Agriculture is considered the backbone of Pakistan's economy, which relies heavily on its major crops. Pakistan's principal natural resources are arable land and water. Agriculture accounts for about 18.9% of Pakistan's GDP and employs about 42.3% of the labour force. The most agricultural province is Punjab where wheat & cotton are the most grown. Mango orchards are mostly found in Sindh and Punjab provinces, making it the world's fourth largest producer of mangoes. Early history Barley and wheat cultivation—along with the domestication of cattle, primarily sheep and goat—was visible in Mehrgarh by 8000–6000 BCE. They cultivated six-row barley, einkorn and emmer wheat, jujubes and dates, and herded sheep, goats and cattle. Residents of the later period (5500 BC to 2600 BC) put much effort into crafts, including flint knapping, tanning, bead production, and metal working. The site was occupied continuously until about 2655 BC. Irrigation was developed in the Indus Valley civilization (see also Mohenjo-daro) by c. 4500 BCE. The size and prosperity of the Indus civilization grew as a result of this innovation, which eventually led to more planned settlements making use of drainage and sewers. Sophisticated irrigation and water storage systems were developed by the Indus Valley civilization, including artificial reservoirs at Girnar dated to 3000 BCE, and an early canal irrigation system from c.2600 BCE. Archaeological evidence of an animal-drawn plough dates back to 2500 BC in the Indus Valley civilization. All agricultural affairs and activities in Pakistan are overseen and regulated by the Ministry of Agriculture. Production Pakistan production (2021): 67.1 million tons of sugarcane (5th largest global producer, behind Brazil, India, China & Thailand); 25.0 million tons of wheat (7th largest producer); 10.8 million tons of rice (10th largest producer); 6.3 million tons of maize (20th largest producer); 4.8 million tons of cotton (5th largest producer); 4.6 million tonnes of potato (18th largest producer); 2.3 million tonnes of mango (including mangosteen & guava) (5th largest global producer, just behind India, China, Thailand & Indonesia); 2.1 million tons of onion (6th largest producer); 1.6 million tons of orange (12th largest producer); 593 thousand tons of tangerine; 1,601 thousand tons of tomatoes; 545 thousand tons of apple; 540 thousand tons of watermelon; 501 thousand tons of carrot; 471 thousand tons of date (6th largest global producer); In addition, smaller production of other agricultural products. Rankings Pakistan is one of the world's largest producers and suppliers of food