s:1174:"%T Aggregate size distribution in a biochar-amended tropical Ultisol under conventional hand-hoe tillage 
%A Fungo B 
%A Lehmann J 
%A Kalbitz K 
%A Thiong'o M K 
%A Okeyo I 
%A Tenywa M M 
%A Neufeldt H 
%X Biochar (or pyrogenic organic matter) is increasingly proposed as a soil amendment for improving fertility, carbon sequestration and reduction of greenhouse gas emissions. However, little is known about its effects on aggregation, an important indicator of soil quality and functioning. The aim of this study was to assess the effect of Eucalyptus wood biochar (B, pyrolyzed at 550 C, at 0 or 2.5 t ha1), green manure (T, from Tithonia diversifolia at 0, 2.5 or 5.0 t ha1) and mineral nitrogen (U, urea, at 0, or 120 kg N ha1) on soil respiration, aggregate size distribution and SOC in these aggregate size fractions in a 2-year field experiment on a low-fertility Ultisol in western Kenya under conventional hand-hoe tillage. Air-dry 2-mm sieved soils were divided into four fractions by wet sieving: Large Macro-aggregates (LM; >1000 m); Small Macro-aggregates (SM, 250–1000 m); Micro-aggregates (M, 250–53 m) and Silt + Clay (S + C, 
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