施肥量对油菜绿肥生物量及养分累积的影响

胡敏　周江霞　李小坤

摘要：通过大田试验研究了30%复合肥（15-7-8）不同施用量0、225、300、375、450、525、600、675 kg/hm2對晚播油菜绿肥生物量、养分含量及累积量的影响，为确定晚播油菜绿肥适宜施肥量提供依据。结果表明，在晚播条件下，通过增加施肥量可以明显提高油菜绿肥的生物量及养分累积量，且随施肥量的增加，油菜地上部生物量及养分累积量呈增加趋势。与不施肥处理相比，施肥量在225～450 kg/hm2范围内，油菜鲜、干重均随施肥量增加而提高，当施肥量>450 kg/hm2时，各处理间油菜干重没有显著差异。当施肥量在525～675 kg/hm2之间时，各处理油菜碳、磷、钾养分累积量没有显著差异，但施肥量在450～675 kg/hm2之间时，各处理油菜碳、氮、磷、钾明显高于其他处理。结合油菜绿肥翻压还田时的生物量、养分归还量及肥料成本，本试验条件下油菜作为绿肥晚播的适宜施肥量为450～525 kg/hm2。

关键词：油菜；绿肥；施肥量；生物量；养分累积量

中图分类号：S553+.9 文献标识码：A 文章编号：0439-8114（2017）11-2028-03

DOI：10.14088/j.cnki.issn0439-8114.2017.11.007

Abstract： A field trial was conducted to study the effect of fertilizing amount on biomass， nutrient content and accumulation of oilseed rape，to provide evidences for the appropriate fertilizing amount on late sowing oilseed rape. The trial included 8 fertilizing amount treatments 0，225，300，375，450，525，600，675 kg/hm2， the fertilizer was 30%（15-7-8） compound fertilizer. The results showed that under the condition of late sowing，by increasing the fertilizer rate could obviously increase oilseed rape biomass and nutrient accumulation，and which of them improved with fertilizer increased. Compared with control， oilseed rape fresh weight，dry weight increased with increasing fertilizing amount 225～450 kg/hm2. While there was no significant difference on dry weights when fertilizing amount was great than 450 kg/hm2. When fertilizing amount 525～675 kg/hm2 in each processing there was no significant difference on C，P，K accumulation of oilseed rape，but C，N，P，K were significantly higher than other treatments. Combined with the biomass，nutrient returns when the oilseed rape returning into field and fertilizer costs，the most suitable fertilizing amount was 450～525 kg/hm2 for late sowing oilseed rape as green manure under this experimental condition.

Key words： oilseed rape； green manure； fertilizing amount； biomass； nutrient accumulation

南方农区的耕作制度主要以双季稻为主，冬季农业非常薄弱[1]。据统计，2012年中国南方冬闲田面积达到870多万hm2[2]，这些冬闲田在水稻收获后一般闲置4～6个月，直到次年春季才种上庄稼，不仅造成大量土地资源和能量的浪费，也造成经济上的损失。近年来，由于土地整治的填、挖，造成土壤肥力不均，生土裸露，肥土被填，大大降低了土壤有机质含量，造成土壤肥力退化[3]。为了充分发挥冬闲田的生产潜力，将冬种绿肥作为有机肥使用，不仅可以充分利用冬季水热资源，还可以在高产稳产的同时改善和提高土壤肥力[4]。