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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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20172
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Subject: Agronomy × End date: 2017 × Start date: 2017 × Type: Thesis ×
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    ThesisItemOpen Access
    PHOSPHORUS MANAGEMENT IN AEROBIC RICE
    (AAU, Jorhat, 2017-07) Ghasal, Kajod Mal; Pathak, Kalyan
    A field experiment entitled „Phosphorus management in aerobic rice‟ was carried out in the Instructional-cum-Research (ICR) Farm, Assam Agricultural University, and Jorhat during autumn season of 2016. The treatment of the experiment consisted of three phosphorus sources viz., S1: single super phosphate, S2: diammonium phosphate and S3: rock phosphate, three doses of phosphorus viz., D1:10kg P2O5 ha-1, D2:20kg P2O5 ha-1 and D3:30kg P2O5 ha-1 and two biofertilizer treatments i.e. B1: without biofertilizer and B2: Azospirillum + PSB. One absolute control was included for comparison. The experiment was laid out in factorial randomized block design (RBD) replicated thrice with the objectives to study the performance of aerobic rice under different sources and levels of phosphorus and to evaluate the phosphorus use efficiency of aerobic rice. The soil of the experimental site was sandy loam in texture, medium in available N (285.36kg ha-1), P2O5 (22.85kg ha-1) and K2O (138.04kg ha-1) and organic carbon (0.62%) with pH value of 5.2. The rice variety “Inglongkiri” was sown on 11th March, 2016 and harvested on 08th July. 2016. The rainfall received during the crop season was only 1350 mm. The weekly average maximum temperature ranged from 24.9 to 33.5°C and minimum temperature 15.9 to 26.1°C, respectively. Out of the three phosphorus sources, rock phosphate recorded the highest grain (26.19q ha-1) and straw (47.05q ha-1) yield followed by single super phosphate. Among the doses, highest grain (27.43q ha-1) and straw (49.39q ha-1) yield were recorded in 30kg P2O5ha-1 and the lowest grain (22.37q ha-1) and straw (37.70q ha-1) yield were found in 10 kg P2O5ha-1. In case of bio-fertilizer, Azospirillum + PSB recorded higher grain yield (26.17q ha-1) than that of without bio-fertilizer (22.87q ha-1). Significantly higher N, P and K uptake were recorded with phosphorus application through rock phosphate which was statically at par with single super phosphate. Rock phosphate recorded higher values of agronomic (39.76kg kg-1) and physiological use efficiency (207.02kg kg-1) of phosphorus which was followed by the source single super phosphate. Application of 30kg P2O5 ha-1 recorded higher values N, P and K uptake by grain, straw and total and significantly higher available P2O5 (31.2 kg ha-1)in soil after harvest. Out of the three doses of phosphorus, application of 10kg P2O5 ha-1 registered highest agronomic use efficiency (36.16kg kg-1) and the highest physiological use efficiency of phosphorus (234.18kg kg -1) was recorded with 30kg P2O5 ha-1. Azospirillum + PSB exhibited significantly higher N, P, K uptake, agronomic use efficiency (39.43kg kg-1) and physiological use efficiency of phosphorus (223.48kg kg-1) than without biofertilizer treatment. So far the economics is concerned, the treatment combination that included application of rock phosphate at the rate of 30kg P2O5 ha-1 inoculated with Azospirillum + PSB recorded the highest net return of .56,717.00 ha-1 and with highest benefit-cost ratio (B:C) of 2.63.
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    ThesisItemOpen Access
    CROP INTENSIFICATION IN RICE-BASED CROPPING SYSTEM IN ASSAM
    (AAU, Jorhat, 2017-07) Deka, Anju Mala; Bora, P.C.
