Micronutrient variability in a lacustrine environment of calcic haplosalids

Micronutrients are important components of plant production. Due to the high pH and calcium carbonate contents, micronutrient deficiencies are widespread in the soils of arid regions. The purpose of this study was to find out the relationships between spatial distribution of soil properties and available micronutrients (Zn, Cu, Fe, and Mn) in a highly saline arid environment. Soils were collected from a 2650 ha field which was divided into square sub-blocks, with 400 m spacing in x and y directions, for sampling procedure. One hundred fifty one soil samples were collected from 0-30 cm of soil surface, and diethylenetriamine penta-acetic acid DTPA-extractable micronutrients Zn, Cu, Fe, and Mn and some of physical and chemical characteristics were determined. Geostatistical techniques were employed to determine the spatial variability of micronutrients. Extractable micro nutrient contents varied from 0.59 to 5.49 mg kg -1 for Fe, from 0.04 to 0.61 mg kg -1 for Zn, from 1.54 to 14.01 mg kg -1 for Cu and from 0.12 to 2.09 mg kg -1 for Mn. The correlations between extractable contents of Fe and Cu were not significant but all the others were significantly important (P<0.01) that was also clearly shown in the spatial distribution maps. The results of semivariance analysis showed that the available Fe and Mn were spatially correlated at a larger distance of 5940 and 5889 m, and the available Cu and Zn were at a shorter distance of 1350 and 1740 m, respectively. Concentrations except Mn were relatively low in the northern part of the study area where the sand content was high. Understanding how plant-available soil micronutrients vary across the land enables to determine the rational management of micronutrient fertility. © by PSP