早稻基施不同用量钙镁水滑石对湘南双季稻产量和稻米品质影响

Effects of Different Base Application Amounts of Calcium-Magnesium Hydrotalcite in Early Rice on Yield andRiceQuality of Double-Cropping Rice in Southern Hunan

为研究钙镁水滑石对双季稻产量和稻米品质的影响,探讨湘南双季稻区钙镁水滑石的最佳施用量,以早稻品种陆两优996(高镉积累品种)和株两优819(低镉积累品种)、晚稻品种玉针香(高镉积累品种)和湘晚籼13号(低镉积累品种)为材料,于湖南省衡阳县开展大田试验,比较不同用量钙镁水滑石(0,T1;早稻基施1500 kg/hm^(2),T2;早稻基施2250 kg/hm^(2),T3;早稻基施3000 kg/hm^(2),T4)4个处理下水稻产量、产量形成特性及稻米品质情况。结果表明,不同用量钙镁水滑石均能提高水稻分蘖数,显著增加水稻叶面积指数、相对叶绿素含量(SPAD值)及干物质积累量,其中以T3和T4处理的效果较好。钙镁水滑石显著提高了水稻产量,各品种均以T3和T4处理产量较高,增产原因主要是提高了有效穗数和结实率。钙镁水滑石对稻米加工、外观及蒸煮品质没有显著影响,但能显著降低糙米镉含量,以T4和T3处理降幅较高。综合考虑不同施用量间水稻产量和稻米品质的差异显著性与经济性,湘南双季稻田以施用钙镁水滑石2250 kg/hm^(2)较为适宜。

In order to study the effect of calcium-magnesium hydrotalcite on the yield and quality of double-cropping rice,and explore the optimal application rate of calcium-magnesium hydrotalcite in the double-cropping rice area in southern Hunan,using early rice cultivars“Luliangyou 996”(high Cd accumulationcultivar)and“Zhuliangyou 819”(low Cd accumulation cultivar),late rice cultivars“Yuzhenxiang”(highCdaccumulation cultivar)and“Xiangwanxian 13”(low Cd accumulation cultivar)as materials,a field experiment was carried out in Hengyang county,Hunan province.Comparative study of rice yield,yield formationcharacteristics and rice quality under different dosages of calcium-magnesium hydrotalcite(0,T1;early rice baseapplication 1500 kg/ha,T2;early rice base application 2250 kg/ha,T3;early rice base application 3000 kg/ha,T4).The results showed that,different dosages of calcium-magnesium hydrotalcite could increase rice tiller number,significantly increased rice leaf area index,relative chlorophyll content(SPAD value)and dry matter accumulation,among which the effects of T3 and T4 treatments were better.Calcium-magnesiumhydrotalcitesignificantly increased the yield of rice,and the yields of all varieties were higher under T3 and T4 treatments.Calcium-magnesium hydrotalcite had no significant effect on rice processing,appearance and cooking quality,but it could significantly reduce the cadmium content of brown rice,and the T4 and T3 treatments had a higher reduction rate.Considering the significant difference in rice yield and rice quality among different applicationrates and the economy,it was more appropriate to apply calcium-magnesium hydrotalcite 2250 kg/ha inthedouble-cropping rice fields in southern Hunan.