密度对旧膜再利用后旱地油用亚麻土壤水分及干物质积累分配的影响

Effects of Planting Density on Soil Water Content and Dry Matter Producing Characters for Used Film Reusing in Aridland Oilseed Flax

为探索干旱半干旱区旧膜再利用后油用亚麻的适宜种植密度和获得高产,在甘肃省定西旱区旧膜再利用生产条件下,研究了7种密度(300万-1200万粒·hm-2,D1-D7)对胡麻田土壤水分、生长特性、干物质积累分配、籽粒产量及水分利用效率的影响。结果表明,低种植密度有利于保持花前主要耕层土壤水分,加速干物质快速积累并向籽粒运转分配,水分利用效率增加,奠定了油用亚麻高产的物质基础。土壤水分对密度的响应差异主要体现在现蕾前营养生长期,为其物质积累及向生殖生长过度提供保证。自枞形期开始,同一时期不同密度下干物质的积累量始终随密度降低而增加,D1较同时期最低积累处理增幅范围为86.93%-147.97%。净同化率(NAR)及相对生长率(RGR)对密度的响应与之一致,基本均以D1为优。成熟期籽粒干重、叶片干重及主茎+分枝+果壳干重均以D1处理为最高,且基本都表现出随种植密度上升而不断下降的变化态势。花前贮藏同化物转运量随密度上升而降低,D1显著高出D7处理508.69 kg·hm^(-2),花后贮藏同化物转运量与之相反,但处理间差异不明显。籽粒产量及水分利用效率均随密度上升而下降,均以D1最高,达1837.95 kg·hm^(-2)和11.71 kg·hm^(-2)·mm^(-1),分别较相应最低D7处理增加27.47%和30.69%。说明,适度稀播是旧膜再利用生产条件下油用亚麻节本增效、保水增产的适宜选择。

Field experiments were conducted to investigate effective planting density in field and its mechanism on yield improvement of oil flax in arid areas for used film reusing. It was compared soil water amount,growth character,dry matter accumulation and distribution,water use efficiency and yield under7 planting density models,such as 3. 0（ D1）,4. 5（ D2）,6. 0（ D3）,7. 5（ D4）,9. 0（ D5）,10. 5（ D6）and 12. 0（ D7） million grains per hectare. The results showed that low- planting density had a remarkable effects on soil water utilization before flowering stage,dry matter accumulation improvement and water use efficiency promotion of oil flax under one film used twice. Differences of soil water content were mainly reflected at the vegetative period before budding stage under 7 planting density models,and keeping essential water from vegetative to reproductive stage. With planting density decreasing,a trend started out from Momi fir stage as dry matter accumulating content increasing under different density treatments in the same stage,and showed the highest in the different growth periods in D1,and it increased significantly by 86. 93% to 147. 97% between D1 and the lowest treatment at the same stage. Net assimilation ratio and relative growth ratio response to the treatments had the same trend as dry matter accumulation,D1 treatments were higher than the other planting density treatments. Grain weight,leaf weight and stem＋ spike axis ＋ kernel husk weight were the highest in maturity stage under D1 treatment. Dry matter translocation amount before anthesis indicated a decreasing trend with planting density increasing,which significantly increased by 508. 69 kg·hm- 2over D7. An opposite trend appeared in dry matter assimilation amount after anthesis,and differences were not significant. The experiment got the highest yield and water use efficiency under D1 treatment,up to 1837. 95 kg ·hm- 2and 11. 71 kg ·hm- 2·mm- 1,increased by 27. 47% and 30. 69% over D7,respectively. The study recommended 3. 0- 4. 5 million grains·hm- 2as the most appropriate density in high- yield for the culture conditions of used film reusing. However,the optimal planting density also needed considerations of local physical conditions and tillage measures.