摘要
在探讨渗灌不同灌水控制下限对土壤氮素形态及其数量剖面分布的影响基础上,评价灌水指标,合理调控土壤水分状况。分层采集连续7年用渗灌灌溉的保护地0～60cm层次土壤样品,测定有机质、全氮及无机态氮和有机态氮含量。结果表明:10,16,25,40,63kPa5个处理0～60cm剖面土壤有机质含量在12.83～17.18g.kg-1范围内变化,其含量随土层深度增加呈现迅速下降趋势,在0～10cm土层,40kPa处理和63kPa处理土壤有机质含量明显低于其他3个处理;30～40cm土层,10kPa处理土壤有机质含量明显低于其他处理。土壤全氮含量的变化范围为1.22～1.70g.kg-1,其含量剖面分布呈上高下低特点,10～30cm土层,63kPa处理土壤全氮含量明显高于其他4个处理。硝态氮、铵态氮分别在10.00～161.59mg.kg-1和6.07～13.94mg.kg-1范围内变化,0～20cm土层,各处理硝态氮含量差异较为明显,以25kPa处理最大,63kPa处理最小。有机态氮含量的变化范围为1201.74～1602.53mg.kg-1,其含量随土层深度增加而下降,在0～30cm土层,63kPa处理土壤有机氮含量明显高于其他处理。保护地渗灌栽培番茄,当渗灌管埋深为30cm时,综合考虑节水、保证作物产量和防止土壤有机物质减少、氮素过量积累等因素,将灌水控制下限土壤水吸力值选定在16～25kPa范围内是适宜的。
The effect of subsurface irrigation scheduling on soil N forms and their profile distribution was studied in a protected field for determining the content of soil organic matter, total N, inorganic N and soil organic N. The same irrigation experiment was conducted for seven years and soils were sampled at different depths within 0-60cm. Results showed that soil organic matter decreased with layer depth changed from 12.83 to 17.18g·kg^-1. At the depth of 0-10cm, the contents of soil organic matter in the treatments of 40kPa and 63kPa were lower than those in other treatments, however, the content in the treatment of 10kPa was lower than that in other treatments at the depth of 30-40cm. Soil total N, NO3--N, NH4^＋-N and organic N changed from 1.22 to 1.70g·kg^-1, 10.00 to 161.59mg·kg^-1, 6.07 to 13.94mg·kg^-1 and 1201.74 to 1602.53mg·kg-1 respectively. Soil total N and organic N decreased with the increase of the layer depth. The content of Soil total N at the depth of 10-30cm and the content of organic N at the depth of 0-30cm in the treatment of 63kPa were higher than those in other treatments. There were significant differences in soil NO3--N at the depth of 0-20cm with the highest content in the treatment of 25kPa and the lowest content in the treatment of 63kPa. With consideration of saving water, ensuring tomato yield, avoiding soil organic matter reduced and nitrogen forms accumulated excessively etc, soil water suction should be controlled between 16kPa and 25kPa with the pipe under 30cm soil depth.
出处
《沈阳农业大学学报》
CAS
CSCD
北大核心
2008年第2期191-196,共6页
Journal of Shenyang Agricultural University
基金
农业部农业科技成果转化资金项目(04EFN212100055)
辽宁省重大农业攻关项目(2006215005)
关键词
保护地
渗灌
灌水量
有机质
全氮
protected field
subsurface irrigation
irrigation quantity
soil organic matter
soil total N
