Effect of organic substrates on growth, yield, and quality of spinach (Spinacia oleracea L.)

The experiment was conducted on organic substrates to determine the efficiency of reusing waste on spinach growth, yield, quality, and economic efficiency. The result showed treatment 2 (the mix of coffee grounds, cow manure, abalone mushroom residue, and rice husk ash) and treatment 6 (coffee grounds, cow manure, abalone mushroom residue, rice husk ash, and soil) were the best results in 9 treatments. Analysis of nutrition showed that these substrates had total N > 0.11%, P 2 0 5 > 0.22%, and K 2 O > 7.39%. Treatment 2 had 25.0 cm of tree height and 29.1 leaves/tree. Leaf length, leaf width (23.8 cm - 8.3 cm), canopy diameter (23.9 cm), chlorophyll 39,6 SPAD Units, root length 14.3 cm, and stem diameter 0.8 cm. The average tree weight and theoretical yield had the highest (76.0 g-2.50 tons/1000 m 2 ). The dry matter percentage was recorded at 12.9%. Treatment 6 was the treatment with the highest Vitamin C content (0.12%). The results of profit, capital efficiency, and marginal income index of treatment two were recorded (45.3 million VND/1000 m 2 -2.2 - 21.6). The formula, including coffee grounds, cow manure, abalone mushroom residue, and rice husk ash, was the best prospect for application in production practices.