this trade is based on trump's tweet:
"If we bought 15 Billion Dollars of Agriculture from our Farmers, far more than China buys now, we would have more than 85 Billion Dollars left over for new Infrastructure, Healthcare, or anything else. China would greatly slow down, and we would automatically speed up!"
This is with regards to american agricultural exports to china -> Soybeans
This is similar to subsidy, if government subsidies consumer, the price goes down,
in this case the producer is subsidised so the price will go up (government will buy no matter what..)