Impact of Different Rice-based Cropping Systems on Soil Biological Properties and Soil Enzymes under Irrigated Conditions of Eastern Uttar Pradesh, India

A field experiment was planned and conducted during the Rainy (Kharif) and winter (Rabi) seasons of 2021-22 and in the Summer (Zaid) season of 2022 at Agronomy Research Farm, Acharya Narendra Deva University of Agriculture & Technology, Kumarganj, Ayodhya (U.P.) to investigate the impact of different rice-based cropping systems on soil biological properties under irrigated conditions of eastern U.P. The experiment was designed using a randomized block design with three replications and ten treatments. T1 Rice(Oryza sativa L.)-Wheat(Triticum aestivum L.)-Fallow, T2 Rice-Wheat-Green gram(Vigna radiata L.), T3 Rice-French bean(Phaseolus vulgaris L.)-Green gram, T4 Rice-Chickpea(Cicer arietinum L.)-Cowpea(Vigna unguiculata L.), T5 Rice-Mustard (Brassica juncea L.)-Green gram, T6 Rice-Linseed(Linum usitissimum L.)-Black gram(Vigna Mungo L.), T7 Rice-Berseem(Trifolium alexandrium L.)-Sorghum( Sorghum Bicolor L.), T8 Rice-Oat(Avena Sativa L.)-Maize(Zea Mays L.)+Cowpea, T9 Rice-Cauliflower(Brassica Oleracea L.)-Okra(Abelmoschus esculentus L.), T10 Rice-Potato(Solanum tuberosum L.)-Cowpea. The soil of the experimental field was silty loam in texture, soil was slightly alkaline in reaction, low in organic carbon and available nitrogen and medium in available phosphorus and potassium. The growth of bacteria (11.68 x 106 cfu g-1 ), fungi (6.55 x 105 sfu g-1) and actinomycetes (7.15 x 104 cfu g-1) was found to be highest in T10 Rice-Potato-Cowpea cropping system. In this investigation, the microbial population was higher under the treatments in which high doses of nitrogen and crop residues were applied. The activity of dehydrogenase enzyme (153.68 µg TPF g-1 soil day-1), urease (217.33 µg urea g-1 soil hr-1) and alkaline phosphate (163.96 µg p-nitrophenol g-1 hr-1) was found significantly higher in T4 (Rice-chickpea-cowpea) cropping system in comparison with the other cropping system.