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以西辽河平原地区广泛种植的春玉米品种金山27为试材,以当地普通高产栽培模式为对照,研究了超高产栽培下春玉米的根系特征。结果表明,超高产春玉米深层根系占总根重比例较大,最大根幅下移,下层土壤根条数增加,且随土层深度增加与对照的差异增大。单株根重随生育进程呈先升后降的变化趋势,吐丝期达到最大且与对照的差异达到显著水平。各生育时期0~20cm土层根重所占比例明显低于对照,40cm以下各土层根重所占比例均高于对照。冠根比生育前期与对照接近,生育后期低于对照。根系活力变化随生育进程呈单峰型变化曲线,在吐丝期达到最大。超高产栽培下各生育时期根系活力随土层深度增加均呈单峰型变化曲线,而对照在不同生育时期有较大的差异。SOD和POD活性在吐丝期和乳熟期各土层超高产栽培均高于对照,而MDA含量低于对照。深松土和优化施肥改善了根系环境条件和养分供应水平,在高密度种植下促进了下层根系的发生,并保持较高的生理活性,为超高产的实现奠定了基础。
Jinshan 27, a spring maize cultivar widely planted in the West Liaohe Plain, was used as a control. The root characteristics of spring maize under super-high-yielding cultivation was compared with that of ordinary high-yielding cultivation. The results showed that the proportion of deep root in super high yielding spring maize was larger than that of the control, and the maximum root amplitude decreased and the root number of the lower layer increased, and the difference with the control increased with the soil depth increasing. The root weight per plant increased firstly and then decreased with the growth process, reached the maximum at silking stage and reached a significant level with the control. The proportion of root weight of 0 ~ 20cm soil layer in each growth period was significantly lower than that of the control, and the proportion of root weight of each layer below 40cm was higher than that of the control. The ratio of crown to root was close to that of the control group at early growth stage and lower at the later stage of growth. Root activity changes with the growth process showed a single peak curve, reached the maximum in the silking stage. Under ultra high yielding cultivation, the root vigor at each growth stage showed a unimodal curve with the increase of soil depth, but the control had greater differences at different growth stages. The activities of superoxide dismutase (SOD) and peroxidase (POD) were higher in the super-high-yielding cultivation than in the control during silking and milking stages, while the content of MDA was lower than that of the control. Subsoiling and optimized fertilization improved root environmental conditions and nutrient supply levels, promoted the development of the lower root system under high density planting and maintained high physiological activity, laying a foundation for the realization of super high yield.