生石灰和钙镁磷肥对晚稻生长及稻米镉含量的影响

为研究不同培肥措施对镉污染稻田的修复效果,采用小区试验的方法,研究了生石灰和钙镁磷肥及与化肥、有机肥配施对土壤镉有效性、水稻生长和稻米镉含量的影响。结果表明:施用生石灰、钙镁磷肥可以显著提高土壤pH值,其增幅为10.5%～16.1%,其中耦合石灰、钙镁磷肥和化肥(NPKML)处理增幅最大,达到16.1%,施用生石灰次之、钙镁磷肥增幅最小。有机肥与生石灰、有机肥与化肥和生石灰配施可使土壤有效镉含量降低7.9%～23.5%、使糙米的镉含量降低35.1%～47.5%,其中NPKML对两者的降低效果最佳。施用生石灰、钙镁磷肥等对水稻生长和稻谷品质没有显著影响。研究表明,有机肥、化肥、钙镁磷肥和石灰合理配施,对镉污染稻田修复具有较好的效果。     

生石灰清塘后主要理化因子变化与鱼种适宜下塘时间的研究

通过对四川地区养殖池塘生石灰清塘后主要理化指标水温、pH值、溶解氧、COD、营养盐等的监测,探讨主要理化因子的变化特点。通过高pH值对岩原鲤鱼种的急性毒性试验,计算出岩原鲤鱼种对pH值的安全值为8.565。研究结果表明,把pH值作为生石灰清塘后确定鱼种下塘时间的主要指标是可行和适宜的。根据四川地区目前的清塘方式,鱼种的适宜下塘时间为清塘后第5 d。     

生石灰施用增加了酸性双季稻田氮素氨挥发损失

选择南方典型酸性双季稻田,采用通气法研究了不同生石灰用量对稻田氨挥发通量、田面水NH_4~+-N浓度和pH值的影响。结果表明:撒施生石灰显著影响稻田田面水NH_4~+-N浓度和pH值,生石灰用量与田面水NH_4~+-N浓度和田面水pH值之间均存在极显著正相关关系;撒施生石灰,显著增加稻田氮素氨挥发损失,早、晚稻季氨挥发损失量较不施生石灰处理分别增加2.20~22.91和3.08~52.44 kg/hm~2,增幅分别达19.28%~200.79%和6.96%~118.48%;当早、晚稻季分别施纯氮150和180 kg/hm~2时,撒施生石灰450~3 750 kg/hm~2,氨挥发损失量分别达13.61~34.32和47.34~96.70 kg/hm2,氮素损失率分别达7.44%~18.78%和21.66%~44.24%;当早、晚稻季生石灰用量分别超过900和1 800 kg/hm2时,稻田氨挥发显著增加。     

Effects of integrated combination and quicklime supplementation on growth and pearl yield of freshwater pearl mussel, Hyriopsis cumingii (Lea, 1852)

The effects of integrated combination and quicklime supplementation on growth and pearl yield of a freshwater mussel, Hyriopsis cumingii (Lea, 1852), were examined through a 137-day growout in land-based enclosures. The integrated combinations examined were either mussel, bighead carp and gibel carp or mussel and bighead carp. Each combination was treated either with or without quicklime supplementation. One half of the mussels in each enclosure were grafted with pieces of the mantle epithelium while the other half were not. During the experiment, gibel carp were fed formulated feed while the mussel and bighead carp were fed natural live food. Quicklime was regularly provided in the enclosures as calcium replenishment. The species composition in the integrated system significantly affected growth in shell size and wet weight of the mussels regardless of the graft and pearl yield, while no significant effects of quicklime supplementation were detected. Growth rates in shell size and wet weight of both grafted and non-grafted mussels and pearl yield were slightly higher in the enclosures with mussel, bighead carp and gibel carp than those with mussel and bighead carp, although these differences were not statistically significant. The non-grafted mussel exhibited faster growth in shell size and wet weight than the grafted mussel within the same treatment. Results of the present study indicate that species combination in an integrated system can affect growth and pearl yield of H. cumingii . The species combination of mussel, bighead carp and gibel carp is recommended for commercial H. cumingii farming.     

