Effect of age of seedling and spacing on yield, economics, soil health and digestibility of rice (Oryza sativa) genotypes under system of rice intensification

A field experiment was conducted at the Institute of Agricultural Sciences, Banaras Hindu University, Varanasi during 2008 to 2010 to evaluate the influence of system of rice intensification (SRI) under different age of seedling and spacing on productivity of rice genotypes and soil health. Rice genotype PHB 71 was significantly superior to NDR 359 with respect to yield attributes, grain yield, economics, nutrient uptake and soil health. Ten days old seedlings were also significantly better than those of other age of 12 and 14 days old seedlings in respect of yield attributes, grain yield, economics, nutrient uptake and soil health. Similarly wider row spacing of 30 cm x 30 cm significantly favoured higher values of yield attributes, grain yield, economics, nutrient uptake, and soil health due to profuse root growth. Rice hybrid PHB 71 had poor digestibility of rice straw having higher values of crude protein content, crude fiber, oxalic acid and lower values of nitrogen free extract and total ash compared to NDR 359.