Omid Nouri Roudsari,; Kazem Arzani,; Aziz Moameni; Mehdi Taheri
Volume 10, Issue 1 , October 2012
Abstract
An experiment was carried out in order to study the spatial variability of soil fertility variables in an irrigated mature olive tree (Olea europea cv. `Zard’) orchard. The orchard is located in the Tarom area of Zanjan Province (48° 56′ to 50° 5′E and 36° 47′ to 37° ...
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An experiment was carried out in order to study the spatial variability of soil fertility variables in an irrigated mature olive tree (Olea europea cv. `Zard’) orchard. The orchard is located in the Tarom area of Zanjan Province (48° 56′ to 50° 5′E and 36° 47′ to 37° 36′ N) and is under olive with trees planted 7×7 m. Soil parameters - including K, P, Na, Cl, EC and OM - were determined in soil samples from 0-60 cm depth in late February 2011. A regular 98×98 m sampling grid was established and the intersection points were georeferenced. The data were analyzed using both classical statistics and geostatistical methods. Maps were created as a basis for orchard soil site-specific management. Interpolations were realized according to thresholds and standard deviation of every parameter. Estimates were used to draw variation maps of each soil fertility component based on Kriging method. High geo-distribution variation was detected. The results showed that an important area is menaced by K deficiency. Indeed, in this area soil K was revealed to be under the 70 ppm threshold level. The geostatistical analysis indicated different spatial distribution models and spatial dependence levels for the soil properties. Sodium and OM were strongly distributed in patches. Phosphorous was moderately spatial dependent, and K did not follow a spatial correlated distribution.
Aziz Moameni; Abbasali Damavandi; Kamran Eftekhari
Volume 10, Issue 1 , October 2012
Abstract
This study described the soil variability in an experimental 10×10 m plot in Zanjan Province. The study was aimed at: (i) characterizing the short-range spatial variability of soil properties that control soil fertility and plant nutrition, (ii) delineating uniform areas within trial sites based ...
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This study described the soil variability in an experimental 10×10 m plot in Zanjan Province. The study was aimed at: (i) characterizing the short-range spatial variability of soil properties that control soil fertility and plant nutrition, (ii) delineating uniform areas within trial sites based on spatial dependence of soil properties, (iii) determining if this variation is large and can be managed at practical scales. Surface soil samples (0-30 cm) were analyzed for clay, silt and sand contents, calcium carbonate equivalent, pH, organic carbon, available phosphorus and available potassium. The spatial variability of soil properties was described using geostatistics. Sampling on a 1 m2 grid, revealed a relatively large spatial variability of soil properties. Clay content exhibited no spatial dependence but other variables investigated were well-described with variogram models and significant short-range variations depicted. Based on the geostatistical analysis, a stratification of the field into potential management zones was possible.
