储备粮随着存放时间的延长，不仅需支付更多的占用资金的时间价值（利息）和储备费用，而且粮食的品质也会逐渐下降，造成价差损失。如果完全按照粮食储存保管期限进行轮换，则还要增加轮换费用。理论上较为经济的办法，是根据我国的粮食形势，结合国际市场的粮价情况，在... With the extension of storage time, the reserve grain will not only need to pay more time value (interest) and reserve cost for the occupied funds, but also the quality of grain will gradually decline, resulting in loss of spread. If the rotation is to be carried out in full compliance with the storage period of the grain storage, the rotation fee will also be increased. The theoretically more economical approach is based on the food situation in China and the grain prices in the international market.