water—2000 millimeters of rainfall during its growth cycle—around five times more than typical food crops. One kilogram of cane sugar represents 145 liters of water, significant, but far less than rice: 2,500 liters of water per one kilogram of rice. Field burning Thailand in the early-21st century has suffered from increasing levels of air pollution. Field burning has been identified as a key contributor. In addition to releasing CO2, sugarcane burning emits acidic fine particles, which have an adverse impact on air quality and human health. Sugarcane is harvested either manually or mechanically using a sugarcane harvester. Before hand harvesting the sugarcane field is burned. Mechanical harvesting does not require field burning. The residue left in the field by the combine can serve as mulch for the next planting, although some farmers persist in burning it. Mechanical harvesting requires substantial capital outlays for machinery, thus much of Thailand's sugarcane is hand harvested. Government policy continues to allow sugar mills to purchase burnt sugarcane, gradually reducing its proportion until phaseout in 2022. The government's sugarcane plan makes no mention of agricultural burning as the primary producer of air pollution. Instead, the government cites "outdoor burning of refuse" as a culprit. A ban on the acceptance of burnt cane, coupled with measures to regulate sugarcane cultivation and milling would solve the problem. Climate impact Models crafted by researchers at Kasetsart University project that, due to changes in climate and diversion of land to non-agricultural uses, future sugarcane yield, harvested area, and production are projected to decrease by 24–33%, 1–2%, and 25–35% respectively in the period 2046–2055 from the baseline years 1989–2016. Tapioca Tapioca (cassava) is grown in 48 of Thailand's 76 provinces. The total area of tapioca plantations in Thailand during crop year 2015-2016 was about 8.8 million rai (1 rai = 1,600 m2), allowing the production of about 33 million tons of native starch. Fifty percent of tapioca in Thailand is grown in the northeast region. The five provinces with the largest tapioca plantations are Nakhon Ratchasima, which alone produces 25 percent of Thailand's total production, Kamphaeng Phet, Chaiyaphum, Sa Kaeo, and Chachoengsao. Thailand produces 28-30 million tonnes of fresh cassava roots yearly from some 500,000 households, worth more than 100 billion baht. Thailand is the world's largest exporter with about 50 percent of the market. In 2017 it exported 11 million tonnes of tapioca products. Its export goal for 2018