微生物肥对羊草植被特征和化学计量学的影响

Effect of bio-fertilizers on vegetation characteristics and stoichiometry of Leymus chinensis

为了解复合微生物肥料在天然草地恢复和改良中的效果,本研究在科尔沁羊草(Leymus chinensis)割草地开展,共设置对照(无添加)、腐植酸、糖蜜发酵、海藻酸和混合微生物肥料(腐植酸+糖蜜发酵+海藻酸)5种处理,研究其对羊草植被特征、品质以及碳(C)、氮(N)、磷(P)生态化学计量特征方面的影响。结果表明,1)与对照相比,复合微生物肥料对羊草地上生物量、高度和密度都有增加作用。糖蜜发酵处理效果最佳,地上生物量和密度均增加了2倍多,高度也显著增加(P<0.05)。2)复合微生物肥料提升了羊草品质。腐植酸处理下中性洗涤纤维和酸性洗涤纤维含量降幅最大,较对照分别降低了20.55%和19.31%。糖蜜发酵处理下羊草粗蛋白含量显著增加(P<0.05),较对照增加了22.01%,中性洗涤纤维和酸性洗涤纤维含量均显著降低(P<0.05)。3)羊草C含量在不同处理间差异不显著(P>0.05)。糖蜜发酵处理下N、P含量显著增加(P<0.05),与对照相比增幅分别为21.97%和13.73%。4)5个处理下羊草的N∶P的变化范围为12.22~13.32,均小于14,可能N是限制当地羊草生长的一个主要因素,P处于相对平衡的状态。综上所述,在未来科尔沁羊草割草地改良中,优先推荐糖蜜发酵复合微生物肥料,同时可适量添加N素,才能使羊草呈现适中的化学计量比。

In order to explore the effects of compound bio-fertilizers on native pasture restoration and improvement,a Leymus chinensis mowing pasture in Horqin was fertilized with five compound bio-fertilizers,including control,humic acid,molasses fermentation,alginic acid,and mixed compound bio-fertilizers(humic acid+molasses fermentation+alginic acid).Their effects on vegetation characteristics,quality,and ecological stoichiometry were studied.The results showed that the compound bio-fertilizers increased above-ground biomass,height,and density of the vegetation,and molasses fermentation showed the best results;the community’s above-ground biomass and density were two times higher than the control,and the height increased significantly(P<0.05),with molasses fermentation.The compound bio-fertilizers increased the quality of L.chinensis,and the neutral detergent fiber(NDF)and acid detergent fiber(ADF)of humic acid were the lowest,i.e.,lower than control by 20.55%and 19.31%respectively.While,molasses fermentation increased the crude protein content significantly,i.e.,higher than control by 22.01%,the NDF and ADF decreased it significantly.The carbon(C)content of L.chinensis showed no significant differences among treatments.The nitrogen(N)and phosphorus(P)contents increased significantly and were higher than those in control by 21.97%and 13.73%,respectively,by treatment with molasses fermentation.The variation range of N/P ratio in the five treatments was from 12.22 to 13.32,all less than 14.Therefore,N could be one of the most limiting factors to L.chinensis growing in the area,and P was the relative balance.In conclusion,the molasses fermentation is recommended preferentially,and mixing N fertilizer moderately could show moderate stoichiometric ratio of L.chinensis in the future.