Agricultural practices modulate the bacterial communities, and nitrogen cycling bacterial guild in rhizosphere: field experiment with soybean.

BACKGROUND: Modern agricultural management approaches are often dependent on the application of chemicals, resulting in adverse impacts on human and environmental health. Therefore, for sustainable agriculture, there is a need to implement integrated agriculture practices that can maintain natural soil microbiome and enhance crop production. Various agricultural approaches influence crop production by impacting the functional bacterial community entailed in biogeochemical cycles, for example, nitrogen (N) cycle. This study aimed to assess the rhizospheric N cycling community of soybean under three agricultural practices, namely, conservation agriculture (CA), conventional treatment (CT), and organic agriculture (OA) for two consecutive years (2017 and 2018).
RESULTS: A field experiment was designed under soybean-wheat cropping system employing CA, CT, and OA modules that included different practices of tillage, crop bedding pattern, crop residue retention, and nutrient application. Assessment of bacterial communities contributing to N transformation was performed with quantitative polymerase chain reaction (qPCR) of important markers (nifH, amoA, narG, and nirK).
CONCLUSION: Results concluded that the practice of conservation agriculture comprising of raised bed, zero tillage, crop residue retention, and application of NPK (nitrogen, phosphorus, potassium) nutrients favorably affected the plant attributes and the abundance of N cycling bacterial community over the two consecutive years. The outcome revealed the mechanistic principle behind enhanced plant growth under conservation agriculture, and opened up the possibility of regulating the N cycling bacterial community to develop sustainable and productive agro-ecosystems.