Effect of sludge, woolen carpet waste and press mud on rice grain quality and soil fertility: A review

Now-a-day's biodegradable organic sources are gaining global importance for the cultivation of crops specially in the rice culture. The organic wastes like digested sludge, wooden carpet waste and press mud proved equally effective in rice crop compared to other organic sources with respect to milling and cooking qualities and volume expansion ratio. The building up the total amylase and protein content in rice grain was more effective when organic sources were used in comparison to inorganic or other sources of N. The soil bulk density and electrical conductivity was reduced by the application of organic sources thereby increasing the water holding capacity and the availability of organic carbon or P, K, S and micronutrients such as Fe, Zn, Cu content of the soil.

The press mud and digested sludge are rich in plant nutrients particularly micronutrients therefore these wastes may be used as organic manures.

As there is a greater requirement of quality rice globally, these organic sources of N holds great promise in the improvement of rice grain quality as well as soil fertility and productivity.