Table 1
Basic properties of soils in two treatments
| Treatment | pH | OM | TN | TP | TK | AN | AP | AK |
|---|---|---|---|---|---|---|---|---|
| g · kg−1 | mg · kg−1 | |||||||
| UT | 7.30 ± 0.05 | 20.70 ± 0.08 | 1.07 ± 0.02 | 1.91 ± 0.04 | 6.34 ± 0.09 | 155.23 ± 3.21 | 89.42 ± 2.12 | 686.05 ± 3.14 |
| TI | 7.12 ± 0.03 | 22.01 ± 0.11 | 1.18 ± 0.05 | 1.69 ± 0.07 | 5.81 ± 0.02 | 163.51 ± 1.51 | 95.61 ± 1.11 | 767.00 ± 1.89 |
[i] AK, available potassium; AN, available nitrogen; AP, available phosphorus; OM, organic matter; TI, tillage; TK, total potassium; TN, total nitrogen; TP, total phosphorus; UT, no-tillage.
Table 2
Oligonucleotide primers for PCR
| Microbes | Regions | Forward primer (5′-3′) | Reverse primer (5′-3′) |
|---|---|---|---|
| Bacteria | V4–V5 | GTGCCAGCMGCCGCGG | CCGTCAATTCMTTTRAGTTT |
| Fungi | ITS1 | CTTGGTCATTTAGAGGAAGTAA | GCTGCGTTCTTCATCGATGC |

Figure 1
Nutrient uptake in melon plant's leaf, stem, and fruit and yield analysis. Differences were considered statistically significant and highly significant at p < 0.05 (*) and p < 0.01 (**), respectively. Abbreviations: TK, total potassium; TN, Total nitrogen; TP, total phosphorus. UT and TL present no-tillage and tillage treatments, respectively.

Figure 2
Microbial community bar plot with cluster tree. Relative abundances of bacterial (A) and fungal (B) phyla in soils under no-tillage and tillage treatments.

Figure 3
Bacterial community heatmap analysis at the genus level.

Figure 4
Fungal community heatmap analysis at the genus level.

Figure 5
OTU Venn (A) and LEfSe (B) analyses of bacteria in no-tillage and tillage treatments.

Figure 6
Redundancy analysis of bacterial (A) and fungal (B) communities in no-tillage and tillage soil samples; heatmap of correlations. * and ** means significant correlations at p < 0.05, and p ≤ 0.01, respectively. Abbreviations: AK, available K; AN, alkaline nitrogen; AP, available P; OM, organic matter.

Figure 7
Biplot of species – environmental variables according to the CCA of bacterial taxa.

Figure 8
Biplot of species – environmental variables according to the CCA of fungal taxa.
Table 3
Soil microbial correlation with melon plant and nutrients
| Microbial groups | Nutrients | Soil microbial genus | Correlation | p-value | Significant level | Plant part |
|---|---|---|---|---|---|---|
| Bacteria | TN, TP and TK | Pirellula | 0.771 | 0.038 | * | Leaf and Fruit |
| TN | Dongia | −0.869 | 0.010 | * | Stem | |
| TN | Gemmatimonas, Hamadaea | −0.927 | 0.002 | ** | Stem | |
| TP | Dongia | −0.811 | 0.024 | * | Stem | |
| TP | Nocardioides, Gemmatimonas | −0.753 | 0.044 | * | Stem | |
| TP | Planctomycetes | 0.927 | 0.002 | ** | Stem | |
| TP | Armatimonadetes | −0.898 | 0.005 | ** | Stem | |
| TP | Patescibacteria | −0.898 | 0.005 | ** | Stem | |
| Fungi | TN, TP and TK | Chaetomium | −0.771 | 0.038 | * | Leaf and Fruit |
| TN, TP and TK | Dendrostilbella | 0.771 | 0.038 | * | Leaf and Fruit | |
| TN | AcrophialophoraCephaliophora | 0.782 | 0.034 | * | Stem | |
| TN | Polyschema | −0.898 | 0.005 | ** | Stem | |
| TN | Cercospora | −0.788 | 0.032 | * | Stem | |
| TN | Scedosporium | 0.779 | 0.035 | * | Stem | |
| TN | Verticillium | −0.927 | 0.002 | ** | Stem | |
| TP | Fusarium | −0.753 | 0.044 | * | Stem | |
| TP | Cercospora | −0.857 | 0.013 | * | Stem | |
| TK | Dendrostilbella | −0.771 | 0.038 | * | Stem | |
| TK | Ascobolus | −0.885 | 0.007 | ** | Stem | |