Central Agricultural University, College of Post Graduate Studies in Agricultural Sciences, Umiam
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ThesisItem Open Access Agronomic evaluation of rice cultivars under delayed transplanting condition in midhills of Meghalaya(College of Post Graduate Studies in Agricultural sciences, CAU , Imphal, 2018) Singh, Laishram Platini; Singh, A. K.Rice (Oryza sativa) is most important food crop of NEH region of India including the state of Meghalaya. Low level of rice productivity associated with its mono cropping make the state dependent on others to meet its food grain requirement particularly the rice, a staple food crop of the state. Hence, increasing the production of rice in the state either through area expansion or productivity enhancement is an urgent requirement. Many low lying fields may occupy under various summer crops and vacated very late by beginning of August onwards. Because of excess rains accompanied with poor drainage, these fields are not suitable for any other late season kharif or even the subsequent rabi crops except rice during next summer or kharif season. These fields can be targeted for late season kharif rice immediate after harvest of summer crops if the seedlings of short to medium duration rice varieties, having ability to adjust in the available rice growing season along with reasonable economic yields is ready for transplanting. Even short to medium duration rice varieties may need to identify for certain unseen condition like very late onset of monsoons in the present climatic scenario. Hence, farmer should have an alternative to choose the right varieties of rice for available growing period under delayed transplanting condition. Hence, present experiment was conducted during later part of kharif 2017 at the experimental field of College of Post Graduate Studies (CAU-I), Umiam to find out the last possible date of rice transplanting with suitable high yielding short duration cultivars. The experiment was conducted in split plot design consisting of three dates of transplanting (5th August, 2017, 15th August, 2017 and 25th August, 2017) in main plots and three cultivars (CAU-R1, CAU-R3 and ARIZE 6129) in sub plots. Results revealed that both date of transplanting and cultivars significantly influenced plant population, mortality percentage, days taken to heading and physiological maturity, yield attributes, yield and nutrient uptake. Maximum grain yield (1.75 t ha-1) was obtained from D1 which was significantly high over the same recorded from D2 and D3 transplanting dates. Significantly least grain yield was recorded from D3. However, D1 is at par with D2 and both these treatments recorded significantly high biological yield and nutrient uptake over D3 transplanting. Among the three rice cultivars, CAU R3 recorded significantly high panicles hill-1, filled grains hill-1, grain weight plant-1, grain yield (t ha-1), harvest index and uptake of N and P over the same observed from CAU R1 and ARIZE 6129 while CAU R1 proved significantly superior for these parameters over the ARIZE 6129. Soil chemical properties did not change markedly due to either of the treatments. Significant interaction between cultivars andplanting time revealed that CAU R3 over CAU R1 gave significantly high grain yield over CAUR3 and ARIZE 6129 while CAU R1 was significantly superior over ARIZE 6129 over on all three planting dates. Maximum net return and B: C ratio was obtained when CAU R3 was transplanted on 5th August 2017 (D1) which was seconded by CAU R1 on the same date of transplanting. CAU R3 gave reasonable return on 15th August, 2017 (D2) transplanting too. Both CAU R 3 and CAU R1 gave negative return on 25th August transplanting while net return from ARIZE 6129 was negative on all three transplanting dates. From the present investigation it could be concluded that CAU R3 is a good rice cultivar for delayed transplanting of rice upto 15th August if such lowland rice land is available for this purpose.ThesisItem Open Access Assesment of water efficient cropping systems for rainfed terraced situation of Meghalaya(College of Post Graduate Studies in Agricultural Sciences, CAU-Imphal, Umiam, 2011) Lyngdoh, Demandson; Das, AnupA field experiment was conducted at the Water Management field, ICAR Research Complex for NEH Region, Umiam, during 2009- l0 on Assessment of Water Efficient Cropping Systems for Rainfed Terraced Situation of Meghalaya. The experiment consisted of two tillage practices as main plots treatments- conventional tillage (CT) and conservation tillage (CST), and eight cropping sequences (4 cropping systems) as sub plot treatments (CS), viz, Maize- Toria (CS I), Maize-Pea (CS2), Rice -Toria (CS3), Rice-Pea (CS4), Ricebean-Toria (CS5), Ricebean-Pea (CS6), Soybean-Toria (CS7) and Soybean-Pea (CSS). The results indicated that conservation tillage recorded significantly higher profile soil moisture content, relative leaf water content, nutrient uptake and water use efficiency (WUE) as compared to conventional tillage. Soil organic carbon (SOC), available NPK, dehydrogenase activity and soil microbial biomass carbon were significantly higher in CST as compared to CT. Overall productivity of crops under CST in terms of grain yield were 25% and 27% higher, while in term of maize equivalent yield, they were 24% and 27% higher as compared to CT for kharif and rabi crops, respectively. The net return and B:C ratio were also higher under CST as compared to CT. At harvest of kharif crops, soil profile moisture was highest under soybean. At sowing of rabi crops, pea and toria succeeded maize recorded the highest soil moisture under conservation tillage. Soil profile moisture had never depleted below 50% of the soil moisture at field capacity under conservation tillage in all cropping sequences involving toria except ricebean-toria. Among kharif crops, N, P and K uptake were maximum in soybean, maize and rice, respectively. While for rabi crops, maximum N and K uptake was recorded in pea of rice-pea sequence and maximum P uptake in toria of maize-toria. Highest WUE was recorded in maize-toria sequence (23.9 kg ha��mm��) followed by maize-pea (19.9 kg ha��mm��). The SOC, soil available N, SMBC, and DHA were highest in soybean-pea sequence. The system productivity in term of MEY was highest in soybean-pea sequence (7.14 t ha��) followed by rice-pea (6.4 t ha��). Soybean-pea sequence recorded highest net return and B:C ratio of 2.9 and 2.4 in CST and CT, respectively. Therefore, from WUE and soil moisture utilization point of view, maize-toria sequence found to be most efficient. Whereas, considering soil health and income soybean-pea sequence was found most efficient.ThesisItem Open Access Assessment of weed diversity and its impact on crop-weed interaction in upland rice-rapeseed cropping system under residue mulch.(College of Post Graduate Studies in Agricultural Sciences, CAU-Imphal, Umiam, 2021-05) N., Premaradhya,; Ram, VishramThe present investigation entitled “Assessment of weed diversity and its impact on crop-weed interaction in upland rice-rapeseed cropping system under residue mulch” was undertaken during two consecutive seasons (kharif and rabi) of year 2016-17 and 2017-18 at the experimental upland Agronomy farm, ICAR-RC NEH region, Umiam to fulfill experimental field objectives (I and III) and chosen paddy fields survey in Ri-Bhoi district of Meghalaya (II). The soil was silty clay, acidic in soil reaction & normal in electrical conductivity, high in organic carbon & low in available nitrogen and sulphur, medium in available phosphorus & potassium. Two experiments were sown on 29th June 2016, 15th Nov 2016, 24th June 2017 and 12th Nov 2018. Experiment I was laid out inrandomized block design with 3 replications comprising ten treatments viz., weeds until 14, 28, 42, 56 days after sowing (DAS) and harvest and weed free until 14, 28, 42, 56 DAS and harvest and Experiment II was laid out in split plot design with 3 replications comprising 10 residual weed competition rice plots {details mentioned in Experiment I} in main plots and 2mulching treatments {M0 – No mulch, M1- straw mulch} in sub-plots with test cultivars of IURON 514 and TS 67 in rice and rapeseed, respectively. In order to achieve the second objective of the present investigation, a study was conducted to assess the distribution and pattern of weed flora prevailing