Browsing by Author "Arun Kumar Jha"

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Combined Application of Azolla and Inorganic Potassium Fertilizer Influence the Growth, Yield and Storability of Onion in Alluvial Soil
(Taylor and Francis Ltd., 2023) Arun Kumar Jha; Mukta Rani; Rajeev Padbhushan; Arun Kumar; Randhir Kumar
Azolla (Azolla pinnata R. Br.) is an aquatic fern that supplies potassium (K) and other plant nutrients with their use and organic matter after decomposition in the soil to improve soil quality. Alluvial soils are deficient in available K due to intensive cropping systems, the use of high-yield varieties (HYVs), and improper fertilizer application. With high demand for K fertilizers and complete dependence on imports in India have affected its availability and cost. Azolla can be an alternative option for a source of K nutrients. Keeping this fact in view, the present study was formulated to understand the effect of K applied through Azolla and inorganic K fertilizer on the growth, yield, and storability of onion (Allium cepa L.). An incubation study was carried out to examine the K dynamics as influenced by levels and sources of K. Results showed that the use of Azolla along with mineral K fertilizer (NPK1/2 + K1/2 through mulching of Azolla and NP+ K1/2 through green manuring (GM) of Azolla + K1/2 through mulching of Azolla) has increased the water-soluble K (WS-K) and available K (Av-K) from 0 to 35 days of incubation (DI) and further decreased thereafter up to 105 DI. Azolla-based K application showed the availability of more K in the soil throughout the incubation period as compared to inorganic sources alone. The highest exchangeable K (Ex-K) was recorded in soil treated with Azolla similar to WS-K and Av-K. A field experiment was also conducted on the onion crop at the Bihar Agricultural College research farm, Sabour. The findings suggest that the maximum bulb weight (32.8 g bulb−1) and bulb yield (12.5 t ha−1) were recorded in the treatment NPK+ K1/2 through mulching of Azolla in two splits increased by 33% and 43%, respectively. Treatments applied with the full dose of recommended inorganic K alone resulted in 14% less bulb yield than the treatment combined with the full dose of recommended mineral K through inorganic fertilizer and half dose of recommended K supplied through Azolla mulching. The results also indicated that Azolla-based K application resulted in higher nutrient uptake, soil available nutrient status, and better storability in onion than conventional mineral K fertilization. Overall, the study concludes that Azolla may maintain K availability by increasing the amount of Ex-K and ensuring constant availability of the nutrient during the entire growth period. © 2023 Taylor & Francis Group, LLC.
Effect of proportional substitution of potassic fertilizer with biofertilizers in onion
(Indian Academy of Horticultural Sciences, 2020) Mukta Rani; Arun Kumar Jha
A fundamental shift has taken place in agricultural research and world food production. Today, the drive for productivity is increasingly combined with a desire for sustainability. A field experiment was carried out in sandy loam soil during kharif 2016-17 with kharif onion cv. Agrifound Dark Red using Azolla and vermicompost for sustainable crop production. The experiment comprised of 8 treatments, T1 (no K application), T2 (50 per cent RDK), T3 (100 per cent RDK), T4 (50 per cent RDK + 50 per cent K by Azolla), T5 (50 per cent RDK + 50 per cent K by Vermicompost), T6 (50 per cent RDK + 25 per cent K by Azolla + 25 per cent K by Vermicompost), T7 (100 per cent K by Azolla) and T8 (100 per cent K by Vermicompost). Full dose of N and P were applied in all the treatments through urea and SSP, respectively. However, potassium was supplied through muriate of potash (MOP) having 60 per cent K2 O, vermicompost (0.8 per cent potassium) and Azolla (2.62 per cent potassium on dry wt. basis). Results from field experiment showed that treatment T7 was found significantly superior over all other treatments to increase plant height of onion at 90 (45.59 cm) and 120 DAT (50.80 cm) and the lowest plant height was recorded in control (T1). Dry matter content (14.34 g plant-1) was found to be the highest with treatment T5 at 120 DAT. However, treatment T4 resulted highest dry matter 0.513, 1.52, 5.54 g plant-1 at 30, 60 and 90 DAT respectively. Equatorial (55.86 mm) and polar (47.59 mm) diameters of onion bulbs were found to be significantly higher with treatment T5 . The highest bulb weight (45.17 g) and yield of onion (13.17 t ha-1) were recorded with treatment T5 which was 16.24 and 41.46 per cent higher bulb yield as compared to that recorded with T3 and T1 respectively. However, the lowest bulb weight (35.10 g) and bulb yield (9.31t ha-1) were recorded in the plots receiving no potassium. Calculation of cost of production and benefit obtained showed that the treatment T3 gave maximum benefit: cost ratio of 2.1. However, B: C ratio of T4 and T5 was 1.9 and 1.6, respectively. © 2020, Horticulture Society of India. All rights reserved.