Reclamation of calcareous soil and improvement of squash growth using brewers’ spent grain and compost

Abstract

Brewer’s spent grain represents approximately 85% of the by-products generated by the beer industry. It is acidic and rich in organic matter and nutrients. In Egypt, spent grain has no value and is available at no cost all year. Incubation and germination experiments were conducted to assess the potential of using spent grain and compost to increase soil fertility and squash (Cucurbita pepo L.) growth in a calcareous soil. Amendments were two rates of spent grain (13.5, 26.7 g kg−1), two rates of compost (24.7, 49.4 g kg−1), a blend of lowest rates of compost and spent grain and a control. Treatments were mixed with calcareous soil, placed in pots and incubated anaerobically under field conditions for one month. After incubation 15 squash seeds were planted in the soil pots. Highest rate of spent grain most effectively increased soil water holding capacity, organic matter, macronutrients, micronutrients, germination parameters, and reduced soil pH. Mixing compost with spent grain was more effective than high rate of compost in increasing water holding capacity, soil nutrients, and decreasing soil pH. While both treatments were equally effective in enhancing squash germination and increasing soil organic matter. Spent grain is more effective than compost in improving properties of calcareous soils, and is much less expensive. Keywords: Brewer’s spent grain, Calcareous soil, Compost, Cucurbita pepo L., Germination, Aridisols