Isfahan University of Technology, Isfahan 84154, Islamic Republice of Iran.
Abstract: (5968 Views)
Tillage systems influence soil physical, chemical and biological characteristics which in
turn may alter, root characteristics, growth, and development. A three year study was
conducted to investigate the effects of seven tillage systems on some soil (fine-loamy
mixed, Typic Haplocambids) physical characteristics and wheat (Triticum aestivum L.)
root morphology. Tillage treatments included moldboard plowing + disking (MD) as conventional
tillage, chisel plowing + disk (CD), chisel plowing + rotary tilling (CR), chisel
plowing (twice) + disking (2CD), plowing with a khishchi (a regional rigid cultivator)
(KD), as non-inversion methods, and till planting with cultivator combined drill (TP), and
no-tillage (NT) as direct drilling methods. Soil texture, bulk density (BD), organic matter
(OM) and compactness (CI) were determined. At the depths 0-0.1, 0.1-0.2, 0.2-0.3 and 0.3-
0.4m, root mass density (RMD) was obtained, root length density (RLD) was determined
and average root diameter (RD), surface area density (RSD), and root fineness (RF) were
calculated. A randomized complete block design consisting of four blocks (replications)
was used. For all treatments, the upper layer (0-0.lm) contained a higher quantity of
RMD, RLD and RSD, but the reverse was observed for the lower layer (0.3-0.4m). The
upper layer (0-0. lm) contained almost 46% of the total RMD (average of all treatments),
while the second (0.1-0.2m) the third (0.2-0.3m) and fourth (0.3-0.4m) depths contained
23, 18.5 and 12.5% of the total RMD, respectively. The average RLD of four depths for
MD, CD, CR and 2CD were significantly (P ≤ 10)higher than KD, TP and NT systems
(24.9, 25.1, 24.2, and 23.8, as compared with 22.3,21.8 and 21.6km m-3 , respectively). Results
of this study showed that, for the arid soils of central Iran, with weak structure and
low organic matter content, as the number of tillage operations increased, root morphological
characteristics improved.
Subject:
Soil Science Received: 2010/05/15 | Accepted: 2010/05/15 | Published: 2010/05/15