Plastic film and organic mulching increases rhizosphere microbial population, plant growth, and mineral uptake in low input grown tomato in the northwestern region of India

Crop management determinants that manipulate population, diversity and function of soil microbiome are crucial for managing plant health and soil quality, nutrients cycling, ecosystem functioning, and plant-soil feedback. Herein, the objectives of the present preliminary investigation were to assess the impact of plastic film (black and silver) and organic (wheat straw) mulching on the different rhizosphere microbial population, plant growth, and mineral uptake in tomato crop. The measurement of rhizosphere microbial population and plant growth attributes was performed at the vegetative and reproductive growth stages of the tomato crop, while, mineral uptake analysis was carried out at the vegetative stage using the inductively coupled plasma optical emission spectrometry (ICP-OES). The result of experiments revealed that soil mulching favored microbial abundance in the crop rhizosphere, improved plant growth parameters and mineral uptake in tomato plants. The highest bacterial (6.75 ± 0.16 log₁₀ colony-forming units per gram of soil (CFUg⁻¹), and phosphorous solubilizing organisms (5.47 ± 0.02 log₁₀ CFUg⁻¹) population was found in silver mulch while wheat straw (as organic mulch) resulted in the higher fungal (4.64 ± 0.04 log₁₀ CFUg⁻¹), actinomycetes (5.68 ± 0.06 log10 CFUg⁻¹) and rhizobial count (3.77 ± 0.07 log₁₀ CFUg⁻¹) during the vegetative growth. Consistently, the rhizosphere microbial population at the fruiting stage was also found higher in either colored plastic film or organic mulch treatment. Soil mulching also led to the substantial improvement in the plants shoot length, shoot girth and the number of secondary branches both at the vegetative and fruiting stage. ICP-OES analysis of mulched plant revealed the better mineral uptake in different parts of plants. The highest concentration for P (4535.67 ± 92.87 mgkg⁻¹), K (11933.33 ± 338.35 mgkg⁻¹), Mg (10263.33 ± 63.86 mg kg⁻¹) and micronutrients uptake values for Fe (1167.67 ± 16.14 mg kg⁻¹), Mn (133.83 ± 2.15 mg kg⁻¹), and Cu (40.11 ± 0.87 mg kg⁻¹) were observed in the silver film mulch treatment. Likewise, tomatoes from soil mulched conditions also recorded the highest uptake of the analyzed mineral nutrients. The present study revealed that soil mulching could be an effective technique for favorably altering beneficial soil microflora and enhancing mineral uptake in crop plants and thus for improving soil quality and productivity in a sustainable manner.