Short Communications Indian Journal of Agricultural Sciences 90 (8): 1626–30, August 2020/Short Communication https://doi.org/10.56093/ijas.v90i8.105980 Effect of zinc oxide nanoparticles embedded NPK fertilizer on growth, yield and zinc concentration and uptake of aromatic rice (Oryza sativa) KIRTTIRANJAN BARAL 1 , DINESH KUMAR 2 and YASHBIR SINGH SHIVAY 3 ICAR-Indian Agricultural Research Institute, New Delhi 110 012, India Received: 31 October 2019; Accepted: 17 December 2019 Key words: Aromatic rice, Productivity, Zinc concentration, ZnO nanoparticles, ZnSO 4 .7H 2 O, Zinc uptake Rice (Oryza sativa L.) is the staple food for half of the world’s population. It not only meets daily protein and energy requirement of a large mass of people all over the world but also supports livelihood and generates employment. Almost 90% of global rice is produced in Asia and in India; it is grown on 43.79 million ha with production and productivity of 112.91 million tonnes and 2.57 tonnes/ha, respectively (DOES 2019). Although total rice production has increased over the years, India is facing plateau in rice productivity in recent years. Productivity of major food crops like rice; wheat etc should be enhanced to sustain the burgeoning population, as scope for increasing area under crops is not a viable option. According to Vision 2050 (NRRI 2013), India will require 137.3 million tonnes of rice by 2050 and there may be decline in rice area by 6–7 million ha by 2050 due to urbanization, competitive crops and industrialization etc. Decline in soil organic matter, imbalanced fertilization, micronutrients defciencies, soil compaction due to puddling, poor resource use effciency and climate change are the major factors behind stagnation in rice productivity. Among these, imbalanced fertilization and low nutrient use effciency are some of the major concerns which should be addressed for sustaining productivity and enhancing proftability in major rice ecologies of India. Majority of farmers are applying NPK fertilizers without addition of organic manures and micronutrients to the soil. In addition, fertilizers application is more skewed towards N which has accelerated the problem like nutrient mining. Likewise, micronutrients particularly zinc (Zn) has emerged as one of the yield–limiting factors as nearly 36.5% of Indian soils are defcient in available Zn (Shukla and Behera 2019). Several investigations were carried out to enhance nitrogen use effciency like use of slow release fertilizers, 1 Ph D Scholar (e mail: kirttiagroiari111@gmail.com), 2 Principal Scientist (e mail: dineshctt@yahoo.com), 3 Ex–Professor and Principal Scientist (e mail: ysshivay@iari.res.in), Division of Agronomy nitrifcation inhibitors and urease inhibitors (Trenkel 2010) etc. However, application of these products has not become popular due to high cost except neem coated urea which has been popularized all over the India due to favorable Indian government policies. Similarly, phosphorus use effciency is very low (10–20%) and mining of potassium continues in rice agroecosystem due to imbalanced fertilization. Meanwhile, India is not self–suffcient in phosphorus fertilizer production and also the entire potassic fertilizer demands of the country are met through import. Thus, balanced application of NPK along with zinc and enhancing nutrient use effciency of applied nutrients are important concerns for enhancement of rice productivity and reduced cost of cultivation. Nanoparticles (size <100 nm) have higher surface area, different crystal property, and unique physical, chemical and magnetic properties than that of bulk materials (Maurice and Hochella 2008). Prasad et al. (2012) reported that application of ZnO nanoparticles of 25 nm diameter resulted higher germination percentage, increased vigour of seedlings and higher plant growth when applied at 1000 ppm in peanut. Application of nanoscale ZnO was reported to increase the grain Zn concentration in rice (Raddy et al. 2017). Likewise, higher plant growth in pearl millet was observed by application of nanoparticles of ZnO (Tarafdar et al. 2014). Adhikari et al. (2015) reported benefcial effect of nanoparticles of ZnO in maize in terms of higher root dry weight, plant height, root length and root volume etc. However, most of the earlier studies were conducted in pot culture under greenhouse conditions. Limited works have been done on the feld scale application of ZnO nanoparticles (ZnO Nps) in conjunction with NPK fertilizer. Thus, present investigation was carried out to evaluate the effect of ZnO nanoparticles in combination with NPK fertilizer in aromatic rice. Two aspects were investigated during this study i) the effect of ZnO nanoparticles application in conjunction with NPK fertilizer on growth parameters and yields of aromatic rice and; ii) to know about the Zn concentration and its uptake by grain and straw as infuenced by ZnO nanoparticles application. 262