Medicago sativa and soil microbiome responses to Trichoderma as a biofertilizer in alkaline-saline soils
Introduction
Soil salinization, which leads mainly to soil compaction and soil nutrient decline, an important abiotic stress that severely affects the development of agriculture and can even destroy ecological environment. Saline-alkali soils, which are characterized by relatively high pH values and salt concentrations and relatively low levels of soil organic matter and nutrient contents, is unable to support the healthy growth of crops (Pascale et al., 2005). The low productivity of saline-alkali soils is attributed primarily to poor microbial activity (Shao et al., 2018). Recently, the cultivation of saline-tolerant forage species adapted to saline-alkali soils has gained increased amounts of attention. Medicago sativa, an excellent perennial leguminous forage grass species, is widely cultivated and has a positive effect on the development of animal husbandry (Hermann et al., 2002). Accumulating evidence (Y.C. Wang et al., 2007; Postnikova et al., 2013; Liu et al., 2018) has shown that M. sativa can tolerate a certain degree of saline-alkali stress. Li et al. (2010) reported that M. sativa is extremely sensitive to saline-alkali stress, especially during the germination and early-seedling phases.
Trichoderma spp., which are well-known plant growth promoters, can significantly accelerate plant growth through a series of mechanisms (Altomare et al., 1999; Naseby et al., 2000; Banani et al., 2013). Many studies have shown that inoculation with Trichoderma significantly promotes the growth of various plant species (Kucuk et al., 2008; Zhang et al., 2018; Singh et al., 2019). The combination of Trichoderma strains and organic fertilizers (OFs) to produce biofertilizers (BOFs) is effective for obtaining high crop yields, and the promotion effect of BOFs is better than that of either OF or Trichoderma strains alone (Zhang et al., 2013a, Zhang et al., 2013b). The application of BOF (including functional microbes) can restore healthy and active soil microflora within a relatively short period, effectively improving soil properties and increasing soil fertility, thus playing a positive role in plant growth. A good soil microflora is an effective guarantee for promoting plant growth (Philippot et al., 2013). Although Trichoderma BOF has a positive role in normal agricultural soils, the facilitation effect of Trichoderma BOF in saline-alkali soils has rarely been reported.
Mowing is one of the most common cultivation practices of forage grass and is primarily employed in M. sativa production (Barać et al., 2012). M. sativa rapidly recovers after mowing, which supports the maintenance of stable yields. Mowing can elevate total plant biomass mainly because it is beneficial to promote plants to generate new leaves (Robson et al., 2007; Zhang et al., 2019). However, the report of Todd et al. (1992) demonstrated that plant shoot removal by mowing can be accompanied by reduced root biomass and related N contents. The suitable stage for M. sativa mowing is the first-flower stage, which guarantees the best nutrient contents and yields (Radović et al., 2009). However, the promotion effects of different fertilization regimes under non-mowed and mowed conditions, especially the effects of the underlying microbial mechanisms, have rarely been studied.
The M. sativa cultivar ‘Zhong-Mu No. 1,’ which is somewhat resistant to saline-alkaline stress, was used in this study. We applied different fertilizers (CK, nonamended fertilizer; OF, organic fertilizer; and BOF, Trichoderma biofertilizer) under non-mowed and mowed conditions to address the following questions: (i) Does BOF significantly increase M. sativa growth more than CK and OF does in both mowed and non-mowed systems? (ii) How do the different treatments impact the soil properties and the soil microbial diversity and community? (iii) Do correlations exist between soil properties, the soil microbial diversity and community, and M. sativa biomass? And (iv) Among these factors (fertilization regime, non-mowed/mowed conditions, and soil properties), which mainly affects the soil microbial community?
Section snippets
Trichoderma strain, seeds, soil and fertilizers used in the greenhouse experiments
The strain NAU-T14 used throughout this study was isolated from soil at the Dongying Comprehensive Experimental Station (37°18′26″ E, 118°38′15″ N), Dongying city, Shandong Province, China; the strain was identified as Trichoderma harzianum (Fig. S1a, b, CCTCC M 2018520, China Center for Type Culture Collection). T. harzianum NAU-14 is usually cultivated on potato dextrose agar (PDA) plates and incubated at 28 °C.
