Biochar for Climate Change Adaptation: Effect on Heavy Metal Composition of Telfairia occidentalis Leaves

Abstract

Gas flaring is a key contributor of greenhouse gases that causes global warming and climate change. Adaptation measures for tackling impacts of climate change have gained much research interest. This chapter assessed vegetable farmers’ perception of gas flaring and the effect of biochar remediation on the heavy metal composition of cultivated Telfairia occidentalis. A gas-flared area, Ohaji/Egbema L.G.A of Imo State, and a non-gas-flared area, Umudike, Ikwuano L.G.A, were selected for this research. Structured questionnaire was used to elicit information from 120 respondents. Soils were collected from the study sites and transported to the greenhouse. Five different rates, 0 t ha-1, 7.1 t ha-1, 13.9 t ha-1, 20.9 t ha-1, and 28.0 t ha-1, of palm bunch biochar were applied to the soils in plastic buckets. After 2 weeks of mineralization, two viable seeds of Telfairia occidentalis were planted in each bucket and watered every other day for 8 weeks. The result revealed that 63% of vegetable farmers where female, while 37% were male in the gas-flared area. A total of 97% of the farmers had knowledge of gas flaring. A total decrease of 55% percent income, 90% yield, and 67% market quality of vegetable farmers was attributed to gas-flared activities. The plant height of cultivated vegetables increased every 2 weeks with greater increase in the test plant. Heavy metal concentration (Pb, and Cr) decreased with increasing biochar rate and was significantly lower for 28.0 t ha-1. Biochar can enhance soil fertility and help immobilize heavy metals. The effect of biochar application on the heavy metal composition is dependent on the rate of application. Biochar use could be a cheap adaptation measure in the face of a changing climate.