Abstract:

In order to explore the effects of applying winter fallow weeds on yield of no-tillage rice under different nitrogen fertilizer levels, a field experiment was conducted using Y Liangyou 1 as the material in Pingtou Village, Yong’an Town, Liuyang City, Hunan Province. Yield and growth physiological characteristics were measured to value the effects of applying winter fallow weeds [W0, 0 kg/hm²; W1, 5 000 kg/hm² (dry weight)] under different nitrogen application rates (N0, 0 kg/hm²; N150, 150 kg/hm²; N225, 225 kg/hm²). The results showed that compared with W0 treatment, W1 treatment increased the yield of no-tillage rice by 28.8% and 4.2% under N0 and N150 levels, the reason for increasing yield was the increase in effective panicles, spikelets per panicle, total spikelets, and thousand grain weight of rice. However, compared with W0 treatment, W1 treatment reduced the yield of no-tillage rice by 5.9% at N225 levels. Compared with the W0 treatment, W1 treatment increased the leaf area index, dry matter accumulation, radiation utilization efficiency, net photosynthetic rate, and SPAD value of mid to late stage rice, while also enhancing the transport capacity of rice leaves stems and sheaths and the harvest index at N0 and N150 levels. At N225 level, W1 treatment significantly increased the ineffective tillering of rice, decreased the panicle formation rate, and at the same time, decreased the transport capacity of leaf stems and sheaths, ultimately reducing the number of grains per panicle, total spikelets, and seed setting rate of rice. In summary, at low nitrogen levels (0-150 kg/hm²), applying winter fallow weed is beneficial for improving the yield of no tillage rice, while at high nitrogen level（225 kg/hm²）, applying winter fallow weed reduced the yield of no-tillage rice.

Key words: no-tillage rice, winter fallow weeds, yield

摘要：

以Y两优1号为材料，在湖南省浏阳市永安镇坪头村开展大田试验，研究不同施氮量（N0，0 kg/hm²；N150，150 kg/hm²；N225，225 kg/hm²）下施用冬闲杂草（折合干物质量W0，0 kg/hm²；W1，5 000 kg/hm²）对免耕水稻产量及生长生理特性的影响。结果表明，N0和N150水平下，与未施用冬闲杂草处理（W0）相比，施用冬闲杂草（W1）分别提高水稻产量28.8%和4.2%，增产的原因是有效穗数、每穗粒数、总颖花量和千粒重提高；N225水平下，W1处理降低水稻产量5.9%。N0和N150水平下，与W0处理相比，W1处理大幅度提高免耕水稻后期叶面积指数、干物质积累量、辐射利用率、净光合速率和SPAD值的同时，还提升了水稻叶茎鞘转运能力和收获指数；N225水平下，W1处理显著增加水稻的无效分蘖，降低成穗率，同时叶茎鞘转运能力降低，最终降低了水稻的每穗粒数、总颖花量和结实率。综上，在低氮（0~150 kg/hm²）水平下，施用冬闲杂草有利于提高免耕水稻产量，在高氮（225 kg/hm²）水平下，施用冬闲杂草反而会降低产量。

关键词: 免耕水稻, 冬闲杂草, 产量