施氮量和密度对盐碱滩涂水稻产量和品质的影响

为明确施氮量和密度互作对盐碱滩涂水稻产量和品质形成特征的影响,以淮稻5号为试验材料, 设置6个施氮量处理:N0(0 kg·hm^-2)、N210(210 kg·hm^-2)、N255(255 kg·hm^-2)、N300(300 kg·hm^-2)、N345(345 kg·hm^-2)、N390(390 kg·hm^-2),2个移栽密度处理:D1(33.4 万穴·hm^-2,12 cm×25 cm)、D2(27.8 万穴·hm^-2,12 cm×30 cm),测定了水稻产量及品质形成的相关因素。结果表明,随施氮量增加,单位面积穗数和每穗粒数呈先上升后下降的趋势,以N300处理最高;结实率和千粒重呈下降趋势。不同密度间比较,高密度处理的穗数和千粒重高于低密度处理,每穗粒数和结实率呈相反趋势。施氮量与移栽密度组合中,以N300D1处理的产量最高,达7 978.83 kg·hm^-2。施氮量的增加提高了稻米的加工品质与营养品质,同时降低了外观品质与蒸煮食味品质。移栽密度的增加提高了稻米的营养品质,但降低了加工品质、外观品质和蒸煮食味品质。综合分析认为,施氮量300 kg·hm^-2和移栽密度33.4万穴·hm^-2, 是盐碱滩涂水稻获得高产优质的栽培措施。本研究结果为盐碱滩涂水稻的高产优质栽培提供了理论依据。

Effect of Nitrogen Application Rate and Density on Rice Yield and Quality in Coastal Saline-alkali Intertidal Zone

To clarify the combined effects of nitrogen application rate and transplanting density on the formation of rice yield and grain quality, a field experiment was conducted in the coastal saline-alkali intertidal zone using Oryza sativa L. cv. Huaidao No. 5. The experiment contained six nitrogen application rates: N0(0 kg·hm ^-2), N210(210 kg·hm^-2), N255(255 kg·hm^-2), N300(300 kg·hm^-2), N345(345 kg·hm^-2) and N390(390 kg·hm^-2). And two transplanting densities: D1(334 000 holes·hm^-2, 12 cm×25 cm) and D2(278 000 holes·hm^-2, 12 cm×30 cm), the yield and quality of rice were determined. The results showed that, with the increase of nitrogen application rate, the number of panicles per unit area and the number of grains per panicle increased first and decreased subsequently, which peaked under N300 treatment, whereas, the seed setting rate and 1000-grain weight showed a decreasing trend. The number of panicles and 1000-grain weight under D1 treatment were higher than those under D2 treatment, while the number of grains per panicle and the seed setting rate showed the opposite trend. Among all treatments, rice grain yield displayed highest under N300D1 treatment, reaching 7 978.83 kg·hm^-2. The increase of nitrogen application rate improved the processing quality and nutritional quality of rice grain, while reduced the appearance quality and cooking and eating quality. The increase in transplanting density improved the nutritional quality of rice, but reduced the processing quality, appearance quality and cooking and eating quality. A combination of 300 kg·hm^-2 (nitrogen), and 334 000 holes·hm^-2 (density) was recommended, for rice high yield and good quality in the coastal saline-alkali intertidal zone. The current research aimed to clarify the co-effects of nitrogen application rates and transplanting density on rice yield and quality under salt stress, which would provide a theoretical basis for the high-yield and high-quality cultivation in the coastal saline-alkali intertidal zone.