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20182
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Subject: Soil and Water Engineering × End date: 2018 × Start date: 2018 × Type: Thesis × Thesis Type: Ph.D ×
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    ThesisItemOpen Access
    Design and Evaluation of Automated Drip Irrigation System
    (Punjab Agricultural University, Ludhiana, 2018) Sandeep Kumar; Jain, A.K.
    An automated drip irrigation system (ADIS) was designed and evaluated in collaboration with JISL, Jalgaon, (Maharashtra). To optimize the design parameters of the system, two types of drip irrigation systems were considered, viz. wired based automated drip irrigation system (IS1) and wireless automated drip irrigation system (IS2). The experiment was carried out for two seasons on tomato crop (Abhinav, Syngentha) using two water sources viz. ground water and treated fruit processing waste water. The study revealed that the quality parameter of tomato was better for treated fruit processing water (WQ2) in comparison of ground water (WQ1) quality. Based on the optimization of ADIS, it was found that the irrigation system and water quality significantly affect the plant height, number of leaves, number of branches, number of fruits and yield. The wireless based irrigation system (IS2) with treated fruit processing waste water (WQ2) was found as best combination. The maximum tomato yield of 37.79 ton/ha was obtained with wireless based irrigation system with pressure compensating drippers (PC) for treated fruit processing waste water (WQ2). Economic analysis has been done to check the commercial viability of the automatic drip irrigation system. The benefit cost ratio for wired based irrigation system was found to be as 1.44 without subsidy and 1.77 with 50 percent subsidy, whereas, benefit cost ratio for wireless irrigation system was found to be as 1.56 without subsidy and 1.90 with 50 percent subsidy. Breakeven point for wired based irrigation system has been achieved after 14 years without subsidy and 10 years with 50 percent subsidy, whereas, breakeven point for wireless based irrigation system has been achieved after 10 years without subsidy and 5 years with 50 percent subsidy. Based upon the above study it was found that wireless irrigation system is more economical and best suited automated drip irrigation system to get higher net returns as compared to wired based irrigation system.
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    ThesisItemOpen Access
    Modeling Microclimate of Naturally Ventilated Greenhouse under Cropped Conditions in Soilless Media
    (Punjab Agricultural University, Ludhiana, 2018) Mahesh Chand Singh; Singh, J.P.
    A study was undertaken to develop mathematical models for simulating microclimate of a naturally ventilated greenhouse under cropped conditions and develop the optimal operating microclimatic conditions for drip fertigated cucumber crop in soilless media. Cucumber crop was grown in coco-peat in a split plot design in three replicates during two successive growing seasons of 2016-17. The treatments included three levels of fertigation in main plots viz. F1=100.0%, F2=85.0% and F3=70.0% of complete nutrient solution under optimal microclimatic conditions. Sub-plots included cultivars viz. V1 (Kafka), V2 (Multistar) and V3 (PBRK-4). Mathematical models for standardizing the temperature of greenhouse cover, air, plant and growing media were developed, calibrated and validated in Simulink MATLAB with a mean model efficiency and coefficient of determination values of 94.7% and 0.96 respectively. Mathematical models of sensible and latent heat balance were developed to predict vertical air temperature profile and vapour pressure and solved analytically. Models for predicting saturation vapour pressure (SVP), actual vapour pressure (AVP) and vapour pressure deficit (VPD) from internal and external climates were developed and solved in Simulink MATLAB. Further, models for predicting temperature of air, leaf, plant root-zone and relative humidity were also developed from external climate. The average fruit yield was obtained in the range of 2.4-3.5 kg plant-1 and 3.3-4.4 kg plant-1 with and without fruit thinning having lowest and highest yield under treatments F3V3 and F1V2. Crop water use efficiency (CWUE) was found in the range of 60.4-86.3 kg m-3 and 84.5-108.9 kg m-3 with and without fruit thinning respectively. The average benefit cost ratio (BCR) was computed to be 1.91 and 1.54 with and without subsidy respectively without fruit thinning. However, BCR decreased by 23.7% and 23.8% with and without subsidy respectively with fruit thinning. The developed models were calibrated and validated separately for both growing seasons and a good agreement was observed between the model predictions and observed data. Thus, the developed models successfully simulated the greenhouse microclimate. Based on microclimate modeling, the desirable range of Tapc, TL, Trz, Eapc, Irad and VPD were worked out to be 22.0-27.0°C, 20.5-25.1°C, 16.9-22.9°C, 60.0-85.0%, 100.0-169 Wm-2 and 0.53-1.10 kPa respectively for optimal plant growth and development.