通过１９９７年的普查，明确了江苏淮北棉区旱连作棉田杂草以马唐为优势种，其平均密度、频度、重要值分别为９８１株／ｍ２、８９９％及７４８，其次是牛筋草；水旱轮作棉田一年生莎草发生量最大，但以稗草发生面最广，危害最大。１９９６、１９９７两年的定点调查结果显示，雨量是制约棉田杂草消长的主要因子，梅雨季节是杂草发生的主高峰期，但雨量只是改变杂草的时间分布，年际间生长季内，杂草发生总量大致相同。另外，地膜覆盖能显著减少棉田杂草发生量。 Through the 1997 census, it was clarified that the average density, frequency and important value of weeds in the cotton weed in cotton field in Huaibei area of ​​Jiangsu Province were 981 plant / m2, 899% and 748 , Followed by the tendon grass; annual rotation of water and drought rotation seeding the largest amount of cotton, but the most widely occurred with barnyardgrass, the most harmful. The results of sentinel surveys in 1996 and 1997 show that rainfall is the main factor restricting the growth and development of weeds in cotton fields. The rainy season is the main peak of weeds occurrence, but the rainfall only changes the time distribution of weeds. During the inter-annual growth season, Weeds occur roughly the same amount. In addition, mulching can significantly reduce the amount of weeds in cotton fields.