To harvest legume crops
Many farmers are accustomed to pulling up the straw by hand when harvesting legume crops. In fact, this method of harvesting is unscientific. Virtually it will waste a lot of organic nitrogen-fixing fertilizer, which is very unfavorable for planting the next season crop. It is well-known that legume crops are nitrogen-fixing crops, and root rhizobia have the effect of fixing free nitrogen from the air. It was determined that a mu of legume crops can fix nitrogen from the air by 7.5 to 10 kilograms, equivalent to 35 to 50 kilograms of ammonium sulfate. Save noodles unless you can't fully absorb them. If it is uprooted at the time of harvest, nodules that store nitrogen will be taken away. Therefore, when farmers harvest legumes, it is best to use a sickle to cut them, so as to lay the foundation for increasing grain production in the next season.