BEIJING - China's Ministry of Agriculture on Wednesday published a guideline on achieving "zero discharge" of agricultural waste by 2030.

The guideline also set targets on agricultural science and mechanization.

China must guarantee to maintain the basic farmland at a level of no less than 1.56 billion mu (about 104 million hectares) by 2020, said the guideline.

Annual water consumption for irrigation should not exceed 372 billion cubic meters, while the utilization rate of irrigation water should rise to 55 percent from the current 50 percent level. One cubic meter of water only produces a kilogram of grain harvested in China, lower than the average of 1.2-1.4 kilograms in advanced countries; a huge waste of water.

The guideline asked farmers to reduce use of chemical fertilizers and pesticides by limiting waste and switching to organic alternatives. Chemical fertilizer use hit 59 million tons in 2013. Manure and waste, agricultural films and crop straw resources should be managed properly, said minister Han Changfu.

China also aims to increase forest coverage rate to 23 percent by 2020. Forest coverage totaled 195 million hectares, or 20.4 percent of the country's total area, at the end of 2008.