Sugarcane/peanut intercropping system improves physicochemical properties by changing N and P cycling and organic matter turnover in root zone soil

Abstract

Background The sugarcane/peanut intercropping system is a specific and efficient cropping pattern in South China. Intercropping systems change the bacterial diversity of soils and decrease disease rates. It can not only utilized light, heat, water and land resources efficiently, but also increased yield and economic benefits of farmers. Methods We determined soil nutrients, enzymes and microbes in sugarcane/peanut intercropping system, and analyzed relevance of the soil physicochemical properties and the genes involved in N and P cycling and organic matter turnover by metagenome sequencing. Results The results showed that sugarcane/peanut intercropping significantly boosted the content of total nitrogen, available phosphorus, total potassium, organic matter, pH value and bacteria and enhanced the activity of acid phosphatase compared to monocropping. Especially the content of available nitrogen, available phosphorus and organic matter increased significantly by 20.1%, 65.3% and 56.0% in root zone soil of IP2 treatment than monocropping treatment. The content of available potassium and microbial biomass carbon, as well as the activity of catalase, sucrase and protease, significantly decreased in intercropping root zone soil. Intercropping resulted in a significant increase by 7.8%, 16.2% and 23.0% in IS, IP1 and IP2, respectively, of the acid phosphatase content relative to MS. Metagenomic analysis showed that the pathways involved in carbohydrate and amino acid metabolism were dominant and more abundant in intercropping than in monocropping. Moreover, the relative abundances of genes related to N cycling (glnA, GLUD1_2, nirK), P cycling (phoR, phoB) and organic matter turnover (PRDX2_4) were higher in the intercropping soil than in the monocropping soil. The relative abundance of GLUD1_2 and phoR were 25.5% and 13.8% higher in the IP2 treatment respectively,and bgIX was higher in IS treatment compared to the monocropping treatment. Genes that were significantly related to phosphorus metabolism and nitrogen metabolism (TREH, katE, gudB) were more abundant in intercropping than in monocropping. Conclusion The results of this study indicate that the intercropping system changed the numbers of microbes as well as enzymes activities, and subsequently regulate genes involved in N cycling, P cycling and organic matter turnover. Finally, it leads to the increase of nutrients in root zone soil and improved the soil environment.

Enhanced Nutrient Uptake in Side-Row Maize and Improved Microbial Community Diversity in Wide-Strip Intercropping of Maize and Peanut

“…Soil Pro and DHO activities were positively correlated with TN (Figure S1), which was consistent with previous studies [31]. Soil Pro are involved in the conversion of amino acids and other nitrogen-containing organic compounds present in soil, and their hydrolysates are one of the nitrogen sources for higher plants [32]. Soil DHO participates in soil carbon cycle and promotes dehydrogenation of carbohydrates and organic acids [31].…”

“…A single bacterium can affect a variety of enzyme activities, so it is necessary to further explore or study the functional properties of each bacterium and the mechanism of soil enzyme activities themselves [35]. It was found that the transport and metabolism of amino acids, carbohydrate transport and metabolism, and metabolism of other amino acids in the secondary functional areas were relatively high in abundance, which was consistent with previous ndings [32,36]. Furthermore, it was speculated that the relative abundance of RB41 and Candidatus-udaeobacter increased.…”

Rhizosphere Bacterial Networks, but Not Diversity, Are Impacted by Pea-Wheat Intercropping

“…Thus, co-occurrence networks have been proposed as an additional parameter to characterize microbial communities ( Barberán et al, 2012 ; Berry and Widder, 2014 ; Morriën et al, 2017 ; de Vries et al, 2018 ; Li and Wu, 2018 ; Jacquiod et al, 2020 ). Concerning IC co-occurrence network, Tang et al (2021) showed, through a shotgun metagenome analysis, that sugarcane and peanut IC increased the abundance of bacterial genes involved in organic matter turnover comparing to SC, without correlating these differences to changes in microbiota diversity. Liu et al (2021) showed differences between the co-occurrence networks between two sugarcane varieties in IC.…”

“…Thus, attempts have been to assess the impact of IC on rhizosphere microbiota. Total microbial communities ( Taschen et al, 2017 ; Li et al, 2018 ; Gao et al, 2019 ; Liu et al, 2021 ; Tang et al, 2021 ) and specific functional guilds (e.g., ammonia oxidizing bacteria, Song et al, 2007 ; diazotrophic Proteobacteria, Solanki et al, 2020 ) from the total root systems of plant genotypes associated in IC have been analyzed. These reports evidenced that rhizosphere microbiota from IC and sole-cropping (SC) differ significantly, these differences being more strongly expressed for bacteria than for fungi ( Gong et al, 2019 ).…”

“…Biotic interactions do not only occur between plant-plant and plants-microbes, but also among microorganisms. An increasing attention is given to interaction networks between rhizosphere organisms ( van der Heijden and Hartmann, 2016 ) and the impact of IC on these networks has recently been stressed ( Liu et al, 2021 ; Tang et al, 2021 ). Thus, co-occurrence networks have been proposed as an additional parameter to characterize microbial communities ( Barberán et al, 2012 ; Berry and Widder, 2014 ; Morriën et al, 2017 ; de Vries et al, 2018 ; Li and Wu, 2018 ; Jacquiod et al, 2020 ).…”