施肥方式和施氮量对寒地水稻产量、品质及氮肥利用的影响

为提高寒地水稻氮肥利用率,采用盆栽试验,比较了施肥方式、施氮量及二者互作对寒地水稻产量、品质、干物质生产、净光合速率（P_n）和氮肥利用率等指标的影响。结果表明,侧深施肥（S2）和点深施肥（S3）分蘖期和灌浆期地上干物质积累量、叶面积和根部性状多优于全层施肥（S1）,齐穗期功能叶相对叶绿素含量和灌浆期P_n低于S1处理。S2处理直链淀粉含量极显著低于S1处理;S3处理糙米率、精米率和蛋白质含量显著或极显著低于S1处理,直链淀粉含量和食味值极显著高于S1处理。S2处理氮肥生理利用率高于S1处理37.63%,S3处理氮肥吸收利用率、生理利用率和偏生产力分别高于S1处理20.14%、67.57%和13.08%。与常规施氮处理相比,减氮15%处理的千粒重、分蘖期和灌浆期地上部干物质积累量、分蘖期叶面积、分蘖期和灌浆期功能叶P_n均显著降低。本试验条件下,点深施肥方式配合减氮15%为兼顾产量、品质和肥料利用率的最优组合。

Effects of Fertilization Method and Nitrogen Application Rate on Yield,Quality and Nitrogen Utilization of Rice in Cold Region

To improve the nitrogen utilization efficiency of rice in cold regions, a pot experiment was designed to compare the difference of yield, quality, dry matter production, net photosynthetic rate (P_n), nitrogen utilization efficiency. The result showed the aboveground dry matter accumulation, leaf area and root characteristics of side-deep fertilization (S2) and point-deep fertilization (S3) at tillering stage and filling stage were better than whole-layer fertilization (S1). The functional leaf SPAD at full heading stage and P_n at filling stage were lower than that of S1 treatment. The amylose content of S2 treatment was significantly lower than that of S1 treatment. Brown rice rate, milled rice rate and protein content of S3 treatment were significant or extremely significant lower than that of S1 treatment, and amylose content and taste value of S3 treatment were significantly higher than S1 treatment. Compared with S1 treatment, N physiological efficiency of S2 treatment increased by 37.63%, N recovery efficiency, physiological efficiency, partial factor productivity of S3 treatment increased by 20.14%, 67.57% and 13.08%, respectively. 1000-grain weight, aboveground dry matter accumulation at tillering stage and filling stage, leaf area at tillering stage, P_n of functional leaves at tillering stage and filling stage of nitrogen fertilizer reduction by 15% were significantly lower than conventional nitrogen application. Comprehensive consideration of yield, quality and nitrogen utilization efficiency, point-deep fertilization combined with nitrogen fertilizer reduction by 15% was the optimal combination.