LIMA—Peruvian President Pedro Castillo imposed a curfew in the capital, Lima, on Tuesday, banning people from leaving their homes in an attempt to curb protests against rising fuel and fertilizer costs that have spread throughout the country. “The cabinet has agreed to declare a ban on the mobility of citizens from 2 a.m. through 11:59 p.m. of Tuesday April 5 to protect the fundamental rights of all people,” Castillo said in an address broadcast nationwide just before midnight. On Monday, a wave of protests against rising fuel and fertilizer prices, triggered by Russia’s invasion of Ukraine, continued into their second week, while the government scrambled to bring prices down. The protests represent a harsh reality for the embattled presidency of leftist Pedro Castillo, a peasant farmer and school teacher who won election last year with the overwhelming support of the rural poor. But his support has quickly waned, even in …