The only guaranteed way of stopping the swans from accessing your rice is to use bird netting. You will need to erect 10 foot high poles (think of electrical poles or logs) and then string bird netting from one pole to another. You will need to calculate the width and length of your rice fields to determine how much netting and how many logs to be placed width and lengthwise to attach the netting. This will keep the swans and even other birds from attacking your rice. The Regal Swan