摘要
通过2年田间试验,在2种肥力、3种氮肥施用水平(不施氮N0,中量施氮N1,高量施氮N2)下,研究了吉林省春玉米连作体系中土壤氮素的矿化、残留特征及氮素平衡,并比较了种植不同玉米品种的效应。结果表明,德惠高肥力土壤中氮素两季总矿化量为203 kg/hm2,是新立城低肥力土壤的2.7倍。中量氮(N1)处理,2试验点2年土壤累计的氮素残留量为103～112 kg/hm2,对环境威胁较小;高量氮(N2)处理,新立城低肥力条件下土壤的氮素残留量为174 kg/hm2,且有下移趋势,而在德惠高肥力条件下,土壤的氮素残留量仅为107 kg/hm2。在新立城低肥力土壤上,施氮量在氮素输入项中起主要作用,在氮素输出项中,作物携出量并不随输入量的增加而有显著的变化,从而导致氮素盈余随着施氮量的增加而显著增加。氮盈余主要以残留Nm in积累在土壤剖面中,变幅为34.0%～88.4%。在德惠高肥力土壤上,土壤矿化氮在2个施氮处理中分别占氮素输入的28.3%和36.5%,在氮素输出中,氮肥表观损失量显著高于新立城,且氮盈余中以表观损失为主,变幅为54.3%～70.8%,平均为65.5%。两个试验点的氮素表观损失可能主要是由生物固持作用引起的肥料氮向土壤氮的转换。不同玉米品种对氮素矿化和表观利用率有一定的影响,在优化施肥中应加以考虑。
A two-year field experiment was conducted to understand the characters of nitrogen（N）mineralization,residue in the soil and N balance in the continuous spring maize cultivation system in northeast China at two locations with three N fertilization levels N0： no N;N1： moderate N;N2： high N.The effect of different maize hybrids on N mineralization and N loss was also evaluated.The results indicated that accumulated mineralized N during the two years was 203 kg/ha in the fertile soil at Dehui,which was as twice as in the infertile soil at Xinlicheng.The residual N across the two sites was 103-112 kg/ha with N1 treatment within two years,which should be safe for the environment.Under the N2 treatment,however,the residual N at Xinlicheng was 174 kg/ha and it had a risk to be leached out.The residual N was only 107 kg/ha in the fertile soil at Dehui.Crop N uptake did not increase with increasing N input,leading to high N surplus at N2 level.At Xinlicheng,The contribution of residual Nmin was 34.0%-88.4% to N surplus in the soil.At Dehui,the proportion of N mineralization was 28.3% and 36.5% for N1 and N2,respectively.The apparent N loss in Dehui was 54.3%-70.8% with an average of 65.5%,much higher than that in Xinlicheng.It was supposed that the apparent N loss at both sites reflected the transfer of fertilizer N to soil N by the way of biological immobilization.Maize cultivars had an effect on N mineralization and apparent recovery,and therefore,should be taken into consideration to optimize N application.
出处
《植物营养与肥料学报》
CAS
CSCD
北大核心
2010年第5期1144-1152,共9页
Journal of Plant Nutrition and Fertilizers
基金
农业部公益性行业科研专项(200803030)
农业部科技支撑计划(2008BADA4B02)项目
农业部“948”项目(2003Z53)资助
关键词
春玉米
连作
氮素矿化
氮肥残留
氮平衡
spring maize
continuous cropping
N mineralization
N residual
N balance
