Impact of Long-Term Application of Organic Manure on Inceptisol Properties, Grain Protein Content and Yield of Wheat

ABSTRACT

A field experiment was conducted to investigate the implications of long-term farm yard manure (FYM) use on chemical and microbial properties of Inceptisol in the North-Western Plain Zone of India, and their correlation with yield and protein content of wheat grains. FYM was used at four different doses (0, 10, 20, 30 t ha⁻¹) with recommended dose of nitrogen, phosphorus and potassium (NPK) as standard practice before sowing of both rice and wheat under rice-wheat cropping system. Application of FYM at 30 t ha⁻¹ significantly enhanced the electrical conductivity (36.36%), nitrogen (29.79%), phosphorus (216.75%), potassium (280.15%), zinc (186.90%), copper (24.23%), organic carbon (130.77%), organic matter (132.43%), operational taxonomic units (OTUs) of top 30 bacterial classes (82.27%), genera (73.95%), plant growth promoting bacteria (PGPB, 86.00%) and lignocellulose degrading bacteria (LDB, 109.14%) over recommended NPK at p value of 0.05. Significantly high plant biomass (14.21 t ha⁻¹) and grain yield (5.69 t ha⁻¹) were obtained in recommended NPK treatment, followed by 30 t ha⁻¹ FYM treatment, whereas significantly higher grain protein was obtained in 30 t ha⁻¹ FYM treatment at p value of 0.05. The abundance of top 30 bacterial classes was highest under 30 t ha⁻¹ FYM (100117), while lowest under recommended NPK treatment (54928). This treatment also witnessed highest presence of all beneficial bacterial classes, top 30 bacterial genera, PGPB and LDB. Highest up-regulated bacterial genes in recommended NPK, and superior soil quality parameters (nutrient profile and microbial diversity) in 30 t ha⁻¹ FYM, indicate that sustainable yields and quality are achievable by using a balanced amount of inorganic fertilizers and organic manure.

KEYWORDS:

• Bacterial abundance
• grain protein and yield
• organic manure
• soil chemical properties
• Triticum aestivum

Acknowledgements

This research did not receive any specific funding. The help extended by director, ICAR-Indian Institute of Wheat and Barley Research, Karnal, India for sanctioning funds for soil samples analysis and out sourcing of metagenomic sequencing is duly acknowledged. The help extended by Dr. Neeraj Kumar and Dr. OP Gupta, scientists at ICAR-IIWBR, Karnal, India is also duly acknowledged.

Disclosure statement

No potential conflict of interest was reported by the authors.