M. sativa seeds (Zhong-Mu No. 1, Zhang et al., 2019) were employed in our
Coupling of soil properties and M. sativa growth
Fertilization, mowing and their interaction had significant (P < 0.001) effects on M. sativa shoot dry weight (Fig. 1a), but only fertilization had a significant (P < 0.001) effect on M. sativa root dry weight (Fig. 1b). Compared with those in the CK treatment, the shoot dry weight and root dry weight in the non-mowed treatment significantly elevated by 34.4% (P = 0.003) and 71.7% (P = 0.004), respectively, when M. sativa was treated with OF but increased by 64.8% (P < 0.001) and 117.4% (P
Discussion
The M. sativa biomass (both shoot dry weight and root dry weight) varied significantly under the different fertilization regimes (CK, OF, and BOF), which was primarily due to the altered soil nutrient contents and the effective activity of the microbial inoculants. The OF and BOF treatments, which have substantial soil organic matter and nutrient contents, improved soil properties and soil fertility better than the other treatments did according to the initial analysis (Jamil et al., 2004). The
Conclusions
Trichoderma BOF and mowing effectively altered soil properties, soil bacterial and fungal diversities, and soil bacterial and fungal communities, which ultimately increased M. sativa biomass in alkaline-saline soils. Soil bacterial HShannon and SChao1 values in the mowed system and fungal HShannon and SChao1 values in the non-mowed system were significantly correlated with M. sativa biomass. Soil properties had a significant influence on soil microbial community composition, which was also
Declaration of competing interest
The authors declare no conflicts of interest of this work.
Acknowledgments
This study was supported by the Earmarked Fund for China Agriculture Research System (CARS-34) and the China Scholarship Council (CSC No. 201906855001). We are very grateful to Y.Q. Huo for her assistance in the greenhouse and to Dr. Z.Z. Shen and Z.B. Zhou for their contribution to our revised work.
References (59)
- et al.
How plants communicate using the underground information superhighway
Trends Plant Sci.
(2004) - et al.
Long-term organic farming fosters below and aboveground biota: implications for soil quality, biological control and productivity
Soil Biol. Biochem.
(2008) - et al.
Characterizing the relationships between soil organic matter components and microbial function and composition along a tillage disturbance gradient
Soil Biol. Biochem.
(2008) - et al.
Soil salinization affects growth, yield and mineral composition of cauliflower and broccoli
Eur. J. Agron.
(2005) - et al.
Neglect of mowing and manuring leads to slower nitrogen cycling in subalpine grasslands
Soil Biol. Biochem.
(2007) - et al.
Relationship between rhizosphere soil properties and blossom-end rot of tomatoes in coastal saline-alkali land
Appl. Soil Ecol.
(2018) - et al.
Shifts in microbial diversity through land use intensity as drivers of carbon mineralization in soil
Soil Biol. Biochem.
(2015) - et al.
Microbial diversity and function in soil: from genes to ecosystems
Curr. Opin. Microbiol.
(2002) - et al.
Development of a cDNA microarray to identify gene expression of Puccinellia tenuiflora under saline-alkali stress
Plant Physiol. Biochem.
(2007) - et al.
Trichoderma harzianum T-E5 significantly affects cucumber root exudates and fungal community in the cucumber rhizosphere
Appl. Soil Ecol.
(2013)
Effects of organic-inorganic compound fertilizer with reduced chemical fertilizer application on crop yields, soil biological activity and bacterial community structure in a rice-wheat cropping system
Appl. Soil Ecol.
Soil microbial communities and function in alternative systems to continuous cotton
Soil Sci. Soc. Am. J.
Human gut microbiome and risk for colorectal cancer
J. Natl. Cancer Inst.
Resistance, resilience, and redundancy in microbial communities
Proc. Natl. Acad. Sci. U. S. A.
