Agriculture and Horticulture

Biography

Biography: Amin Reza Jamshidi

Abstract

This study has investigated the effects of conservation tillage on the soil aggregate characters. Three tillage systems were used as follow: cyclotiller (speed of rotation):( a) 150 rpm, 200 rpm, and 250 rpm at a depth of about 200 mm. The experimental design was a split–split plot method which was based on randomized completely block design with three replication in 2015-16. The three soil water contents (W) were considered as the main plot and also three tillage systems (TI) were considered as split plot, and three tractor passages (P) for implement were considered as split–split plot. Each plot size was 3×15m².The experimental sites were plowed each year in the winter. Crop rotation pattern was canola which was for 2 years earlier than this study. The study was carried out in Khuzestan (Iran). The Soil aggregate mean weight diameter (MWD), geometric mean diameter (GMD) using wet saving method was measured. Results showed that effects of tillage on the mean weight diameter in depth of 0 - 300 mm with the speed of cyclotiller (200 rpm) and mean weight diameter (0.75 mm) produced the largest soil aggregates in the soil. As GMD index was compared, it was shown there are no significant differences with three tillage methods intensity. Tillage in soil used with 0.7 plastic limits was shown most stable soil aggregate with 0.75 mm MWD and 0.66 mm which were the most stable soil aggregates. In the wet saving, results showed that the most of the aggregates were unstable, and the MWD and GMD of water-table aggregates showed the trend of 200 rpm > 100 rpm>250 rpm.  At the layer of 0-30 cm, the fractal dimension (D) of water-stable aggregates under with a speed of 200 rpm cyclotiller was lower than when it was under a speed of cyclotiller (150 rpm) and with a speed of cyclotiller (250 rpm). The results showed a significant correlation between crop yield in different depths of the soil bulk density and the cone index was negative and significant (P> 0.01), the results showed the soil bulk density and the cone index were increased and the potato yields was decreased. Therefore they showed a correlation between the bulk density and the cone index traits in the different depths significant (P> 0.01), there is significant positive correlation. Consequently increasing of the bulk density, soil cone index increased. The results obtained in the experiment which was selected as useful models for the bulk density mean and the cone index in the different depth that were related to the potato performance crop. Regression equations has shown number of the tractor passes for the period of the season tillage factor in the equation had negative the potato yield and the soil moisture coefficient in equation of the yields positive.