Figure 1:
Diagram of one block of the experiment, showing the split-plot experimental design, with entire tree rows allocated either microsprinkler or drip irrigation, and five ST randomly allocated to 5-m long subplots within each row. The four trees per subplot are denoted by “x.” The entire experiment consisted of 6 blocks for a total of 12 rows. ST, soil treatments.
Figure 2:
Change through time in the percentage of plots with M. xenoplax for drip irrigation (Drip) (30 plots) and MS irrigation (30 plots). Error bars are the standard errors of the proportions (n = 30). Asterisks (*) denote individual sample dates at which differences were significant (Chi-square, P ≤ 0.05). MS, microsprinkler.
Table 1:
Main-factor means and mixed model repeated measurement ANOVA summaries for the three nematode population parameters from 2019 through 2023, and cherry tree TCA in 2023.
| M. xenoplax 100 cm−1 soil | P. penetrans 100 cm−1 soil | P. penetrans g−1 root | 2023 TCA cm2 | |
|---|---|---|---|---|
| Irrigation (whole-plot) means | ||||
| Drip | 78* | 17* | 136* | 80 |
| MS | 34 | 24 | 268 | 72 |
| ST (subplot) means | ||||
| Compost (C) | 115a | 15b | 108 | 78 |
| BC | 20b | 25a | 181 | 79 |
| C + BC | 26b | 25ab | 253 | 78 |
| Fumigated | 103a | 20ab | 293 | 76 |
| Untreated | 19b | 19b | 176 | 69 |
| ANOVA summary (P-values) | ||||
| Irrigation (I) | 0.004 | 0.004 | 0.039 | 0.071 |
| ST | 0.048 | 0.017 | 0.079 | 0.599 |
| I × ST | 0.482 | 0.267 | 0.245 | 0.515 |
| Year (Y) | 0.005 | <0.001 | <0.001 | NA |
| Y × I | 0.408 | 0.036 | 0.961 | NA |
| Y × ST | 0.068 | 0.178 | 0.024 | NA |
| Y × I × ST | 0.964 | 0.253 | 0.369 | NA |
Figure 3:
Changes over five annual sample dates in population densities of M. xenoplax (100 cm−1 soil) and P. penetrans (100 cm−1 soil) under drip irrigation and MS irrigation in a sweet cherry orchard. Each data point is a main-factor mean of five ST and six blocks (n = 30). Error bars are (±) pooled standard errors from mixed model ANOVA of raw data. ANOVA P-values (log-transformed data) for irrigation × sample date interaction and irrigation main-factor effects were 0.408 and 0.004 for M. xenoplax, and 0.036 and 0.004 for P. penetrans, respectively. Individual sample dates at which drip irrigation differs from microsprinkler (P < 0.05) are denoted by “*” and “†” for M. xenoplax and P. penetrans, respectively. ANOVA, analysis of variance; MS, microsprinkler; ST, soil treatment.
Figure 4:
Changes over five annual sample dates in number of P. penetrans g−1 dry fine root tissue in five ST in a sweet cherry orchard. Each data point is a mean of two irrigation treatments and six blocks (n = 12). Error bars are (±) pooled standard errors from mixed model ANOVA of raw data. ANOVA P-value (log-transformed data) for the ST × sample date interaction was 0.024. ANOVA, analysis of variance; ST, soil treatment.
Table S1:
Macronutrient concentrations and estimates of cumulative macro-nutrient inputs for the compost and bark chip treatments.
| C (%) | N (%) | P (%) | K (%) | Mg (%) | Ca (%) | |
|---|---|---|---|---|---|---|
| AWC | 18.9 | 1.22 | 0.30 | 0.84 | 0.55 | 2.40 |
| YWC | 22.5 | 1.25 | 0.30 | 0.98 | 0.65 | 2.40 |
| BC | 47.6 | 0.34 | n.d. | n.d. | n.d. | n.d. |
| Cumulative additions, 2014–2023 (Mg/ha−1 orchard area) | ||||||
| Compost (C) | 39.6 | 2.455 | 0.6 | 1.75 | 1.15 | 4.8 |
| BC | 59.5 | 0.421 | n.d. | n.d. | n.d. | n.d. |
| C + BC | 99.1 | 2.876 | n.d. | n.d. | n.d. | n.d. |
[i] The AWC was applied in 2014, 2019, and 2021, while the municipal YWC was applied in 2016. Each compost application was at 50 Mg · ha−1 orchard area but concentrated in a 1.5 m band centered on the tree row.
AWC, agricultural waste compost; BC, bark chips; n.d., not determined; YWC, yard waste compost.
Table S2:
Volumetric water contents (cm−3 H2O · cm−3 soil) in treatment plots under MS and drip irrigation regimes.
| Year | |||||
|---|---|---|---|---|---|
| 2018 | 2020 | 2021 | 2022 | 2023 | |
| MS | |||||
| Compost (C) | 0.179 | 0.241 | 0.259 | 0.280 | 0.116 |
| BC | 0.168 | 0.183 | 0.165 | 0.200 | 0.082 |
| C + BC | 0.179 | 0.224 | 0.165 | 0.208 | 0.139 |
| Fumigated | 0.179 | 0.185 | 0.174 | 0.167 | 0.096 |
| MS average | 0.176 | 0.208 | 0.191 | 0.214 | 0.108 |
| Drip | |||||
| Compost (C) | 0.181 | 0.249 | 0.190 | 0.194 | 0.149 |
| BC | 0.209 | 0.296 | 0.259 | 0.317 | 0.222 |
| C + BC | 0.165 | 0.215 | 0.195 | 0.186 | 0.127 |
| Fumigated | 0.172 | 0.279 | 0.228 | 0.257 | 0.171 |
| Drip average | 0.181 | 0.260 | 0.218 | 0.239 | 0.167 |