高寒区栽培措施对燕麦人工草地系统碳氮储量及分配机制的影响

Effect of Different Agronomy Treatments on the Carbon and Nitrogen Stock and Allocation of the Oat Cultivation Grassland on Alpine Meadow

为系统评价不同栽培措施下燕麦人工草地系统固碳、固氮潜力,在青藏高原高寒地区采用燕麦品种、施肥水平和箭筈豌豆混播水平的三因素四水平正交试验设计[L_(16)(4~5)],开展不同措施对乳熟期燕麦人工草地土壤层次碳氮储量的影响研究,并讨论不同措施下的燕麦人工草地系统碳、氮储量分配机制。结果表明,品种、施肥和混播均显著影响了土壤C、N储量分配,施肥和混播对C、N储量分配影响较大。尿素+磷酸二铵+有机肥处理下,系统总C、N储量最大,分别达184.45 t·hm^(-2)和12.51 kg·hm^(-2);箭筈豌豆混播75 kg·hm^(-2)处理下,系统总C、N储量最大,分别达182.76 t·hm^(-2)和11.90 kg·hm^(-2)。燕麦乳熟期各土层C、N储量分配模式均依次表现为0~10 cm>10~20 cm>20~30 cm>30~40 cm>40~50 cm;其中,各土层C储量分配为27.35%、24.50%、21.39%、14.38%和11.08%,土壤N储量分配为28.62%、24.43%、17.95%、15.47%和12.49%。0~50 cm土层C、N储量分别占整个系统的98.69%和98.96%,而植物仅占1.31%和1.04%;植物茎、叶、穗和根生物C储量仅占系统的0.58%、0.30%、0.28%和0.15%,N储量仅占系统的0.28%、0.42%、0.29%和0.06%。本研究结果为高寒地区燕麦人工草地系统固碳、固氮方面的研究提供了理论基础。

To reveal the carbon and nitrogen storage allocation mechanism of the oat cultural grassland,the study investigated the effect of the varieties,fertilization level and legume mixture on the carbon and nitrogen storage allocation.Oats varieties,levels of nutrient addition and four legume mixture levels were designed to analysis the carbon and nitrogen stock and allocation characters under different soil depth.As the results showed,the factors of variety,fertilizer and mixture significantly affect the soil carbon and nitrogen storage,the effect of fertilizer and mixture are greater.Under the IM+OM treatment,the system carbon and nitrogen storage are greater than the other fertilizer treatments(184.45 t·hm-2and 12.51 kg·hm-2),the carbon and nitrogen storage under the legume mixture of 75kg·hm-2are much higher than the other mixture levels(182.76 t·hm-2and 11.90 kg·hm-2).The distribution model of soil carbon and nitrogen sequestiation in different soil layers were 010 cm>1020 cm>2030 cm>3040 cm>4050cm at the milk stage of oats.The carbon and nitrogen decreased as the soil depth increased,and the carbon allocation at the different soil layers is 27.35%,24.50%,21.39%,14.38%and 11.08%,and the nitrogen allocation at the different soil layers is 28.62%,24.43%,17.95%,15.47%and 12.49%,respectively.The carbon and nitrogen storage at the 050 cm soil layer took up 98.69%and 98.96%,while the plant only took up 1.31%and 1.04%,especially for plant stem,leaf,ear and root on take up 0.58%,0.30%,0.28%and 0.15%of carbon,and 0.28%,0.42%,0.29%and 0.06%of nitrogen,respectively.This finding provides a theoretical basis for studying the carbon and nitrogen storage allocation of the cultural grassland on Alpine Meodow.