QLF Agronomy L-CBF BOOST™ 4-0-3-2S (liquid carbon based fertilizer) is a combination of balanced crop nutrients with complex carbon sources. Feeding soil biology and enhancing plant nutrient availability. 30% sugars and packaged with a fermentation yeast extract in L-CBF BOOST™ help increase soil microbes and support plant growth. Microbes help make nutrients more plant-available, improve soil structure and speed residue decomposition. L-CBF BOOST™ has a low pH (3.7) and can be applied to corn, soybeans, alfalfa and small grains.