Effect of Different Rotation Systems on Production and Quality of Black Morel (Morchella importuna)

Abstract

Morchella importuna is a highly priced edible and medicinal mushroom. Crop rotation is an important management technique to improve soil health. In this study, the morphological characteristics, chemical composition, and nutritional quality of the M. importuna fruitbody under five different rotation systems (named RSA to RSE) were investigated. The results showed that the fruitbodies of M. importuna in rotation system C (RSC, Rice–Pea–M. importuna rotation) grew best (with the highest yield of 6804.90 kg/hm2) and were of higher quality, which showed significant increases in crude protein (37.32 g/100 g) and decreases in crude fat (4.04 g/100 g), crude fiber (10.06 g/100 g), and total ash (9.32 g/100 g). The heavy metal contents (Pb, Cd, and Hg) in the fruitbodies from all rotation systems were rare or none, which meets the standards of the Chinese Green Food Standard and the maximum limit in foodstuffs of the European Union Standard. In addition, the free amino acid compositions of morel under different rotation systems were analyzed. The ratio of essential amino acids to total amino acids (EAA/TAA) was highest in RSC (37.11%). The tested morels were abundant in umami, sweet, aromatic, and medicinal amino acids (UAA, SAA, AAA and MAA). Combining amino acid score, chemical score, and other nutrition indexes, RSC had the best impact on the yield and quality of morel. Our results demonstrate the feasibility and effectiveness of the cultivation model of rotating “Rice–Vegetables–Fungi” for the production of M. importuna in a way that develops high-quality agriculture.