India has a rich diversity of aromatic rice rice and among them, the long grained superfine aromatic rice are the unique gift of nature to our country. Because of their unique aroma quality (due to 2-acetyl-1-pyrroline compound), superfine grains and exceptionally good cooking qualities, is nature’s gift to Indian subcontinent therefore demand for aromatic rice is growing rapidly in the international market. There is a huge potential to export aromatic rice produced in the country (Anon., 2007). India and Pakistan are largest producers and exporters of Basmati rice “Queen of Fragrance” also called pearl of rice is due to its unique cooking quality characteristics (Singh et al., 2009 a. ).
Aromatic rice contributes a small portion but an important subgroup of rice production. The steady increase in production and the growing demand for Basmati rice in the international market made India an important rice exporting country of the world (Rani, 2013). India stood as third largest exporter of rice after Thailand and Vietnam. During 2012-13 the quantum of Basmati rice exports was 34,59,898,92 metric tonnes that earned 19 billion foreign exchange to the country (IIRR, 2014). Total aromatic rice production is about 0.297 million tons in 2013 from 0.158 million ha of land in India. The indigenous aromatic rice varieties are, however, poor yielders having poor response to fertilizer application (Singh et al., 2009 b.).
Aromatic rice which elongate comparatively more and soft after cook enjoy a preferential price treatment both in domestic and international market. In the post WTO-era and in the light of globalization and liberalization, aromatic rice has become a commodity of export and it is no more simply a food item. So, there is an immense scope for India to cultivate aromatic rice enhancement in profitability through rice production as well as for sustaining the export of rice in international market fetching invaluable foreign exchange for the country. However, export of rice is primarily dependent on the quality it possess. The quality is mainly a genetically function specific to specific variety.
But, agronomic management is also capable of regulating grain quality to considerable extent. It is not only the quality of nutrients which entails upon the rice grain quality, but the source of nutrient is also important. Aromatic rice occupies a pivotal position in world because of their high quality. Traditional tall varieties of basmati constitute a sizable proportion of export, but their productivity is very low as compared to non-basmati varieties.
The organic manure are expected to improve the quality of rice grain. Inorganic fertilizer is one of the key factors to increase the rice productivity. Thus, various organic-inorganic combination will have to be tested to find out a dose and type of source to have a balance between the yield and quality of aromatic rice. For boosting crop production chemical fertilizers play a major role but in the recent years, crop productivity has stagnated or decreased in spite of consumption of increased rate of chemical fertilizers (Khan et al., 2004; Kamble, et al., 2008 and Chen, et al., 2011) because of chemical fertilizers applications reduce the post-harvest soil nutrients and their increasing prices, soil health deterioration, sustainability and pollution consideration in general have led to renewed interest in the use of organic manures.
However it is not possible to supply all the nutrient requirements of crops wholly through organic manures. Therefore, in order to make the soil well supplied with all the plant nutrients in the readily available form and to maintain good soil health, it is necessary to use organic manures in conjunction with inorganic fertilizers to obtain optimum yields (Ramalakshmi et al., 2012).
Results have also shown that integrated nutrients management increases the yield and nutrient uptake (Mohanty et al., 2013). In general, organic manures improve the physico- chemical properties of the soil and improve the microbial activity which resulted in maintaining the soil fertility and quality parameters like hulling percentage, milling percentage and protein contents also increased due to use of organic manures (Dixit and Gupta, 2000).
Organic sources of plant nutrients offer the twin benefits of increase in organic matter content and improvement in physical, chemical and microbiological properties of soil while meeting a part of nutrients need of crops (Chettri and Bandhopadhya, 2005). In this context, use of organic manures such as vermicompost, may supply sufficient amount of micro nutrients with major nutrients in available form to crops and improve the quality of the agricultural produces (Maynard, 1993). Besides supplying various nutrients to the aromatic rice, they often leave substantial residual effect to succeeding crops.
Vermicompost contains most nutrients in plant available form such as nitrates, phosphates and exchangeable calcium and soluble potassium (Edwards, 1998; Orozco, 1996). Vermicompost have large particulate surface areas that provide many micro sites for microbial activity and for the strong retention of nutrients (Shi-wei and Fu-Zhen, 1991).
