Winter cropping improves yield, dry matter accumulation and translocation and nitrogen uptake of double-cropping rice

Winter cropping is widely considered as an effective way to increase rice yield. Therefore, this study was performed to find optimal winter cropping patterns in middle and lower reaches of the Yangtze River, China. Five experimental treatments were set up based on the long-term field experiment including winter fallow (CK), Chinese milk vetch winter cropping pattern (CRR), rapeseed winter cropping pattern (RRR), garlic winter cropping pattern (GRR), and winter multiple cropping rotation (ROT). The effects of different winter cropping patterns on the yield, dry matter accumulation and translocation, and plant nitrogen uptake were explored in double-cropping rice. The results showed that compared with CK, winter cropping increased the early and late rice yield by 7.91-10.70% and 3.57-6.89%, respectively. Similarly, compared with CK, winter cropping patterns also increased the number of spikes in early rice by 19.36-25.81% and CRR and ROT increased the effective number of spikes in late rice by 25.58% and 23.26% respectively. The dry matter (DM) translocation by stem and leaf of early rice under CRR was highest, with a 36.2% increase compared with CK, however, DM accumulation after heading in early rice under CRR was lowest. GRR decreased the dry matter translocation by stem and leaf in early rice but increased DM accumulation after heading in early and late rice by 65.28% and 13.44% as compared to CK. Moreover, ROT increased the dry matter translocation by stem and leaf in late rice by 112.63%. Additionally, GRR and ROT treatments increased the stem nitrogen uptake in early rice by 61.76% and 58.61% as compared to control, while CRR increased the nitrogen uptake by stem, leave and spike in late rice by 40.76%, 49.51% and 42.92%. In conclusion, CRR is more beneficial to increase DM accumulation and translocation by stem and leaf in double-cropping rice, and nitrogen uptake by rice plants.