Survey of the plant-available silicon status of agricultural soils in Louisiana

Adequate silicon nutrition in plants has shown positive effects on the growth and yield of the crop and physico-chemical properties of the soil. Hence, this study was initiated to survey the plant-available silicon in the agricultural soils of different parishes of Louisiana. Soil samples were collected from 212 representative agricultural fields of 27 agrarian parishes of Louisiana. Poor correlations between deionized water, calcium chloride, and other extractants suggest that the unbuffered calcium chloride extraction may reflect only a transient status of soil soluble silicon similar to deionized water extraction procedure. Also, acetic acid-2 extraction procedure may reflect the net effects of the sorption/desorption reactions by extracting the readily as well as the slowly releasable silicon that control solubility, thus giving a true measure of current availability. Compared to the previously established critical soil silicon levels, several agricultural fields of Louisiana were deemed to be low in plant-available silicon.