ABSTRACT.
Effects of continuous straw return and fertilization on rice lodging resistance

Qinglei Zhao1, Caiyun Xin1, Qihua Liu1, Xu Jiang1, Jun Yang1, and Hui Ma1*
 
As a common problem in rice (Oryza sativa L.) production, lodging will not only increase harvest costs and reduce rice production, but also affect rice taste seriously and reduce its commercial value. There is still a lack of systematic research on the effect of lodging resistance of rice after returning wheat (Triticum aestivum L.) straw to the field. The study evaluated the effects of continuous straw returning and different fertilizer input levels on the lodging resistance of rice stalks based on years of experiments, using a split zone design with two factors including full return of straw to the field and straw removal, and three fertilization levels (conventional fertilization, 50% of conventional fertilization and no fertilization) under each factor, for a total of six treatments. Results suggested that under the same level of chemical fertilizer application, treatments of straw returning significantly increased stalk flexural resistance up to 33.74% as well as decreased the lodging index by a maximum of 33.86% compared with straw removal. Decrease of chemical fertilizer application increased significantly stalk flexural resistance, while decreased significantly lodging index. Rice plant height, center of gravity height, internode length, stem wall thickness and internode dry weight were main factors that influence rice lodging resistance. Compared with straw removal, straw returning combined with chemical fertilizers applying cold significantly increase rice yield up to 19.62%. The increase in rice yield increased the risk of rice lodging. The continuous return of straw to the field combined with the application of chemical fertilizers reduced the risk of rice lodging to a certain extent, and meanwhile it achieved successive annual increase in rice production, which has a good promotion prospect.
Keywords: Lodging index, Oryza sativa, returning straw to the field, rice, rice-wheat rotation, Triticum aestivum.
1Institute of Wetland Agriculture and Ecology, Shandong Academy of Agricultural Sciences, Jinan 250100, China.
*Corresponding author (mahui8.18@163.com)