in the rice fields of Ri-Bhoi district of Meghalaya with the help of remote sensing and GIS tools. It includes a random field survey, diversity indices analysis, development of spatial and attribute database of rice fields using high resolution satellite imagery and thematic weed diversity maps. The results in Experiment I revealed that the weed dynamics such as weed density, weed biomass, nutrient NPK removal by weeds was tended to decrease with increasing weeds free condition up to harvest. The lowest weed dynamics was observed in weed free until harvest. While season long weedy treatment resulted in the highest weed dynamics. The growth attributes such as plant height, leaf area index and dry matter production, physiological parameters (CGR, RGR, NAR, chlorophyll (SPAD value)) and yield attributes viz., number of panicles plant-1, number of filled grains panicle-1, panicle weight and 1000 grain weight, grain and straw yield, harvest index, nutrient NPK content and uptake by rice crop were realized highest with season long weed free treatment followed by weedy for the first 14DAS, weed free until 56DAS and the lowest was observed in season long weedy treatment. Based on the 5% level of yield loss, the critical period for weed competition was between 9 – 56 DAS in 2016 and 14 to 57 DAS in 2017, whereas the estimated critical period for upland rice at 10% RYL was between 17 to 43 and 24 to 44 DAS in 2016 and 2017, respectively. The dry matter content filled grains and number of panicles were direct relationship with significant to increasing grain yield and Positive correlation was observed between plant height, number of tillers, leaf area index and grain weight. Significant but negative correlation was obtained between the relative yield loss, spikelet sterility, weed biomass, and nutrient removal of nitrogen, phosphors and potash from weed plants of respective treatment for grain yield. In experiment II, among the weed species encountered in the survey under low land and upland rice, the species, Cyperus iria, Commelina diffusa and Echinochloa colona are commonly distributed in both type of cultivation. The weed flora on number wise doesn’t differ with each other counting around 21 (± 4). But by family wise the weeds are found vary in nature. Out of 21 wetland weeds recorded, the species belong to Cyperaceae and Poaceae had more than 5 species each whereas, in upland rice ecosystem, the weeds belong to 10 different families in which the family, Asteraceae with 10 species, followed by Poaceae was with four species. The wetland weeds which had higher relative abundance in descending order in both the years (2016 and 2017) were Rotala indica (27.11 and 22.21), Cyperus laevigatus (23.45 and 21.95), Monochoria vaginalis (15.12 and 18.16), Sagittaria sagittifolia (14.60 and 17.53) and Cyperus iria (14.19 and 16.02) and in upland rice ecosystem during the year 2016, weeds with higher relative abundance in descending order were Spermoce latifolia (20.27 and 16.87), Ageratum conyzoides (18.13 and 11.73), Ambrosia artemisiifolia (6.64 and 6.78) Conyza sumatrensis (6.02 and 7.80) and Bidens pilosa (5.35 and 7.61). Further, results from weed diversity indices revealed that wide range (medium to high) of weed density was observed in Umling and upper Umsning block in both the years of study. The diversity values ranged from 3 to 10 species per sq m in species richness, Margleaf index (0.48 to 2.28), the Shannon (H') diversity index (0.69 to 2.08), Simpson’s index (0.01 to 0.9), Pielou’s evenness (0.43 to 0.9) and Parker index (0.21 to 0.81). Weed species were more evenly distributed in lowland than the upland rice sites. Umling though had high to moderate levels of diversity, no new weed species were present compared to other blocks of the district. In experiment III, The growth attributes such as plant height, number of primary branches and dry matter production, physiological parameters (CGR, RGR, NAR, chlorophyll (SPAD value), relative water content, leaf thickness, leaf temperature) and yield attributes viz., number of siliqua plant-1, number of seeds siliqua-1 and 1000 grain weight, seed and stover yield, harvest index, nutrient NPKS content and uptake by toria crop were failed to have significant variation with residual weed competition plots of rice however, maximum values were recorded with longer duration weed free treatments than weedy plots and further, straw mulched plots were recorded significantly higher values in all the parameters except in stomatal and root traits, which was found higher with no mulch treated plots of toria. Interaction effect of different treatments of residual weed competition of rice plots and mulch practices were found non-significant with all the parameters except dry matter, root studies and in S nutrient, which was found significant during the study. The data on gross return and net return was observed highest with treatment’s kept weed free for longer duration in rice crop growth and vice versa. The significantly higher gross return of Rs. 57,432; net return of Rs. 27,238 and B: C ratio of 0.90 was found with season long weed free treatment which is followed by treatment T9, T1 and T8 respectively. The gross return Rs. 18,050; net return of Rs. 7196; B: C ratio of 0.66 of rapeseed was observed significantly higher under straw mulch than no mulch treatment, during both the years of investigation. Further, among the treatments, season long weed free treatment (T10) differed significantly and recorded higher rice equivalent yield (REY), system productivity, monetary net returns and production efficiency but land use efficiency was recorded higher with weed free until 56DAS during the study period.ThesisItem Embargo Development of critical nitrogen dilution curve and simulation for rice-rice system under climate change(College of Post Graduate Studies in Agricultural Sciences, CAU-Imphal, Umiam, 2022-03) Bharti, Chandrabhan; Ram, VishramThe experiment entitled “Development of Critical Nitrogen Dilution Curve and Simulation for Rice-Rice System under Climate Change" was conducted at the trial field of the College of Post Graduate Studies, (CAU), Umiam, Ri-Bhoi district of Meghalaya during kharif and boro season, 2018-19 and 2019-20 respectively. A field experiment with 6 nitrogen levels such as 0, 30, 60, 90, 120, 150 kg ha-1 and 3 split application, 1st Split (50% as basal + 50% at 45 DAT as top dressing), 2nd Split (50% as basal + 25% at 45 DAT and 25% at 60 DAT as top dressing) and 3rd Split (25% as basal + 25% at 45 DAT, 25% at 60 DAT and 25% at 75 DAT as top dressing) during 2018-19 and 2019-20. Agronomic data were recorded throughout the crop growth period. Daily weather data related to the minimum and maximum temperature, rainfall and solar radiation were collected from the nearest meteorological station at ICAR Research Complex for NEH Region, Umiam, Meghalaya. The study undertaken to develop nitrogen dilution curve based on plant dry matter (PDM), to determine light and nitrogen distribution pattern with grain filling characteristics to study simulated performance of rice with rising temperature and CO2. The result showed that all the growth parameter viz., plant height, tillers hill, dry matter production, Leaf Area Index (LAI), growth indices like Crop Growth Rate (CGR), Relative Growth Rate (RGR) and Net Assimilation Rate (NAR) improved with succession of crop growth period i.e.15-90 days after transplanting (DAT) as well as at harvest. Among the levels of nitrogen and split application recorded significantly higher plant height, dry matter production, LAI, CGR, RGR, NAR, yield and yield attributes, were found at 150 kg N ha-1 followed by 120, 90, 60 and 30 kg N ha-1 . The result showed that N concentration (Nc) were decreased with the dry matter accumulation in rice. Nitrogen application rate had a significant effect on plant biomass accumulation and Nc. Critical N dilution curve (kharif pooled Nc= 6.754 PDM-0.562 and boro pooled Nc= 19.752 PDM-0.82) at the rate 150 kg N ha-1 (N5) followed by other treatment. The critical N dilution curve can be used as a tool for diagnosing the status of N in rice. The N nutrition index (NNI) calculated from this critical N dilution curve was significantly related to grain yield. Based on plant dry matter for an (NNI > 0.97 and NNI > 0.99) the grain yield was near 1 in both kharif and boro pooled 2018-19 and 