[Effects of tillage and sowing practices on plant growth, soil nutrient uptake and utilization of wheat after rice].

From 2016 to 2018, a field trial on three tillage and sowing practices, deep rotary tillage before sowing (DRT), shallow rotary tillage with simultaneous sowing (SRT), and strip tillage under no tillage conditions along with sowing (NT), was conducted to evaluate shoot growth, soil nutrient uptake, and utilization of wheat (Triticum aestivum) after rice (Oryza sativa) in Guanghan, Sichuan Province, China. Compared with DRT, both SRT and NT improved tillering capacity and fertile shoot rate. In 2016-2017, grain yield did not differ among the treatments, whereas in 2017-2018, NT had significantly higher grain yield (10.

[Effects of different tillage and sowing practices on root growth, soil moisture, and soil nitrate nitrogen content of wheat after rice].

With deep rotary tillage before sowing (DRT) as control, the effects of shallow rotary tillage with simultaneous sowing (SRT) and strip tillage under no tillage conditions along with sowing (NT) on root growth, soil moisture, and soil nitrate content of wheat (Triticum aestivum) after rice (Oryza sativa) were examined from 2016 to 2018. Compared with DRT, NT and SRT resulted in higher soil water content, and lower soil nitrate content in the plow layer before booting. There was no significant difference in root weight density and root surface area density among the treatments at jointing and anthesis stages.

[Effect of nitrogen management modes on grain yield, nitrogen use efficiency and light use efficiency of wheat].

A nitrogen management experiment with three nitrogen levels (0, 120, and 180 kg·hm, namely N, N, N) and three nitrogen allocation modes (N: base fertilizer 100%; N: base fertilizer 70% + seedling fertilizer 30%; N: base fertilizer 60% + jointing fertilizer 40%) was conducted at four sites (Chongqing, Renshou, Guanghan and Xichang) during two consecutive years, the SPAD value, canopy photosynthetic rate (CAP), photosynthetically active radia-tion (PAR) interception efficiency and grain yield were determined, and the nitrogen use efficiency and PAR use efficiency were calculated. The results showed that the SPAD of upper-most three leaves, CAP, PAR interception efficiency and grain yield were promoted with increasing nitrogen fertilizer, but nitrogen fertilizer use efficiency, productivity efficiency, uptake efficiency and use efficiency were decreased. The promoting effects of nitrogen fertilizer postponing were different among nitrogen levels, with the highest SPAD in N treatment and the highest CAP in N treatment.

[Effect of waterlogging on physical traits and yield of wheat in Sichuan, China].

Following a two-factor split plot design, two popular varieties ( Neimai836 and Chuanmail04) were used to study the effects of waterlogging at four growth stages (seedling, jointing, booting and anthesis) on wheat growth and yield formation during two growing seasons (2011-2012 and 2012-2013). The resulted showed that the greatest yield penalty occurred when waterlogging happened at the seedling stage (10% - 15% decrease), and it was alleviated when waterlogging happened at the other stages. Waterlogging during the seedling stage significantly reduced SPAD of 2nd-6th leaves, tillers and spike number per plant, productive ears, dry matter accumulation after flowering and dry matter at maturity.