Burial effects on seed germination and seedling establishment of Prosopis juliflora (SW.) DC

Seed germination and seedling establishment are critical stages in plant life history, and both processes may be affected when buried under soil. Our aim was to investigate the effects of soil burial on the germination and seedling establishment of invasive Prosopis juliflora (Fabaceae). We studied the effects of burial, from soil surface to 4?cm deep, under greenhouse conditions and the effects of seed-storing in burial conditions at two depths (5 and 20?cm) and two storing periods (during 6 and 12?months) in field conditions. Soil burial limited the germination and the establishment of P. juliflora, which did not germinate at soil depths deeper than 3?cm. Some seedlings coming from seeds germinated at 2?cm, and every seedling at the soil surface and at 3?cm deep died. In contrast, survivorship of emerged seedlings was close to 90% between 0.5 and 2?cm depth. Seedlings developed the longest shoots at 1?cm deep, indicating that P. juliflora was able to get advantage at a moderate soil depth. Un-embedded seeds survived buried in the soil for months; however, their germination and the emerged seedling survivorship decreased after burial for 12?months.     

Modelling DUALEM-2 measured soil conductivity as a function of measuring depth to correlate with soil moisture content and potato tuber yield

Precision Agriculture - Electromagnetic induction (EMI) is a non-destructive technique to measure the apparent electrical conductivity (ECa) of agricultural soils. It has become popular in...     

Surface drainage nitrate loading estimate from agriculture fields and its relationship with landscape metrics in Tajan watershed

Pasture, forest, and farmland are the dominant land covers in the Tajan River watershed and this landscape status has a direct connection with nitrate pollution. Understanding the correlations between landscape variables and nitrate pollutant is a priority in order to assess pollutants loading and predicting the impact on surface water quality. The soil and water assessment tool was used to simulate nitrate loads in different land cover types in different years. The landscape pattern was calculated by FRAGSTATS. The contributing share of each land use/land cover shows nitrate pollutant produced by grassland (5.7%) and forest (29%) are less than those produced by agricultural land (64.2%). Agricultural land was identified as the main source of nitrate pollution. Paddy fields and orchards had the most intensive soluble nitrate loss especially in spring and summer. Statistical analysis indicated that nitrate was positively associated with patch density, edge density, patch number, total edge, effective mesh size, largest patch index, and landscape shape index (p ≤ 0.01). We then analyzed how nitrate was related to landscape attributes in six different sites. Also the regression analysis results suggested that landscape metrics could account for more than 94% of the variance of nitrate in the whole catchment. The regression models confirmed the great importance of the agriculture metrics and forest metric in predicting nitrate in watershed. Defining the generation and extent of pollution in this particular watershed which discharges into the Caspian Sea can constitute an important step toward protecting this ecosystem.