The dynamic change of Eh of reddish paddy soil and the preliminary study of its impact factors
The oxidation reduction potential (Eh) of three kinds of fertilization paddy soil under high (20 cm) and low (80cm) underground water level in a long-term fertilization experiment was on-site measured to clarify the paddy soil Eh dynamics during the late rice growing period and preliminarily explore the main factors that effect paddy soil Eh.The results indicated that the Eh variation tendencies of all treatments were similar,which reached the lowest level in the turning-green stage,being low level and small variation in the early tillering stage,tillering stage,jointing stage,flowering stage and filling stage,finally significantly increased until the roast field stage; the tested soil Eh average value during the flooding period and roast field period were respectively between-144.79 ～-107.05 mV and 140.27 ～ 372.60 mV.Repeated anova analysis showed that the observation period (group effect) had significant effect on Eh,which showed that the change of factors which influencing paddy soil Eh was drastic and their effects on Eh were significantly different in different periods.The test results showed that moisture was the key factor that determined change of Eh,soil water and soil Eh was significantly negative correlated (r =-0.364 **,n =126),and the ground water level of paddy soil had significant effect on Eh change (p ＜ 0.05).The lower the water level,the higher the Eh,the Eh of low ground water level treatments were about 37.4％ higher than those of the high ground water level treatments,and the influence of ground water level on Eh was relatively stable.The effect of fertilization also had a significant effect on Eh during whole growth period (p ＜ 0.05),but the influence of fertilization on Eh was unstable,which had significant effect on Eh change only at the turning-green stage,early tillering stage and roast field stage;organic fertilizer reduced the soil Eh during the turning-green period and early tillering stage.The near-root Eh was greater than far-root Eh in all treatments at different growth stages of the late rice,indicating that rice root could slightly increase the paddy soil Eh.In addition,changes in Eh was significantly related with soil temperature in 5 cm depth and had no significant correlation with soil organic carbon content with the masking of organic fertilizer.
Eh of paddy soilground water levelfertilizationrootorganic carbonsoil temperature
NETL
NSTL
万方数据
维普
