海涂土壤结构改良对水稻叶绿素荧光参数和产量的影响

Effects of soil structure improvement on chlorophyll fluorescence parameters and yield of rice in a coastal reclamation region

为探索添加生物炭和聚丙烯酰胺(PAM)改良海涂围垦区土壤结构对水稻叶片叶绿素荧光特性和产量的影响,开展测坑栽培试验.试验供试土壤分别设置3个水平生物炭(0%、2%、5%,分别表示为B1、B2和B3,占表层0~20 cm土重比)和PAM(0‰、0.4‰、1‰,分别表示为P1、P2和P3,占表层0~20 cm土重比)添加量处理.3年试验结果表明:添加适宜生物炭和PAM有利于改善水稻叶片荧光特性,而高浓度生物碳和PAM对其影响不明显,甚至出现抑制现象.各生育期水稻叶片最大光化学量子产量(Fv/Fm)、实际量子产量(Φ(PSⅡ))、光化学淬灭(qP)和非光化学淬灭(NPQ)均在B2P2组合处理下达到峰值.生物炭添加量处理间水稻叶片叶绿素量(SPAD值)无明显差异,而PAM添加量不同导致水稻叶片SPAD值差异显著,添加0.4‰PAM(P2)下水稻叶片SPAD值最高.添加生物炭和PAM改良盐渍土对水稻产量影响显著,在B2P2组合处理下产量最高,达到7236 kg·hm^-2;与对照组(B1P1)相比,产量提高了28.5%.添加生物炭和PAM改良海涂盐渍土对水稻产量的影响主要是通过对水稻千粒重、每穴穗数、每穗粒数和结实率的影响而实现的.添加适量生物炭和PAM改良滩涂围垦区土壤结构有利于提高水稻叶绿素荧光特性和产量.

To examine the effects of soil structure improvement due to the amendment of biochar and polyacrylamide(PAM)on the chlorophyll fluorescence characteristics of rice leaves and the yield of rice,a pit cultivation experiment was carried out in a coastal reclamation region.Three levels of biochar(0%,2%and 5%by the mass of 0-20 cm surface soil and noted as B1,B2 and B3,respectively)and PAM(0‰,0.4‰and 1‰by the mass of 0-20 cm surface soil and noted as P1,P2 and P3,respectively)were applied to the adopted soil,respectively.The results of the threeyear experiment showed that an appropriate application quantity of biochar and PAM could improve the fluorescence characteristics of rice leaves.However,high levels of biochar and PAM had no obvious or even a negative effect.Among all the treatments,the B2P2 treatment always had the highest the maximum photochemical efficiency(Fv/Fm),the actual photochemical efficiency of photosystem II(ΦPSⅡ),the photochemical quenching coefficient(qP)and the non-photochemical quenching coefficient(NPQ)values during the whole growth period.The chlorophyll content(SPAD value)of rice leaves showed no significant difference among different biochar application levels.However,it showed significant differences among different PAM application levels,with the highest value under the soil amended with 0.4‰PAM(the P2 treatment).The application of biochar and PAM had significant impacts on rice yield,with the highest yield,namely 7236 kg·hm-2,presenting under the B2P2 treatment,which was 28.5%higher than that of the control.The improved soil structure of the coastal saline soil due to the amendment of biochar and PAM affects rice yield mainly through its influences on the 1000-grain weight,the spike number per hole,the grain number per spike and the seed setting rate.It is concluded that improving soil structure by applying an appropriate quantity of biochar and PAM is conducive to increase the chlorophyll fluorescence characteristics and the yield of rice in the coastal reclamation region.