镁锌肥追施时期对优良食味粳稻产量及品质的影响

Effects of Topdressing Magnesium and Zinc Fertilizers at Different Periods on Yield and Quality of Japonica Rice with Good Eating Quality

【目的】旨在研究不同时期追施镁锌肥对优良食味粳稻产量和稻米品质的影响,以期为优良食味粳稻保优调优栽培提供理论依据与技术参考。【方法】大田试验条件下,以优良食味粳稻南粳9108和南粳505为材料,于基肥、蘖肥、穗肥时期分别设置镁肥单施、锌肥单施和镁锌配施处理,并设置不施镁锌肥为CK,研究优质食味粳稻产量和稻米品质对不同时期追施镁锌肥的响应特征。【结果】随追施时期的延迟,追施镁肥处理的产量呈上升趋势,追施锌肥处理的产量呈下降趋势,而镁锌配施处理的产量则呈先下降后上升的趋势。与CK相比,穗肥时期追施镁肥和镁锌配施产量显著提高,且镁锌配施处理产量最高。穗肥时期镁锌配施处理高产的主要原因是增加了单位面积穗数,提高了千粒重,每穗粒数和结实率减少,但最终颖花量仍显著提高。对稻米品质而言,蘖肥和穗肥时期追施锌肥可以改善稻米加工品质。穗肥时期追施镁肥,加工品质和外观品质得到显著改善,蛋白质含量、消减值减少,直链淀粉含量、崩解值增加,最终黏度显著下降,食味值变优;穗肥时期镁锌配施利于加工品质和营养品质改善,但外观品质、蒸煮食味品质等指标有变劣趋势,淀粉RVA谱中最高黏度、热浆黏度、崩解值显著降低,消减值、糊化温度显著提高。【结论】优良食味粳稻穗肥时期追施镁肥具有提高产量和优化稻米品质的作用,可能是保优调优栽培途径之一。

【Objective】The objective of this experiment was to investigate the effects of topdressing magnesium and zinc microelement fertilizers at different periods on grain yield and quality of japonica rice with good eating quality.The results could provide a theoretical basis for optimum cultivation of japonica rice with good eating quality.【Method】Japonica rice with good eating quality including Nanjing 9108 and Nanjing 505 were adopted as test materials.The effects of microelement fertilizer（Mg fertilizer,Zn fertilizer,and Mg-Zn mixed fertilizer）topdressing at different fertilizing stages（basic fertilizer stage,tillering stage,and panicle initiation stage）on the grain yield and rice quality were studied,and set no magnesium zinc fertilizer treatment as CK.【Result】With the delay of fertilization time,the topdressing Mg fertilizer treatments increased rice grain yield,while the treatments of topdressing Zn fertilizer showed the opposite trend,the grain yield of topdressing mixed Mg-Zn fertilizer decreased first and then increased.Compared with CK,the yield were increased significantly when topdressing Mg fertilizer and mixed Mg-Zn fertilizer at panicle initiation stage,and the highest yield were obtained with mixed Mg-Zn fertilizer.Although the spikelets number per panicle and seed setting rate were decreased with mixed Mg-Zn fertilizer topdressing at panicle initiation stage,the 1000-grain weight and the total spikelets were increased.The process quality was improved with Zn fertilizer topdressed at tillering or panicle initiation stage.With Mg fertilizer topdressed at panicle initiation stage,both the process and the appearance quality were significantly increased.And the best tasting quality was achieved with the lowest protein content and setback value,and with the highest amylose content and breakdown value.Compared with the treatment of topdressing Mg at panicle initiation,although the process quality could be improved with the mixed Mg and Zn,the quality of appearance,tasting and nutrition were deteriorated because of the decreased peak viscosity,trough viscosity and breakdown,and the increased setback and pasting temperature.【Conclusion】Therefore,the topdressing of Mg at panicle initiation stage could not only increase the grain yield,but also improve the rain quality of rice,which could be one of the best ways to optimize rice quality in the high yield production.