Please LIKE, your LIKE will ENCOURAGE me very much. Thank you! SUBSCRIBE to watch more great video: https://bit.ly/3aDXZlr In this video:Early methods of weed control included mowing, flooding, cultivating, smothering, burning, and crop rotation. Though these methods are still important, other means are perhaps more typical today, particularly the use of herbicide (plant-killing) chemicals. Another technique is to introduce insects that attack only the unwanted plant and destroy it while leaving the crop plants unharmed.
During the ninety years until 1970, land-labor ratios increased in all countries, especially after 1950. These increases reflect the rapid declines in agricultural labor forces as people moved to industry and off the land. The United States, however, had an increase in agricultural land as well as a reduction in the agricultural labor force, so that differences in land-labor ratios between it and other countries increased.