Improvements of soil biological properties with hairy vetch (Vicia villosa Roth) and rye (Secale cereale L.) and the contributions to lettuce (Lactuca sativa L.) production
Hairy vetch (Vicia villosa Roth) and rye (Secale cereale L.) are cover crops which can improve the abundance of soil microorganisms and their activities, as well as improving the yield of subsequent crops. However, the relationship between the improvement of microbes and crop yields is not well documented although this relationship is a key factor to improve soil fertility. We conducted a pot experiment in greenhouse. Three cover crop treatments were applied; hairy vetch (HV), rye and control (without any cover crops), in triplicates. The applied amount of these cover crops was 40 g dry weight pot‑1. At five days after the incorporation, five lettuce (Lactuca sativa L.) seedlings were transplanted. The HV decomposed significantly faster than rye, supplying larger amount of inorganic-nitrogen (38.5 mg N kg‑1 soil) than rye (12.5 mg N kg‑1 soil). Soil DNA at the harvest time of lettuce was extracted and analyzed for bacterial and fungal abundance using quantitative-polymerase chain reaction (q-PCR) approach with 16S and ITS primers, respectively. Rye showed 2.6 folds higher fungal abundance than control. Due to high nitrogen content of HV, microbial biomass nitrogen (MBN) in HV treatment (6.9 mg N kg‑1 soil) was significantly higher than rye and control (average of 3.8 mg N kg‑1 soil). The lettuce yield was significantly increased in HV (up to 313 g plant‑1) compared with the control (251 g plant‑1) and rye (258 g plant‑1), in which lettuce yield in rye and control were not significantly different. We demonstrated that cover crops application does not significantly increase the abundance of microorganisms, except rye effect on fungi. However, the MBN showed a positive correlation to lettuce yield (r=0.84), suggesting that microbial uptake of N as their biomass contributes to lettuce production.
Chinta, Y.D., Uchida, Y. and Araki, H. (2020). Improvements of soil biological properties with hairy vetch (Vicia villosa Roth) and rye (Secale cereale L.) and the contributions to lettuce (Lactuca sativa L.) production. Acta Hortic. 1286, 111-118
leguminous, gramineous, microbial biomass, microbial quantity, decomposition, lettuce