添加不同颗粒沸石粉对沙壤玉米NPK吸收和水分、养分淋溶的影响

将不同颗粒组成的沸石粉添加到砂壤土耕层,研究其对玉米生长、NPK养分吸收、水分和养分淋洗的影响,以科学有效利用沸石资源改良土壤和对环境保护提供理论依据。土柱试验采用长100cm、直径10cm的PVC管进行,设8个处理,分别为:CK0(不施肥+0g沸石粉体)、CK(施肥+0g粉体)、A(施肥+8g粉体a)、B(施肥+添加8g粉体b)、C(施肥+8g粉体c)、D(施肥+8g粉体d)、E(施肥+8g粉体e)、F(施肥+添加8g粉体f)。结果表明,与单施肥CK处理相比,所有施肥添加粉体处理均可提高玉米生物量,其中粘粒级颗粒含量最高的2个处理E、F分别提高了71.36%和63.69%,达到显著水平。与CK相比,处理E显著减少淋溶水14.94%。添加粉体处理均可促进N、K的吸收,处理F对N的吸收量为74.52%,达到显著水平,处理E、F对K的吸收量分别达63.39%和63.62%,达到显著水平。与对照CK相比,添加粉体处理对NH4+-N、NO3--N、P和K淋洗量没有显著减少,但与最粗沸石颗粒组成的处理A相比,处理C、D、E的NH4+-N淋洗量分别显著降低了49.21%,71.42%和60.32%,处理D、E、F的NO3--N淋洗量分别显著降低84.91%,94.34%和83.02%,处理C、D的P淋洗量分别显著降低36.84%和42.11%,处理E、F的K淋洗量分别显著降低37.81%和34.25%。由此可知,在沙壤中添加粘粒级颗粒含量较高的粉体有利于促进植株生长和对N、K的吸收,减少水分、养分淋洗对环境的污染。

氮肥用量和水分淋溶对土壤和小麦氮素平衡的影响

:利用标记15N尿素研究不同施肥量和淋溶对小麦生长的影响 ,结果表明水分淋溶对小麦生长的影响不明显 ;地上部生物产量与肥料利用率成正相关 .小麦根系越发达 ,收集到的淋溶液越少 ,损失的肥料N越少 .施用相同量的氮肥 。

Salt－Water Dynamics in Soils：IV．Changes of Ionic Composition in Soil Profiles During Water Evaporation and Infiltration

Through a simulation test carried out with soil columns (61.8 cm in diameter), the changes of ioniccomposition in soil profile during the processes of water evaporation and infiltration were studied. Underevaporation conditions, ions moving upward with fresh groundwater were mainly Cl￣-, SO, Ca￣(2+), andNa￣+. When the mineralized groundwater took part in the salt accumulation, the ionic composition in soilswas close to that in ground water supplemented. Under rainfall infiltration conditions, the salt-leaching roleoccurred mainly in the top soil. With the decrease of total salt content, NO and Cl￣- reduced rapidly, SOdecreased slowly, but HCO had a little change only. Among cations, Na￣+ and Ca￣(2+) contents lowered atthe same speed, and Mg￣(2+) decreased slowly.