Growth, Nutrient Uptake, and Foliar Gas Exchange in Pepper Cultured with Un-composted Fresh Spent Mushroom Residue

He Zhu,Jingmin Yang,Yunqing Luo,Wei Cui,Wencong Liu,Lingquan Meng,Shujie Zhao,Minghui Wang,Bo Hong

doi:10.15835/nbha47111307

Abstract

Spent mushroom substrate (SMS) can be used as the component of growing medium for the culture of crop plants. Fresh SMS may have the potential as an alternative to peat to raise horticultural plants. In this study, five container media characterized by the proportions of SMS to commercial peat in 0% (control), 25%, 50%, 75%, and 100% were used to raise pepper (Capsicum annum L.) plants. Initial SMS was found to have low available nitrogen (N) content (<20 mg kg-1) but moderate extractable phosphorus (P) content (900 mg kg-1). In the second month photosynthetic rate was found to decline in the 75% treatment. At harvest in the third month, plants in the 100% treatment nearly died out. The 25% treatment resulted in the highest height (19 cm) and diameter growth (0.3 cm), shoot (0.6 g) and root biomass accumulation (0.13 g), fruit weight (3 g), and shoot carbohydrate content (98 mg g-1), but lowest foliar acid phosphatase activity (30 µg NPP g-1 FW min-1). With the increase of SMS proportion in the substrate, the medium pH and electrical conductance (EC) increased with the decrease of foliar size. The available N and P contents in the substrates showed contrasting relationship with N and P contents in pepper plants. Therefore, fresh SMS cannot be directly used as the substrate for the culture of pepper plants. According to our findings fresh SMS was recommended to be mixed in the proportion of 25% with commercial peat for the culture of horticultural plants.

Highlights

Mushroom production is one of the largest solid-state fermentation industries all over the world (Soccol and Vandenberghe, 2008)
We used fresh spent mushroom substrate (SMS) as one component in the substrate, we found that the SMS proportion of 25% can result in better height and diameter growth (Table 2) and greater shoot and root biomass accumulation (Fig. 2A)
The 25% proportion of SMS in the substrate was found to be the best treatment because it induced best height and diameter growth, biomass accumulation in shoot and root parts, fruit number and weight

Summary

Introduction

Mushroom production is one of the largest solid-state fermentation industries all over the world (Soccol and Vandenberghe, 2008). The spent residue is considered “spent out” and abandoned as weathered fresh substrate, generating a by-product of mushroom cultivation. Every production of 1 kg of mushroom would generate 2.5-5 kg of spent mushroom substrate (SMS) (Semple et al, 2001; Ünal, 2015). The porosity of SMC would probably favour the root develop to increase the efficiency of nutrient and water uptake. These properties all contribute to the suggestion of SMC as one component in the growing media for crop plant culture (Chong et al, 1994; Tam and Wang, 2015; Nguyen and Wang, 2016)

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Discussion

Conclusion