科研之友
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摘要
The invasive species Imperata cylindrica is a dominant grass covering a large part of degraded lands of India. Imperata is managed through traditional annual burning, a practice that is prevalent throughout tropical grasslands. A field experiment was conducted to quantify the effects of burning on aboveground and belowground biomass production and soil organic carbon (SOC), total nitrogen (TN), available phosphorus (Ave P), potassium (K+), calcium (Ca+), and magnesium (Mg+) concentrations in 0- to 15-cm soil depth under Imperata grassland. The burnt site had 44% and 14% higher aboveground and belowground biomass over the un-burnt control plots after 300 days of the fire event. The concentrations of SOC, TN, and Ave P increased soon after the fire but decreased regressively with time after the fire in both micro and macro soil aggregate size fractions. In contrast, concentrations of K+, Ca+, and Mg+ increased up to 30 days after the fire in both soil aggregate fractions. Burning did not significantly alter the stoichiometric ratios (C : N, C : P, and N : P) in macro aggregates. However, burning significantly reduced the C : N, C : P, and N : P ratios in micro aggregates during the first 0-30 days. Fire increased nutrient stocks (kg ha(-1)) by 20-35% in the burnt site in comparison to an un-burnt control site. It is concluded that the conventional practice of annual burning increases soil nutrients in surface soils and supports higher biomass production in Imperata-covered degraded lands.
- 出版日期2017-7
