稻秆还田方式对油菜产量及养分效率的影响

Effects of Rice Straw Returning Patterns on Rapeseed Yields and Nutrient Efficiency

为探讨稻秆还田方式对油菜干物质积累、籽粒产量及氮磷钾吸收利用效率的影响,2017-2018年在中国农业科学院油料作物研究所武昌本部网室,选择2个不同地点、pH值差异较大的水稻土,设置稻秆不还田(CK)、稻秆焚烧后灰烬与土壤混匀还田(焚烧)、稻秆粉碎与土壤混匀还田(翻压)、稻秆粉碎后覆盖还田(覆盖)4个处理的盆栽试验。结果表明:稻秆还田能增加油菜干物质积累量和籽粒产量,其中以覆盖处理最好,相比CK,油菜苗期、花期和成熟期的干物质积累量,平均分别提高16.9%,18.5%,16.8%,籽粒产量平均提高13.9%;除麻城土苗期翻压处理外,覆盖处理各生育期的干物质积累量及籽粒产量均显著高于其他处理。稻秆还田能提高油菜氮磷钾吸收效率,同样以覆盖处理最好,相比CK,油菜苗期、花期和成熟期的养分吸收效率,氮素平均提高18.8%,17.4%,12.9%;磷素平均提高22.3%,18.6%,21.7%;钾素平均提高22.8%,20.0%,17.5%。花期是油菜氮磷钾吸收效率最高时期;成熟期是生理利用效率最高时期,根系在整个生育期内均保持较高的氮磷钾生理利用效率。从产量和肥料利用效率分析,稻秆覆盖还田是一种较为适宜的秸秆资源有效利用途径。

In order to investigate the effects of rice straw returning on the dry matter accumulation,yield,NPK uptake and utilization of rapeseed,two pot experiments which was different in acid and alkaline soils fed from two locals of paddy soil were carried out in a greenhouse of the Oil Crops Research Institute,Chinese Academy of Agricultural Sciences from 2017 to 2018.Four treatments were arranged:no straw returning(CK),returning of ashes from straw burning to soil(Burning),returning of chopped straw to soil(Turning),mulching of chopped straw on soil(Mulching).The main results showed that:different rice straw returning patterns had effects on rapeseed dry matter accumulation and yield of rapeseed.Mulching treatment was the best pattern among the 4 treatments.Compared with the CK,the biomass of rapeseed in mulching treatment was increased by 16.9%,18.5%and 16.8%in seedling,florescence and maturing stage,and the seed yield of rapeseed increased by 13.9%,respectively.There were significant differences among the mulching and other treatments(except of turning in seedling period of Macheng soil)full growth period in the biomass and seed yield of rapeseed.Rice straw returning could increase NPK nutrients uptake efficiency of rapeseed.Compared with the CK,N nutrient uptake efficiency of rapeseed in mulching was increased by 18.8%,17.4%and 12.9%in seedling,florescence and maturing stage of rapeseed,respectively.P nutrient uptake efficiency of rapeseed in mulching was increased by 22.3%,18.6%and 21.7%in seedling,florescence and maturing stage of rapeseed,respectively.K nutrient uptake efficiency of rapeseed in mulching was increased by 22.8%,20.0%and 17.5%in seedling,florescence and maturing stage of rapeseed,respectively.Florescence was the period of maximum NPK nutrient uptake efficiency,and maturing stage was the period of maximum NPK physiological utilization efficiency of rapeseed.During the whole growth period of rapeseed,the root maintained a high level of NPK physiological utilization efficiency.The overall results suggested that rice straw mulching is one of the promising measurements of cyclic utilization of rice straw in rice-rapeseed rotation system.