Intercropping perennial cereal and legumes for improving biological soil health and microbial drought resilience

Sammanfattning

Conventional annual cereal production relies on synthetic inputs and intensive agronomic practices that compromise soil health and increase vulnerability to drought. In contrast, perennial cereals such as intermediate wheatgrass (IWG) provide continuous soil cover and deep root systems for several years, making them promising for improving soil health and drought resilience. Soil microbes, particularly arbuscular mycorrhizal (AM) fungi, play a critical role in plant growth and drought resistance. Intercropping IWG with legumes may support beneficial soil microbes during drought and further improve soil health by increasing long-term crop diversity. However, the effects of IWG on soil microbial communities and their responses to drought stress remain poorly understood. This thesis investigates the interactions among IWG, legumes, and soil microbes under drought conditions. Controlled pot and field experiments were conducted to assess the yield and interspecific interactions in IWG-legume intercropping. The results showed that intercropping maintains or increases IWG grain yield and nitrogen (N) content, particularly under N-limited or drought conditions, due to the complementary use of N. A simulated drought experiment using in-situ rainfall reduction and phospholipid fatty acid analysis demonstrated the importance of soil microbial community composition and AM fungal biomass in maintaining the grain yield and N content of IWG under drought. IWG cropping shifted microbial communities towards a higher abundance of fungi and AM fungi and increased drought resilience. Furthermore, IWG increased soil total carbon in the upper soil layers. Overall, this thesis highlights the potential of perennial cereal-legume intercropping to improve soil biological health, enhance microbial drought resilience and stabilise grain yield, making it a promising strategy for climate change adaptation and mitigation.

Nyckelord

drought; intercropping; intermediate wheatgrass; microbial biomass; microbial community; perennial; PLFA; rainfall reduction; resistance and resilience

Publicerad i

Acta Universitatis Agriculturae Sueciae
2024, nummer: 2024:92
Utgivare: Swedish University of Agricultural Sciences

SLU författare

• Li, Shoujiao

  • Institutionen för biosystem och teknologi, Sveriges lantbruksuniversitet
    

UKÄ forskningsämne

Markvetenskap
Jordbruksvetenskap
Miljö- och naturvårdsvetenskap

Publikationens identifierare

• DOI: https://doi.org/10.54612/a.4ve4ma46ur
• ISBN: 978-91-8046-383-6
• eISBN: 978-91-8046-419-2

Permanent länk till denna sida (URI)

https://res.slu.se/id/publ/130487