Sammanfattning

The aim of the study was to examine interspecific plant interactions that contribute to plant nitrogen (N) and phosphorus (P) acquisition and are likely the reason for overyielding in intercropping. We conducted a field and a rhizobox experiment with the same soil. Maize (Zea mays L.) was grown alone or intercropped with the companions faba bean (Vicia faba L.), soy (Glycine max (L.) Merr.), blue lupin (Lupinus angustifolius L.), or white mustard (Sinapis alba L.). We determined the isotopic N signature (delta N-15) of maize as well as soil parameters (pH, phosphatase activity, nitrate) in the field experiment. We analyzed phosphatase activities and rhizosphere pH by soil zymography and pH imaging in the rhizobox experiment. Maize N and P contents were larger in intercropping than monocropping, especially with soy and lupin in the field, indicating intercropping advantages for maize N and P acquisition. Intercropping with legumes decreased maize delta N-15 in the field, suggesting that 11-20% of maize aboveground biomass N was transferred from legumes to maize. Soil zymography revealed high phosphatase activities in the rhizosphere of lupin and faba bean. pH imaging showed a rhizosphere alkalinization by mustard, and a rhizosphere acidification by faba bean. These changes in the companions' rhizosphere likely mobilized P and were also beneficial for maize in intercropping. Taken together, our study provides evidence that the companions' ability to mobilize N and P in the rhizosphere promotes increases in maize nutrient contents and causes maize overyielding in intercropping and thus can contribute to fertilizer savings.

Nyckelord

Plant nitrogen acquisition; Plant phosphorus acquisition; Rhizosphere; Nitrogen transfer; Phosphatase activity; pH changes

Publicerad i

Journal of Soil Science and Plant Nutrition
2022, Volym: 22, nummer: 3, sidor: 3868-3884
Utgivare: SPRINGER INT PUBL AG

SLU författare

• Spohn, Marie

  • Institutionen för mark och miljö, Sveriges lantbruksuniversitet
    
  • Universität Bayreuth

UKÄ forskningsämne

Jordbruksvetenskap
Markvetenskap


Publikationens identifierare

DOI: https://doi.org/10.1007/s42729-022-00936-3

Permanent länk till denna sida (URI)

https://res.slu.se/id/publ/118571