Fertilization using manure minimizes the trade-offs between biodiversity and forage production in agri-environment scheme grasslands

Finally, for indicators related to the plant community, NPK+FYM had lowest forb species richness among all treatments. Similarly, NPK+FYM had the lowest nectar productivity among treatments. While not significant at the 5% level, the probability of FYM having a lower forb species richness than the no-fertilizer control was 93%. We did not observe signifi- cant differences in diversity of all plants among treatments. When comparing the group aver- age, FYM and NPK+FYM showed a lower mean performance than no-fertilizer (P < 0.05). Meanwhile NPK+FYM had a significantly lower group mean for plant community indicators than FYM and NPK (P < 0.05). All comparisons and P-values for individual indicators are available in Table 2 and for groups average in Table 3 in S1 File. Standardized range of values of each indicator are shown in Fig 2. Identification of the optimum fertilizer regime supporting forage, plant communities and insect communities When comparing the weighted mean between fertilizers, FYM was the only treatment that showed significant differences with some other treatments (Fig 3, Table 4 in S1 File). Thus, FYM had a significantly higher weighted mean than the control (P = 0.03) and NPK (P = 0.03), although there was no significant difference to NPK+FYM (P = 0.1). However, when comparing the weighted standard deviation among treatments, FYM has significant lower weighted standard deviation than NPK +FYM (P = 0.008). In fact, NPK+FYM showed a significantly higher weighted standard deviation than the rest of the treatments (P < 0.05). No

significant differences in weighted standard deviation were observed among FYM, NPK and Table 2. Pairwise comparisons of the weighted mean between fertilizer treatments for each of the 12 indicators. Probability of weighted mean > weighted mean of no-fertilizer Forage Insect community Plant community Ash Cp Mw Re Ba Dh Pp Dpa Dpo Dpl Fs Np FYM 0.31 0.99* 0.99* 0.99* 0.12 0.55 0.99* 0.34 0.2 0.14 0.07 0.13 NPK 0.38 0.98* 0.99* 0.17 0.03* 0.12 0.2 0.46 0.47 0.37 0.22 0.16 NPK+FYM 0.46 0.99* 0.97* 0.74 0* 0.62 0.81 0.82 0.13 0.11 0* 0* Probability of weighted mean > weighted mean of farmyard manure No Fe 0.69 0.004* 0.01* 0.01* 0.87 0.45 0.02* 0.65 0.79 0.86 0.93 0.86 NPK 0.53 0.07* 0.07 0.01* 0.5 0.17 0.03* 0.61 0.78 0.73 0.83 0.6 NPK+FYM 0.59 0.53 0.63 0.22 0.25 0.57 0.27 0.87 0.4 0.32 0.001* 0.05* Probability of weighted mean > weighted mean of NPK (20:10:10) No Fe 0.62 0.02* 0.001* 0.83 0.97* 0.88 0.8 0.54 0.53 0.63 0.78 0.85 FYM 0.46 0.93* 0.93 0.99* 0.5 0.83 0.97* 0.39 0.2 0.26 0.16 0.4 NPK+FYM 0.56 0.96* 0.87 0.91 0* 0.85 0.92 0.81 0.18 0.16 0* 0.01* Probability of weighted mean > weighted mean of NPK+FYM No Fe 0.54 0.004* 0.02* 0.26 1* 0.37 0.19 0.18 0.86 0.88 1* 1* FYM 0.41 0.47 0.37 0.78 0.57 0.43 0.73 0.13 0.62 0.67 0.99* 0.95* NPK 0.44 0.04* 0.12 0.08 1* 0.15 0.08 0.19 0.81 0.84 1* 0.99*

The probabilities correspond to the number of times out of the 10,000 randomizations, that the mean of the first treatment was higher than the mean of the second treatment. We set the two-tailed probability of significant difference as 0.1 (P < 0.05 or >0.95). * indicates significant differences. Forage: Re: Ruminant metabolizable energy. Mw: Mean dry weight 2011–2014. Cp: Crude protein. As: Ash. Insect community: Pp: Percent of parasitism. Dpo: Shannon-Weiner diversity of pollinators. Dpa: Shannon-Weiner diversity of parasitoids. Dh: Shannon-Weiner diversity of herbivores. Ba Abundance of bumblebees. Plant community: Np: nectar productivity. Fs: Forb species richness. Dpl: Diversity of plants. No Fe: No-fertilizer. NPK: mineral fertilizer (20:10:10), FYM: farm yard manure, NPK+FYM: mineral fertilizer and farm yard manure. N = 24. https://doi.org/10.1371/journal.pone.0290843.t002 PLOS ONE Manure minimizes trade-offs between biodiversity and forage production in agri-environment scheme PLOS ONE | https://doi.org/10.1371/journal.pone.0290843 October 4, 2023 9 / 18