M. A. Hajabbasi,
Volume 3, Issue 1 (Number 1 - 2001)
Abstract
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.
O. L. Rashidi, M. A. Hajabbasi, H. Naghavi, M. Gheysari, J. Razmjoo,
Volume 25, Issue 6 (11-2023)
Abstract
One way of developing sustainable agriculture is to increase crop Water Productivity (WP). In drought conditions, cultivation management should result in reducing water consumption as well as lowering the negative impacts on crop yield and quality. This experiment was conducted to determine the influence of irrigation levels (full and deficit irrigation, providing 100 and 75% of the irrigation water requirement, respectively) and soil water retaining materials (organic fertilizer, superabsorbent at depths of 30 and 40 cm, superabsorbent mixed with soil, band application of superabsorbent, plastic installation at depths of 30 and 40 cm and control) on WP, leaf Relative Water Content (RWC), Electrolyte Leakage (EL), photosynthetic pigments, yield and yield components of wheat during the growing seasons of 2017 and 2018. The deficit irrigation caused an increase in WP and EL and decreased yield, yield components, RWC, and photosynthetic pigments, while the soil water retaining materials improved these properties. The average yields in the organic fertilizer treatment and installation of plastic at a depth of 40 cm were 9.55 and 8.76 tons ha-1, respectively. The highest WP (1.89 kg m-3) was observed in the organic fertilizer treatment. Application of cow manure and installation of plastic membrane did not have significant effect on wheat properties in the two water conditions. Overall, utilizing organic fertilizer and nylon membranes under deficit irrigation, improved wheat characteristics and WP. However, to reach a comprehensive conclusion, it is necessary to evaluate these treatments for several consecutive years with different soil and water conditions.
