Short answers, pulled from the story.
In 2015, approximately 2 billion people survived as smallholder farmers working less than 2 hectares of land. These individuals represent slightly more than 25% of the global population and operate outside the logic of modern capitalism.
Subsistence agriculture largely disappeared from Europe by the beginning of the twentieth century and began to decline in North America during the 1930s and 1940s. Semi-subsistence agriculture reappeared in Central and Eastern Europe after 1990 but declined or disappeared by 2004 or 2007 when most countries joined the European Union.
The vanishing village phenomenon in India has led to increased farmer suicides and a widening income gap between lower and higher castes. Rural unemployment and increased poverty affect those who remain in rural areas while those who move to urbanized areas can increase their income.
Extreme temperatures linked to climate change reduce crop yields and force farmers to increase land and labor inputs that threaten long-term productivity. Rates of production for cereal crops such as wheat, oats, and maize have been declining due to heat effects on crop fertility.
Shifting cultivation is called dredd in India, ladang in Indonesia, and jhumming in North East India. This method involves clearing patches of forest through felling and burning to allow soil fertility to recover after two to three years.
Subsistence agriculture serves as a safety net for food-price shocks and food security in countries where 80% of the poor live in rural areas. Agriculture is more successful than non-agricultural jobs in combating poverty for people with an income of $1 per day who are poorly educated and have fewer opportunities.