The Impact of Hairy Vetch Incorporated as a Green Manure on the Phosphorus Uptake, Growth, and Yield of Silage Corn in South Kanto, Japan

Abstract

Hairy vetch （Vicia villosa Roth.） is often recommended as a green manure to relieve nitrogen （N） losses and to improve the performance of subsequent corn （Zea mays L.） in cropping systems. However, it is unclear whether hairy vetch impacts phosphorus （P）-mobilizing capacity and P availability of corn. Therefore, the aim of this 2-year field study is to determine the impact of hairy vetch cropping on the P-mobilizing capacity （phosphatase activity）, P uptake, and yield of subsequent silage corn. Throughout the study period, cultivation of hairy vetch increased EC, NO₃−N, ACP, and ALP activities compared with those treated with fallow. In addition, under the hairy vetch treatment, the plant length and stem diameter at the V6 stage in 2017, and leaf area index of the corn at the V6 stage in 2016 tended to be higher than those under the fallow treatment. P uptake in the corn under the hairy vetch treatment at the V6 and R1 stages tended to be higher than that under the fallow treatment. Moreover, under the hairy vetch treatment in 2016, the grain yield, grain number, and 100-seed weight of corn tended to be higher than those under the fallow treatment. However, the grain yield and yield components were not changed between hairy vetch and fallow treatments in 2017. Taken together, these findings suggest that soil biochemical properties, such as soil phosphatase activity, can be associated with P-mobilization arising from cultivation of hairy vetch, leading to increased growth and yield of subsequent corn in this study. Further research to improve the P availability, growth and yield of subsequent corn is needed to determine optimal hairy vetch cropping systems.