I should have added that not all increased agricultural productivity took place under capitalism - much of it was down to the People's Republic of China. Socialist goverments used the same mix of fertilisation and motorisation that increased output in the west (though thanks to its poor distribution network, a lot of Soviet produce rotted in railway sidings) - even India's 'green revolution' was led more by government than private industry. Cuba's agronomists were in the forefront of genetic modification until the European Union made it clear that they would not buy any GM produce.