No-tillage effects on grain yield and nitrogen requirements in hybrid rice transplanted with single seedlings: Results of a long-term experiment
HUANG Min1, 2, CHEN Jia-na1, CAO Fang-bo1, ZOU Ying-bin1, Norman Uphoff2
1 Southern Regional Collaborative Innovation Center for Grain and Oil Crops (CICGO), Hunan Agricultural University, Changsha 410128, P.R.China 2 International Programs-College of Agriculture and Life Sciences (IP-CALS), Cornell University, Ithaca 14853, USA
This study was conducted to determine whether, and if so how, the grain yield and nitrogen (N) requirements of hybrid rice transplanted as single seedlings are affected by no-tillage (NT) practices. A fixed field experiment was done at the Experimental Farm of Hunan Agricultural University in Changsha, Hunan Province, China, from 2004 to 2014. Grain yield and yield attributes (panicle number per m2, spikelet number per panicle, spikelet filling percentage, grain weight, total biomass, and harvest index) were evaluated as well as the N-use characteristics (total N uptake, internal N-use efficiency, and N requirements) of hybrid rice transplanted as single seedlings comparing NT with conventional tillage (CT). A significant finding was that there were no significant differences in grain yield, yield attributes, and N-use characteristics between CT and NT. Averaged across the 11 years, grain yield and N requirements were 9.51 t ha−1 and 20.2 kg t−1 under CT and 9.33 t ha−1 and 20.0 kg t−1 under NT, respectively. There were significant yearly variations in grain yield, yield attributes, and N-use characteristics observed under both CT and NT. The yearly variation in grain yield was related to simultaneous changes in spikelet number per panicle, grain weight, total biomass, and harvest index. Also, it was found that grain yield was positively correlated with internal N-use efficiency but negatively correlated with N requirements. It is concluded that grain yield and N requirements in hybrid rice when transplanted as single seedlings are not affected adversely by NT. The results of this study suggest that (1) compatible relationships among yield attributes can be established in hybrid rice that is transplanted as single seedlings, and (2) higher grain yield and higher N-use efficiency can be concurrently achieved in hybrid rice transplanted as single seedlings.
Fund: This work was supported by the National Key R&D Program of China (2017YFD0301503), the National Natural Science Foundation of China (31301267), and the earmarked fund for China Agriculture Research System (CARS-01).
HUANG Min, CHEN Jia-na, CAO Fang-bo, ZOU Ying-bin, Norman Uphoff. 2019. No-tillage effects on grain yield and nitrogen requirements in hybrid rice transplanted with single seedlings: Results of a long-term experiment. Journal of Integrative Agriculture,