2019-20, respectively. Canopy N and light profile parameter, i.e. the light extinction coefficient (KL) and for Nitrogen extinction coefficient (KN) and their relation enhance to yield. Crop management practice better-quality canopy eco-physiological features (lower KL, higher KN) to the scattering of light and N inside the canopy to make best use of canopy photosynthesis and give higher yield. Rice grain filling rate increased linearly with increasing levels of nitrogen and accumulated heat units such as growing degree days in °C day. The maximum grain filling was observed at the rate of 150 kg N ha-1 (N5) (0.38 to 0.28 mg grain-1 degree-1 day-1). The higher rice grain yield was recorded at rate of 150 kg N ha-1 (N5) followed by other treatment (4.11 and 4.24 t ha-1) both the kharif and boro pooled 2018-19 and 2019-20, respectively. When the temperature was increased by +1, +2, +3 ºC with enrichment in CO2 level from the current condition, it was reported gradual increase in the grain yield with the subsequent increase of temperature. Increasing temperature +1, +2, +3 ºC and CO2 408, 458, 508 and 558 ppm the yield increase by 7.89%, 13.48 to 61.43 % at rate of 150 kg N ha-1 during both the years and pooled 2018-19 and 2019-20, respectively.ThesisItem Embargo Development of mathematical models for maize- weed competition.(College of Post Graduate Studies in Agricultural Sciences, CAU-Imphal, Umiam, 2022-09) Pusparani, Ngangbam; Ram, VishramA field experiment entitled “Development of mathematical models for maize-weed competition” was conducted in Kharif season of 2021-22 at the experimental farm of College of Post Graduate Studies in Agricultural Sciences (CAU, Imphal), Umiam. The experiment comprised of 14 treatments, which were divided into two sets, viz., weedy and weed free. The weedy set of treatments consisted of weed free following 10, 20, 30, 40, 50 and 60 DAS and weed free control, whereas the weed free set consisted of weed free plot until 10, 20, 30, 40, 50 and 60 DAS and never weed free. The treatments were replicated thrice and arranged in a Randomised Block Design. The results of the experiments demonstrated that a longer weed-free period had a synergistic effect on plant growth parameters, physiological parameters, biochemical parameter, yield attributes, grain yield, stover yield, harvest index, nutrient content, and uptake by plants. Weed samples for its density and diversity analysis were collected using the standard quadrant approach. Further, diversity indices such as Shannon Wiener Index, Simpson’s Index, Margalef Index etc. were calculated and interpreted as per standard protocols. The research findings also revealed that the field was infested with 15 different weed species belonging to six different families. However, Eleusine indica, Ageratum houstonianum, Bidens alba, Cressocephalum crepidiodes, and Gallinsoga parviflora were dominant and the most common weed species infesting the field, irrespective of the treatments. The weed density and dry matter accumulation increased up to 90 DAS and decreased thereafter. The relative yield of weedy and weed free set of treatments followed logistic and Gompertz equation, respectively. The experimental results show that at 5 percent RYL, the critical period for maize weed competition began at 12 DAS and persisted until 58 DAS, which is equivalent to 150 to 740 GDD. Furthermore, radiation in the wavelength range of 350 to 2500 nm with a variable bandwidth was measured at a height of 1 m above the crop using a portable single-beam field spectroradiometer (model SVC-HR-1024). And the outcome showed that, as a result of various weedy and weed-free durations, spectral reflectance and vegetation indices differed dramatically. The practical implication of the study is that, in order to provide maize a competitive edge over weeds, weeding should begin at 12 DAS and continue throughout the critical time, which lasted up to 58 DAS. It also demonstrates how the maize-based cropping system in Meghalaya is seriously threatened by weeds from the families Asteraceae and Poaceae.ThesisItem Open Access Development of nitrogen dilution curve for baby corn based on leaf and plant dry matter(College of Post Graduate Studies in Agricultural Sciences, CAU, Imphal, 2018) Laishram, Shayana; Ram, VishramMaize (Zea mays L.) is the third most important cereal crop next to rice and wheat in India, second most important crop in Meghalaya. Baby corn maize is one of the valued vegetables gaining popularity throughout the world. Baby corn is the ear of maize plant harvested young especially when silks have either emerged or no fertilization has taken place, depending on the cultivar grown. Baby corn is a low calorie vegetable, low-carbohydrate, high fibre and fat free vegetable. Baby corn has low glycemic index than regular corn and good for controlling blood sugar levels. It is also called as “miracles crop” and also “queen of cereals” due to its immense potential yield. N plays an important role in increasing growth and development of plants, being a constituent of protein and it increases the food value. Nitrogen dose have distinct relationship between leaf area index and its productivity. Most of N fertilizers are water soluble, mobile and more losses that need to N management for improving N use efficiency and crop yields. Optimizing the quantity of N required at each crop growth stage is critical for increasing baby corn yield, improving agronomic N use efficiency (NUE) and environmental sustainability. Accurate diagnosis of nitrogen (N) fertilizer required for crop growth can serve as a guide for N management by improving N use efficiency and baby corn yields. The critical N concentration (Nc), the minimum N required for maximal crop growth has been widely used to determine crop N status. From the experimental finding application of N4 (80 kg N ha-1) produced the maximum LAI, dry matter production of baby corn and also CGR, RGR and NAR of baby corn. The chlorophyll and SPAD value increased with the increasing N levels and significantly higher values were observed with N6 (120 kg N ha-1). Application of N4 (80 kg N ha-1) produced the maximum yield of baby corn as well as green fodder compared to other treatment. In dilution curve based on plant dry matter (PDM) and plant nitrogen concentration (PNC) , the strongest relationship was found with R2 values of 0.98 and 0.99 were observed at knee high and tasseling stages of baby corn. Whereas, leaf dry matter (LDM) and leaf nitrogen concentration (LNC), the strongest relationship was found with R2 values of 0.98 and 0.99 at seedling growth and knee high stages for baby corn in kharif and post kharif season, respectively. In normalised spad index (NSI), the strongest relationship was found with R2 values of 0.96 and 0.99 were observed at early vegetative and knee high stages for baby corn in kharif and post kharif season, respectively.ThesisItem Embargo Development of water production function for garden pea under mid hills of Meghalaya(College of Post Graduate Studies in Agricultural Sciences, CAU-Imphal, Umiam, 2022-10) Swetha, Konga; Ray, Lala I. P.Garden pea (Pisum sativum L. var. hortense) is an important rabi season crop grown in Indian subcontinent commonly known as 'matar' or 'pea'. Pea is the third most important legume of the world after beans and chickpea, grown for both fresh market and food processing industry. Peas are also known to leave behind 50-60 kg ha-1 residual nitrogen in soil with help of Biological Nitrogen fixation. As pea is a rabi season crop the main sowing seasons are October and November in which around 90% of pea is cultivated. During rabi season country receives very less rains and crops grown during rabi season experience moisture stress which is one of the reasons for low productivity. In such water limiting situations, deficit irrigation is a water management strategy in which water is supplied in less amount than what is required by the crop to meet the crop evapotranspiration (ET) demand without compromising the potential yield. Crop Water Production Functions (CPWF) will be developed through which irrigation water can be allocated efficiently, and thus increasing the water productivity. Keeping above considerations, an agronomic field trial entitled “Development of water production function for Garden pea under mid hills of Meghalaya” has been proposed to be carried out with