高寒区施肥和混播对燕麦人工草地土壤碳氮储量及碳氮垂直分布特征的影响

Vertical Soil Carbon and Nitrogen Stock Characters of Oats Grassland in Alpine Area Under Fertilization and Mixed Sowing

为了解高寒地区燕麦人工草地在燕麦品种、施肥措施和混播水平下土壤碳氮储量潜力及垂直分布动态,采用三因素四水平正交试验设计[L_(16)(4~5)],在燕麦各生育期研究了3个因素对土壤C、N储量的影响及其垂直分布特征。结果表明:3个因素在燕麦生长期对土壤C储量的影响表现为施肥>混播>品种,收获后期表现为混播>施肥>品种;各时期对土壤N储量的影响均表现为施肥>混播>品种。采用尿素37.5 kg/hm^2+磷酸二铵75 kg/hm^2+有机肥750 kg/hm^2的施肥措施,混播75 kg/hm^2箭筈豌豆时燕麦人工草地土壤C、N储量最高。施肥措施造成燕麦人工草地各时期不同土层间土壤C、N储量差异。在3种措施影响下燕麦人工草地0～50 cm土层土壤C、N储量潜力分别为176.78 t/hm^2和11.78 t/hm^2。土壤C、N储量随着土层的加深而逐渐下降,但0～20 cm土层土壤C、N储量显著高于其他土层。

To study the soil carbon and nitrogen potential stock and vertical dynamic of oat artificial grassland in alpine region under different oat varieties, fertilization modes and mixed sowing, orthogonal test of L16(45)was conducted. The results showed that the oat variety, fertilization and mixed sowing all significantly affected the carbon and nitrogen stock, for carbon, the order was fertilization > mixed sowing > oat variety in growth period, and was mixed sowing > fertilization > oat variety in late harvest period;for nitrogen, the order was fertilization > mixed sowing > oat variety in all periods. Under the treatment of urea 37.5 kg/hm2+ diammonium phosphate 75 kg/hm2+ organic fertilizer 750 kg/hm2 and mixed sowing with Vicia sativa of 75 kg/hm2, the soil carbon and nitrogen stock reached a peak value, the difference of carbon and nitrogen stock of different soil layers at different growth periods was due to the fertilization. The carbon and nitrogen potential stock was 176.78 t/hm2 and 11.78 t/hm2 respectively under the three factors. The carbon and nitrogen stock decreased with the soil layer increase, the carbon and nitrogen stock of the 0-20 cm soil layer was greater than that of the other soil layers.