缓释肥和无机肥配施对滨海盐碱地水稻生长和食味品质的影响

研究旨在探讨滨海盐碱地缓释肥与无机肥配施情况下,氮素在各时期的用量分配对水稻生育期、生长特性、产量及食味品质的影响。以中粳中晚熟水稻品种‘南粳9108’为试验材料,在3‰~6‰土壤盐分条件下,设计了5种施肥方式,在生育期的关键节点测定水稻的根系指标、叶面积指数、各部位干物质积累,并比较各施肥处理水稻的生长指标和食味品质。结果表明,配施缓释肥与无机肥且减少氮素用量20%的T3处理组,水稻的生殖生长期占全生育期的比例较全氮量施肥且施用无机肥的T1处理组缩短0.25%,营养生长期占全生育期的比例增长0.23%,全生育期减少2天。水稻的总根系长度、叶面积指数、单位叶面积干物质积累、单位面积茎鞘干物质及产量总体趋势为T3>T1>T2>T4>T5。稻米中蛋白质含量与食味值呈现负相关性,蛋白质含量越高,食味值越低;稻米中直链淀粉含量与食味值之间呈现负相关,直链淀粉含量越高,食味值越低。氮肥用量的提高显著降低了稻米的食味品质,不施用氮素的T5处理组食味值最高,配施缓释肥与无机肥处理土壤肥效增强,但稻米的食味值也最低。缓释肥与无机肥配施,减少氮素用量20%,且穗肥不追施任何氮素处理时,水稻的生长指标、稻米的食味值显著的提高。

Effects of Combined Application of Slow-Release Fertilizer and Inorganic Fertilizer on Rice Growth and Eating Quality in Coastal Saline Alkali Land

The effects of N application on rice growth period, growth characteristics, yield and eating quality under the combination of slow-release fertilizer and inorganic fertilizer were studied. ‘Nanjing 9108’ was taken as the experimental material, five fertilization treatments were designed under the condition of 3‰-6‰ soil salt content. The root index, leaf area index and dry matter accumulation were measured at the key nodes of growth period, and the growth index and eating quality of rice were compared. The results showed that, the reproductive growth period ratio in T3 group (the treatment group with slow-release fertilizer and inorganic fertilizer and 20% reduction of N content) was 0.25% shorter than that in T1 group (the treatment group with total N fertilizer and inorganic fertilizer), and the ratio of vegetative growth period increased by 0.23% and the whole growth period decreased by 2 days. The total root length, leaf area index, dry matter accumulation per unit leaf area, stem sheath dry matter per unit area and yield trend of rice were T3> T1> T2> T4> T5. There was a negative correlation between protein content and eating value in rice. The higher the protein content, the lower the taste value. There was also a negative correlation between amylose content and taste value in rice. The higher the amylose content, the lower the taste value. With the increase of nitrogen application, the eating quality of rice reduced significantly. The T5 treatment group without N element had the highest taste value. The combination of slow-release fertilizer and inorganic fertilizer enhanced the soil fertility, but the rice had the lowest taste value. When slow-release fertilizer and inorganic fertilizer were applied together, and the N content was reduced by 20% and panicle fertilizer was not applied with any N treatment, the growth index and eating value of rice could be significantly improved.