Supplementary data: Table S1, Table S2, Table S3, and Table S4.

Table S1: Experiment schedule (transplanting, weeding, soil, plant, and water sampling) on organic fields. We used 0WF, 2WF, 4WF, 6WF, and 8WF for the intervals of mechanical weeding of 0, 2, 4, 6, and 8. Table S2: Effect of weeding frequencies on weed biomass (g m^–2) in each species at 60, 88 and 110 DAT (days after transplanting). Values are given as mean ± standard deviation. Value followed by different letter in each column are statistically different at P<0.05 based on the Tukey’s HSD test. 0, 2, 4, 6, and 8 was the frequency of mechanical weeding until 49 DAT. n.d: no data. Table S3: Effect of weeding frequencies on nitrogen concentration (%) in each weed species at 60, 88 and 110 DAT (days after transplanting). Values are given as mean ± standard deviation. Value followed by different letter in each column are statistically different at P<0.05 based on the Tukey’s HSD test0, 2, 4, 6, and 8 was the frequency of mechanical weeding until 49 DAT. n.d: no data. Table S4: Effect of weeding frequencies on nitrogen concentration (g N m^–2) in each weed species at 60, 88 and 110 DAT (days after transplanting). Values are given as mean ± standard deviation. Value followed by different letter in each column are statistically different at P<0.05 based on the Tukey’s HSD test0, 2, 4, 6, and 8 was the frequency of mechanical weeding until 49 DAT. n.d: no data.