According to the situation of rural credit card loans, the borrowing amount is 50,000 yuan. Regarding the calculation of interest rates, the following is a detailed explanation:

1. Interest rate calculation method: Generally speaking, the interest rates for rural credit card loans are set by commercial banks themselves, and the specific calculation methods may be different. The commonly used method is to calculate based on the annual interest rate, that is, calculate the loan interest annually and convert it into the corresponding interest rate.

2. Repayment term: The repayment term of the loan is also a key factor. The repayment period is not mentioned in the question, assuming the loan has a repayment period of 1 year.

3. Interest calculation: If the loan interest rate is the annual interest rate and the repayment period is 1 year, then the loan amount and interest rate can be brought into the following formula for calculation: Interest = Loan amount × annual interest rate. Assuming the annual interest rate is 5, then interest = 5,000 (yuan) × 0.05 = 250 (yuan).

To sum up, a rural credit card loan of 50,000 yuan, assuming a repayment period of 1 year, calculated based on an annual interest rate of 5, the interest is 250 yuan.

Extended information:

Rural credit card loans provide convenient lending services to rural areas and help farmers solve their short-term capital needs. Interest rate is one of the important factors to consider in the borrowing process. The interest rate of rural credit card loans may vary according to the policies of different banks and regions. In actual operation, factors such as the repayment period, borrowing amount, and personal credit will also affect the interest rate. Therefore, it is best to conduct detailed consultation with the relevant bank or financial institution before taking out a loan to understand the specific interest rate calculation methods and relevant regulations in order to make better borrowing decisions.