following objectives.1. To estimate water productivity and develop crop water production function for garden pea. 2. To assess the effect of deficit irrigations on growth and yield of garden pea. 3. To find out the benefit cost ratio (BCR) of garden pea crop production. The field trial was laid under split plot design with irrigation scheduling’s based on maximum allowed depletion (MAD) under main plot with four irrigations i.e., 20% of MAD, 40% of MAD, 60% of MAD and 100% of MAD and with four different cultivars (V1- VM 10, V2 - VM 12, V3 - VL Sabji Matar 15, V4 - VL Sabji Matar 13) under sub plot, and was replicated thrice. From the experiment the following results were obtained: The growth and yield parameters such as plant height (65.85 cm), no. of branches per plant (13.75) and dry matter accumulation (7.33 g), no. of pods per plant (11.81) and green pod yield (8.19 t ha-1) were found significantly highest in treatment I1. However, treatment I2 was statistically at par with I1 in all the growth and yield parameters with plant height of 64.46 cm, no. of branches per plant (13.59) and dry matter accumulation (7.11 g), no. of pods per plant (11.28) and green pod yield (7.91 t ha-1). The significantly highest water productivity was found in treatment I4 – 3.93 kg m-3 over I2 – 3.56 kg m-3, I3- 3.34 kg m-3 and I1 - 2.63 kg m-3. The crop water production function was obtained as Y = -0.0001x2 + 0.0633x - 1.5064; with R² = 0.96 on pooled analysis of all cultivars. Among the cultivars highest yield and water productivity was noticed in V4 as 7.23 t ha-1 and 3.70 kg m-3. Similarly, the highest BCR was observed in main plot treatment, I1- 2.30 and in cultivar V4 – 2.06. Based on the field trial it may be suggested that, under given irrigation regimes winter season of Meghalaya, irrigation at 40% of MAD may be recommended in which marginal reduction in yield was seen but it does not compromise with maximum potential yield eventually the higher water productivity over I1.ThesisItem Open Access Dynamics of mineralization of crop residues under baby corn- baby corn system(College of Post Graduate Studies in Agricultural Sciences, CAU Imphal., 2018) Roy, Shreyosi; Ram, VishramMaize (Zea mays L.) is the third most important cereal crop next to rice and wheat in India. It covers area of 8.85 M ha with the production and productivity of 22.84 M t and 2.58 t ha-1, respectively (Agricultural Statistics, 2016). In North Eastern Hill Region maize is the second most important food crop next to rice and grown in 17.4 lakh ha area with the production and productivity of 26.5 lakh tones and 1.5 t ha-1, respectively (AgriculturalStatistics, 2015). Being a C4 plant, maize is an efficient converter of food and also considered as a ‘Miracle crop’ due to its immense potential yield. It is grown with equal success in temperate, subtropical and tropical regions of the world in more than 130 countries. It is of great importance for both the human and animal feeding. Baby corn (Zeamays L.) is a vegetable taken from sweet corn or standard maize (corn) plants, which is harvested early, while the ears are very small, immature and just after the emergence of white silk (2-3 cm length). Its miniature size is as appealing as its taste, colour and crunch. Baby corn cultivation provides tremendous avenues for crop diversification, crop intensification, value addition and revenue generation. Despite of its better economic return and increasing demand in international market, the cultivation of baby corn faced some constraints. One of them are nutrient management. Maize is an exhaustive crop and requires a balanced supply of all nutrients. But availability of required fertilizer in NER is very less and application of inorganic fertilizers also discouraged due to organic farming policy in NER of India. The areas like North Eastern region of India and other hilly areas, where a lot of biomass is available from forest, weeds, crops etc. organic farming would be more economical. Sometimes local people burn the forest area which not only waste the available environmental resources but also pollute the environment and disturb the different biological cycles occurring in that eco-system. The use of crop residues as mulches is an important agriculture practice in some parts of India. As North Eastern Hill region is now comes under organic farming zones, we should look for alternative nutrient supply such as crop residues, weed biomasses and other organic plant and animal waste products. Crop residues can be used as organic mulches or be incorporated into the soil because these residues improve soil fertility. These residues contain essential plant nutrients which are released as plant available forms during residue decomposition. Decomposition and nutrient release patterns of different organic residues with different ORQI value like rice (4.35), Elusine (4.56), ambrosia (6.04), groundnut (9.16) and mixed weed biomass (4.90) were investigated under field conditions, using litterbags which allowed access of soil fauna. The decomposition rate constants ranged from 0.007 to 0.023 Days-1, decreasing in the following order; Groundnut > mixed weed biomass >ambrosia > elusine > rice residue. Negative relationships were observed between decomposition rate constants and C:N ratio, percent lignin and polyphenol content of plant residues. A positive relationship was observed between decomposition rate constant.These results indicate that both the chemical composition of plant residues and nature of the decomposer played an important role in plant residue decomposition. Nutrient release differed with quality of plant residues and there nutrient mineralization rate constant. For N and P release the mineralization constant vary from 0.018 to 0.034 Day-1 and 0.11 to 0.033 day-1, respectively and release of nutrient from organic residues were in following order; For N: groundnut> Ambrosia> mixed weed biomass> elusine> rice and for P: groundnut>ambrosia=mixed weed biomass> elusine> rice residue. Groundnut could therefore improve the nutrition of fast growing and nutrient exhaustive crop like baby corn whereas rice straw would rather play a role in the build-up of soil organic matter in the long term and provide nutrient to long duration crop or in a cropping system.ThesisItem Open Access Effect of climate change on the performance of lowland rice (Oryza sativa L.) under N- levels through DSSAT CERES- rice model(College of Post Graduate Studies in Agricultural Sciences, CAU, Imphal, 2018) Lampung, Tage; Bora, P. K.A field experiment was carried out during the kharif season 2017 at the experimental farm of the College of Post Graduate Studies (CAU, Imphal). The experiment was conducted in Two Factorial Randomized Block Design with 4 replications for 3 rice cultivars (CAU R1, Shahsarang1, Lumpnah1) under different N levels (80, 100, 120 and140 kg ha-1). Agronomic data were recorded throughout the crop growth period. Daily weather data related to the minimum and maximum temperature, rainfall and solar radiation were collected from the nearest meteorological station at ICAR Research Complex for NEH Region, Umiam, Meghalaya. The study was undertaken to validate CERES-Rice model, to conduct model sensitivity analysis to nitrogen levels and to study the impact of climate change on the yield of rice. The results showed that all the growth parameters viz., plant height, tillers hill-1, dry matter production, Leaf Area Index (LAI), growth indices like Crop Growth Rate (CGR), Relative Growth Rate (RGR) improved with succession of crop growth period i.e. 30-90 days after transplanting (DAT) as well as at harvest. Among cultivars, Shahsarang1 recorded significantly higher plant height, dry matter production, LAI, CGR, RGR, yield and yield attributes over Lumpnah1 and CAU-R1. Among different nitrogen levels, significantly higher magnitude of above parameters were found at 140 kg N ha-1 followed by 120, 100 and 80 kg N ha-1. Shahsarang1 was found to be the better performer interms of growth and yield over other two cultivars viz. Lumpnah1 and CAU-R1. The CERES-Rice model has been validated against the observed data (days to physiological maturity, grain yield and tops weight) recorded during kharif season 2017 for which model was calibrated in an experiment in 2016. Simulated values for different cultivars under varied nitrogen levels were in close agreement with