有机无机肥长期定位配施对冬小麦^(13)C同化物分配及产量的影响

Effects of Long-term Mixed Application of Organic-inorganic Fertilizers on Distribution of ^(13)C-assimilate and Yield in Winter Wheat

为研究有机无机配施对冬小麦不同时期光合同化物转运分配及产量的影响,以石麦15(SM15)为供试品种,牛粪为有机肥,采用^(13)CO_2标记的方法,设置不施氮肥(CK)、单施尿素(U)、单施牛粪(M)和有机无机配施(U+M)4种施肥方式进行试验。结果表明,^(13)C同化物在挑旗期、开花期主要向茎秆和叶鞘分配,灌浆期则主要向籽粒分配;成熟期约有87.5%的灌浆期同化产物分配到籽粒中,约75.4%的开花期同化产物分配到籽粒中,而仅15.2%的挑旗期同化产物分配向籽粒,灌浆期同化产物对籽粒重的贡献最大。成熟期不同施肥处理间相比,挑旗期及开花期的^(13)C同化物均是不施氮与配施处理向籽粒的分配较多,单施尿素处理滞留于茎鞘中较多;灌浆期13C同化物以单施有机肥与配施处理向籽粒的分配较多,最终配施处理向籽粒分配的挑旗期、开花期、灌浆期的同化产物均较多。单施有机肥处理千粒重较高,单施尿素处理穗数较高,配施处理产量结构更平衡且产量最高。由此可知,有机无机肥配施能促进各时期同化产物向籽粒的分配并有利于产量的提高。本研究结果为有机肥的合理施用及籽粒产量的提高提供了理论依据。

In order to clarify the effects of mixed application of inorganic and organic nitrogen on translocation, distribution of 13^C_assimilates and grain yield of winter wheat, a field experiment was conducted using the winter wheat variety Shimail5 and the technology of 13 CO2 labeling, the source of organic nitrogen was cow manure, and the fertilizer was applied as four different treatments： no N fertilizer application, single application of urea, single application of cow manure, and mixed application of urea and cow manure. The results indicated that most of the 13^C-assimilates were distributed to the stem and sheath at flag leaf stage and anthesis stage, while the 13^C-assimilates at early grain filling stage were mainly distributed to the grains. At the mature period, about 87.5% of the 13^C assimilated at early grain filling stage distributed to mature grains, about 75.4% of the 13^C assimilated distributed to mature grains at anthesis stage, and only 15.2% of the 13^C assimilated distributed to mature grains at flag leaf stage, hence the assimilation of grain filling stage made most contributions to grain yield. In addition, among the four treatments, no N fertilizer application and mixed application treatments, all distributed more 13^C-assimilates of flag leaf stage and anthesis stage to the mature grains. However, the single application of urea treatments retained more 13^C-assimilates in the stem and sheath. What＇s more, single application of cow manure and mixed application treatments distributed more 13^C- assimilates at grain filling stage to the mature grains, the two treatments also maintained longer grain filling duration. Consequently, the mixed application treatments distributed more 13^C-assimilates at all the three stages to the mature grains compared to the other treatments. After harvest, the single application of cow manure treatments got a higher grain weights, while the single application of urea treatments got a higher spike numbers, moreover the mixed application treatments had a more balanced yield components and finally got highest grain yield. Overall these results suggest that, mixed application of organic-inorganic nitrogen helped to distribute more photosynthates to grains, which resulted in a higher grain yield, and this experiment also provided a theoretical basis for rational use of organic fertilizer and the increasing of grain yield.