Changes in Biological Soil Health Properties in Response to Increased Crop Diversity in a Dryland Wheat-Based Cropping System

ABSTRACT

Diversifying wheat (Triticum aestivum L.)-based cropping systems is important for the sustainability of dryland agriculture. Research has focused on the agronomic benefits of increased crop diversity in semi-arid environments, but less is known about the impacts of increased crop diversity on the soil microbial community. This work compared soil health parameters between a continuous wheat crop sequence to a diverse sequence that included pea (Pisum sativum L.), proso millet (Panicum miliaceum L.), safflower (Carthamus tinctorius, L.), and spring wheat. Respiration was higher (p < .005) in the diverse sequence while activity of N-acetyl-β-d-glucosaminidase was lower (p < .05) with a mean rate of 26.3 and 16.3 mg ρ-nitrophenol kg⁻¹ soil h⁻¹ for the continuous wheat and diverse sequences, respectively. The mean net nitrogen mineralized during the growing season was 33.2 ± 2.5 kg ha⁻¹ and was not different between treatments (p > .05). No difference was observed in bacterial alpha diversity, while fungal community diversity was 52% lower in the diverse rotation. The results of this work suggest that specific crops in a rotation may impact microbial processes related to nitrogen mineralization and that the soil fungal community may be more sensitive to changes in crop sequence than the soil bacterial community.

KEYWORDS:

• Enzyme assay
• microbial activity
• mineralization
• nitrogen
• nutrient cycling

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

The DNA sequencing data generated and analyzed in this study are available in the NCBI BioProject repository, https://www.ncbi.nlm.nih.gov/bioproject/PRJNA833079

Supplemental data

Supplemental data for this article can be accessed online at https://doi.org/10.1080/00103624.2024.2345153

Additional information

Funding

This work was supported by the Montana Fertilizer Advisory Committee and the USDA National Institute of Food and Agriculture, Hatch project 1015780.