对北京西山地区31a油松林降水化学进行定位监测与分析。结果表明:(1)大气降水流经油松林过程中,其营养元素(除Na+外)的浓度出现梯度变化:树干茎流高于穿透雨高于大气降水,并且有明显的月际变化,表明从林冠、树干淋洗大量的营养元素,林...对北京西山地区31a油松林降水化学进行定位监测与分析。结果表明:(1)大气降水流经油松林过程中,其营养元素(除Na+外)的浓度出现梯度变化:树干茎流高于穿透雨高于大气降水,并且有明显的月际变化,表明从林冠、树干淋洗大量的营养元素,林冠和树干中养分元素迁移是森林生态系统养分循环重要的组成部分。(2)营养元素变化中,浓度差异变化较大的元素是NO3--N和K+,NO3--N在穿透雨和树干茎流的浓度分别是大气降水的4.4倍9、.9倍,它们中的K+浓度分别为大气降水的4.1倍和8.1倍。(3)降水经过油松林,养分淋溶总量为54.12 kg hm-2,淋溶量较多的元素是Ca和K,淋溶强度最大的元素是K+。(4)北京西山地区大气降水输入林地的养分66.38 kg hm-2,较多的元素是Ca、N。降水经过油松林输入林地养分总量为120.50kg hm-2,Ca元素最高,为61.22 kg hm-2,其次是N元素(NH4+-N+NO3--N),为31.34 kg hm-2,K元素为16.49 kg hm-2,Mg元素为8.11 kg hm-2,Na元素最少,为3.34 kg hm-2。展开更多
An understanding of nutrient movement in soil is important for developing management strategies to minimize nutrient leaching and surface movement, thus improving nutrient uptake by plants, maintaining a sustainable s...An understanding of nutrient movement in soil is important for developing management strategies to minimize nutrient leaching and surface movement, thus improving nutrient uptake by plants, maintaining a sustainable soil system, and even protecting groundwater quality. Polyacrylamide (PAM) is known as one of soil conditioner that functions to stabilize soil structure, increase infiltration, and reduce surface runoff. This study assesses the effects of PAM on the vertical movement of soil-water and major/minor nutrients (NO3-N, NH3-N, T-N, PO4-P, T-P, K, Ca, Mg, and Fe) in soils. Saturated hydraulic conductivity (Ksat) increases with increasing PAM concen- trations up to 10 mg·L-1 for sand and 20 mg·L-1 for a mixture of sand and clay. Decreases in the loss of soluble nutrients, particularly NH3-N, PO4-P and T-P, are observed as PAM concentrations increase. In contrast, PAM concentration has no effect on nitrate and minor nutrient levels. These results indicate that the application of PAM may be a viable method for protecting water bodies from excessive nutrients and improving nutrient availability for plants.展开更多
文摘对北京西山地区31a油松林降水化学进行定位监测与分析。结果表明:(1)大气降水流经油松林过程中,其营养元素(除Na+外)的浓度出现梯度变化:树干茎流高于穿透雨高于大气降水,并且有明显的月际变化,表明从林冠、树干淋洗大量的营养元素,林冠和树干中养分元素迁移是森林生态系统养分循环重要的组成部分。(2)营养元素变化中,浓度差异变化较大的元素是NO3--N和K+,NO3--N在穿透雨和树干茎流的浓度分别是大气降水的4.4倍9、.9倍,它们中的K+浓度分别为大气降水的4.1倍和8.1倍。(3)降水经过油松林,养分淋溶总量为54.12 kg hm-2,淋溶量较多的元素是Ca和K,淋溶强度最大的元素是K+。(4)北京西山地区大气降水输入林地的养分66.38 kg hm-2,较多的元素是Ca、N。降水经过油松林输入林地养分总量为120.50kg hm-2,Ca元素最高,为61.22 kg hm-2,其次是N元素(NH4+-N+NO3--N),为31.34 kg hm-2,K元素为16.49 kg hm-2,Mg元素为8.11 kg hm-2,Na元素最少,为3.34 kg hm-2。
文摘An understanding of nutrient movement in soil is important for developing management strategies to minimize nutrient leaching and surface movement, thus improving nutrient uptake by plants, maintaining a sustainable soil system, and even protecting groundwater quality. Polyacrylamide (PAM) is known as one of soil conditioner that functions to stabilize soil structure, increase infiltration, and reduce surface runoff. This study assesses the effects of PAM on the vertical movement of soil-water and major/minor nutrients (NO3-N, NH3-N, T-N, PO4-P, T-P, K, Ca, Mg, and Fe) in soils. Saturated hydraulic conductivity (Ksat) increases with increasing PAM concen- trations up to 10 mg·L-1 for sand and 20 mg·L-1 for a mixture of sand and clay. Decreases in the loss of soluble nutrients, particularly NH3-N, PO4-P and T-P, are observed as PAM concentrations increase. In contrast, PAM concentration has no effect on nitrate and minor nutrient levels. These results indicate that the application of PAM may be a viable method for protecting water bodies from excessive nutrients and improving nutrient availability for plants.
