Intensive Agriculture And Its Environmental Impacts

Agricultural intensification through the use of high-yielding crop varieties, chemical fertilizers and pesticides, irrigation, and mechanization has contributed substantially to dramatic increases in food production. To a certain extent, it has helped solve the problem of fast growing population and declining cultivated land, so it will be the only way of agricultural development. But intensification which is unilaterally dependent on high energy-inputs is unreasonable in many aspects; it wastes the resources and also alters the biotic interactions and patterns of resource availability in ecosystems and can have serious local, regional, and global consequences such as water pollution by leaching of nitrate and pesticides, soil compaction and degradation, reduced biodiversity and pollution of air by pesticides, NO₂ and CO₂. The necessity of these environmental problems calls for the utmost prudence to treat agricultural intensification. Based on detailed expatiation of intensive agriculture, this case study was carried out in the town of Shipan of Jianyang Municipality where a demonstration of rotation of edible mushroom Stropharia rugoso-annulata and rice. In this rotation system, the edible mushroom replaces oil rapeseeds after harvesting of rice, using crop residues as the basis for mushroom cultivation. Compared to conventional oil rapeseed cultivation, cultivation of the edible mushroom can improve soil fertility. Soil organic matter, available and total phosphorus increased respectively. But content of nitrogen decreased by. Apart from soil fertility change, farmers' income has also improved considerably. The income from the mushroom cultivation is some 20 times of oil rapeseed cultivation.