水旱轮作下穗肥氮用量对机插粳稻生长特性及经济效益分析

为了研究水旱轮作系统中水稻氮肥减量施用技术,在高原粳稻区小麦–水稻和蚕豆–水稻模式中,以当地主栽水稻品种隆科16为材料,在不施基蘖氮肥的条件下,分别施纯氮0、90、120、150、180和210kg/hm²作穗肥,按促花肥:保花肥=6:4进行施肥,并以常规施纯氮285kg/hm²作为对照（基肥:分蘖肥:促花肥:保花肥=0.25:0.25:0.25:0.25）,分析了水稻的群体生长特性和经济效益。结果表明,2种轮作模式中,不施基蘖氮肥,只施用适量（180kg/hm²）穗肥氮,水稻产量与对照相持平。在水稻有效分蘖临界叶龄期,小麦–水稻和蚕豆–水稻模式不施基蘖氮肥处理的最低水稻分蘖数分别达到对照的91.09%和87.62%,最高分别达到对照的95.05%和91.11%,成熟期有效穗数与对照差异不显著,不施基蘖氮肥只施穗肥氮能显著提高水稻成穗率。与对照相比,施穗肥氮后水稻的有效穗数、干物质积累量和阶段增量以及群体生长速率明显加快。小麦–水稻和蚕豆–水稻模式中,穗肥氮用量为180kg/hm²处理,氮肥投入比对照减少36.84%,水稻经济效益最高,达到了节本增效的目的。

Analysis of Growth Characteristics and Economic Benefit of Mechanical Transplanted Japonica Rice with Applying Panicle Nitrogen under Rotation of Paddy-Upland

In order to study the cultivation techniques of rice nitrogen reduction in paddy-upland rotation system, in the wheat-rice and broad bean-rice rotation system in the plateau Japonica rice region, Longke 16, a local rice variety, was used as the material, and six nitrogen (N) rates of 0, 90, 120, 150, 180 and 210kg/ha were topdressed as flower promoting and flower preserving fertilizer in ratio of 6:4. Local recommended N management (N 285kg/ha in total, evenly divided and applied as basal, tillering, flower promoting and flower preserving fertilizer in ratio of 0.25:0.25:0.25:0.25) was used as control. The population growth characteristics and economic benefits of rice under two rotation systems were systematically compared. The results showed that in the two rotation patterns, the yield of rice was the same as that of the control when 180kg/ha panicle N was applied without basal N and tillering N, and in the critical leaf stage of productive tillers of rice, the lowest tillering number of rice was 91.09% and 87.62% of the control, and the highest was 95.05% and 91.11% of the control, respectively, under the wheat-rice and broad bean-rice rotation system without basal N and tillering N application. There was no significant difference in the number of effective panicles in the mature period from the control, and applying panicle N without basal N and tillering N could significantly increase percentage of earbearing tillers. Compared with no N application, the effective panicle, dry matter accumulation and population growth rate at filling stage of rice increased after applying panicle N. The application of 180kg/ha pure N without basal N and tillering N as panicle fertilizer reduced 36.84% of N input compared with the control, and the economic benefit of rice was the highest. The goal of saving cost and increasing efficiency of rice was achieved.