Varying levels of spent mushroom substrate as soil conditioner for simultaneous

The use of spent mushroom substrate as a soil conditioner in roselle cultivation may provide economic rewards, but their potential to aid in soil reclamation and the development of technology related to roselle production in the Philippines must be carefully considered. The research was conducted on an approximate area of 127.5 m2 at the Don Mariano Marcos Memorial State University-College of Agriculture, Nagtagaan, Rosario, La Union. Using Randomized Complete Block Design, the area was split into three blocks. Five treatment combinations made up each block. The treatments were; T0 = 100% soil (control), T1 = 10% spent mushroom substrate + 90% soil, T2 = 20% spent mushroom substrate + 80% soil, T3 = 30% spent mushroom substrate + 70% soil, and T4 = 40% spent mushroom substrate + 60% soil. The application of 10% to 30% spent mushroom substrate to the soil positively affected growth and yield of roselle. A highly significant variation revealed on the mean stem diameter and mean number of fully developed primary branches while significant results were observed on the mean final plant height, mean number of fruits, mean fruit equatorial diameter, mean fresh fruit weight, mean fresh calyx weight, mean dried calyx weight and mean numbers of seeds. The performance of roselle is adversely affected by the level of alkalinity in T4, which measures 8.14. Soil treated with the increasing volume of spent mushroom substrate was observed physically and chemically improved except for phosphorus declined at the 10% level and soil pH stabilized at 30% level. The result testifies that by adding 10% to 40% amount of spent mushroom substrate could potentially treat deficient and acidic soils and serve as a useful soil conditioner for the concurrent production of roselle.