以水稻武香粳14和扬粳9538为材，大田设麦秸还田与不还田、不施氮肥、习惯施肥法（FFP）和基于叶绿素仪(SPAD)测定值的氮肥管理(SSNM)等处理。结果表明，SSNM较FFP氮肥施用量减少40.0%~41.7%，而产量平均增加3.81%。秸秆还田的较秸秆未还田的产量平均增加2.49%。氮肥的农学利用率、吸收利用率和生理利用率均以秸秆还田高于秸秆不还田处理。与秸秆未还田或FFP相比，秸秆还田和SSNM降低了生育前期的分蘖数、叶面积指数和干物质积累（但抽穗及以后差异较小）；提高了茎蘖成穗率、结实期叶片光合速率和根系活力。说明秸秆还田和SSNM有利于生育后期群体光合生产和提高物质生产效率。秸秆还田和实地氮肥管理提高了氮收获指数和氮肥利用效率。对秸秆还田和SSNM的产量、生育特性及氮肥利用效率进行了讨论。
The annual total amount of crop residue straw exceeds billion tons in China. However, about 45%–60 % of them are burnt or discarded, which not only wastes organic fertilizer source, but also pollutes the environment. Meanwhile, heavy use of nitrogen fertilizer has become a serious problem in rice production in this country. The purposes of this study were to investigate the effects of wheat straw incorporation to soil and site-specific nitrogen management (SSNM) on the growth and grain yield of rice. Two mid-season japonica rice cultivars, Wuxiangjing 14 and Yangjing 9538, were field-grown with three nitrogen (N) fertilizer treatments, no nitrogen application, farmers’ fertilizer-N practice (FFP), and SSNM base on chlorophyll measurement meter (SPAD) readings. The results showed that, compared with FFP, SSNM reduced N application by 40.0%–41.7% and increased grain yield by 3.81%, on average. The grain yield in the wheat residue-incorporated treatment was 2.49%, on average, higher than that in the residue-removed treatment. The agronomic efficiency, recovery efficiency and physiological efficiency of nitrogen fertilizer under wheat residue incorporation were higher than those under the residue-removed. In comparison with those under the residue removal and FFP, the number of stems and tillers, leaf area index, and biomass accumulation were less or lower under the residue incorporation and SSNM during the early growth period, but the differences were reduced at heading and thereafter. Both the residue incorporation and SSNM increased the percentage of productive tillers, photosynthetic rate of flag leaves and root activities during grain filling. The results suggest that both the residue incorporation and SSNM benefit the photosynthetic production of rice during the later growth period and an increase in the production efficiency. Wheat residue incorporation and SSNM increased nitrogen harvest index and agronomic efficiency, recovery efficiency, physiological efficiency, and partial factor productivity. Reasons for the characteristics of the grain yield, growth and development and nitrogen fertilizer use efficiency under the residue incorporation and SSNM were discussed.
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