秋施不同缓释氮肥对坪用草地早熟禾抗寒性影响的研究

秋季对草地早熟禾(Poa pratensis L.)草坪施用MU(亚甲基脲)、IBDU(亚异丁基二脲)、SUD1(大颗粒尿素+硝化抑制剂)、SUD2(大颗粒尿素+硝化抑制剂)、SUDT₂(大颗粒尿素+2种硝化抑制剂)、木质素肥和有机氮肥7种不同类型的缓释氮肥,以及速效氮肥尿素,于冬季不同时期,测定与抗寒性相关的过氧化氢酶(CAT)活性和可溶性蛋白质(SP)、可溶性糖(WSS)、游离脯氨酸(Pro)、丙二醛(MDA)含量,以探查缓释氮肥对草坪草抗寒性的影响。结果表明:与不施氮的对照相比,秋季施氮肥有助于提高草地早熟禾的抗寒性;7种缓释氮肥的抗寒性效应较尿素更为全面和显著,均增强了CAT活性,提高了Pro,SP和WSS含量,降低了MDA含量。MU,IBDU,SUD1,SUD2,SUDT₂和木质素肥6种缓释氮肥对5种生理生化指标的影响基本相同,但MU和IDBU对MDA活性的影响较低(P<0.05);有机肥除了对CAT,Pro和SP的影响较小外(P<0.05),对MDA和WSS的影响与缓释氮肥具有相同效果,因此,秋施有机氮肥也是提高草地早熟禾抗寒性的有效措施。根据Fuzzy数学隶属函数综合评判法计算的缓释氮肥抗寒性数值,8种肥料对抗寒性影响的大小排序为SUDT₂>SUD2>IBDU>木质素肥>SUD1>MU>有机肥>尿素(速效肥),也可按其对抗寒性影响的大小分为高、中、低3组,SUD2和SUDT₂为高效组,有机肥和MU属于低效组,其余为中效组。

Influence of Applying Slow Release Nitrogen Fertilizers in Autumn on Cold Resistant Turf-type Bluegrass (Poa pratensis L.)

This study applied 7 kinds of slow release nitrogen fertilizers(MU,IBDU,SUD1,SUD2,SUDT2,lignin fertilizer,and organic fertilizer) and one kind of fast release fertilizer(Urea) on turf in autumn.The cold resistance of bluegrass(Poa pratensis L.) was studied by measuring the contents of catalase(CAT),soluble protein(SP),water sloluble sugar(WSS),proline(Pro) and malonaldehyde(MDA) in different stages during winter.Result indicated that the application of nitrogen in autumn could increase the cold resistance of turfgrass compared with control.The cold resistance of 7 slow released nitrogen fertilizers was more effective than Urea and they did increase the activity of SOD,the contents of Pro,SP and WSS,but reduced the content of MDA.The effect of MU and IDBU on MDA activity was significantly lower(P<0.05) than control.The effect of organic fertilizer on CAT,Pro and SP was also lower(P<0.05) than control,and its effect on MAD and WSS was similar with slow release fertilizers.Results indicatethat it was also an effective way to apply organic fertilizer in autumn to improve cold resistance.Based on the cold-resistance value calculated by the Fuzzy method,cold-resistance of bluegrass was ranked as SUDT2>SUD2>IBDU>lignin fertilizer>SUD1>MU>Organic fertilizer>Urea.All fertilizers could be divided into 3 groups according to cold-resistance improvement,SUD2 and SUDT2 as high group,organic fertilizer and MU as low group.