Phosphorus transitions in traditional eco-knowledge versus chemical based agri-amendment systems of stress-prone semi-arid tropics: Finding the real game-changer

Abstract

Fixation of Phosphorus into locked forms hampers the availability of this important soil element. Phosphate Solubilising Microorganisms (PSM) play an important role of solubilisation and mineralization of these fixed forms into bio-available forms through reactions that are complex but provide simple solutions to P deficiency in soils. Semi-arid soil may have high total phosphorus concentrations but as most of the P is in an unavailable form, it leads to deficiency of this essential macronutrient in the crop. The use of microbial inoculants (biofertilisers) that possess the Phosphate solubilizing activities in agricultural soils is considered as an eco-friendly alternative to chemical based P fertilizers. The present study is a first of its kind attempt to understand the impact of Traditional Ecological Knowledge (TEK) (A1) vis-à-vis conventional chemical intensive integrated (A2) based agriculture amendment systems in altering/modifying the Phosphorus dynamics of the soil in the semiarid tropical region of Kachchh, Western India. The study was carried out for the pre, mid and post-harvest phases of crops for six seasons spread across 4 years.Higher Phosphorus Activation Coefficient (PAC), which is the ratio of available P (AP) to total P (TP) was observed in A1, that coincided with higher soil organic carbon (SOC) as well, across all seasons. The present study tried to answer questions as to how indigenous knowledge-based systems suited to local supply/demand complex system are precursors/indicators of a better microcosm in agriculture ecology studies that owing to its organic matter content improves SOC and PAC and in turn the overall P availability.