Response of Basmati Rice to Integrated Nutrient Sources in Lateritic Soil of Eastern India Y.S. PRAKASH 1 , P.B.S. BHADORIA 1 , A. RAKSHIT 1 , and A. WAIS 2 1 Agriculture and Food Engineering Department, Indian Institute of Technology, India 2 Institute of Chemistry and Dynamics of the Geosphere, University of Goettingen, Germany Corresponding Author: P.B.S. Bhadoria, Agriculture and Food Engineering Department, Indian Institute of Technology, Kharagpur - 721302, India.Tel.: +91 3222 83106; Fax: +91 3222 55303; E-mail: pbsb@agfe.iitkgp.ernet.in Received: 16 January 2001. Accepted: 15 November 2002. Ital. J. Agron., 6, 2, 143-150 ABSTRACT BACKGROUND. Human health hazards and pollution of the environment are becoming increasingly evident in India. Chemical fertilizers added with organic ma- terials in soil fertility management could be the al- ternative to come out of ‘vicious spiral’ of agro- chemical menace. METHODS. Field experiments were carried out to eval- uate relative efficacy of organic manures in combina- tion with chemical fertilizers (CF) to assess the useful- ness of such treatments against application of only CF. Organic manures were applied at 50% recommended N equivalent basis and balanced with chemical fertiliz- ers to attain the recommended N, P and K levels. RESULTS. Results of the experiment indicate that or- ganic manure treatment on balancing with chemical fertilizers to the recommended dosage of N, P and K favored higher dry matter production and grain yield as compared to application of only CF. The extent of increases in yield (average of two years) with treat- ments PCW (Processed City Waste) + CF,VC (Ver- miCompost) + CF, OCP (Oil Cake Pellets) + CF, FYM (FarmYard Manure) + MC + CF and FYM + CF were 20%, 16%, 4%, 26%, and 23% respectively over CF. Among the different manures tested, FYM + MC + CF proved best while OCP + CF has been least effective. A higher total uptake of N, P and K by rice was recorded in treatments with organic ma- nures in combination with CF. CONCLUSIONS. Combined application of organic ma- nures and chemical fertilizers should provide higher benefit towards crop yield as compared to application of only chemical fertilizers in lateritic sandy loam soil. Key-words: organic manures, chemical fertiliser, lat- eritic soil, productivity, rice. INTRODUCTION Growing demand for food in the country due to burgeoning human population on one hand and progressive shrinking of agricultural land available per capita on the other have led to in- tensification of time and space dimensions in In- dian agriculture through to use chemical fertil- izers and plant protection chemicals repeatedly in high amounts. The three major nutrients sup- plied by fertilizers (nitrogen, potash and phos- phate), tend to flood the soil solution at the ex- pense of minor ones, which produces a situation of unbalanced nutrient supply to the crop. Nat- ural resistance and fertility of soil dwindles with the continued use of soluble fertilizers and as a consequence, soil demand more and more fer- tilizers to produce the same yield. This is quite evident in most parts of this country where yield is either declining or remaining stagnant in spite of liberal application of the chemical fertilizers. The trend of decline in land productivity is quite visible in the lateritic tract of West Bengal, where rice based cropping systems are in vogue. Neglecting the importance of soil organic mat- ter in crop production and prolonged overuse of soluble chemical fertilizers on lowering land productivity, increased crop infestation of pests and diseases, human health hazards and pollu- tion of the environment are becoming increas- ingly evident (U.S.D.A., 1980). It is now consid- ered that chemical fertilizers with organic ma- terials in soil fertility management could be the alternative to come out of ‘vicious spiral’ of agrochemical menace (Palaniappan and An- nadurai, 1999). The quantity and proportion of N, P and K required by crops can vary and thereby limit the efficiency of the organic ma- nures. Hence, the challenge is to combine or- ganic manures of different quality with chemi- cal fertilizers to optimize nutrient availability to crop-plants (Palm et al., 1997). Using these