observed values.The validation result was further supported by the statistical results where the per cent difference between observed and simulated values for various growth and yield parameters were well within the acceptable range of ±15%, with R2 values above 0.9, low root mean square error (RMSE) and d-stat values greater than 0.5 except for maturitydays. The validated CERES-Rice model was then run for local sensitivity analysis where the sensitivity with respect to levels of nitrogen was considered. The model was found to be behaving satisfactorily to nitrogen levels for CAU-R1 and Shahsarang1 but not for Lumpnah1 cultivar of rice. Further calibration of Lumpnah1 may be required with crop data of few more years. At current CO2 conc. decrease in rainfall average to -19% and -50% increased the grain yield by 0.3-18.7% while increase in average rainfall to +19 and +50% reduced the grain yield by -6.2 to -12.6%. However, for all change in temperature (±10C, ±20C and±30 C), reduction in grain yield by -1.4 to -43.1% was recorded. At 450 ppm CO2 conc. Increase in grain yield by 1.3-10.6% was obtained for all rainfall regimes. Similarly, for all changes in temperature scenario grain yield was increased by 1.6-8.9% except for 120 and 80 kg N level where the grain yield was reduced by 0.2 and 1.6%. Similar result was recorded for change in rainfall and temperature where the grain yield increased by 3.2-14.9% and 2-13% respectively. As for the combination, highest increase and decrease in grain yield at 450 ppm was reported for +1oC and +50% and -2oC and +50% of average rainfall, respectively. At 500 ppm, highest increase and decrease in grain yield was reported for +1oC and -50% and -2oC and +50% of average rainfall, respectively. However, at -3oC reduction in temperature, no grain was produced for all the cases. It was due to the drop of minimum temperature to lower than 150C at reproduction stages of the crops.ThesisItem Embargo Effect of doses and split application of nitrogen on Frenchbean (Phaseolus vulgaris L.) in mid hills of Meghalaya(College of Post Graduate Studies in Agricultural Sciences, CAU-Imphal, Umiam, 2022-10) M. P., Shashidhar; Singh, A. K.The levels and time of fertilizer application have a significant impact on how well crops respond to fertilizer. Under current intensive agriculture, applying N as a basal is a common practice that has not considerably increased frenchbean yield. To determine the effect of doses and split application of nitrogen on frenchbean, a field experiment was conducted at the research farm of the College of Post Graduate Studies in Agricultural Sciences, CAU-I, Umiam, Meghalaya during summer season of 2021-2022. The experiment was laid out in randomized block design (RBD) with four replications comprises four levels of nitrogen (0, 30, 60 and 90 kg ha-1, respectively) as fully basal and 2/3rd as basal and 1/3rd as split application having a total of seven treatments. The experimental soil was moderately acidic in reaction, high in soil organic carbon and soil available N, P and K are in medium range. The results revealed that the growth parameters such as plant height (cm), number of branches plant-1, dry matter accumulation (g plant-1) are significantly different with increase in doses of both as basal and split application of nitrogen. LAI was significantly differed in all the treatments except at 20 DAS. The maximum LAI was observed from 90 kg N ha-1 and the lowest LAI was observed from control plots. Root: Shoot ratio, growth rates such as CGR (g m-2 d-1), RGR (mg g-1 d-1) and NAR(mg cm-2d-1), initial plant population (‘000 ha-1), mortality rate (%), number of root nodules are at par with each other with application of full basal and 2/3rd as basal and 1/3rd of N as split application, respectively. The maximum CGR, RGR and NAR were observed in 90 kg N ha-1 in 40-60 DAS stage and the minimum values of same recorded from control plots. Developmental stages such as days taken to emergence, flowering, pod formation and physiological maturity are at par with each other in all the treatments. Maximum Grain yield (kg ha-1), straw yield (kg ha-1), biological yield (kg ha-1), harvest index (%), protein content (%) and yield(kg ha-1) differed significantly with increase in nitrogen doses as basal and split application of nitrogen. Whereas, stover yield (kg ha-1), harvest index (%), protein content (%) and yield (kg ha-1), yield attributes such as number of pods per plant, number of grains per pod, test weight and pod weight per plant (gm) were at par with each other with application of N as full basal and 2/3rd as basal and 1/3rd of as split application respectively. Plant total N, P and K uptake (kg ha-1) differed significantly with increase in doses of nitrogen as basal and split application methods. The maximum total uptake of N, P and K were recorded from 90 kg N ha-1 and minimum value of same recorded from control plots. Soil available nitrogen, phosphorus and potassium (kg ha-1) after harvest were differed significantly with increase in N doses and lowest value of same recorded from control plots. Gross returns, net returns and benefit cost ratio were also differed significantly among all the treatments. From the above results it can be concluded that application of N as both basal and split gives better performance of frenchbean in mid hills of Meghalaya.ThesisItem Embargo Effect of doses and split application of Nitrogen on wheat (Triticum aestivum L.) in mid hills of Meghalaya(College of Post Graduate Studies in Agricultural Sciences, CAU-Imphal, Umiam, 2022-01) KARNAKAR, AKKIREDDY; Singh, A. K.To study the effect of doses and split application of nitrogen on wheat, a field experiment was conducted at the Research Farm of the College of Post Graduate Studies in Agricultural Sciences, CAU-I, Umiam, (Meghalaya) during Rabi season of 2019-2020. The experiment was conducted in factorial randomized block design (FRBD) with three replications comprised of four doses of nitrogen (0, 40, 80 and 120 kg ha-1, respectively) and three split applications (all N as basal, 1/2 N at basal +1/4 N at CRI +1/4 N at booting and 1/3 N at basal +1/3 N at CRI +1/3 N at booting) having a combination of ten treatments. The experimental soil was moderately acidic in reaction, high in soil O.C. and soil available P and medium in available N and K. The weather prevails during the crop growth period was normal for the wheat growth. The results revealed that the growth parameters corded as plant height, number of tillers plant-1, dry matter accumulation (g pl-1), LAI, yield attributes as no. of panicles plant-1), panicle length (cm), grains panicle-1), grains plant-1, test weight and wheat yields namely grain yield (t ha-1), straw (t ha-1) and biological yield (t ha-1) differed significantly both due to doses and their split application of nitrogen fertilizer. N fertilized treatments recorded significantly higher values of growth parameters, yield attributes, biological, grain and straw yield, uptake of N, P and K both in grain and straw as well as their total uptake. N fertilized treatments also recorded significantly higher net return and B:C ratio as compared to non-N fertilized (control) treatment. Among the different N doses, maximum values of growth parameters, yield attributes, yields, nutrient uptake and net return and B:C ratio was observed with N dose of 120 kg ha-1 which was in many cases, at par with N dose of 80 kg ha-1 but both these doses recorded their significant superiority over the N dose of 40 kg ha-1. Among the different split application of N, maximum values of all the growth parameters, yield attributes, yields, nutrient uptake and net return and B:C ratio was observed with the treatment 1/3 N at basal +1/3 N at CRI +1/3 N at booting sage when N was applied in three equal splits which was at par with N split application 1/2 N at basal +1/4 N at CRI +1/4 N at booting stage but both the split N treatments maintained their significant high values over the treatment where all N was applied as basal application. However, attaining of different developmental stages namely days taken to crop emergence, heading and physiological maturity did not vary markedly due to various N treatments and no significant interaction between doses and split N application was observed for the above said parameters of investigation.ThesisItem Open Access Effect of sowing time on