Effects of paddy-upland rotation on control of Pomacea canaliculata and rice yield

Objective To investigate the influence of paddy-upland rotation on controlling Pomacea canaliculata and rice yield.

Method Four farming measures including winter potato rotation system, winter ryegrass rotation system, and two winter fallow rice fields treatments with water cover or without any water cover (two controls) were employed. The field population structure of snails in the previous and subsequent rice field, and early rice yield in the subsequent season were investigated.

Result and conclusion The results showed that winter potato rotation treatment was helpful for snails control and rice yield increase in the subsequent farming season, but the snail population recovery accelerated in the early rice growing period because of this rotation treatment. Winter ryegrass rotation treatment was unsatisfactory for snails control while it was beneficial for the early rice output of the next season. Winter-planting rotation was negative for controlling snail eggs, while the eggs were relatively few and most of them were distributed on weeds along field ridges. The eggs could be collected conveniently and efficiently at the beginning of the early rice growing season.