    A field experiment entitled “Crop intensification in rice-based cropping system in Assam” was conducted at the Shillongani farm of Regional Agricultural Research Station, Nagaon, Assam during kharif, rabi and summer seasons in the year 2014-15 and 2015-16 to study the effect of dates of rice transplanting under different methods of cultivation on productivity of Sali rice and their effect on rice-relay system in rabi and thereafter on fodder maize + green gram intercropping system during summer. The treatments of the experiment comprised three dates of rice transplanting viz. 20 June, 5 July and 20 July, and two methods of rice cultivation viz. conventional method and SRI method with four relay crops viz. lentil, pea, toria and niger. The experiment was laid out in a factorial randomized block design for the treatments in rice during kharif season and a split plot design for treatments of relay crops in rabi season assigning dates of planting and method of cultivation in the main plots and relay crops in sub plots with three replications. During summer, fodder maize and green gram in 1:1 row ratio was grown as intercrop in each plot. The soil of the experimental field was medium low land, moderately well drained, sandy loam in texture having organic ‘C’ content of 0.82%, acidic in reaction (pH 5.61), medium in available N (296 kg/ha) and K2O (195 kg/ha), and low in available P2O5 (21 kg/ha). Bulk density of 0-15 cm soil layer was 1.33 g/cc and that of 15-30 cm layer was 1.36 g/cc while the particle density of the layers was 2.06 and 2.08g/cc, in the respective layers. Total porosity was 35.44 % and 34.61% in the respective soil layers. All the crops were fed with recommended doses of fertilizers. The results revealed that among the different dates of rice transplanting, 20th June transplanted crop recorded significantly higher plant height, number of tillers/m2, number of panicles/m2, number of filled grains /panicles and grain yield of rice as compared to the later dates of transplanting and it was followed by 5 July transplanted rice. Rice transplanted on 20th June recorded higher values in respect of growth, yield attributes, yield of relay as well as summer intercrops, REY of rice-relay, intercropping and whole system; production efficiency of the whole system; N, P and K uptake by rice, relay and intercrops as well as soil fungal and bacterial populations after harvest of rice, relay and intercrops. However, the soil available N, P2O5 and K2O content at the end of two year-crop cycle in 5th and 20th July transplanted rice were significantly higher than that of 20th June transplanted crop. SRI method of rice cultivation recorded significantly higher values in respect of plant height, LAI, CGR, RGR, root: shoot ratio, panicles/m2, panicle length and weight, filled grains/panicle and 1000-seed weight, grain yield and harvest index of rice as compared to conventional method. In relay cropping, higher values of all the growth and yield attributes, seed yield, REY and harvest index of lentil and niger relay crops were found under SRI method of rice cultivation as compared to conventional method, while, in case of pea and toria relay crops, these were found to be slightly higher under conventional method of rice cultivation. In summer, SRI method of rice cultivation recorded higher values of all the growth and yield attributes, land equivalent ratio and relative crowding co-efficient of fodder maize and greengram in intercropping system. Further, under SRI method, higher uptake of N, P and K by rice, relay and intercrops and higher soil fungal and bacterial populations after harvest of rice, relay and summer intercrops as well as REY and production efficiency of the whole cropping system were observed as compared to conventional method. However, conventional method of rice cultivation recorded significantly higher values of soil available N, P2O5 and K2O content at the end of two year-crop cycle over that of SRI method. Among the relay crops, pea and lentil relay recorded higher yield as compared to toria and niger. However, rice-lentil and rice-pea system were found most promising in respect of REY and economics of rice- relay system compared to rice-toria and rice-niger system. In fodder maize and greengram intercropping system during summer, relay crops had significant effect on growth and yield attributes of fodder maize and greengram. Significantly higher values of plant height and green fodder yield of maize as well as competition index and competition ratio of intercropping system were recorded when summer intercrops were grown after rice-lentil and rice-pea relay crops as compared to rice-toria and rice-niger relay. However, significantly higher values in respect of number of pods/plant, seed yield and stover yield of greengram, higher land equivalent ratio and higher relative crowding co-efficient of intercropping system were found after rice-toria and rice-niger relay crops as compared to that of rice-lentil and rice-pea relay. Significantly higher values of REY and production efficiency of whole cropping sequence, and higher soil moisture content at 60 and 90 days after sowing of relay crops were found in rice-pea and rice-lentil system as compared to rice-toria and rice-niger. The soil fungal and bacterial populations after harvest of relay and summer intercrops were found more after lentil and pea relay crops as compared to toria and niger relay crops. However, lower values of residual available soil N, P2O5 and K2O content at the end of two year-crop cycle were found under the system involving pea and lentil relay crop as compared to toria and niger relay. Rice transplanted on 20th June under SRI method relayed by lentil and followed by summer intercrops of fodder maize and greengram recorded the highest REY, production efficiency and benefit: cost ratio of whole system in both the years. Rice transplanted on 20th June under SRI method relayed by pea and followed by summer intercrops of fodder maize and greengram was more efficient in utilizing the soil available N, P2O5 and K2O resulting in the highest N, P and K uptake and thereby the lowest available soil N, P2O5 and K2O was recorded under this system.