Yield and quality of multi-cut forage sorghum (Sorghum sudanense) as influenced by integrated nitrogen management

An experiment was conducted at Anand during rainy (kharif) season of 2004 and 2005 to study the effect of integrated N management on yield and quality of multi-cut forage sorghum (Sorghum sudanense L.). Application of 75 kg N through urea + 25 kg N/ha through farmyard manure (FYM) recorded significantly higher green-forage, dry-matter and crude-protein yields than other treatments, except application of 75 kg N through urea + 25 kg N/ha through castor cake. The increase was 11.1 – 18.6% in dry-matter yield and 19.4 – 20.0% in crude-protein yield over application of 100 kg N/ha through urea. Application of 50 kg N through FYM + 50 kg N/ha through castor cake was significantly inferior in forage production and was poor in quality as evident from low crude-protein yield and higher neutral detergent fibre (NDF) content. The maximum green-forage, dry-matter and crude-protein yields of forage sorghum were recorded under Azotobacter + Azospirillum inoculation compared with their individual inoculation or no inoculation of biofertilizer, but the effect on green-forage yield was non-significant. The maximum NDF content was recorded under no biofertilizer treatment, which was significantly higher than other treatments except Azospirillum inoculation. The application of 75 kg N through urea + 25 kg N/ha through castor cake along with Azospirillum inoculation was found superior in forage quality and recorded maximum crude-protein yield.