|Response of grain crop yield to manure application in different regions of China
|英文关键词: grain crops, yield, manure, chemical fertilizer, soil nutrients
| 探明全国不同气候、土壤和作物类型条件下，化肥配施有机肥对产量的影响及其增产效果的主控因素，可为粮食增产和有机肥的合理施用提供重要的理论依据。本研究通过收集109篇已公开发表的文献，建立了包含不施肥（CK）、单施化肥（NPK）和化肥配施有机肥（NPKM）处理的402组作物产量的数据库。采用整合分析（Meta-analysis）方法分析了不同施肥处理对小麦、玉米和水稻产量的影响，以及不同土壤性质和气候条件下有机肥的增产差异；采用随机森林（Random forest）方法量化土壤和气候因素对有机肥增产效果影响的重要度。全国来看，与NPK相比，NPKM处理下作物的产量平均增幅4.7%，其中小麦、玉米和水稻的增产率分别为5.6%、7.6%和4.5%；作物的平均增产率在西北地区最高，东北和华北地区次之，南方和华东地区较低。配施有机肥对产量的提升作用在我国温带大陆性气候区和温带季风性气候区显著高于亚热带季风性气候区，其中年降雨量是影响小麦和水稻产量对有机肥响应的主要因素，年均温和无霜期是影响玉米产量对有机肥响应的主要因素。有机质和全氮含量是土壤性状中影响有机肥增产效果的主要因素，其中土壤有机质和全氮含量越低，配施有机肥后产量的增幅越高。总的来说，化肥配施有机肥可显著提高作物的产量，尤其在低温少雨、土壤养分含量较低的地区，可通过化肥配施有机肥来进行增产促产。
| Manure application is an important approach for improving soil fertility and grain production. The effectiveness of the nutrients in manure is affected by many factors, such as climatic conditions and soil properties, which may lead to different contributions of manure to crop yield. This study was carried out to explore the increment in grain yield with manure application in different climatic regions and soil types for understanding the effect of manure application on crop yield at national and regional levels in China. The results can be helpful for developing manure management strategies. This study was conducted using 402 grain yield datasets collected from 109 published articles regarding three major food crops, namely wheat, maize, and rice. The treatments tested were no fertilization(CK);chemical N, P, and K fertilization(NPK); and NPK fertilization combined with manure application(NPKM). Differences in yield among the application of CK, NPK, and NPKM in the three crops across four regions of China were studied using meta-analysis. The importance of climatic parameters and soil properties on positive manure effects was quantified using random forest analysis. Compared with NPK, NPKM treatment resulted in increments of 5.6%, 7.6%, and 4.5% in grain yield for wheat, maize, and rice, respectively, with an average increase of 4.7% across the three crops. The yield increment by manure application varied across regions as follows:northwestern China > northeast and north China > southern China > eastern China. The highest yield enhancement by manure application was observed in the temperate continental climate zone, followed by the temperate monsoon and subtropical monsoon climate zones. Average annual rainfall was the main factor that affected the yield response to manure for wheat and rice, while the main factors affecting the yield response of maize were the mean annual temperature and frost-free period. The yield increment by manure application was higher in soils with lower soil organic matter(SOM)and total nitrogen(TN)content than those with higher SOM and TN content, suggesting that SOM and TN are essential factors that influence the ability of manure to improve grain production among the analyzed soil properties. Nationally, manure application can significantly increase crop yields, especially in areas with insufficient soil nutrients, low temperature, and low rainfall.