灌溉和修剪对沟叶结缕草生长、土壤无机氮及氮平衡的影响  

Responses of Zoysia matrella growth,soil mineral nitrogen,and nitrogen balance to different levels of irrigation and mowing

作　　者：王云鹏 范博 张海阔 沈玉叶 张宝刚 陈有超 余兵 李永夫[1] 蔡延江 WANG Yunpeng;FAN Bo;ZHANG Haikuo;SHEN Yuye;ZHANG Baogang;CHEN Youchao;YU Bing;LI Yongfu;CAI Yanjiang(State Key Laboratory of Subtropical Silviculture/College of Environmental and Resource Sciences,College of Carbon Neutrality,Zhejiang A&F University,Hangzhou 311300,Zhejiang,China)

机构地区：[1]浙江农林大学省部共建亚热带森林培育国家重点实验室/浙江农林大学环境与资源学院、碳中和学院,浙江杭州311300

出　　处：《草业科学》2023年第11期2787-2799,共13页Pratacultural Science

基　　金：国家自然科学基金面上项目(41877085、42277286);浙江农林大学科研发展基金项目(2018FR005、2018FR006、2020KJ003、2021LFR035)。

摘　　要：作为城市绿地生态系统中的主要景观类型,城市草坪频繁受到人为管理措施的强烈干扰。本研究以沟叶结缕草(Zoysia matrella)为对象,通过控制3个灌溉水平(I_(1):4.00 L·m^(-2)、I_(2):5.71 L·m^(-2)、I_(3):7.43 L·m^(-2))和3个修剪水平(M_(1):不修剪、M_(2):留茬2 cm、M_(3):留茬6 cm)的盆栽试验,探究不同灌溉和修剪水平对草坪草生长、土壤无机氮及氮素表观平衡的影响。结果表明:相同灌溉水平下,M_(2)处理草坪草地上生物量显著低于M_(1)和M_(3)处理,但M_(2)处理草坪草地上部分和地下部分氮含量均显著高于M_(1)处理(P<0.05)。在草坪草生长末期,相同灌溉水平下M_(2)处理土壤无机氮(N_(min))含量较M_(1)、M_(3)处理下降了0.6%~54.1%。各处理淋溶液中N_(min)均以铵态氮(NH_(4)^(+)-N)为主要形式,不过,N_(min)淋失量仅占氮输出总量的0.4%~1.3%。相同灌溉水平下,M_(2)处理的氮平衡相较于M_(3)处理表现出更为明显的盈余特征(P<0.05),但M_(3)处理在高灌溉量下会更趋于氮素收支平衡。综上可知,重度修剪(M_(2)处理)显著抑制了草坪草生长,增加了氮素损失风险,但却提高了草坪草氮素吸收量,因此,在本研究条件下,建议灌溉量(5.71~7.43 L·m^(-2))略高于一般灌溉水平,同时适度修剪(保持留茬高度为6 cm),既可以保证草坪草良好的生长状况,也可维持土壤氮素基本收支平衡,提高氮素利用效率。The major landscape type in urban green space ecosystems,urban turfgrass is strongly disturbed by anthropogenic management practices.In this study,three irrigation levels(I_(1):4.00 L·m^(-2);I_(2):5.71 L·m^(-2);I_(3):7.43 L·m^(-2))and three mowing levels(M_(1):no mowing;M_(2):2 cm stubble;M_(3):6 cm stubble)were simulated to investigate the effects of different irrigation and mowing levels on Zoysia matrella(a warm season turfgrass)growth,soil mineral nitrogen,and the apparent soil nitrogen balance.The results showed that the above-ground biomass(AGB)of turfgrass in M_(2) treatment was significantly lower than those in M_(1) and M_(3) treatments under the same irrigation level.Meanwhile,the nitrogen concentration of above-ground or below-ground part of turfgrass in M_(2) treatment was significantly higher than that in M_(1) treatment.At the end of turfgrass growth,soil mineral nitrogen(Nmin)concentration decreased by 0.6% to 54.1% in the M_(2) treatment compared to the M_(1) and M_(3) treatments under the same irrigation level.Ammonium nitrogen(NH_(4)^(+)-N)was the main form of leachate N in all treatments,and Nmin leaching only accounted for 0.4%~1.3% of the total nitrogen output.More nitrogen surplus was observed in the M_(2) treatment compared to the M_(3) treatment under the same irrigation level(P<0.05).Meanwhile,more balanced nitrogen occurred in the M_(3) treatment at the higher irrigation level.In summary,heavy mowing(M_(2) treatment)significantly inhibited turfgrass growth and elevated the risk of nitrogen loss,but increased turfgrass nitrogen uptake.Therefore,based on our study findings,it can be suggested that irrigating slightly more water than the conventional level ranging from 5.71 to 7.43 L·m^(-2) in combination with mowing moderately and keeping the stubble height at 6 cm are favorable to ensure suitable growth conditions of turfgrass and to maintain the balance of soil nitrogen and improve nitrogen utilization efficiency.

关 键 词：人为管理措施 城市草坪 生物量 土壤无机氮 淋溶损失 氮盈余 氮素表观平衡 

分 类 号：S688.4[农业科学—观赏园艺]