Quantifying the fertility status and relationship between soil properties under major tea estates of North-western Himalaya

摘要

Tea is being grown on the gentle slopes of Himachal Pradesh located in the north-western region of mighty Himalaya, since 1850s. However, degrading soil health due to rampant usage of agrochemicals, and long-run tea cultivation adversely affects the productivity potential of the region. Analyzing soil-nutrient status is of great value to meet the crop nutrient demand. The research aimed to identify the vulnerable soil properties and their assessment for soil restoration under major tea estates of the North-western Himalaya. The study examined the physico-chemical and biological properties of soils of 37 tea estates. The large variation among different sites for physical parameters signifies the textural difference between the sites under study. Meanwhile, the soil pH of tea estates varied from extremely acidic to slightly acidic reaction, with an overall pH (H2O) of 5.33 in the top soils and 5.47 in the subsoils. High OC (13.35 g kg(-1)) under overall soil depth of tea estates presumably correlated with higher concentration of available nutrients, i.e. N (r = 0.641), K (r = 0.492), and S (r = 0.623) alongside exchangeable Ca (r = 0.724) and Mg (r = 0.718). The substrate carbon availability due to higher amount of organic matter in the top soils (16.1 g kg(-1)) leads to increased biological activity (MBC and DHA) in the surface soils as compared to subsoils. The unscientific approach of fertilizer application led to huge variability in green leaf yield across different tea estates. Thus, to achieve higher yield, it should be necessary to adopt nutrient application in a judicial manner in the tea plantations.