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轮作是控制大范围土传病害的自然屏障。试验（１９８９－１９９１）结果表明，冬大麦和冬小麦混作能降低由眼斑病菌（ｐｓｅｕａｏｃｅｒｃｏｓｐｏｒｅｌｌａｈｅｒｐｏｔｒｉｃｈｏｉｃｌｅｓ）、镰刀菌（Ｆｕｓａｒｉｕｍｓｐｐ．）、小麦全蚀病菌（Ｇａｅｕｍａｎｎｍｙｃｅｓｇｒａｍｉｎｉｓ）和丝核菌（Ｒｈｉｏｃｔｏｎｉａｃｅｒｅａｌｉｓ）引起的茎腐病。前茬为谷类混作的，后茬大麦和小麦健茎数目增加。前作为混作时，大麦拔节期和成熟期Ｆｕｓａｒｉｕｍｓｐｐ．的发病率显著降低（降低幅度大于５０％）；在大麦成熟期，Ｇ．ｇｒａｒｍｉｎｉｓ的发病率从４４％（前作大麦）降低到９％（前作混作）。小麦全蚀病的发病率没有因为前作的不同而明显不同。前作为大麦的混作小麦。眼斑病的发病率增加，且病原菌间发生互作，表明竞争的差异。大麦和小麦连续２年混作，控制病害的效果提高。这种情况下，小麦病害降低的程度与小麦单作施杀菌剂效果相似。利用选择性培养基测定小麦下胚轴和根组织的病原频率表明：Ｇ．ｇｒａｒｍｉｎｉｓ在小麦组织中的频率从１４％（前作大麦）和７％（前作小麦）降低到１％（前作混作），Ｆｕｓａｒｉｕｍ．ｓｐｐ的频率一般不受前作的影响。
Crop rotation is a natural barrier that controls a wide range of soil-borne diseases. The results of the trial (1989-1991) show that winter barley and winter wheat can reduce stalk rot caused by pseuaocercosporellaherpotrichoicles, Fusariumspp., Gaeumannomyces graminis and Rhioctoniacerealis . The former crop was mixed with cereals, and the number of stems of barley and wheat after the previous crop increased. Fusariumspp as a pre-mixed, barley node and maturity stage. The incidence was significantly reduced (greater than 50% reduction); barley maturity, G. The incidence of grarminis decreased from 44% (formerly barley) to 9% (previously mixed). The incidence of wheat ecliposis was not significantly different from the previous one. Mixed wheat as barley before. The incidence of eye spot disease increased, and the interaction between pathogens, indicating differences in competition. Barley and wheat mixed for 2 years in a row, the effect of disease control increased. In this case, the degree of disease reduction in wheat is similar to that of wheat alone. The use of selective medium to determine the pathogen frequency of wheat hypocotyls and root tissues showed: The frequency of grarminis in wheat decreased from 14% (formerly barley) and 7% (formerly wheat) to 1% (formerly mixed), Fusarium. The frequency of spp is generally unaffected.