秸秆还田对中国主要粮食作物病害影响的Meta分析

秸秆还田作为一项重要的生态农业措施，对于农作物病害的影响一直备受关注却尚未形成完全一致的观点。为明确秸秆还田对中国主要粮食作物病害的影响及其在不同病害类型、环境条件和农业管理方式下的具体表现，该研究采用Meta分析法，系统分析了公开发表的中国范围内秸秆还田对作物病害影响相关研究。结果表明：秸秆还田会显著增加中国主要粮食作物病害发病率和病情指数，增幅分别达9.5%和12.2%（P<0.05）。病害类型、环境条件和农业管理措施会显著改变秸秆还田对作物病害发生的影响。具体地，病毒病害和土传病害对秸秆还田的响应较为敏感；亚热带季风气候下还田病害显著减轻，温带季风气候下显著加重，水田下还田有利于病害减轻，旱地，尤其是冬小麦与春玉米轮作下还田病害加重显著，微酸性土壤中还田病害轻于微碱性土壤，此外，有机质含量大于15 g/kg、还田量小于7 000 kg/hm2、初始碳氮比大于15时还田均会导致病害的加重。线性回归分析显示，秸秆还田病害发生与年平均降雨量、有机质含量呈显著负相关，与初始碳氮比和土壤pH值呈正相关。综上，通过增加初始氮肥用量、调节土壤酸碱至微酸性以及改善土壤墒情，可最大限度地减少秸秆还田下中国主要粮食作物的病害发生。研究为改善病、虫、草害的发生以及促进秸秆资源高效利用与粮食作物生产提供依据。

Meta-analysis for the impacts of straw return on the diseases of major grain crops in China

Straw returning has been one of the most important practices in agricultural management. At the same time, crop diseases, in this case, have been always concerned in China. It is a high demand to clarify the effect of straw returning on the prevalence of diseases of main grain crops. In this study, a meta-analysis was conducted to determine the overall impact of straw returning on the occurrence of the main grain crop diseases. The key factors were also evaluated in response to various environmental factors and agronomic interventions. The data was collected from the published studies before December, 2021. The effective data was selected from the works of literature including: 1) the experiments were conducted in the croplands of China, and 2) the same experiment needed to include the paired treatment and control group. The treatment group was the straw returning to the field, and the control group was no straw returning. The rest experimental conditions of the treatment and control group were strictly consistent, except for whether the straw returned to the field or not. 3) The collected articles contained the incidence rate or disease index data. 4) The crops and returned straw were set as the main food crops rice, wheat, and maize. A total of 369 data sets were obtained to classify, according to the environmental conditions and agricultural management measures. Specifically, the environmental conditions included the climate type, soil pH, and soil organic matter (SOM). Agricultural management measures included the land use type, crop type, straw type, straw returning amount, and initial C/N. The results showed that the straw returning to the field significantly increased the incidence rate and disease index of the main grain crops, indicating an increase of 9.5% and 12.2%, respectively (P<0.05). There was a most serious increase in the virus and soil-borne diseases. Different environmental conditions and agricultural management practices presented a significant impact on the occurrence of major grain crop diseases under straw returning. Among them, the diseases of returning farmland decreased significantly in the subtropical monsoon climate, whereas, there was an increase in the temperate monsoon climate. Returning rice straw to the paddy field was beneficial to the reduction of the diseases. The disease increased significantly in the dry land, especially the wheat-corn rotation. The disease in the slightly acidic soil was lower than that in the slightly alkaline soil. In addition, the occurrence of diseases significantly increased under the conditions of soil organic matter (SOM), the straw returning amount, and the initial C/N were greater than 15 g/kg, 7 000 kg/hm2, and 15, respectively. The linear analysis demonstrated that there was a strong negative correlation of the annual precipitation and organic matter content with the occurrence of straw-returning disease, whereas, the initial C/N and soil pH presented a substantial positive correlation. Therefore, straw returning to the paddy fields and acidic soil cultivation greatly contribute to the fewer diseases in China with the high annual average rainfall and warmth. At the same time, a better way is to raise the initial application rate of nitrogen fertilizer.