不同肥料运筹对不同茬口水直播稻群体及产量的影响

Effects of Different Fertilization Strategies on the Population and Yield of Water Direct-seeding Rice in Different Cropping Systems

随着农业劳动力的老龄化越来越严重,农活用工也越来越紧张,已经影响了机插水稻的育秧和栽插环节,因此直播稻近年来又逐步兴起。江苏省农垦农业发展股份有限公司新洋分公司近几年引进西瓜种植后,水稻种植的茬口分为西瓜-小麦茬和水稻-小麦茬。为了解不同肥料运筹对当地不同茬口直播稻苗情动态、群体质量及产量构成因素的影响,设计了水稻-小麦茬施氮量21.0、24.0、27.0 kg/667 m^(2)3个水平,西瓜-小麦茬施氮量19.0、22.0、25.0 kg/667 m^(2)3个水平,每个施氮量水平中有穗肥1遍(倒2.5叶施用)和2遍(分别在倒3.5叶、倒1.5叶施用)2个处理。结果表明:水稻-小麦茬直播稻施用纯氮24.0 kg/667 m^(2)、2遍穗肥处理的RN2S2产量最高,为583.43 kg/667 m^(2);西瓜-小麦茬直播稻施用纯氮19.0 kg/667 m^(2)、2遍穗肥处理的WN1S2产量最高,为642.81 kg/667 m^(2)。因此,水稻-小麦茬直播稻一生用氮量在24.0 kg/667 m^(2)左右,西瓜-小麦茬直播稻一生用氮量在19.0 kg/667 m^(2)左右,且在倒3.5叶、倒1.5叶施用2遍穗肥时取得的产量最高。

With the increasingly serious problem of labor force aging,agricultural labor force shortage has become more and more prominent,which affects the cultivation process,especially the stages of seedling raising and transplanting of machine-transplanted rice.Therefore,direct seeding rice has been gradually rising in recent years.At Xinyang Branch of Jiangsu Provincial Agricultural Reclamation and Development Corporation,since watermelon planting was introduced a few years ago,rice cropping arrangements have been divided into two types:the watermelon-wheat-rice cropping system,and the wheat-rice cropping system.This study aimed to investigate the effects of different fertilization strategies on local water direct-seeding rice cultivation under different rice cropping arrangements,with respect to seedling dynamics,population quality and yield components.In a field trial,three nitrogen application rates(21.0,24.0,and 27.0 kg/667 m^(2))were set up for rice grown in the wheat-rice cropping system,and another three nitrogen application rates(19.0,22.0,and 25.0 kg/667 m^(2))for rice cultivated in the watermelon-wheat-rice cropping system.Corresponding to each of these nitrogen application rates,two urea application modes were set up:one application of it as a panicle fertilizer at the stage of last 2.5 leaves;two applications of it as a panicle fertilizer at the stages of last 3.5 leaves and 1.5 leaves.The results showed that among the treatments under rice-wheat rotation,the highest yield of 583.43 kg/667 m^(2) was attained by the treatment with the total nitrogen application at 24.0 kg/667 m^(2) and urea applied twice as a panicle fertilizer,while among the treatments under watermelon-wheat-rice rotation,the highest yield of 642.81 kg/667 m^(2) was achieved by the treatment with the total nitrogen application at 19.0 kg/667 m^(2) and urea applied twice as a panicle fertilizer.Thus,the direct-seeding rice utilized nitrogen at about 24.0 kg/667 m^(2) under rice-wheat rotation and 19.0 kg/667 m^(2) under watermelon-wheat-rice rotation in its whole growth period,and the highest yield was obtained by applying urea as a panicle fertilizer twice in the stages of last 3.5 leaves and 1.5 leaves.