施硅对夜间增温下南方水稻生长、产量和品质的影响

Effects of silicate application on rice growth,yield and quality under nighttime warming in southern China

气温增幅夜间大于白天是全球气候变暖的显著特征之一。夜间增温引起南方单季稻减产,而施硅可提高水稻产量。本研究通过田间模拟试验,分析了施硅对夜间增温下水稻主要生育期植株分蘖数、生物量等生长指标以及产量和品质的影响。增温设2水平:常温对照(CK)和夜间增温(NW),采用被动式夜间增温方法,即夜间(19:00—6:00)用铝箔膜覆盖植株冠层以模拟夜间增温;硅肥(钢渣)用量设2水平:不施硅(Si0)和施硅(Si1,200 kg SiO_(2)·hm^(-2))。结果表明:与常温对照比,夜间增温使水稻生长期冠层和5 cm土层夜间平均温度分别升高0.51~0.58℃和0.28~0.41℃。夜间增温使分蘖数和叶绿素含量分别较CK降低2.5%~15.9%和0.2%~7.7%;而施硅使分蘖数和叶绿素含量较不施硅分别提高1.7%~16.2%和1.6%~16.6%。与CK相比,夜间增温下施硅显著提高了灌浆-成熟期地上部干重、全株干重和产量,增幅分别为64.1%、55.3%和7.1%;显著增加了精米率、整精米率和淀粉含量,增幅分别为2.3%、2.5%和41.8%。夜间增温引起水稻有效穗数、结实率和千粒重下降,空秕粒增加,进而使水稻减产;而施硅可使水稻有效穗数、每穗实粒数、结实率和千粒重增加,空秕粒减少,进而使水稻增产。综上,施硅可有效减轻夜间增温对南方单季稻生长、产量和品质的不利影响。

The main feature of climate warming is that nighttime warming is higher than the daytime warming.Nighttime warming reduced single rice production in southern China,while silicate application increased rice yield and stress resistance.It is still unclear regarding the effects of silicate application on growth,yield,and especially quality in rice under nighttime warming.We performed a field simulation experiment to investigate the effects of silicate application on tiller number,biomass,yield and quality of rice.Warming was set at two levels,ambient temperature(control,CK)and nighttime warming(NW).The open passive nighttime warming method was used,with rice canopy being covered with aluminum foil reflective film at night(19:00-6:00)to simulate nighttime warming.Silicate fertilizer(steel slag)was applied at two levels,i.e.,Si0(0 kg SiO_(2)·hm^(-2))and Si1(200 kg SiO_(2)·hm^(-2)).The results showed that,compared with the control(ambient temperature),average temperature at nighttime on rice canopy and at 5 cm soil layer increased by 0.51-0.58℃and 0.28-0.41℃during rice growing season,respectively.Nighttime warming decreased tiller number and chlorophyll content by 2.5%-15.9%and 0.2%-7.7%,respectively.In contrast,silicate application increased tiller number and chlorophyll content by 1.7%-16.2%and 1.6%-16.6%,respectively.Under nighttime warming,silicate application increased dry weight of shoot,total dry weight of the whole plant,and yield at grain filling-maturity stage by 64.1%,55.3%,and 7.1%,respectively.Under nighttime warming,silicate application significantly increased milled rice rate,head rice rate,and total starch content by 2.3%,2.5%,and 41.8%,respectively.Nighttime warming reduced rice yield by decreasing the number of effective panicles,seed setting rate,and 1000-grain weight,but increasing empty grains.Silicate application increased rice yield by increasing the number of effective panicles,filled grains per panicle,seed setting rate and 1000-grain weight,but reducing empty grains.In conclusion,silicate application could effectively alleviate the suppressive effects of nighttime warming on growth,yield,and quality of single rice in Southern China.