Soil properties, nutrient dynamics, and soil enzyme activities associated with garlic stalk decomposition under various conditions

Abstract

The garlic stalk is a byproduct of garlic production and normally abandoned or burned, both of which cause environmental pollution. It is therefore appropriate to determine the conditions of efficient decomposition, and equally appropriate to determine the impact of this decomposition on soil properties. In this study, the soil properties, enzyme activities and nutrient dynamics associated with the decomposition of garlic stalk at different temperatures, concentrations and durations were investigated. Stalk decomposition significantly increased the values of soil pH and electrical conductivity. In addition, total nitrogen and organic carbon concentration were significantly increased by decomposing stalks at 40°C, with a 5:100 ratio and for 10 or 60 days. The highest activities of sucrase, urease and alkaline phosphatase in soil were detected when stalk decomposition was performed at the lowest temperature (10°C), highest concentration (5:100), and shortest duration (10 or 20 days). The evidence presented here suggests that garlic stalk decomposition improves the quality of soil by altering the value of soil pH and electrical conductivity and by changing nutrient dynamics and soil enzyme activity, compared to the soil decomposition without garlic stalks.

Figure 1. Effects of the duration of garlic stalk decomposition on soil pH (A) and EC (B).

Error bars represent as the standard error of the mean. Different letters above the error bars indicate significant differences at the 0.05 level (ANOVA and Duncan’s multiple range test), n = 3.

Figure 2. Effects of duration of garlic stalk decomposition on soil enzyme activity.

Effects of different durations of garlic stalk decomposition on soil sucrase activity (A), soil urease activity (B) and soil alkaline phosphatase activity (C). Error bars represent the standard error of the mean. Different letters above the error bars indicate significant differences at the 0.05 level (ANOVA and Duncan’s multiple range test), n = 3.

Figure 3. Effects of different garlic stalk decomposition temperatures on soil pH (A) and EC (B).

Error bars represent the standard error of the mean. Different letters above the histograms indicate significant differences at the 0.05 level (ANOVA and Duncan’s multiple range test), n = 3.

Figure 4. Effects of different garlic stalk decomposition temperatures on soil enzyme activities.

Effect of different decomposition temperature of garlic stalk on soil sucrase activity (A), soil urease activity (B) and soil alkaline phosphatase activity (C). Error bars represent the standard error of the mean. Different letters above the histograms indicate significant differences at the 0.05 level (ANOVA and Duncan’s multiple range test), n = 3.

Figure 5. Effects of different concentrations of decomposed garlic stalk on soil pH (A) and EC (B).

Error bars represent the standard error of the mean. Different letters above the error bars indicate significant differences at the 0.05 level (ANOVA and Duncan’s multiple range test), n = 3.

Figure 6. Effects of different concentrations of decomposed garlic stalk on soil enzyme activities.

Effects of different concentrations of decomposed garlic stalk on soil sucrase activity (A), soil urease activity (B) and soil alkaline phosphatase activity (C). Error bars represent the standard error of the mean. Different letters above the error bars indicate significant differences at the 0.05 level (ANOVA and Duncan’s multiple range test), n = 3.