The effect of rye green manure application with nitrogen fertilizer on soil water storage, soil aggregate stability and soil water infiltration rate in Maragheh dryland condition.

With the aim of green manure application improving soil physical characteristics important to soil water retention in dry land condition , this study was carried out with or without rye green manure along with 4 nitrogen fertilization treatments (0, 26, 103 and 337 (kg N/ha) in 3 rotation system (green manure-wheat) between 2001 – 2007 years. Results showed that the green manure application effects were significant for soil aggregate stability. Results showed that the green manure application effects were significant on the soil bulk density and soil moisture indexes such as FC and PWP. N-fertilizer application with green manure in order to decrease C/N ratio for best activation of soil microorganisms accelerated these effects. High AWC occurred for C/N=20 treatment. Our data showed that there are regression relationships with highly correlation coefficients between the levels of N–application with green manure and soil moisture indexes. Our results also showed that green manure application had a significant effect on soil water infiltration rate for dry land condition. Higher and lower infiltration rates occurred for C/N=36 and C/N=20 treatments respectively at 30 min. A soil water infiltration prediction Kostiakov model was determined as a best model for its higher R square (R 2 = 0.90) and lower standard error (SE=0.30). The model predicted about 90 % of variation in soil water infiltration rate for all of the treatments in this study.