品种、密度与覆膜方式对旱地春玉米产量和水分利用效率的影响

Effects of hybrid,plant density and plastic film mulching on yield and water use efficiency of dryland maize

探求品种、密度和覆膜方式对旱地地膜玉米群体特征、耗水量、产量及水分利用效率的影响,以期高效利用和开发有限的自然降水资源。试验采用裂区设计,主区为全膜双垄沟覆盖(FFDRF)和窄膜覆盖(NF)2个处理,裂区为紧凑型中晚熟先玉335和紧凑型中熟吉祥1号及平展型早熟酒单4号3个杂交种,裂裂区为低密度(4.5万株/hm2)、中密度(6.75万株/hm2)和高密度(9.0万株/hm2)3个处理。测定不同处理玉米的株高、叶面积指数、干物质积累量、0~2 m土层土壤贮水量,结合作物产量分析农田水分利用效率。结果表明,全膜双垄沟覆盖可以有效地保蓄小量降水(小于10.7 mm),改善玉米生长条件,能快速提高苗期玉米株高和叶面积指数,干物质积累量、产量和水分利用效率较窄膜覆盖增加15.6%、14.3%和8.8%。随着密度的增加,百粒重、穗粒数表现为下降趋势,但增加种植密度的群体优势大于单株植株性状的综合劣势,玉米群体干物质积累量、产量和水分利用效率随着种植密度的增加而增加,9.0万株/hm2条件下,玉米干物质积累量、产量和水分利用效率较6.75和4.5万株/hm2依次增加8.3%、5.2%、3.4%和2 7.7%、3 2.9%、2 8.1%。不同品种适应密度改变的能力也不同,紧凑型的先玉3 3 5和吉祥1号适应密度改变能力强,耐密植,平展型酒单4号较弱,其中,先玉335产量和水分利用效率最高,较吉祥1号和酒单4号分别增加3.7%、1.7%和43.8%、37.1%。随着种植密度的增加,玉米耗水量呈增加趋势。不同品种间耗水量呈现出显著的差异,表现为先玉335>吉祥1号>酒单4号。可见,品种、密度、覆膜方式对旱地玉米群体结构、耗水量、籽粒产量和水分利用效率均有一定的调控作用,表现为品种>密度>覆膜方式。在实际生产中,应根据玉米种植区域降水特征,选择适宜的品种及其播种密度和覆盖方式,充分释放玉米增产潜力。降水量为530 mm左右的旱作区,"先玉335+9.0万株/hm2+全膜双垄沟覆盖"组合可以显著提高玉米产量和水分利用效率。

The objective of this experiment was to study the effects of hybrids,plant density and plastic film mulching on plant traits,water consumption,grain yield and water use efficiency of dryland maize to help identify opportunities to more effectively utilize limited water resources. A split-split plot designed field experiment was established; the main plot treatments were full plastic film mulching on double ridges and planting in catchment furrows（ FFDRF） and flat planting with narrow plastic film mulching（ NF）. The split-plot treatment was hybrid; Xianyu3 3 5,Jixiang1 hao and Jiudan4 hao and the split-split-plot treatment was plant density; 4. 5 × 10^4（ Low）,6. 75 × 10^4（ Middle） and 9. 0 × 10^4（ High） plants/ha. Plant height,leaf area index（ LAI）,dry matter,soil moisture at 0-2 m depth,grain yield and water use efficiency were assessed. The results showed that FFDRF increased height,LAI,grain yield and water use efficiency because it more allowed more effective utilization of limited precipitation compared with NF. Increased plant density reduced 1 0 0-grain weight and grain number per spike however,increased density resulted in increased dry matter,grain yield and water use efficiency. The 9. 0 × 10^4 plants/ha density increased dry matter, grain yield and water use efficiency by8. 3 %,5. 2 %,3. 4 % and 2 7. 7 %,3 2. 9 %,2 8. 1 % compared with the 6. 7 5 × 10^4 and 4. 5 × 10^4 treatments,respectively. Xianyu3 3 5 and Jixiang1 hao performed better than Jiudan4 hao at high plant densities;grain yield and water use efficiency were highest in Xianyu3 3 5; 3. 7 %,1. 7 % and 4 3. 8 %,3 7. 1 % higher than Jixiang1 hao and Jiudan4 hao,respectively. Water consumption increased with increasing plant density and differed among hybrids; Xianyu3 3 5 Jixiang1 hao Jiudan4 hao. Hybrids,plant density and plastic film mulching influenced the optimum plant population, water consumption, grain yield and water use efficiency of dryland maize,varieties had the greatest effect followed by plant density and mulch. Selection of appropriate hybrids and plant densities when using and plastic film mulch modes should be undertaken to maximize potential yields.