稻草与生石灰添加介导的温室内土壤团聚体稳定性及碳分布特性

土壤中稳定的团聚体为碳的固定提供良好的物理保护,同时土壤中的碳又会促进团粒结构的形成,二者相辅相成,但在长期稻草和生石灰添加介导的设施内土壤中二者如何变化,却少见报导。以长期施肥定位试验为依托,采用湿筛法研究了施用鸡粪(M)的基础上,配施稻草(R)和生石灰(Ca)对设施土壤团聚体组成、稳定性及碳分布的影响,以不施肥(CK)为对照。结果表明:(1)在鸡粪基础上加入稻草(MR)或生石灰(MCa),与单施鸡粪(M)相比,0.25mm团聚体含量分别增加了123%和37%;稻草和生石灰同时添加可显著增加5~2mm大团聚体含量,较MR、MCa、M分别提高12%,59%,141%。(2)在鸡粪基础上施入稻草或生石灰均可增加MWD、GMD、R_(0.25),提高团聚体的稳定性,其中MR处理最高,MRCa处理次之,二者均显著高于MCa、M、CK处理。(3)在鸡粪基础上加入稻草或生石灰,均可提高土壤全碳含量,其中MRCa处理最高,较MR、MCa、M分别增加20%,40%,55%;稻草和生石灰同时施入可显著增加5~2mm大团聚体中碳含量;加入生石灰可增加0.5~0.25mm团聚体中碳含量;施入稻草或生石灰均可显著增加0.25mm团聚体中的碳对土壤全碳的贡献。(4)土壤全碳含量与5~2,2~1,1~0.5mm团聚体含量呈显著正相关,与0.25mm微团聚体含量呈显著负相关;MWD、GMD、R_(0.25)均与0.25mm团聚体含量呈显著正相关,与0.25mm微团聚体含量呈显著负相关。设施土壤在施入鸡粪的基础上同时加入稻草和生石灰,可改善土壤结构,提高土壤碳水平,有利于缓解设施生产中因长期连作所导致的土壤结构劣变问题。     

泼洒石灰水对鱼蚌混养水体中浮游生物群落结构的影响

研究了泼洒石灰水后鱼蚌混养水体系统中浮游生物的演化规律.实验设计了三组Ca2浓度水平(6、18、45 mg/L),时间为2个月.结果发现:施加不同浓度石灰水后,池蝶蚌(Hyriopsis schlegeli养殖系统水体中浮游生物的数量、生物量和优势种群随时间出现变化.浮游植物总数的变化和Shannon-Wiener多样...     

Nitrogen Mineralization in Soils Treated with Fly Ash–Amended Wastewater Sludges

Abstract

Alkaline‐treated wastewater sludges with varying doses of fly ash were added to a clay soil at rates equivalent to 100 t (dry weight) raw sludge ha^?1 soil, and the variations in ammonium, nitrate, and total nitrogen contents were monitored throughout an incubation period of 360 days at 28°C. The results showed that inhibition of organic nitrogen mineralization occurred in soil amended with fly ash–containing sludge during the first 90 days of incubation. After the total incubation period of 360 days, the inhibition effects of alkaline sludge amendments totally disappeared. In fact, mineralization was enhanced in alkaline pasteurized sludges containing 80% and 120% fly ash. The overall results indicated that application of sludges amended with fly ash may prolong the use (3 to 6 months) of nitrogen from the organic nitrogen pool in sludge.     

施用生物质炭和生石灰对连作辣椒生长的影响

为探究生物质炭和生石灰对连作辣椒生长的影响,以辣椒为材料,采用大田方式,设置8个处理,即对照处理(不加任何生物质炭和生石灰的辣椒连作土,CK);单施生物质炭处理(1.5 kg·m^-2,T2);生物质炭+生石灰处理(1.5 kg·m^-2生物质炭+0.15 kg·m^-2生石灰,T3;1.5 kg·m^-2生物质炭+0.225 kg·m^-2生石灰,T4;3.0 kg·m^-2生物质炭+0.3 kg·m^-2生石灰,T5);单施生石灰处理(0.15 kg·m^-2生石灰,T6;0.225 kg·m^-2生石灰,T7;0.3 kg·m^-2生石灰,T8),研究各处理对连作辣椒生长指标、果实特征及产量疫病发病率以及土壤理化性质的影响。结果表明,在辣椒连作土壤中添加适量的生物质炭和生石灰能够显著促进辣椒的生长发育,改善辣椒根际土壤环境。单施生石灰或生物质炭对辣椒的各项生长指标促进效果差异较大,而适量的组合施用生石灰和生物质炭处理(T4)的辣椒株高、茎粗以及壮苗指数总体上高于其他处理,对辣椒生长促进作用最为明显。单施生物质炭处理(T2)并不能显著增加辣椒植株的鲜重和干重,而单施生石灰处理后随着施用量的增加会表现出抑制作用。T4对辣椒植株鲜重和干重增加效果明显,定植90 d时,辣椒地上部干重和鲜重、辣椒根系干重和鲜重分别增加了21.34%、21.34%、14.40%、13.34%;同时,辣椒的单株产量和总产量较CK均增加了23.37%,但与其他处理差异不显著。施用生物质炭和生石灰能够显著降低辣椒疫病的发生率,与CK相比,T5的发病率和病情指数均最低,分别为8.33%和3.47,对病害的控制作用最显著。施用生石灰和生物质炭对辣椒土壤中养分含量的增加有促进作用;各处理对土壤pH值无显著性差异(P>0.05),均在6.3~6.8之间。本研究结果为缓解辣椒连作障碍及生产实践提供了理论指导。