春小麦调亏灌溉对土壤氮素养分的影响

本文对河西绿洲灌区春小麦调亏灌溉两年后的土壤碱解氮和全氮的变化进行了研究,并用配对样本t检验(双尾检验)对小麦收获时土壤氮素养分指标年际间的差异及其与全生育期调亏供水量间的关系进行了回归分析,旨在为该区春小麦调亏灌溉对土壤氮素养分的影响研究提供一些可靠的信息.结果发现,春小麦调亏灌溉对2003年和2004年两个试验年度0～20cm、20～40cm及O～40cm土层土壤氮素养分有显著影响;而小麦收获时土壤氮素养分指标配对样本t检验发现,2004年0～20cm土层土壤全氮、碱解氮,20～40cm土层全氮,0～40cm土层全氮显著高于2003年,然而20～40cm土层碱解氮、0～40cm土层碱解氮在2003年和2004年问差异不显著.0～40cm土层土壤全氮量与小麦全生育期供水量呈线性负相关,而碱解氮则与全生育期供水量呈线性正相关.

Effect of regulated deficit irrigation on soil nitrogen in spring wheat fields

The dynamics of soil available nitrogen (SAN) and total nitrogen (STN) in spring wheat fields following two years (2003 and 2004) of regulated deficit irrigation (RDI) was studied in Hexi oasis irrigation region. The differences in soil nitrogen index at harvest (between the two experimental years) were analyzed using Paired-Sample T-Test (2-tailed), and regression relations between SAN,STN and total irrigation water (IR) for the entire wheat growing season developed. The regression relations provided relevant hints for analyzing the effects of RDI on soil nitrogen in spring wheat fields. Results show that RDI significantly affect soil nitrogen in the 0 ~ 20 cm, 20 ~ 40 cm and 0 ~ 40 cm soil layers in spring wheat fields for 2003 and 2004, while Paired-Sample T-Test on soil nitrogen at wheat harvest indicates that STN and SAN in the 0 ~ 20 cm soil layer, STN in the 20 ~ 40 cm and 0 ~ 40 cm soil layers in 2004 are significantly higher than in 2003. However, no significant difference exists in SAN in the 20 ~ 40 cm and 0 ~ 40 cm soil layers for 2003 and 2004. Furthermore, STN in the 0 ~ 40 cm soil layer has a negative linear correlation with IR during wheat growing seasons, while SAN has a positive linear correlation with IR.