Fig. 1: Changes in soil physical and chemical properties.
Percentage changes relative to the baseline in a bulk density, b soil pH, c soil organic carbon (SOC), d total nitrogen, e C to N ratios and f available P following 1–3 seasons of repeated application of sole manure (at a rate of 0.3-30 t ha−1; median rate: 6 t ha−1), manure + NP(K) fertilizer, the recommended synthetic fertilizer (Recom NP(K)) or the no-input control in our meta-analysis. Notches in the box plots represent the 95% confidence limits of the medians, while the whiskers represent the most extreme values defined as Q1–1.5×IQR and Q3 + 1.5×IQR. The red horizontal line represents no change with treatment relative to the baseline (% change = 0). When the horizontal red line falls within the 95% confidence limits, the soil health indicator is deemed to have not significantly changed relative to its baseline value following a particular treatment. Figures were created using the PAST (Paleontological Statistics) software Version 4.11.