summer pulse(s) in lowland rice fallows(College of Post Graduate Studies in Agricultural Sciences, Central Agricultural University , Imphal, 2018-03) Mayanglambam, Bishonath Singh; A. K. SinghPulses are the second important group of crops after cereals, providing high dietary protein (20 to 25 %). In NER of India, farmers mostly go for monocropping of rainfed rice. Due to various reasons such as cultivation of long-duration rice varieties, water logging and excessive moisture, non-availability of seeds of short duration varieties of Rabi crops, more than 5 lakh ha of such low lying area remain as rice fallows after harvest of rice during Rabi season. Such fallow land can be brought under cultivation, with short duration varieties of summer pulses. To identify suitable summer pulse(s) for low landrice fallow and to determine their optimum sowing date, the current study was undertaken. Higher grain yield of all the summer pulses was obtained when sowing was done on 4th March and it got reduced with either early (19th and 26th February) or late sowing (11th March). Lower grain yield of cowpea was recorded when sown on 26thFebruary over all other dates of sowing (19th February, 4th March and 11th March) while, in frenchbean lower grain yield was recorded when sown on 11th March. Both blackgram and greengram recorded lower grain yield when sown on 19th February. The comparative performance of summer pulses was assessed in term of rice equivalent yield, protein yield,benefit cost ratio (B:C) and changes in soil fertility status after crop harvest. French bean gave higher rice equivalent yield over all summer pulses in all sowing dates, except on 11thMarch where cowpea while, being at par with frenchbean recorded higher rice equivalent yield. Among summer pulses greengram recorded lower rice equivalent yield at all date of sowing. Sowing on 4th March gave higher rice equivalent yield in all summer pulses; minimum rice equivalent yield was recorded when sowing was done on 11th March. Similarly higher protein yield and B:C was recorded when summer pulses were sown on 4th March. Minimum protein yield was recorded from 19th February sowing while, lower B: C ratio was recorded from both 19th February and 11th March sowing. Among summer pulses cowpea gave maximum protein yield over all the summer pulses in all date of sowing, except on 26th February where frenchbean while, being at par with cowpea gave higher protein yield. Greengram recorded minimum protein yield in all dates of sowing. Benefit cost ratio of all summer pulses was found to be higher when sowing was done on 4thMarch while, lower B: C was recorded from both 19th February and 11th March sowing dates. Maximum benefit cost ratio was recorded from cowpea in all dates of sowing, except on 26th March where frenchbean gave higher benefit cost ratio. Cowpea also left higher residual soil available N, P and K as compared to other summer pulses. Hence it can be concluded that cowpea perform better over other pulses followed by frenchbean and their optimum sowing date is 4th March.ThesisItem Open Access EFFECTS OF IN-SITU RESIDUE MANAGEMENT ON CARRY OVER SOIL MOISTURE CONSERVATION PRACTICES AND GROWTH AND PRODUCTIVITY OF MUSTARD (Brassica campestris) IN MID-HILL ALTITUDE(College of PG Studies, Central Agricultural University, Imphal., 2009) Kharkrang, Enboklang; Ghosh, P. K.The field experiment was conducted at the Water Management field, ICAR Research Complex for NEH Region, Umiam during the year 2008-09 to study the effect of in-situ residue management on carry over soil moisture conservation practices and growth and productivity of mustard (Brassica campestris) in mid-hill altitude. The experiment was laid out in Split Plot design with two main plot treatments, six sub-plot treatments and replicated thrice. The main plot treatments were conventional tillage and zero tillage. The sub-plot treatments consisted of different combinations of mulching materials, comprising maize stalk, Ambrosia weed biomass, FYM and poultry manure, which are tried for their moisture conservation abilities. In general, the soil moisture was higher under zero tillage than conventional tillage. Zero tillage also increased the soil temperature and soil organic carbon (OC). Adoption of FYM @10 t/ha + maize stalk cover (MSC) poultry manure @5t/ha + Ambrosia @5 t/ha + MSC or Ambrosia @10 t/ha +MSC proved to be more efficient than other organic materials, regardless of the tillage. Further, all the mulching treatment improved the soil physical properties and resulted in much better yield than the control. The Bulk densities of surface (0-15 cm) soils during the growing season of both maize and mustard crops were significantly affected by different conservation measures. In general, available Nitrogen (N) and potassium (K) was found to be higher in the conventional tillage plots, but the amount of available phosphorous was higher in the zero tillage system. In terms of yield, the mulching practices (maize stalk with or without Ambrosia) performed better and produced 1.5 to 4.5 times higher yield than the control. The improvement in the crop performance was evident from the difference of the treated plots, when compared with the control, where the lack of moisture caused lower growth, branching and pod formation leading to lower biomass and relative turgidity. Taking the economics of cultivation into consideration, Ambrosia@ 10t/ha was found to be superior to all the other treatments, for both the tillage system.ThesisItem Open Access Estimation of plant biomass and agronomic management in Jhum cycle of Northeast India(College of Post Graduate Studies in Agricultural Sciences, CAU-Imphal, Umiam, 2015-09) Kalita, Hari Charan; Ram, VishramThe slashing and burning of secondary forest biomass is a key traditional hill agricultural practice followed over the centuries by Jhumias in Northeast India. To date, the estimates on secondary biomass production and emission of greenhouse gases (GHGs) due to biomass burning from different jhum cycles are lacking. The aims of the present study were 4-folds: (i) estimation of plant biomass production in secondary forest fallows, (ii) estimation of GHGs (CO2, CO, CH4, NOx, N2O and SO2) from burning of plant biomass, (iii) weed diversity in burnt (unmulched) and unburnt (mulched) crop fields of different jhum cycles and (iv) agronomic management (mulching, sowing time and relay crop) on yield components of mixed crops. Field surveys for plant biomass estimation and weed diversity were carried in Mokokchung district (Nagaland) and Aizawl district (Mizoram). Field experimental plots {3 fallow periods under both burnt (unmulched) and unburnt (mulched) x 4 sowing times} were carried out in Changki village (Nagaland) during 2 years cropping phase (2012-13 and 2013-14). The jhum areas of Mokokchung and Aizawl district were decreased 8.99% to 6.31% and 5.08% to 3.04% from its total geographical area during 1988 to 2012, respectively. In Mokokchung district, the highest jhum area was under 20 yrs cycle (817.23 ha) followed by 5 yrs cycle (783.02 ha), 10 yrs cycle (591.9 ha) and 15 yrs cycle (684.55 ha). In Aizawl district, more areas under jhum cycles were in the order of 5 yrs (2524.30 ha) > 10 yrs (1761.73 ha) > 7 yrs (1464.36 ha) > 15 yrs (538.77 ha). The total estimated above ground biomass in Mokokchung district were 178.36 t ha-1, 127.18 t ha-1, 97.20 t ha-1 and 52.44 t ha-1 for 20, 15, 10 and 5 yrs jhum fallow, respectively. The total estimated above ground biomass of Aizawl district were 114.80 t ha-1, 104.85 t ha-1, 58.62 t ha-1 and 6.01 t ha-1 in 15, 10, 7 and 5 yrs fallow, respectively. Higher emission of GHGs from jhum fallows were in the order of 20 yrs (83.44 t ha-1) > 5 yrs (71.89 t ha-1) > 15 yrs (61.29 t ha-1) > 10 yrs (54.08 t ha-1) in Mokokchung district. Whereas the higher emission of GHGs from jhum fallows was in 7 yrs (80.33 t ha-1), followed by 10 yrs (74.43 t ha-1), 15 yrs (70.61 t ha-1) and 5 yrs (8.23t ha-1) in Aizawl district. Jhum fallow cycles had significant influences on weed diversity indices. Among, 20 yrs fallow had higher values of Shannon-H) index i.e. 0.264 and 0.113 in mulching and burning treated plots respectively. The yield attributing characters of rice and relay crops, yield of each crop component of mixed crops, rice equivalent yield and production efficiency were higher in burnt fields of 20 yrs followed by 10 