Among the organics, daincha @ 12 t ha^-1 incorporation recorded higher cooking time due to the increased hardiness of grain (Omar Hattab, 1995), total amylose content, crude protein content, and lowest loss of gruel. These increased parameters might be due to ensured supply of N nutrients and favorable soil condition. Though daincha in situ incorporation increased the cooking time it was at par with sunnhemp incorporation and FYM application. The highest loss of gruel was observed with no organic manure. Regarding to biofertilizer and inorganics, Azospirillum with 100 per cent of the recommended N resulted in higher cooking time and it was at par with Azospirillum + 75 per cent of the recommended N and Azospirillum plus 50 per cent of the recommended N. Inoculation of Azospirillum with 50 per cent of the inorganic N recorded significantly more amylose, crude protein content and lowest loss of gruel.

The effect of in situ incorporation of daincha was superior in registering higher grain (6374 kg ha^-1) and straw (8411 kg ha^-1) yields than other sources (Table 2). The grain yield was 15.7 per cent and 12.5 per cent higher in daincha and sunnhemp incorporation over no manure application. The marked increase in grain yield was due to the enrichment of soil fertility through green matter addition in the soil (Gopalsamy and Vidhyasekaran, 1987) and improved growth parameters and yield attributes (Thiagarajan, 1991). Azospirillum inoculation with 50 per cent of the inorganic N registered higher grain (6431 kg ha^-1) and straw yield (8528 kg ha^-1). It recorded an yield increase of 234 kg and 436 kg of grain over Azospirillum with 75 per cent of the inorganic N and Azospirillum with 100 per cent of the inorganic N respectively. Increased yield might be due to promoted root function (Abdel Salam and Klingmuller, 1987). Azospirillum inoculation increased the grain and straw yields over inorganic N alone due to atmospheric N fixation (Gopalsamy and Vidhyasekaran, 1987) and reduction in the N loss (Murali and Purshothaman, 1987). Inoculation of Azospirillum and application of 50 per cent to 75 per cent inorganic N substantially increased yield over 100 per cent of inorganic N alone. This indicated that inoculation of Azospirillum could reduce the bill of inorganic fertilizer N by 25 to 50 per cent.

From this studies, it was concluded that Azospirillum inoculation plus 50 per cent inorganic N with daincha or sunnhemp incorporation improved the quality and yield of rice.

REFERENCES :

Abdel Salam, M.S. and Klingmuller, W. 1987. Transponson Tn⁵ mutagenesis in Azospirillum lipoferum isolation of indole acetic acid mutants. Molecular General Genetics. 210. 165 – 170.

Alok Kumar and Yadav, D.S. 1995. Use of organic manure and fertilizer in rice – wheat cropping system for sustainability. Indian J. Agric. Sci. 65: 703 – 707.

Gopalsamy, G. and Vidhyasekaran, P. 1987. Effect of green leaf manure on soil fertility and rice yield. IRRN. 12(2): 41.

Meelu, O.P. and Morris, R.A. 1987. Integrated management of green manure, FYM and inorganic nitrogen fertilizers in rice and rice based cropping sequences. In Efficiency of nitrogen fertilizers for rice, pp. 185-193. IRRI, Los Banos, Philippines.

Murali, K.J. and Purushothaman, D. 1987. Effect of Azospirillum inoculation on upland rice. IRRN. 12: 6-34.

Omar Hattab, K. 1995. Studies on the combined effect of organic and inorganic nitrogen sources on nutrient release, yield and quality of rice, Ph.D Thesis, Tamil Nadu Agrl. University, Coimbatore.

Thiagarajan, M. 1991. Yield maximization in rice through green manuring, plant duration and time of phosphorus application. M.Sc (Ag.) Thesis, Tamil Nadu Agrl. University, Coimbatore.