Why is barley grown in rotation?? Scientific and agricultural reasons?
I am doing an agricultural science project. I am trying to express why barley is grown in rotation but I'm stuck. I need some agricultural reasons and some science reasons :) Thanks!
Barley does not restore nitrogen to the soil, it removes it. Leguminous crops like alfalfa and beans add nitrogen to the soil; however barley, being a grass, actually needs a fair amount of biologically available nitrogen in the soil in order to grow well.
The main reason that barley is rotated is to break the life cycle of diseases and insect pests that are specific to barley. In the United States, the major fungal pest of barley (and also of wheat) is Fusarium head blight. Fusarium spores can overwinter in the soil or in fallen seeds, and then infect a newly planted crop the following spring. Crop rotation prevents a buildup of fungal spores in the soil, as long as wheat or barley is alternated with a crop that is not susceptible to Fusarium.
The purpose of rotating crops is to give the soil a chance to regroup and replenish itself in some manner that will be beneficial to the production of future crops. You mentioned you need scientific reasons as well as agricultural reasons, but really, the two go hand-in-hand. Agriculture is a science all in itself, mankind has been praticing the science of growing things for quite some time now. Specifically, barley has a short growing season, does quite well in cooler climates, and has shown itself to be drought-resistant. Barley is a grain that has its uses in breads, alcohol production in malt beers and whiskeys, and as a livestock feed. Barley use in the area of crop rotation would give the land an opportunity to restore nitrogen to the soil, as well as lessening the insect and bacteria pestulence specific to other crop types. So there are advantages to growing different crops on your land, such as barley.