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Assam Agricultural University, Jorhat

Assam Agricultural University is the first institution of its kind in the whole of North-Eastern Region of India. The main goal of this institution is to produce globally competitive human resources in farm sectorand to carry out research in both conventional and frontier areas for production optimization as well as to disseminate the generated technologies as public good for benefitting the food growers/produces and traders involved in the sector while emphasizing on sustainability, equity and overall food security at household level. Genesis of AAU - The embryo of the agricultural research in the state of Assam was formed as early as 1897 with the establishment of the Upper Shillong Experimental Farm (now in Meghalaya) just after about a decade of creation of the agricultural department in 1882. However, the seeds of agricultural research in today’s Assam were sown in the dawn of the twentieth century with the establishment of two Rice Experimental Stations, one at Karimganj in Barak valley in 1913 and the other at Titabor in Brahmaputra valley in 1923. Subsequent to these research stations, a number of research stations were established to conduct research on important crops, more specifically, jute, pulses, oilseeds etc. The Assam Agricultural University was established on April 1, 1969 under The Assam Agricultural University Act, 1968’ with the mandate of imparting farm education, conduct research in agriculture and allied sciences and to effectively disseminate technologies so generated. Before establishment of the University, there were altogether 17 research schemes/projects in the state under the Department of Agriculture. By July 1973, all the research projects and 10 experimental farms were transferred by the Government of Assam to the AAU which already inherited the College of Agriculture and its farm at Barbheta, Jorhat and College of Veterinary Sciences at Khanapara, Guwahati. Subsequently, College of Community Science at Jorhat (1969), College of Fisheries at Raha (1988), Biswanath College of Agriculture at Biswanath Chariali (1988) and Lakhimpur College of Veterinary Science at Joyhing, North Lakhimpur (1988) were established. Presently, the University has three more colleges under its jurisdiction, viz., Sarat Chandra Singha College of Agriculture, Chapar, College of Horticulture, Nalbari & College of Sericulture, Titabar. Similarly, few more regional research stations at Shillongani, Diphu, Gossaigaon, Lakhimpur; and commodity research stations at Kahikuchi, Buralikson, Tinsukia, Kharua, Burnihat and Mandira were added to generate location and crop specific agricultural production packages.

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  • ThesisItemOpen Access
    DYNAMICS OF ZINC FRACTIONS AND AVAILABLE NUTRIENTS AS INFLUENCED BY ZINC FERTILIZATION ON RICE CULTIVARS
    (AAU, Jorhat, 2018-07) Baishya, Bhupen Kumar; Basumatary, A.
    A field experiment was carried out at the Instructional-cum-Research (ICR) farm, Assam Agricultural University, Jorhat during Kharif season, 2014 and 2015 to study the influence of zinc fertilization on the dynamics of zinc fractions, available nutrients status in the soil and crop yield and quality of rice grain of different cultivars. The treatments consisted of zinc applied through soil with or without foliar spray and five different rice cultivars. Total of twenty treatment combinations were laid out in factorial RBD with three replications. Distribution of different zinc fractions in soil were assessed during different stages of crop period of rice. Perusal of experimental findings showed that zinc fertilization exerted a significant positive effect on different zinc fractions in the soil during both the years of investigation. Among zinc treatments, concentration of all the zinc fractions were maximum with application of Zn @ 5 kg ha-1 + 0.5% foliar spray of Zn over other treatments. The study revealed that the concentration of the water soluble plus exchangeable Zn, complexed-Zn and crystalline sesquioxide bound-Zn fractions showed a decreasing trend from tillering stage to the harvest stage of the crop, while, availability of amorphous sesquioxide bound Zn, residual-Zn and total-Zn fractions followed an increasing trend with respect to concentration with the advancement of time. Among the zinc fractions, water soluble plus exchangeable form made the lowest contribution while residual fraction made the highest contribution to the total zinc pool than other fractions of Zn at all the growth stages of the crop. At harvest, zinc concentration in various fractions of Zn in soil varied in the following order: watersoluble plus exchangeable < complexed < crystalline sesquioxide bound < amorphous sesquioxide bound < residual fraction< total zinc. There was significant positive correlation among the Zn fraction in soil indicating existence of dynamic equilibrium of Zn in soil. The available fraction of all nutrients was initially higher and gradually decreased with advancement of crop growth. The maximum availability was obtained at tillering stage and thereafter as crop age advanced nutrient availability decreased. Analysis of pooled data revealed that application of Zn @ 5 kg ha-1 in soil + 0.5% foliar spray resulted in higher availability of nitrogen, potassium, sulphur and DTPAZn in soil at different stages of crop and recorded highly significant and positive correlation with different zinc fractions. Availability of phosphorus, DTPA-Fe, DTPAMn and DTPA-Cu were decreased with zinc application and the lowest content was found at treatment Zn @ 5 kg ha-1 in soil + 0.5% foliar spray and exhibited a significant but inverse correlation with different zinc fractions. Zinc fertilization influenced the crop yield and nutrient uptake. Highest grain yield was recorded in treatment receiving Zn @ 5 kg ha-1 + 0.5% foliar spray of Zn (53.40 q ha-1) and the lowest was in control (38.69 q ha-1). Among the cultivars, variety JKRH-401 recorded the highest grain yield (64.27 q ha-1) whereas variety Kolajoha recorded the lowest grain yield (30.50 q ha-1). Among different treatment combinations, application of Zn @ 5 kg ha-1 + 0.5% foliar spray of Zn in combination with cultivar JKRH-401 recorded the highest yield (71.82 q ha-1) . The highest straw yield was recorded in treatment receiving Zn @ 5 kg ha-1 + 0.5% foliar spray of Zn. Among the cultivars, the highest straw was recorded in JKRH-401(71.22q ha-1) while, the lowest was found in Aghunibora(49.27 q ha-1). Uptake of nitrogen, potassium, magnesium and sulphur by rice was significantly influenced by Zn-fertilization and the highest was found in treatment with treatment receiving Zn @ 5 kg ha-1 and 0.5% foliar sprays of Zn over other treatments. On the other hand, in respect of copper and manganese, application Zn @ 5 kg ha-1 and 0.5% foliar spray of Zn resulted the lowest uptake during all crop growth period. The cultivars, JKRH-401 recorded the highest uptake of all the nutrients at all stages of crop growth. In economic terms, combined application of Zn @ 5 kg per ha and 0.5% foliar spray of Zn in combination with cultivars, JKRH- 401 recorded the highest gross return, net return and B:C ratio (2.96 ). Zinc fertilization had significant impact on the nutrient content in both brown and polished rice grains. The treatment receiving Zn @ 5 kg ha-1 + 0.5% foliar spray of Zn recorded the highest concentration of nitrogen, potassium, sulphur and zinc for both brown and polished rice. Protein content was found to be the highest in treatment receiving Zn @ 5 kg ha-1 + 0.5% foliar spray of Zn and cultivar JKRH-401 exhibited the highest content of 10.71 % and 8.75 % in brown and polished rice, respectively. Highest amylase content (18.73 % and 20.42 %) was observed in same treatment and the cultivar Kolajoha recorded the highest amylase of 22.52 % and 24.16% in brown and polished rice, respectively.