四川几种轮套作体系的产量及小麦玉米磷素利用效率研究

Studies on Yields and Phosphorus Use Efficiency of Wheat and Maize with Different Rotation and Relay-intercropping Systems in Sichuan

通过2011和2012年2年田间试验研究了"蚕豆-玉米"、"小麦-甘薯"、"小麦-大豆"3种两熟轮作体系和"小麦/玉米/甘薯"、"小麦/玉米/大豆"2种三熟套作体系的产量、小麦玉米磷素积累分配及磷利用效率的变化。结果表明:三熟套作具有明显的产量优势,小麦/玉米、玉米/大豆和玉米/甘薯的土地当量比(LER)分别为1.79、1.51、1.62,小麦/玉米/大豆、小麦/玉米/甘薯周年体系的LER平均分别为2.13、2.32,与同面积单作相比,两体系周年作物产量分别提高了12.5%和31.5%。小麦、玉米产量套作比单作分别高30.3%、12.3%,而大豆和甘薯产量在套作与单作间无显著差异。套作较单作显著提高了小麦和玉米的地上部磷素吸收总量、籽粒磷积累量、磷肥偏生产力,小麦分别提高34.3%、39.3%、29.1%,玉米分别提高11.1%、19.8%、12.4%。玉米磷收获指数套作比轮作平均高7.8%。套作促进了小麦、玉米磷营养从营养器官向籽粒的转运分配。表明三熟套作相对两熟轮作(单作)能显著提高周年产量,促进小麦、玉米对磷素的吸收利用,一定程度提高了磷肥利用效率。

Field experiments were conducted in 2011 and 2012 to investigate grain yield, phosphorus accumulation,distribution and phosphorus use efficiency of wheat and maize in different planting patterns in Sichuan. The experimental treatments included three double-harvest crop rotation systems such as 'faba bean-maize', 'wheat-sweet potato','wheat-soybean', and two triple-harvest relay-intercropping systems such as 'wheat/maize/sweet potato'and'wheat/maize/soybean'. The results showed that: The triple-harvest relay-intercropping systems hadapparent yield advantages, LER(Land equivalent ratio) of wheat/maize, maize/soybean and maize/sweet potato were 1.79, 1.51, 1.62,respectively, and LER of wheat/maize/soybean and wheat/maize/sweet potato annually systems were 2.13 and 2.32,respectively. Compared with the same area of relevant monocultures, the annual crop yields of wheat/ maize/soybean and wheat/maize/sweet potato systems increased by 12.5% and 31.5%, respectively. Yields of relay-intercropped wheat and maize were higher by 30.3% and 12.3% respectively than that of sole crop, while the yields of soybean and sweet potato had no significant difference between relay-intercropping and sole. Compared with sole crop, relay-intercropping markedly enhanced aboveground total phosphorus uptake, grain phosphorus accumulation and PFP-P(phosphorus partial factor productivity) of wheat with 34.3%, 39.3%, 29.1% and of maize with 11.1%, 19.8%, 12.4%, respectively.Phosphorus harvest index of relay-intercropped maize was higher by 7.8% than that of sole maize. The relay-intercropping patterns improved phosphorus nutritive element transfer from vegetation organs to seeds of wheat and maize. Inconclusion, triple-harvest relay-intercropping systems could significantly improve systematic yield and phosphorusabsorption and utilization, and soincreasephosphorusfertilizer useefficiency.