Integrated nutrient management for basmati rice(oryza sativa L) production

Abstract

A study entitled “Integrated nutrient management for basmati rice (Oryza sativa L.) production” was undertaken at the Cropping Systems Research Centre, Karmana, Thiruvananthapuram, Kerala, from September 2006 to January 2007, with the main objective of evaluating the relative efficiency of different integrated nutrient management practices on the yield and quality of basmati rice.

The experiment was laid out in (4 x 2) + 2 Randomized Block Design with three replications. The treatments comprised two organic sources (M1- FYM, M2- FYM + neem cake) and four levels of inorganic substitution with organics (L1- 25 percent substitution, L2- 50 percent substitution, L3 - 75 percent substitution, L4 -100 percent substitution.) compared against two controls (absolute control, standard practice). The test variety was Pusa Basmati-1.

The response of the growth characters (plant height, tiller count and LAI) was more pronounced with respect to the levels of substitution than the organic sources. Substituting the entire quantity of the standard dose of fertilizers (SDF) and 50 percent substitution of SDF with organics were more or less equally effective in boosting the vegetative growth of basmati rice.

Between the two organic sources tried, the application of FYM and among the levels of substitution, 25 percent substitution recorded higher shoot biomass. The combined application of FYM + neem cake (M2) and 50 percent substitution of SDF with organics (L2) resulted in higher panicle biomass.

The higher number of productive tillers, spikelets per panicle and a lower sterility percentage supported by substituting 50 percent of SDF with FYM + neem cake, reflected upon the grain yield also. This treatment combination was at par with the standard practice. Though the cooking properties were not influenced by INM, in general, the optimum cooking time was lower and the volume expansion and grain elongation ratios were higher at 50 percent substitution of SDF with organics. Integration of chemical fertilizers and organics maintained a higher crude protein and intermediate amylose content. The organoleptic test rankings were higher for 75 percent and 50 percent substitution with FYM + neem cake. Integrated nutrient management was observed to produce grains, which were as good as or even better than the market sample, with the respect to grain quality attributes studied.

Application of FYM to the substitute chemical fertilizers resulted in higher uptake of nitrogen and potassium. The phosphorus uptake was maximum with 100 percent organic nutrition.

The agronomic efficiency and apparent recovery efficiency of basmati rice improved significantly when 50 percent of the chemical fertilizers were applied as FYM + neem cake. This treatment was at par with the standard practice.

The organic carbon, available nitrogen and available phosphorus status of the soil remained unaffected after the experiment. Application of FYM in conjunction with neem cake as a substitute for chemical fertilizers, improved the available potassium status of the soil.

Considering organic sources tested, application of FYM was more remunerative than the combined application of FYM + neem cake. The effect of substitution on net income and BCR was not significant. Between the various treatment combinations including controls, the standard practice, 25 percent substitution of chemical fertilizers with FYM and 50 percent substitution fertilizers with FYM + neem cake were at par.

The study indicated that the response of basmati rice to INM was at par with the standard practice. However, considering the multifaceted benefits of organics, on crop yield, quality and soil health, integrated nutrient management needs to be emphasized. Thus it could be concluded that, the treatment combination where in 50 percent of the standard dose of fertilizers was substituted with a combination of FYM and neem cake, was a better option than the application of chemical fertilizers alone for achieving higher yields and quality in basmati rice.

Substituting the entire dose of chemical fertilizers with organics (L4) was found to improve the growth, yield, nitrogen use efficiency and nutrient uptake in basmati rice. The volume expansion and crude protein content were better at 100 percent organic nutrition. Thus the present study also revealed the possibility of adopting organic nutrition in basmati rice without any appreciable reduction in yield and quality.