Potential of coffee grounds as a sandy soil amendment and its effect on growth and fruit quality of strawberry

Abstract

Coffee grounds are discarded as solid waste in landfills which makes them an environmental hazard since it contains great quantities of caffeine and tannins. The efficiency of coffee grounds use in sandy soils is still scientifically unsupported and still lacks confirmation on its effect on fruit crops. The study aimed at assessing the potential of Coffee grounds (fresh FCG vs. composted CCG) as a sandy soil amendment and its effect on strawberry growth and fruit quality. The experimental design was a two factorial design conducted in a green house in a Randomized Block Design. Treatment ratios were 3kg of sandy soil as constant mixture with 1kg and 2kg of Coffee Grounds (composted and fresh) and control (Co), replicated 16 times for each treatment. The sandy soil nutrient content (N, P, K, Mg and Ca levels) were significantly high (P-value < 0.05) in CCG (2kg) and FCG (2kg) than in the FCG (1kg), CCG (1kg) and control (Co) at post-harvest analysis. Both CCG treatments produced strawberry plants with highest germination percentage and seed vigour indexat 14 days after planting. FCG treatments inhibited plant growth in the first 2 weeks after planting which improved greatly thereafter with no significant difference with the CCG treatments in plant vegetative growth by week 12. CCG (2kg) produced the best significant value for total number of fruits at 86.33 and fruit weight at 7.907. The FCG (2kg) and CCG (2kg) had the highest titratable acidity, soluble sugars and total soluble solids. CCG (2kg) had the highest mean value at 64.61 of ascorbic acid. This study delivered new understanding that experimental treatment of composted coffee grounds in rates of (2kg) gave significantly better results for strawberry in sandy soils compared to the lower rates of (1kg) and the control treatments.