Abstract
Postal Code 21110, P.O. Box 422, Irbid, Jordan
* Corresponding author ( nidal{at}just.edu.jo )
Many soil physical properties and crop yield are affected by compaction. The effects of compaction of two axle loads resulting from wheel traffic on soil bulk density and crop growth were investigated. Subsoiling as a method to alleviate or reduce effects of soil compaction was evaluated. As a result of compacting loads in 2000, corn ( Zea mays L.) yield was reduced by 26.8 and 14.5% in 2000 and 2001. Even two years after compaction, soil bulk density was 1.6 to 6.1% greater than the zero-load from 10- to 50-cm depths by 8- and 19-Mg axle loads. Plants in compacted plots had a greater concentration of roots near the base of the plant compared with the plants in the zero-load plots. Plants in the subsoiled plots had fewer roots concentrated near the base of the plant compared with the plants in the nonsubsoiled plots for each load. Plant height was also significantly reduced by compaction. Compaction affected plant and soil properties, but subsoiling removed the compaction effect and improved soil properties, growth, and yield.
Abbreviations: LCML, lower critical mechanical limit • UCML, upper critical mechanical limit