秸秆还田与实地氮肥管理对水稻产量及品质的影响

以扬粳9538为材料,通过秸秆还田与氮素管理与秸秆不还田(对照)比较试验,研究了水稻产量及品质的表现。结果表明:秸秆还田与实地氮肥管理(SSNM)可以在减少氮肥施用量,秸秆全量还田的同时,增加水稻的产量,降低单位面积穗数,提高每穗粒数、结实率。秸秆还田与实地氮肥管理降低稻米的垩白米率、垩白度和直链淀粉含量,改善稻米的外观品质和营养品质,淀粉谱的最高粘度和崩解值增加,消减值减低,稻米食味品质得到改善,该技术同时减少穗分化前干物质积累,增加抽穗期光合速率、根系活力与ATP酶活性,促进同化物向籽粒的运转,减少茎杆中非结构性碳水化合物的残留。对秸秆还田与不同氮素管理在产量、品质上的差异进行了讨论。

Effect of Straw Residue Returned and Site-specific Nitrogen Management on Yield and Quality of Rice

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 grain yield and quality of rice. With Yangjing 9538 as a material, rice yield and quality were evaluated under straw residue returned and different N management. The results showed that the yield was increased with all straw residue returned and lower nitrogen input. Stems and tiller numbers were decreased; spikelets per spike and ripened grains were improved under straw residue returned and N management (SSNM, applying nitrogen based on the timing, amount of nitrogen and values of chlorophy11 meter). The differences in the milling quality and nutrient quality of rice were not significant between straw returned and straw removed. Grains from the technique (straw residue returned and N management) had lower chalkiness and amylose content, longer gel consistency, indicating that appearance quality and cooking quality is improved. Peak viscosity and breakdown value were increased and setback value decreased under the technique, also suggesting that the eating quality of the rice grown is advanced. As the same, this technique promotes carbon remobilization from culms and sheaths to grains and NSC (non-structural carbohydrate) residue in the stems at heading stage increased, the reversed result was observed at maturity. The results showed that ATPase activity in the grains photosynthesis ratio and root activity were also improved in the process of grain filling under the technique. Reasons for the differences in the formation of grain yield and quality were discussed in the paper.