西北地区小麦生产环境风险时空特征

利用CROPWAT模型和生命周期评价(LCA)方法，对西北地区2005—2020年小麦生产的投入、环境风险和水分需求进行分析和评价。结果表明：西北地区氮、磷、钾平均肥料投入量分别为238、142、62.5 kg·hm^-2;农药、柴油、种子、人工的投入量分别为4.35 kg·hm^-2、1.26 L·hm^-2、305 kg·hm^-2、771 h·hm^-2。西北地区平均小麦产量3.68 t·hm^-2,排放温室气体3 589 CO₂-eqkg·hm^-2,土壤酸化潜值87.0 SO₂-eqkg·hm^-2,消耗能量3.3×10⁸ J·hm^-2。肥料投入对温室气体排放和能量消耗的贡献最大，分别达到86.5%和77.8%;农作阶段在土壤酸化潜值中贡献率最高，占比达90%以上。西北地区小麦生产平均需水量为331 mm,平均灌溉需水量为227 m...

Spatial and temporal characteristics of environmental risks of wheat production in Northwest China

Using CROPWAT model and life cycle assessment (LCA) method, the input, environmental risk and water demand of wheat production in Northwest China from 2005 to 2020 were analyzed and evaluated. The results showed that, the average fertilizer input in Northwest China was 238 kg·hm^-2, 142 kg·hm^-2, and 62.5 kg·hm^-2 respectively; the pesticide, diesel, seed, and labor input amounts were 4.35 kg·hm^-2, 1.26 L·hm^-2, 305 kg·hm^-2, and 771 h·hm^-2, respectively. The average wheat yield in Northwest China was 3.68 t·hm^-2, emit 3 589 CO₂28 J·hm^-2 of energy. The largest contribution rate of fertilizer input to greenhouse gas emissions and energy consumption was 86.5% and 77.8%, respectively. The agricultural stage had the highest contribution rate in soil acidification potential, accounting for more than 90%. The agricultural stage contributed the most to soil acidification potential, accounting for more than 90%. In Northwest China, the average water demand for wheat production was 331 mm, the average irrigation water demand was 227 mm, and the average crop water profit and loss index was -65.7%. In 2020, the unit yield of wheat production increased by 37.7% compared to 2004, while the planting area decreased by 6.55%. In 2004, nitrogen, phosphorus and potassium fertilizer input increased by 48.6%, 40%, and 115%, respectively. Pesticides and diesel oil input decreased significantly over the last 17 years, and manual input was gradually decreasing, and now 50.8% lower than in 2004. The seed input increased first and then decreased in 17 years, reaching the highest value of 346 kg·hm^-2 in 2011. Compared with 2004, greenhouse gas emissions per unit area, soil acidification potential and energy consumption in 2020 increased by 54.1%, 57.3% and 31.7% respectively. There was no obvious trend in the time scale of water demand, rainfall and irrigation water demand for wheat production in Northwest China. The ecological environment risk and water demand law of wheat production in different Provinces (regions) in Northwest China were quite different. Inner Mongolia had the highest environmental cost of wheat production in Northwest China in terms of greenhouse gas emissions, soil acidification potential, energy consumption and irrigation water demand, but the rainfall was low, requiring the highest amount of irrigation. Since Shanxi had the highest rainfall and the lowest greenhouse gas emissions, potential for soil acidification, and energy consumption. It also had the lowest overall ecological environmental risk and irrigation needs for wheat production.