Hydration of Activated Anhydrate Phosphogypsum

Phosphogypsum（PG） calcined at 500 ℃ was activated by K2SO4 and salt lime with loose structure as seed crystal. To determine the effect of activation, hydration of the anhydrate PG activated was investigated by examination of the setting time, the proportion of hydrated anhydrate PG, the microstructure of the hardenite and the resistance to water. Results show that activated anhydrate PG hydrates much more rapidly than that in the absence of activators. The activated anhydrate PG has proper setting time and hydrated proportion. The resistance to water was greatly improved. SEM photos show that the set activated PG has hydrated products of rod-like and closely connected crystals. The different addition of activator leads to different compact structure.

不同施肥措施对番茄连作土壤酚酸含量和微生物功能多样性的调节

设施内蔬菜连作土壤酚酸含量和微生物功能多样性的异常是导致连作障碍的关键因素。利用毛细管电泳及BiologECO生理学研究法研究了鸡粪(M)、鸡粪+K2SO4(MK)、鸡粪+稻草(MR)、鸡粪+稻草+K2SO4(MRK)对温室内番茄连作6年土壤中对羟基苯甲酸、苯甲酸、阿魏酸及肉桂酸及微生物功能多样性的影响,以不施肥处理为对照(CK)。结果表明:与CK相比,不同物料组合施用能够显著降低土壤中酚酸含量,其中MRK处理降低效果最明显,土壤中对羟基苯甲酸、苯甲酸分别降低7.11%~57.04%、81.84%~83.32%。不同物料组合施用提高了土壤微生物对碳源的利用强度,其中MRK处理土壤微生物对碳源利用能力最强,且微生物多样性指数最高,其Shannon和Mch Intosh多样性指数比其他处理平均提高3.93%~10.07%、6.22%~27.47%。主成分分析表明,M处理土壤的微生物功能多样性差异主要是由于氨基酸、羧酸类、聚合物或酚酸类碳源引起的,而MR处理则是由碳水化合物或胺类碳源引起。微生物多样性指数与土壤中对羟基苯甲酸、苯甲酸、阿魏酸及肉桂酸含量呈显著负相关。MRK处理番茄产量分别比MK、MR、M、CK提高5.87%、11.34%、22.85%、30.13%,但MK番茄产量与MRK相差不明显。设施栽培条件下,鸡粪、稻草和K2SO4配合施用对提高土壤微生物功能多样性,降低土壤酚酸类物质含量,减缓连作障碍具有重要意义。