with P-AL:P-DGT＜0.1 L g-1)and 61.9 ug L-1(all soils),falling within the range reported for other European and Australian soils(6.0-142 ug L-1).We show that in the investigated Swedish soils,DGT performed better than the quantity and intensity tests,which is attributed to its ability to capture P diffusion and resupply from the soil solid phase,similar to plant roots in the rhizosphere.

Walter W.WENZEL;Cornelia MESMER;Eric J.FLORIDA;Markus PUSCHENREITER;Holger KIRCHMANN

Institute of Soil Research,Department of Forest and Soil Sciences,University of Natural Resources and Life Sciences Vienna,Konrad-Lorenz-Straβe 24,Tulln A-3430(Austria);College of Agriculture and Forestry,Mindanao State University at Naawan,Naawan 9023(Philippines);Department of Soil and Environment,Swedish University of Agricultural Sciences,Box 7014,75007 Uppsala,Lennart Hjelms v?g 9,Uppsala 75651(Sweden)

土壤圈（英文版）

[1]Walter W.WENZEL;Cornelia MESMER;Eric J.FLORIDA;Markus PUSCHENREITER;Holger KIRCHMANN-.Wheat yield prediction by zero sink and equilibrium-type soil phosphorus tests)[J].土壤圈（英文版）,2022(04):543-554

RYs

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