Vermicomposts are rich in microbial populations and diversity, particularly fungi, bacteria and actinomycetes (Edwards, 1998; Tomati, 1987). It is widely recognized that neither use of organic manures alone nor chemical fertilizers can achieve the sustainability of the yield under the modern intensive farming. The efficiency of nutrient use may be raised by the combined use of organic and inorganic fertilizers. Organic fertilizers not only act as the source of nutrients, but also provide micronutrients and modify soil-physical behaviour as well as increased the efficiency of applied nutrients (Pandey et al., 2007).
Weeds are the most severe constraints and pose major problem in rice production, by diminishing the quantity as well as quality (Rajkhowa et al, 2007) Hence timely weed management plays an important role in increasing productivity of rice. Weed are the main biological limitation to the production of rice crop. In such situation, the application of pre-emergence herbicides like Pre-emergence herbicides plays significant role in controlling weeds (Singh and Singh, 2010) and Bispyribac sodium herbicide which are considered to be an alternative/Supplement to hand weeding (Khaliq et al.,2012). Bispyribac-sodium has been applied as post-emergence herbicide to control many weeds.
Bispyribac sodium is a systemic herbicide that moves with production of plant enzymes necessary for growth, acetolaclate synthetase (Berra and Gosh, 2013). Weeds can be controlled by manual weeding and herbicide use. Labour, however, is becoming scarce and expensive mainly because of migration from rural areas to cities. It is seldom that labour is available at the critical time of weeding.
By the time labour becomes available, yield losses have already occurred due to weed competition. Herbicides are being widely used to control weeds, but there is hardly any herbicide that can control different kinds of weeds with one herbicide. Due to less availability of new and effective herbicide molecules, increased cost of chemical control and issues related to environmental pollution.
Therefore, to increase the sustainability of conservation agriculture, there is a need to manage weeds by using integrated weed-management strategies. So, emphasis should be given to increase the rice yield through the adoption of proper management especially weed control and nutrient management that might be technically effective and feasible, economically viable, socially acceptable and environmentally sound.
The integrated approach for nutrient and weed management in scented rice not only enhances the yield but also improves soil health and grain quality besides sustaining the productivity. Keeping the above mentioned facts in view the problems like heavy weed infestation and low nitrogen use efficiency encountered by the farmers in rice cultivation, the present study on an experiment entitled “Integrated nutrient and weed management on growth, yield and quality of aromatic rice (Oryza sativa L.)” was conducted at Research Farm of Dr. Rajendra Prasad Central Agricultural University, Pusa with the following objectives:
- To study the effect of different sources of nitrogen and weed management on the growth, yield and quality of aromatic rice.
- To find out the weed dynamics as affected by different sources of nitrogen and weed management practices.
- To work out the economics of different treatments.
- Anonymous 2007. Progress Report, 2006. Vol. 3. Crop production (Agronomy, Soil Science and Physiology). All India Coordinated Rice Improvement Programme (ICAR). Directorate of Rice Research, Rajendranagar, Hyderabad, A.P., India. p. 4.86-4.88.
- Bera, S. and Ghosh, R.K. 2013. Soil physico-chemical propertieis and microflora as influenced by bispyribac sodium 10% SC in transplanted kharief rice. Rice Science 20(4): 298-302.
- Chen, X. P., Cui, Z. L., Vitousek, P. M., Cassman, K. G., Matson, P. A., Bai, J. S., Meng, Q. F., Hou, P., Yue, S. C., Römheld, V., and Zhang, F. S. 2011. “Integrated Soil-Crop System Management for Food Security.”Proceed. of Nat. Acad. Sci. USA 108 (16): 6399-404.
- Chettri, M. and Bandhopadhaya, P. 2005. Effect of integrated nutrient management on fertilizer use efficiency and changes in soil-fertility status under rice-based cropping system. Indian Cultivars.” American Journal of Plant Sciences 2 (3):297-302.
- Dixit, K.G. and Gupta, B.R. 2000. Effect of farm yard manure, chemical and biofertilizers in yield and quality of rice (Oryza sativa L.) and soil properties. J. Indian Soc.Soil Sci. 48: 773-780.