高寒区施肥和混播对燕麦人工草地植物器官碳氮储量分配的影响

Effects of fertilization and mixed crops on carbon and nitrogen allocation of the different plant organs on oat cultivation grassland on alpine area

为了解青藏高原高寒地区燕麦品种、施肥和箭筈豌豆混播比例对燕麦人工草地植物各器官生物C、N储量分配的影响,采用4个燕麦品种、4个施肥水平(B1:不施任何肥料,CK 0;B2:尿素75 kg·hm^-2 +磷酸二铵150 kg·hm^-2 ,IM;B3:有机肥1 500 kg·hm^-2 ,OM;B4:尿素37.5 kg·hm^-2 +磷酸二铵75 kg·hm^-2 +有机肥750 kg·hm^-2 ,IM+OM)和4个箭筈豌豆混播水平(C1:0 kg·hm^-2;C2:45 kg·hm^-2;C3:60 kg·hm^-2;C4:75 kg·hm^-2 )的三因素四水平正交试验设计[L 16 (4 5 )],研究施肥和混播对不同品种燕麦乳熟期器官C、N储量的影响,C、N储量分配模式和地上、地下器官C、N储量相关关系。结果表明,品种、施肥和混播均对燕麦草地各器官和组分生物C、N储量分配具有显著影响。品种主要影响箭筈豌豆茎、根生物C储量分配,混播主要影响燕麦茎、叶、穗、根和箭筈豌豆叶生物C储量分配;品种主要影响燕麦茎、叶、穗、根生物N储量分配,而混播主要影响箭筈豌豆茎、叶、根生物N储量分配。燕麦人工草地建植时,燕麦各器官C、N储量分配在选用青燕1号、施尿素37.5 kg·hm^-2 +磷酸二铵75 kg·hm^-2 +有机肥750 kg·hm^-2 ,单播燕麦时,其燕麦茎、叶、穗和根生物C、N储量分配最高,其C储量分配分别达40.21%、15.48%、 23.02%和9.89%,,N储量分配分别达20.70%、20.79%、32.09%和5.19%;箭筈豌豆各器官C、N储量分配在选用青海444、不施肥情况下混播箭筈豌豆75 kg·hm^-2 时,箭筈豌豆茎、叶和根生物C、N储量分配最高,其C储量分配分别达11.27%、13.57%和2.27%,N储量分配分别达13.03%、32.18%和0.95%。燕麦人工草地总生物C、N储量分配分别为茎(44.39%)>叶(23.99%)>穗(20.38%)>根( 11.24%)和叶(42.14)>茎(26.77%)>穗(25.96%)>根(5.13%)。燕麦和箭筈豌豆混播栽培草地中,燕麦茎和穗,箭筈豌豆叶是主要的C、N储藏器官。

To understand the effect of oat variety, fertilizer, and legume mixture on the carbon (C) and nitrogen (N) stock and allocation of different plant organs on oat cultivation grassland, we carried out a experiment including four oats varieties and four levels of nutrient addition (B1: No addition CK0;B2: urea 75 kg·hm^-2 + diammonium phosphate 150 kg·hm^-2 ,IM;B3: organic fertilizer 1 500 kg·hm^-2 ,OM;B4: urea 75 kg·hm^-2 + diammonium phosphate 150 kg·hm^-2 + organic fertilizer 1 500 kg·hm^-2 IM+OM) and four legume mixture levels (C1:0 kg·hm^-2;C2:45 kg·hm^-2;C3:60 kg·hm^-2;C4:75 kg·hm^-2 ) to analyze the effect of different agronomy procedure and C and N allocation pattern and the relationship between the C and N stock below and above ground and the growth. As the results shown, three kinds of agronomy procedures significantly affected C and N allocation. The variety played an important role in legume plant stem and root carbon stock and allocation, mixture affected the legume stem, leaf and root nitrogen allocation. Under the agronomy procedure ( Avena sativa L.cv. Qingyan No.1 monoculture,urea 37.5 kg·hm^-2 and diammonium phosphate 75 kg·hm^-2 and organic fertilizer 750 kg·hm^-2 ), the carbon and nitrogen stock in the stem, leaf, spike and root of the oat were highest compared with other agronomy procedures (carbon stock, stem 40.21%, leaf 15.48%, spike 23.20% and root 9.89%;nitrogen stock, stem 20.70%, leaf 20.79%, spike 32.09% and root 5.19%). When mixture with Avena sativa L. cv. Qinghai No.444, the cultivation of Vicia sativa L. under 75 kg·hm^-2 without fertilization got a highest carbon and nitrogen stock and allocation in stem, leaf and root (carbon stock, stem 11.27%, leaf 13.57% and root 2.27%;nitrogen stock, stem 13.03%, leaf 32.18% and root 0.95%). The allocation pattern of the oat cultivation grassland was stem(44.39%)> leaf(23.99%)> spike(20.38%)> root(11.24%) for C and leaf(42.14)> stem(26.77%)> spike( 25.96%)> root(5.13%) for N. In the oat and legume mixture grassland, the stem and spike of oats and the legume leaf were the main carbon and nitrogen stock organs.