Improvement of soil quality and optimisation of plant growth with biochar

Abstract

With little agricultural land, Singapore imports majority of its foods, resulting in growing concerns of food sustainability and security. There is a definite need to identify strategies for effective local food production. However, complications arise in the form of rapid urbanisation, which has led to considerable anthropogenic impact on the foods that we now consume. Harmful human behaviour has increased both on the individual and corporate scales, and the resulting negative implications have been ever-growing. These include greater water, land and air pollution, due to the production of hazardous contaminants such as lead. There is a need to identify strategies for safe and sustainable food production, and to tackle this issue, this study investigates the safety of consumption and the availability of high nutritional value in foods such as green leafy vegetables. Using Choy Sum in particular, research is conducted using the addition of biochar of different sizes in non-contaminated and lead contaminated soils. Using Choy Sum in particular, research is conducted using the addition of biochar of different sizes in non-contaminated and lead contaminated soils. In the experiment, the presence of biochar of sizes: >4.00mm, 1.18 - 4.00 mm and < 1.18 mm were used and soil with 250ppm of lead was used to represent a medium contamination of lead contaminated soils. Choy Sum vegetables were grown in 3 reptations for each variable in biochar size and presence of lead in the soil. The study subsequently finds that in non-contaminated soils, the addition of different sized biochar aids the improvement the nutritional uptake value of calcium and iron, as well as the general rate of growth of the Choy Sum plant. The findings of the experiment also indicate that adding biochar in lead-contaminated soils may not help to reduce the uptake of lead into Choy Sum in the quest to make it safe for consumption. Conversely, an alternative solution is presented, as it is proposed that biochar can effectively act as a hyperaccumulator to remediate the lead-contaminated soils.