种植密度和施肥水平对青海旱地覆膜种植甜高粱草产量及品质的影响

以甜高粱(Sorghum dochna)吉甜5号和九甜杂3号为材料,在海拔2 040m的青海旱地覆膜进行了不同种植密度(行株距分别为40cm×40cm、40cm×30cm、40cm×20cm)和追施不同尿素量(0、150和225kg·hm~(-2))对草产量及品质影响的研究。结果显示,吉甜5号和九甜杂3号两个品种在行距×株距为40cm×20cm(12.00万穴·hm~(-2))时的鲜草产量和干草产量最高,鲜草产量分别达99.75和108.17t·hm~(-2),干草产量分别达17.89和22.58t·hm~(-2);在生长中期追施150kg·hm~(-2)尿素时草产量较高,品质较好,两个品种的粗蛋白分别达5.47%和4.80%,粗脂肪分别达5.67和7.57g·kg~(-1),酸性洗涤纤维较低,综合表现良好。以上结果表明,青海旱地甜高粱种植密度为12.00万穴·hm~(-2),生长中期追施尿素150kg·hm~(-2)最为适宜。

Effects of different planting densities and fertilization levels on yield and quality of sweet sorghum grown under covering film cultivation in the dry land of Qinghai

In this experiment,Jitian 5 and Jiutianza 3 were used as materials in an experimental study on the effects of different planting densities.Linespacing×plant spacing:(40 cm×40 cm,40 cm×30 cm,40 cm×20 cm)and amount of urea (0,150,225 kg·ha-1 )in the topdressing on the yield and quality of sweet sorghum were studied at an altitude of 2040 m on dry land in Qinghai by covering film cultivation.The results showed that the fresh and hay yields of two cultivars were the highest at the spacing of 40 cm × 20 cm (120000 hole·ha-1 ).The yield of fresh grass was 99.75 and 108.17 t · ha-1 .The hay yieldswere 17.89 and 22.58 t·ha-1 ,respectively.The yield was higher and quality was better at 150 kg·ha-1 urea at the jointing stage. The crude protein of the two cultivars was 5.47% and 4.80%,crude fat was 5.67 and 7.57 g·kg-1 ,acidic de-tergent fiber was low,and comprehensive performance was good.In conclusion,a planting density of 120000 hole·ha-1 and topdressing urea of 150.0 kg·ha-1 at the jointing stage are most suitable for sweet sorghum in the Qinghai dry land.