Influence of Organic and Natural Farming Nutrient Management Practices on Soil Microbial Biomass Carbon and Enzymatic Activity in Arecanut and Black Pepper Cropping System

Abstract

Soil microbial biomass carbon, an essential component of soil organic matter, serves as an indicator of microbial activity and can influence soil fertility and overall agroecosystem productivity. The conventional farming practices employed in the cultivation of these crops have raised concerns related to environmental sustainability, soil health and long-term productivity. The present investigation was carried out with an objective to study the impact of organic farming and natural farming practices on soil microbial biomass carbon and enzymatic activities in arecanut-black pepper cropping system at Horticulture Research and Extension Center, Sirsi. The treatments included (1) Integrated nutrient management practices (INM), (2) Organic farming practices, (3) Natural farming practices, (4) Chemical farming practices. The details of the four treatments imposed in arecanut and black pepper are T1: INM (100:40:140 g N/P/K per palm per year + 25 ton of Farm yard manure (FYM) + 5-6 ton of vermicompost + biofertilizers was applied as recommended by the University of Horticultural Sciences, Bagalkot). T2: Organic farming (25 ton of FYM + 5-6 ton of vermicompost + biofertilizers were applied), T3: Natural farming (Ganajeevamrutha 400 kg/acre in split doses during the pre-monsoon (200 kg/acre) and post-monsoon (200 kg/acre) period. Jeevamrutha was sprinkled on soil (200 l/acre) at 15-day intervals) and T4: Chemical farming (100:40:140 g N/P/K per palm per year was applied as recommended by the University of Horticultural Sciences, Bagalkot). Pre-incubation of soil samples was done to restore the normal biological activities. A known quantity of soil was moistened to field capacity (60% of MWHC) and incubated at 37 ± 2 0C in a BOD incubator, three days for dehydrogenise and 7 days for phosphatase.Data obtained during the investigation was subjected for a factorial RCBD. By taking nutrient management practices and soil depth as factors. Statistical analysis was performed at a 5 % level of significance using OPSTAT software. The study reveals that the higher microbial biomass carbon (270.20 mg kg-1), microbial biomass nitrogen (28.42 mg kg-1), dehydrogenase (18.55 ug TPF g-1 24 hr-1) and acid phosphatase (19.22 ug PNP g-1 h-1) activity was recorded at the surface soil (0-20cm) of organic farming practice followed by natural farming practice as compared to integrated nutrient management practice and chemical farming practice. The study also reveals that natural farming and organic farming practices contribute positively to soil health by enhancing the soil organic carbon, microbial biomass carbon and enzymatic activities. So, it can be concluded that both organic and natural framing practices contribute to sustainable agriculture by enhancing soil health, which is essential for long-term crop productivity and ecosystem resilience.