Solubilization of phosphates and micronutrients by the plant-growth-promoting and biocontrol fungus Trichoderma harzianum Rifai 1295-22
Appl. Environ. Microbiol.
Characterization of resistance mechanisms activated by Trichoderma harzianum T39 and benzothiadiazole to downy mildew in different grapevine cultivars
Plant Pathol.
Testing results of mower with different cutting devices in alfalfa mowing
Res. J. Agr. Sci.
The Nature and Properties of Soils
QIIME allows analysis of high-throughput community sequencing data
Nat. Methods
Global patterns of 16S rRNA diversity at a depth of millions of sequences per sample
Proc. Natl. Acad. Sci. U. S. A.
Comparative resistance and resilience of soil microbial communities and enzyme activities in adjacent native forest and agricultural soils
Microb. Ecol.
Manipulating the soil microbiome to increase soil health and plant fertility
Biol. Fertil. Soils
Soil bacterial diversity in the Arctic is not fundamentally different from that found in other biomes
Environ. Microbiol.
Relationship between soil properties and patterns of bacterial b-diversity across reclaimed and natural boreal forest soils
Microb. Ecol.
UPARSE: highly accurate OTU sequences from microbial amplicon reads
Nat. Methods
Distinct soil microbial diversity under long-term organic and conventional farming
ISME J.
Evaluation of hay-type and grazing-tolerant alfalfa cultivars in season-long or complementary rotational stocking systems for beef cows
J. Anim. Sci.
Environmental factors shaping microbial community structure in salt marsh sediments
Mar. Ecol. Prog. Ser.
Impact of organic wastes (Bagasse Ash) on the yield of wheat (Triticum aestivum L.) in a calcareous soil
Int. J. Agric. Biol.
Cited by (24)
Abundant and rare bacteria possess different diversity and function in crop monoculture and rotation systems across regional farmland
2022, Soil Biology and BiochemistryCitation Excerpt :However, although comparative studies on crop monoculture and rotation systems have been conducted, it is still unclear whether significant differences exist in soil microbial community diversity characteristics at the regional scale. Maize and soybeans are important food crops in Northeast China and this area is also a major alfalfa planting area in China (Liu et al., 2008; Zhang et al., 2020). We employed high-throughput sequencing technology to study the soil bacterial communities of the typical crops (maize, soybean, alfalfa) in CM and CR systems: alfalfa monoculture, continuous cropping of maize and soybean in CM system; maize-alfalfa rotation, maize-soybean rotation and soybean-maize rotation in CR system (Table S1).
Trichoderma biofertilizer facilitating Leymus chinensis production in different growth stages is strongly linked to dynamically altered soil microbiomes
2022, Agriculture, Ecosystems and EnvironmentCitation Excerpt :The application of Trichoderma BIOF improved L. chinensis growth across the whole growth stages, indicating that the plant growth promoting effect of BIOF was stable, with a long lifespan. Bioorganic fertilizer provides the same function as organic fertilizer and contains functional microbes, which, when applied to soil, colonize the rhizosphere to promote plant growth by increasing nutrient supply or availability (Zhang et al., 2020b). Consistent with our findings, Caporale et al. (2019) and Sharma and Borah (2021) also demonstrated the positive role of Trichoderma in facilitating plants growth.
Strengthening grazing pressure management to improve grassland ecosystem services
2021, Global Ecology and ConservationCitation Excerpt :In addition, the study used the statistical yearbook of Inner Mongolia Xilingol League to count the number of heads of livestock in the study area at the end of June each year as the total number of livestock grazing in that year, and analyzed the changes of livestock numbers in the study area over the past 20 years to verify the accuracy of modeling regional grazing pressure through the moving window method. Variance partitioning analysis (VPA) is often used to quantitatively assess the proportion (contribution) of different environmental factors to explain changes in community structure (Panettieri et al., 2020; Zhang et al., 2020a). Some scholars have extended the application of the VPA method to ecosystem services research (Felipe-Lucia et al., 2018).