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调查分析了陕西榆林2块19500kg·hm-2以上超高产春玉米田的产量构成、干物质分配和0～100cm土层根系分布及土壤理化性状指标.结果表明:其种植密度为105000～123000株·hm-2、成穗率97.7%～102.2%、千粒重320g以上,果穗干物质积累量占整株干物质积累量的60.2%～65.5%.0～100cm土壤平均容重为1.28～1.33g·cm-3,层间(每层20cm)土壤容重、孔隙度和田间持水量均呈“M”型变化.玉米根系主要分布在0～60cm,0～20cm土层根系量占根系总量的64.8%～72.1%,20～60cm土层根系量占根系总量的23.30%～28.17%.根系分布与土壤理化性状关系密切,0～20cm土层玉米的根系量与土壤有机质、全氮和全磷含量呈显著正相关,20～60cm土层根系量与土壤容重和田间持水量显著相关.因此,选择通透性和保水保肥能力良好的土壤,实行宽窄行双株密植栽培是获得玉米高产的关键.
The yield components, dry matter partition and root distribution of 0-100 cm soil layer and the indices of soil physical and chemical properties were analyzed in two high-yielding spring maize fields in Yulin, Shaanxi Province, China.The results showed that the planting density was 105000 ~ 123000 · Hm-2, the ear-forming rate was 97.7% -102.2% and the dry weight of 1000-grain weight was above 320g, the ear dry matter accumulation accounted for 60.2% -65.5% of the whole plant dry matter accumulation. The average bulk density of 0-100cm soil was 1.28-1.33g · cm -3, and the soil bulk density, porosity and field water holding capacity all changed “M ” between layers (20cm in each layer) .The root system of maize mainly distributed in 0 ~ 60cm, the root system of 0 ~ 20cm soil layer accounted for the total amount of root system 64.8% -72.1%, the root system of 20-60 cm soil layer accounted for 23.30% -28.17% of the total root system.The root distribution was closely related to soil physical and chemical properties, the root system of maize in 0-20 cm soil layer was related to soil organic matter, Phosphorus content was significantly and positively correlated, and the root mass of 20 ~ 60cm soil layer was significantly correlated with soil bulk density and field water holding capacity.Therefore, choosing the soil with good permeability and water retention and fertilizer-holding capacity, key.