光敏型高丹草复种穴播高效栽培模式研究

Efficient double cropping pattern of photoperiod-sensitive sorghum-sudangrass hybrids in summer after winter wheat

为了探讨光敏型高丹草夏播复种的高效栽培模式,在陇东旱塬麦茬后用免耕露地、翻耕露地和翻耕覆膜3种穴播方式复种了海牛、BJM和大卡(褐色中脉、BMR)3个光敏型高丹草品种,观察比较了各品种的物候期和农艺性状,测定分析了不同品种和穴播方式下刈割1茬和2茬的草产量。结果表明,在刈割1茬(早霜前1周刈割)条件下,各品种间在株高、茎粗、节间数、叶片数、单株鲜重、单株叶重、单株茎重和分蘖数性状上差异极显著(P<0.01),穴播方式对各品种株高和节间数影响显著(P<0.05),对叶片数、单株鲜重、单株叶重、单株茎重和分蘖数影响极显著(P<0.01),品种和穴播方式互作仅对单株叶重影响显著(P<0.05)。以65%含水量标准鲜草产量为指标,3个品种刈割1茬的产量均高于刈割2茬之和的产量,前者平均产草量是后者的3.21倍;品种在刈割2茬第1次、第2次和两次之和的产量之间均差异极显著(P<0.01),而在刈割1茬的产量间差异显著(P<0.05);穴播方式间刈割1茬、刈割2茬第1次和两次之和的产量均差异极显著(P<0.01);品种和穴播互作对刈割1茬、刈割2茬第1次和2次之和的产量影响极显著(P<0.01)。在刈割1茬时,3个品种的标准鲜草产量表现为翻耕覆膜比免耕露地平均增产62.21%、比翻耕露地增产36.45%、翻耕露地比免耕露地增产21.08%。在本试验条件下,在陇东旱塬地区麦茬后夏播复种高丹草以翻耕覆膜穴播、刈割1茬(早霜前1周刈割)和BJM品种相组合的生产模式为最优;但种植者如选择多次刈割,则以海牛品种结合翻耕覆膜穴播的种植模式为佳。

We evaluated double-cropping patterns of photoperiod-sensitive sorghum-sudangrass hybrids after a winter wheat crop in the Longdong dryland area,Gansu province.We conducted a field experiment with three dibbling methods（no tillage or mulching,tillage without mulching,tillage with plastic mulching）,three varieties[Monster,BJM,and Big kahuna（BMR）],and two cutting treatments（once or twice）.The phenology,agronomic traits,and grass yield of the varieties were compared among these treatments.In the once-cut treatment（before the early frost）,plant height,stem diameter,number of internodes,number of leaves,plant fresh weight,leaf weight per plant,stem weight per plant,and number of tillers showed highly significant differences among varieties（P〈0.01）;plant height and number of internodes showed significant differences among dibbling modes（P〈0.05）;and number of leaves,plant fresh weight,leaf weight per plant,stem weight per plant,and number of tillers showed highly significant differences among dibbling modes（P〈0.01）.The variety×dibbling mode interaction was significant only for leaf weight（P〈0.05）.For each variety,the fresh grass yield（65% moisture）was higher in the once-cut than in the twice-cut treatment.The average yield across the three varieties was 3.21 times higher in the once-cut treatment than in the two-cuts treatment.There were highly significant differences in grass yield in the first cut,the second cut,and the sum of two cuts among the three varieties in the two-cuts treatment（P〈0.01）.The grass yield also differed significantly among the three varieties in the once-cut treatment（P〈0.05）.The difference in grass yield among dibbling modes was highly significant in both cutting treatments（P〈0.01）.The variety×dibbling mode interaction was highly significant for grass yield in both cutting treatments（P〈0.01）.In the once-cut treatment,the average fresh grass yield of all three varieties in the plastic-mulching treatment was 62.21% higher than that in the no tillage without mulching treatment,and 36.45% higher than that in the tillage without mulching treatment.The fresh grass yield averaged across the three varieties in the tillage without mulching treatment was 21.08% higher than in the no tillage without mulching treatment.Under these conditions in the Longdong dryland area,the best combination of cultivation practices for photoperiod-sensitive sorghum-sudangrass hybrids after a winter wheat crop is tillage with plastic mulching,the BJM variety,with one cutting event.If growers prefer to conduct two or more cuttings,then the Monster variety combined with tillage with plastic mulching is preferable.