Comparison of yield formation mechanism of different cultivation practices of wheat after rice in Southwest China

Article Type: Full Length Research Article A thorough understanding of winter wheat yield production to the most widespread cultivation practices under rice-wheat rotation system in Southwestern China is crucial for achieving sustainable agriculture. This study simulated 3 main cultivation practices namely as super high-yielding practice (SHY, no tillage, straw mulch, ~270 seedlings m -2 , 180 kg nitrogen ha -1 with 60% applied at base, 40% at jointing), traditional high-yielding practice (THY, no tillage, no mulch, ~180 seedlings m -2 , 180 kg nitrogen ha -1 with 70% applied at base, 30% at seedling) and farmers’ practice (FP, no tillage, straw mulch, ~375 seedlings m -2 , 225 kg nitrogen ha -1 with 100% applied at base) using a field experiment initiated in 2013 and aimed to analysis the tiller population, grain yield (GY), economic profit, nitrogen use efficiency (NUE) and water use efficiency (WUE) performances. The results obtained show that SHY significantly increased GY, economic profit and dry matter (DM) when compared with THY and FP. Moreover, the relationship between GY and DM was well correlated (R 2 = 0.79), suggesting changes in GY were mainly due to changes in DM accumulation. SHY enhanced soil water storage and nitrogen use in the entire life cycle of wheat. Furthermore, under the condition of SHY, leaf senescence delayed, photosynthetic rate promoted, and optimizing leaf area index (LAI) development, which provided the dry matter basis for the grain number m -2 and grain weight development. Compared with THY and FP, the SHY showed more favorable impacts on WUE, nitrogen uptake efficiency (NupE), NUE and nitrogen fertilizer productivity (NfP). Due to higher planting density, FP showed a lower shoot dry matter weight and higher lodging ratio than SHY and THY. These results indicating that SHY can be successfully used for wheat production under rice-wheat rotation system in Southwest China and other similar environments. ©2019 BluePen Journals Ltd. All rights reserved