Effect of integrated use of biochar, FYM and nitrogen fertilizer on soil organic fertility

The study was conducted to determine the interactive effects of biochar application in combination with farm yard manure (FYM) and nitrogen (N) fertilizer on soil organic matter (SOM) and mineral nitrogen at Agricultural Research Farm of Khyber Pakhtunkhwa Agricultural University Peshawar in 2010-2011. Soil samples at 0-15 cm depth were collected from maize and mungbean plots at harvest stage (May, 2011). Both maize and mungbean crops received biochar alone and in combination with FYM before sowing (November, 2010). The soil samples were analyzed for soil organic matter and mineral N. The results showed that the effect of fertilizer N and FYM on accumulation of soil organic matter (SOM) was generally inconsistent. However, the biochar exerted considerable influence on the accumulation of SOM. The residual SOM content after crop harvest were maximum in treatments rece iving the highest level of biochar. The values for SOM increased with increasing level of biochar. The soil mineral nitrogen was generally greater in treatments receiving fertilizer N at 30 kg than at 15 kg ha -1 . However, the effect of biochar and FYM on soil mineral N was inconsistent as differences in soil mineral N between the nil and maximum biochar treatments were not remarkable. These results suggested that biochar application resulted in the accumulation of SOM. However, biochar and FYM had no considerable influence on accumulation of soil mineral N whereas fertilizer N resulted in the accumulation of mineral N in soil to some extent.