
%0 Journal Article
%A Fischer, RA 
%A Kono, Y 
%A Howe, GN 
%T Direct drilling effects on early growth of wheat: studies in intact soil cores
%J Australian Journal of Experimental Agriculture
%D 1994/03/01
%V 34
%N 2
%P 223-227
%K 
%R https://doi.org/10.1071/EA9940223
%U https://www.publish.csiro.au/paper/EA9940223 
%X Tillage experiments with wheat (Triticum aestivum L.) were conducted at 2 sites in south-eastern Australia: one cool and wet (Murrumbateman), the other warmer and drier (Yanco). Following crop residue removal, direct drilling treatments with complete surface disturbance to 3 cm depth of the medium-textured topsoils (D), or with disturbance only in the narrow seeding slots (DN), were compared with drilling into a surface prepared by cultivating to about 7 cm depth (control). At the 4.5 leaf stage, seedlings from D and DN treatments had less shoot dry weight than the control except at Murrumbateman under very wet post-seeding conditions. Simulation of the above tillage treatments in intact soil Cores from both sites kept under controlled temperature and moisture conditions confirmed that DN treatment, with only 11% of the volume of soil disturbance of the control, reduced early growth, especially at Yanco and if post-sowing conditions were drier. Reduced shoot growth was associated with relatively larger effects on the extent of root exploration. Treatment D, with 43% of the volume of disturbed soil, did not reduce shoot growth relative to the control under any circumstances. Although results suggest a minimum volume of disturbed soil for maximum growth, interactions with biotic stresses as reported recently cannot be ruled out. 
