辽河平原区玉米旱田氮磷流失特征研究

采用田间试验方法,2016～2017年原位监测不同试验处理下地表径流与地下淋溶水分和氮磷流失过程.结果表明,径流和淋溶流失均集中发生于6～8月,且流失水量与降雨密切相关.氮磷在径流和淋溶水中均以可溶态为主(径流水中磷除外),且淋溶水氮浓度高于径流,径流水磷浓度高于淋溶.氮流失负荷在两年监测中均表现为淋溶高于径流,磷流失...

Characteristics of Nitrogen and Phosphorus Loss in Dry Farmland of Liaohe River Plain

The field experiment was conducted to in-situ monitor the water flow and N and P loss by runoff and leaching under the different treatments from 2016 to 2017. The results showed that the runoff and leaching events mainly occurred from June to August, which was closely related to rainfall. The dissolved N and P were the main forms of N and P in the leaching and runoff water(excluding P in runoff water). N concentrations in the leaching water were higher than runoff, whereas P concentrations in the runoff water were more than leaching. N leaching loss was higher than runoff in both 2016 and 2017, while greater runoff P loss was determined in 2016 and approximately equivalent P loss by leaching and runoff these two approaches in 2017. Compared to the conventional fertilization(CF) and optimized fertilization treatment(OF), the water flow of runoff and leaching was decreased in the optimized fertilization combined with straw incorporation treatment(OFS), especially with 20.3% and 14.9% lower runoff flow in OFS than CF and OFS in 2016(p<0.05). The average concentrations of total N, dissolved N, NO₃^--N, and NH₄⁺-N were compared among the different treatments as follow: CF>OF>OFS, while there was little difference of P concentrations among the three treatments. Compared to CF, both OF and OFS treatments reduced N and P loss, especially with 31.0% lower runoff N loss and 19.3% lower runoff P loss in OFS than CF in 2016(p<0.05). In conclusion, N leaching was the main contribution to the nutrient loss in the dry farmland of Liaohe River plain, and straw incorporation based on optimized fertilization had the potential on controlling N and P loss.