模拟氮沉降和收获期对秋萌东方旱麦草生长与饲用品质的影响

Effects of Simulated Nitrogen Deposition and Harvest Period on the Growth and Forage Quality of Autumn-germinated Eremopyrum orientale

短命植物东方旱麦草(Eremopyrum orientale)广泛分布于新疆北部,适时萌发,有助于缓解春季饲草短缺。为探究氮沉降和收获期对秋萌东方旱麦草生长与饲用品质的影响,本试验采用人工模拟方式,设置0 kg·ha^(-1)·a^(-1),30 kg·ha^(-1)·a^(-1),60 kg·ha^(-1)·a^(-1)3个氮添加处理和2个收获时期(拔节孕穗期和开花期),分析不同处理下秋萌东方旱麦草生长指标和饲用品质指标变化。结果表明:在30 kg·ha^(-1)·a^(-1),60 kg·ha^(-1)·a^(-1)氮添加条件下,秋萌东方旱麦草的株高、叶长、叶宽、分蘖数、茎粗、平均地上鲜重、粗蛋白和粗脂肪含量均高于0 kg·ha^(-1)·a^(-1);同时,中性洗涤纤维、酸性洗涤纤维含量降低。与第一收获期相比,第二收获期东方旱麦草粗蛋白含量显著降低,中、酸性洗涤纤维与粗脂肪含量升高,平均地上生物量无差异。综合考虑东方旱麦草秋萌株的生长与饲用品质,在第一收获期(拔节孕穗期)和60 kg·ha^(-1)·a^(-1)氮添加下可获得最优饲草,但30 kg·ha^(-1)·a^(-1)较低水平氮沉降也能显著提升其生产力与饲用品质。

Eremopyrum Orientale is a common ephemeral plant which is widely distributed in northern Xinjiang,germinated properly,and be good for the alleviation of forage shortage.To explore the effects of nitrogen deposition and harvest period on the growth and forage quality of autumn-germinated E.orientale,three nitrogen deposition treatments were set up in this experiment:0 kg·ha^(-1)·a^(-1),30 kg·ha^(-1)·a^(-1),60 kg·ha^(-1)·a^(-1),and two harvest periods,the growth index and forage quality index were analyzed.The results showed that the plant height,leaf length,leaf width,number of tillers,stem diameter,fresh weight of aboveground per plant,crude protein and ether extract content of the autumn-germinated E.orientale under 30 kg·ha^(-1)·a^(-1) and 60 kg·ha^(-1)·a^(-1) nitrogen addition were higher than that of 0 kg·ha^(-1)·a^(-1)treatment;meanwhile,the content of neutral detergent fiber and acid detergent fiber decreased.Compared with the first harvest period,the crude protein content of the autumn-germinated E.orientale under the second harvest period was significantly reduced,the content of neutral detergent fiber,acid detergent fiber,and ether extract were increased,there was no difference in fresh weight of aboveground per plant.From the perspective of growth and forage quality of autumn-germinated E.orientale,the best forage was obtained at the first harvest period supplemented with 60 kg·ha^(-1)·a^(-1) nitrogen,and meanwhile even a low-level nitrogen deposition could significantly improve the productivity and forage quality of ephemeral E.orientale which distributed in a desert.