and 5 yrs crop phase of jhum cycles. Sole population of each crop performed better in 5 yrs cycle, but the yield advantages of mixed cropping was superior in cropping phase of 20 and 10 yrs fallows. Moreover, sole cropping of ginger and colocasia was more productive in cropping phase of 5 and 10 yrs fallows. The sowing after 1st day after burning produced higher yields of ginger and colocasia. But the crops like rice, pumpkin and chili produced higher yields when it was sown 7 days later. However, 14 days later sowing maximized maize, okra, sesamum and brinjal yields in the system. The relative higher yields of pea and rajmah grown as relay crops were achieved in burnt jhum fields as compared to mulched fields. The yields of relay crops increased with the increase in the length of jhum cycle. In conclusion, findings revealed that plant biomass production increases with the age of the secondary forest fallow, whereas production of GHGs seems to be related with the combined effect of biomass quantity and its type. Burning and mulching had differential influence on weed diversity indices as evident from higher values of diversity indices under mulching (un-burnt) compared to that under burnt (un-mulched). Our results also corroborated the traditional practice of different sowing times for different crops under mixed situation. It was noticeable that burning treatments supported higher yields of mixed crops and relay crops and also maintained higher soil fertility levels till 2nd year of cropping. Overall, the medium length (10 yrs) jhum cycle under burnt situation seems to be the optimum fallow length in terms of yields of mixed and , , weed diversity and soil fertility status.ThesisItem Open Access Evaluation of sweet corn hybrids under varied date of sowing in mid hill of Meghalaya / by Sidhartha Priyatam(College of Post Graduate Studies in Agricultural Sciences, CAU-Imphal, Umiam, 2019) Priyatam, Sidhartha; Ray, Lala I. P.A field experiment was conducted during kharif season of 2018 at the College of Agriculture, Kyrdemkulai, (Central Agricultural University, Imphal), Ri-bhoi district, Meghalaya to evaluate the sweet corn hybrids comprising of various sowing window in mid hill of Meghalaya. The experiment was carried out in a split plot design with three numbers of main- plot treatments, viz., sowing date on 2nd July (S1), 12th July (S2) and 22nd July (S3) four numbers of sub- plot treatments, viz., ASKH-1 (V1), ASKH-4 (V2), ASKH-6 (V3) and SWEET-77 (V4) and replicated thrice. In context to growth parameters, viz., plant height, leaf area, and biomass accumulation S1 and V3 registered the uppermost value followed by S2 and S3 among the main- plot treatments and V1, V4 and V2 among the sub-plot treatments. Interaction effect of sowing dates and hybrid on dry matter accumulation per plant (g) was found to be significant at 30, 45 and 60 DAS. The highest biomass was exhibited by S1V3 (13.13g) followed by S1V1 (11.03g) and S2V3 (9.07g) at 30 DAS. Similar trend of interaction continued up to 60 DAS. The mean number of days for 50% tasseling and silking was 60.25 and 65.75 days, respectively with (S1) and it was statistically at par with (S2). The highest number of days for attaining tasseling and silking was observed by (V3) and was at par with AKSH-1. There was no significant difference among the sowing dates in regard to crop growth rate except at 30-45 DAS. At 30-45 DAS (S1) witnessed for highest crop growth rate followed by (S2) and (V3) reported significantly more crop growth rate of 1.20, 4.24, 0.96 mg cm-2 day-1 at 30-45, 45-60 and 60-75 DAS, respectively. Interaction effect at 45-60 DAS stated that S1V3 recorded highest CGR (129.37 mg cm-2 day-1). RGR was significantly varied in both main plot and sub plot treatments only at 30-45 DAS and among the hybrids (V2) noted the highest relative growth rate and (V3) recorded the lowest relative growth rate. In regards to yield attributes the highest cob numbers per plant (1.20), cob length (16.29 cm) cob weight (113.53) and cob diameter (6.02) was recorded by S1. Similarly, V3 (1.29) registered higher cob number, cob length (15.94 cm) and cob weight (110.87) and was followed by V1, V4 and V2. Among the main-plot treatments (S2) (6.59 t ha-1) exhibited highest grain yield and stover yield (9.97 t ha-1) was significantly superior over remaining treatments. While, among the sub-plot treatments (V3) witnessed significantly highest cob yield with (6.20 t ha-1) followed by (V1) (5.60 t ha-1), (V4)) (4.89 tha-1) and (V2) (4.40 t ha-1). The interaction effect of sowing dates and hybrids revealed that treatment combination S1 V3 (7.26 t ha-1) gave the highest cob yield followed by S1V1 (6.73 t ha-1). Between the sowing dates S1 (11.50%) registered highest amount of TSS. Whereas, (V3) recorded both highest amount of TSS (10.88%) and protein (10.44%) which was found to be nearly equal with (V1) followed by (V4). Among the sub-plot treatments highest nitrogen, phosphorous, and potash concentration were listed by (V3) (1.67, 0.25 and 1.27%, respectively) which were significantly greater over V2 (1.63, 0.21, and 1.23%, respectively). Both main plot and sub-plot treatments reported significant difference with respect to uptake of N, P2O5 and K2O (kg ha-1) in sweet corn. Among the sowing dates and hybrids, highest nitrogen uptake was resulted by (S1) (40.43 kg ha-1) and (V3) (39.17 kg ha-1). Whereas, in case of P2O5 and K2O uptake by sweet corn grain followed similar trends in both main-plot and sub-plot treatments. Total cost of cultivation was lower in S3 as compared to S1 and S2. The highest cost of cultivation was in (V4). The highest gross return, net return and B: C ratio was reported by S1 and V3.ThesisItem Open Access Evaluation of urine as an alternative fertilizer source for crop production in North East India(College of Post Graduate Studies in Agricultural Sciences, CAU-Imphal, Umiam, 2017-01) Singh, Sanjenbam Dayananda; Ram, VishramA two years research experiment was conducted during 2014-15 and 2015-16 at upland Agronomy Farm of the ICAR research complex for NEH region, Barapani, Meghalaya. The experiment was undertaken to evaluate the effect of urine application as the alternative source of fertilizers in maize-toria cropping system on its yield, crop quality, fertility of soil after harvest of the crops and cropping system efficiency. Chemical fertilizer (T2), human and cow urine applied once (T3 and T4) were significantly highest in crop growth among the treatments in early stage of maize but in middle stage, human and cow urine either in split application or in combination with urea (T6, T7, T8 and T9) were far better than chemical (T2), human and cow urine applied once as basal (T3 and T4) and FYM (T5), but at later stage or at harvest, either human and cow urine in combination with urea (T8 and T9) produce better growth of maize. Grain yield of the maize were significantly highest in human urine in combination with urea (T8). But in 2nd season crop (toria), FYM (T5) produced significantly highest growth, yield attributes and yield of toria than other treatments. Primary elements (viz. nitrogen, phosphorus, potassium) contents in maize grain were highest either in human and cow urine in combination with urea (T8 and T9). However, the secondary elements viz. sulphur, calcium, magnesium were utmost in human urine in split application (T6). Among the micro nutrients, Zn content was statistically similar to all the treatments but significantly higher than chemical (T2), cow urine in combination with urea (T9) and control (T1), but the Fe content was highest in chemical (T2) treated plots of maize. In toria seed, the primary nutrient content was highest in FYM (T5) treated plots except nitrogen, where all the treated plots produced similar nitrogen content. Pooled analysis of secondary nutrient content in toria seed showed that human urine in split application (T6) was higher among the treatments. Among the micro- nutrients, zinc content was highest in human urine applied in split application (T6) but the iron content was lesser in treated plots than the control (T1). Increase in pH and EC in human urine in split application (T6) were observed, however, FYM (T5) produced higher OC content in soil after harvesting of maize. Among the soil primary nutrient elements, the highest N and P was observed from T (FYM), however, it was at par with human