Apple-Based Farming Systems Improve Production and Rhizosphere Microbiome in The North-West Himalayan Region's Dry Temperate Environment

Abstract

This research monitored the effect of integrated fruit-based farming system on production and rhizosphere microbiome of apple under dry temperate climate. The study also aims to understand the relationships among soil properties, production parameters and fruit yield of apple trees. Six cropping systems including, apple + pea, apple + kidney beans, apple + barley, apple + maize, apple + buckwheat, apple + garlic and apple monoculture were studied. The cropping systems treatments were cultivated with integrated farming approach, where measurements of the key indicators of productivity and nutrient cycling. Three blocks of district Kinnaur viz., Nichar, Kalpa and Pooh were selected. A representative sample size of five sub-locations with four orchards in each sub-location and six apple-based cropping systems (CS) was collected from each block. The current study also examined the significance of microbial communities on nutrient dynamics and biological cycling on apple in legumes, pulses and millets-based cropping systems. Apple + pea increased plant height, tree girth, canopy diameter, shoot growth, and apple leaf area of trees. Maximum generative traits of trees were recorded for apple + pea and apple + kidney bean cropping systems. Fruit yield in apple + pea was determined higher than apple + buckwheat. Soil pH changed towards neutral. When compared to monoculture, apple + pea cropping system showed an increase in post-harvest soil chemical indicators. Microbial biomass in terms of bacteria, actinobacteria, soil fungi, AM fungi, Azotobacter and phosphorus solubilizing bacteria were also improved. Path analysis revealed a positive direct influence of soil chemical and microbial properties on yield. PCA determined that the first principal component caused maximum cumulative variance of 97.19 per cent. Soil organic carbon, microbial biomass carbon, rhizosphere microbial population and nutrient availability were improved as a consequence of intercropped residues left over after harvest. In this study, apple-based cropping systems significantly improved nutrient dynamics, rhizosphere and microbial biomass due to crop residual management by intercropped companion crops left over in soil. Adoption of apple with pea intercrop has shown significant improvements in yield and soil fertility compared to conventional methods. The study thus concluded that transitioning to cropping systems has positive effects on apple cultivation which can be a viable alternative to conventional farming.