جستجوی مقالات مرتبط با کلیدواژه « گندم زمستانی » در نشریات گروه « آب و خاک »

Soil moisture (SM) is the major factor controlling plant growth particularly in rainfed lands. It varies due to the change of climatic parameters such as precipitation and air temperature and evaporation. This study was conducted to found climatic factor influencing soil moisture under rainfed conditions. A field experiment with two cultivated conditions: under fallow and cultivated with winter wheat was designed in a rainfed land with 10% slope steepness in the University of Zanjan during growth period from 2016 to 2017. Toward this, six plant plots with 2m × 5m dimensions were installed along the slope orientation similar to conventional tillage method in the area. Volumetric soil moisture was measured in 7-day interval using TDR model IDRG SMS-T2 set during growth period Climatic variables including air temperature (AT) and precipitation (P) along with soil temperature (ST) were determined during growth period. Based on the results, SM in cultivated plots was about 11% less than the follow plots, and this difference was statistically significant between the two. Amount of soil moisture significantly varied among different months (p<0.001). Significant correlations were found between SM and P, AT and ST in the two cultivation conditions (p<0.05). Higher dependency of SM on AT (r=0.44) and ST (r=0.51) was observed in fallow plots as compared to planted plots. This study revealed that ST is the most effective property controlling SM in fallow and planted lands in the area.

Soil water content (SWC) plays an important role in plant growth, particularly in rainfed lands in arid and semi-arid regions. Knowledge of the variability of SWC is critical for understanding a range of hydrological processes including infiltration, runoff, and evapotranspiration. It is an integrative state variable affected by climate, soil properties, land cover, and topography. In this study, the variability of SWC was investigated in seven wheat rainfed lands with 4%, 8%, 11%, 15%, 18%, 20%, and 24% slope under fallow conditions in west of Zanjan province. The SWC was measured at a depth of 20 cm in three plots (1.5 m×2.5 m) with 5-day interval during the growing period of winter wheat from 2014 to 2015. The SWC showed a large variation during the study period which was associated with the monthly variation of precipitation. Significant (P