urine in combination with urea (T8) in case of P and the highest K was recorded from human urine in combination with urea (T8). The highest sulphur content in soil was found in FYM (T5) but Ca and Mg content were more in human urine in split application (T6). Among micro-nutrients, the highest Zn content was found under human urine in split application (T6) but chemical (T2) produced highest iron content in soil. The highest soil microbial activities vis. SMBC, SMBN and SMBP were highestunder human urine in split application (T6), similarly, the dehydrogenase and phosphatase enzyme activities were highest in human urine in split application (T6) but almost all the treated plots produce statistically similar dehydrogenase enzyme activities. However, urease enzyme activities were dominant in T8 than other treatments. In soil after harvesting of toria, the pH and EC were highest in human urine in split application (T6) but FYM (T5) recorded the highest OC content in soil. Among the essential macro nutrients, N, P and S were highest in FYM (T5) but K, Ca and Mg were highest in human urine in combination with urea (T8) and human urine in split application (T6), respectively. Similarly, Zn content in FYM (T5) recorded the highest, however, cow urine applied once (T4) proved the highest content of Fe in soil after harvest of toria. Soil microbial activities and enzyme activities were highest in FYM (T5) but the enzyme dehydrogenase was higher in human urine in split application (T6). The maize-toria cropping system efficiency was significantly highest under human urine in combination with urea (T8).ThesisItem Embargo Growth, yield and nutritional quality of cowpea (vigna unguiculata l.) as influenced by zinc fertilization(College of Post Graduate Studies in Agricultural Sciences, CAU-Imphal, Umiam, 2022-01) Baruah, Manashi; Singh, A. K.Cowpea (Vigna unguiculata L.) is one of the well-recognized legume crop for Kharif and Summer season in different states of the country and is grown for its grain, pods (vegetable), forage and as green manuring. This grain legume could potentially contribute to improved dietary zinc (Zn) nutrition as its seeds contain about 3.37 mg of zinc in each 100 g. In NEH region, cowpea is one of the important vegetable cum pulse crop where zinc is a deficient element in most the soils. In Meghalaya, about 57% soils are deficit in phyto available zinc (Govt. of Meghalaya, Dept. of Agriculture). So, zinc fertilization in cowpea is needed to be introduced. Hence, present experiment was conducted at the experimental site of College of Post Graduate Studies in Agricultural Sciences, Umiam, Meghalaya during kharif 2019 to study the growth, yield and nutritional quality of cowpea (Vigna unguiculata L.) as influenced by zinc fertilization. The experiment was conducted in randomised block design (RBD) consisting of eight treatments (T1: RDF @ 20:60:40 kg ha-1 foliar application of Zn @ 0.5% at pod initiation stage; T4: RDF + soil application of Zn @ 2.5 kg ha-1; T2: RDF + soil application of Zn @ 5 kg ha-1 (in the form of ZnSO4 @ 15.15 kg ha-1); T3: RDF + -1 + foliar application of Zn @ 0.5% at pod initiation stage; T5: FYM @ 5t ha-1 + 25 kg P2O5 as SSP, T6: FYM @ 5t ha-1 + 25 kg P2O5 as SSP + soil application of Zn @ 5kg ha-1; T7: FYM @ 5t ha-1 + 25 kg P2O5 as SSP + foliar application of Zn@ 0.5% at pod initiation stage and T8: FYM @ 5t ha-1 + 25 kg P2O5 as SSP + soil application of Zn @ 2.5 kg ha-1 + foliar application of Zn @ 0.5% at pod initiation stage) and replicated thrice. The results of the investigation revealed that application of zinc as soil application + foliar spray at pod initiation significantly influenced number of leaves plant -1.34 t ha- organic carbon (%), soil available N and K didn’t change markedly due to either of the treatments. But there is significant increase in soil available P and Zn is noticed in the experiment. Maximum net return and B: C ratio was obtained from soil application of Zn @ 2.5 kg ha-1, dry matter accumulation plant-1, dry weight of root nodules, numbers of pod plant-1, pod length (cm), fresh pod weigh plant-1 (g), number of grain pod-1 at harvest, test weight (g), grain weight plant-1 (g), yield and nutrient uptake in comparison to no zinc (control) or soil or foliar application alone. Maximum grain yield (-1) was obtained from treatment T4. Significantly least grain yield was recorded from treatment T5. However, T4 is at par with T8 and both these treatments recorded significantly high biological yield, harvest index and nutrient uptake over other treatments. But there is no noticeable effect seen in CGR, RGR and NAR due to zinc application. Soil pH, -1 followed by foliar application of Zn @ 0.5% at pod initiation stage and FYM (T8). From the present investigation it could be concluded that the growth, yield and nutritional quality of cowpea respond positively and differentially to the Zn fertilization strategies in presence of organic and inorganic sources. Zinc fertilization in combined form of both soil and foliar application gives better result than soil or foliar application alone and combination of RDF with zinc fertilizer gives better result than combination of zinc fertilizer with FYM.ThesisItem Open Access Integrated nutrient management in groundnut (Arachis hypogaea l.) in acidic soils of Meghalaya(College of Post Graduate Studies in Agricultural Sciences, CAU-Imphal, Umiam, 2020-09) Panda, Sushree; Singh, A. K.To study the effect of integration of locally available organic sources (weed biomass, FYM) with inorganic fertilizers and biofertilizers on growth, yield and economics of groundnut (Arachis hypogaea L.), a field experiment was conducted on Research Farm of the College of Post Graduate Studies in Agricultural Sciences (CAU-Imphal), Umiam, Meghalaya during the Kharif, 2019. The experiment was conducted in RBD with nine treatments and three replications. Experimental soil was sandy clay loam in texture with pH 5.09, low in organic carbon and nitrogen, medium in phosphorus and low in potash. The experimental site experienced 2192.6 mm of rainfall, maximum and minimum temperature variation ranges from 23.3-27.5℃ and 16.4- 20.3℃, respectively while net radiation varied from 113.9 to 137.9 MJ m-2. Application of organic or inorganic sources and their integration significantly affected plant height, leaf area, leaf area index (LAI) and dry matter accumulation of experimental crop at all stages of observation. Crop developmental stages recorded as days taken to flowering, days taken to peg initiation and days taken to maturity did not differ markedly due to variation in treatments. Yield attributes differed markedly due to various integration of nutrient sources and maximum pods plant-1 (24.3), pod weight plant-1 (10.7), shelling% (71.1%) was recorded from the treatment T9 (integration of biofertilizers, inorganic fertilizers, dairy manure and Eupatorium green leaf manuring) which was at par with T3 (RDF) and significantly more over the remaining treatments, however, kernels pod-1 and test weight remained at par. Maximum pod yield, kernel yield and biological yield was also recorded from the treatment T9 which was at par with treatment T3) but significantly higher over remaining treatments while Harvest index remained at par. Nutrient uptake (N, P, K and S) and economic returns largely depend on economic and haulm yield, therefore, it also followed the same trend of yield. Treatment T9 recorded significantly higher net return over all the remaining nutrient treatment. However, B:C ratio was at par between T9 (2.11) and T3 (1.92) but recorded significantly more over the remaining treatments. Further, soil physico-chemical and bio-chemical properties also differed significantly due to integration of various nutrient management practices except pH and soil available K2O. An improvement in soil properties over their initial values was also recorded due to application of various nutrient treatments over the control. Treatment T9 left maximum soil organic carbon (1.38%), available nitrogen (325.7 kg ha-1), exchangeable Ca (2.12 cmol (+) kg-1) and Mg (1.06 cmol (+) kg-1) as compared to the remaining treatments but in case of available phosphorous (20.64 kg ha-1) and available sulphate (1.14 mg kg-1), it was at par with RDF. T9 also resulted in significantly more amount of DHA and PHA activity and SMBC, SMBN and SMBP after crop harvest.