栽培技术优化对冬小麦根系垂直分布及活性的调控

Regulative Effect of Optimized Cultivation Practice to the Root Vertical Distribution and Activity in Winter Wheat

为探索优化小麦根系构建,促进小麦根系功能发挥,以达到小麦高产高效的栽培技术,于2012—2013和2013—2014年度小麦生产季,通过大田试验,比较研究了鲁原502在旋耕-基肥撒施（RT-SF）,深翻-基肥撒施（PT-SF）和苗带旋耕-间隔深松-分层深施肥（SRT-SS-DT）3种栽培技术下产量及其构成,研究麦田0~90 cm内不同土层根系形态分布及生理特性的差异。与RT-SF和PT-SF处理相比,SRT-SS-DT处理显著提高了小麦的千粒重及单位面积穗数,使最终产量提高了3.96%~13.29%。SRT-SS-DT处理促进了小麦根系生长发育,拔节后15~60 cm土层内的根长密度和根干重密度、30~75 cm土层内根系总吸收表面积和活跃吸收面积较其他处理显著提高,尤其是在施肥层（15~30 cm土层）。开花后20 d,15~30 cm土层SRT-SS-DT的根系总吸收表面积和活跃吸收面积较RT-SF提高了66.3%和56.5%,较PT-SF提高了75.9%和59.8%。SRT-SS-DT增强了15~90 cm土层的根系活力,同时减缓了生育后期根系活力的下降,开花期至花后20 d,15~30 cm土层根系活力下降值在SRT-SS-DT处理下较RT-SF和PT-SF降低了28.5%和14.9%。此外,在花后20 d,SRT-SS-DT处理小麦15~90 cm土层根系表现较低MDA含量和较高SOD活性,尤其是15~30 cm土层,根系SOD活性分别比PT-SF和RT-SF处理高20.6%和10.9%。15~90 cm土层根系活力和根干重占比与小麦产量呈显著正相关。结果表明,通过对苗带旋耕、间隔深松和分层深施肥等栽培技术的集成和优化,可以有效扩展深层土壤根系的分布,提高深层土壤根系的活性,尤其是施肥层,有助于小麦产量提高。

To find out the cultivation practices, optimizing the construction of winter wheat root system, promoting root function, and enhancing the final grain yield, in the growing seasons of 2012–2013 and 2013–2014, we compared the root vertical distribution and activity in 0–90 cm soil layers, as well as grain yield and its components of winter wheat cultivar Luyuan 502, with three treatments of cultivate techniques, viz., plow tillage-surface fertilization（PT-SF）, rotary tillage-surface fertilization（RT-SF） and seedling belt rotary tillage-subsoiling-deep fertilization in different soil layers（SRT-SS-DF）. Compared to PT-SF and RT-SF, SRT-SS-DF significantly increased thousand-kernel weight and spike number per hectare, resulting in 3.96–13.29% increase of grain yield. Root growth was stimulated in SRT-SS-DF treatment. For example, the root length density and dry weight density in 15–60 cm soil layer and total root surface area and active absorption area in 30–75 cm soil layer were significantly higher in SRT-SS-DF than in other treatments after jointing stage, especially in the fertilized soil layer（15–30 cm）. At 20 days after anthesis（DAA）, the total absorbing surface area and the active absorbing area of root in SRT-SS-DF were 66.3% and 56.5% higher than those in PT-SF and 75.9% and 59.8% higher than those in RT-SF, respectively. Besides, SRT-SS-DF alleviated the decline of root activity at late grain filling stage. From anthesis stage to 20 DAA, the reduction of root activity in 15–30 soil layer was 28.5% and 14.9% lower in SRT-SS-DF than in RT-SF and PT-SF, respectively. At 20 DAA, low root MDA content and high SOD activity in 15–90 cm soil layer were observed in SRT-SS-DF. Especially, the SOD activity in 15–30 cm soil layer in SRT-SS-DF was 20.6% and 10.9% higher than those in RP-SF and PR-SF, respectively. The root activity and the ratio of root dry weight（root dry weight in different soil layers/total root dry weight in 0–90 cm soil layer） in 15–90 cm had a significant positive correlation with final grain yield. Our results suggest that optimizing integrated practices of seedling belt rotary tillage, seedling belt subsoiling and deep fertilization could be able to extend the root distribution in deep soil and increase the root activity, especially in fertilized soil layer, resulting in higher grain yield.