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251.
为了研究磺胺类兽药抗生素对麦田NH3挥发的影响,采用了田间原位观测试验,对比分析了不同浓度磺胺二甲嘧啶(SMZ)在不同氮肥类型条件下对麦田NH3挥发的影响.试验共设9个处理,分别为:无氮肥无抗生素(CK);复合肥为基肥,分别加施0,5,15,30mg/kg土的磺胺二甲嘧啶处理(CF、CF+SMZ5、CF+SMZ15、CF+SMZ30);猪粪为基肥,分别加施0,5,15,30mg/kg土的磺胺二甲嘧啶处理(CM、CM+SMZ5、CM+SMZ15、CM+SMZ30).所有施肥处理追肥均为尿素.结果表明:基肥阶段各处理之间的NH3挥发速率无显著差异(P > 0.05),追肥阶段各处理之间有极显著差异(P<0.01),中高浓度SMZ表现为明显的促进作用(P<0.05).整个观测期,CF、CF+SMZ5、CF+SMZ15、CF+SMZ30和CM、CM+SMZ5、CM+SMZ15、CM+SMZ30处理的NH3-N损失百分比分别为5.5%、6.6%、13.9%、10.7%、11.0%、12.4%、11.9%、16.9%,其中CF+SMZ15、CF+SMZ30和CM+SMZ30处理显著增加了NH3-N挥发累积量(P<0.05),其导致的NH3-N损失比分别是同种基肥零抗生素添加的2.5、2.0和1.5倍,表明磺胺二甲嘧啶与复合肥的混施对土壤NH3挥发的促进效应要高于与猪粪的同步混施.兽药抗生素对土壤NH3挥发的影响不容忽视.因此,需大力加强对兽药抗生素的管控,并进一步探明不同兽药抗生素对土壤NH3挥发的影响机制,为减缓兽用抗生素的环境污染生态效应作支撑. 相似文献
252.
生物炭配施缓控释肥对稻田田面水氮素动态变化及径流流失的影响 总被引:6,自引:0,他引:6
在太湖流域,通过田间试验研究了控释肥(CRF)、生物炭配施控释肥(BC+CRF)、生物炭配施稳定性肥(BC+SF)、生物炭配施控释肥和稳定性肥(BC+CRF+SF)4种施肥处理对稻田田面水p H、氮素动态变化、氮素径流流失的影响.结果表明,田面水平均p H介于5.64~8.15,生物炭配施控释肥和稳定性肥田面水p H降低3.16%~4.48%.田面水平均全氮(TN)质量浓度介于19.05~25.23 mg·L~(-1),生物炭配施控释肥和稳定性肥田面水TN质量浓度显著降低4.75%~6.58%.田面水无机氮素以铵态氮(NH_4~+-N)为主,NH_4~+-N和硝态氮(NO_3~--N)平均质量浓度分别介于0.01~17.26 mg·L~(-1)和0.24~3.11mg·L~(-1).与单施控释肥相比,各处理田面水NH_4~+-N和NO_3~--N质量浓度分别显著降低35.89%~48.78%和20.54%~37.01%.生物炭配施稳定性肥显著降低了田面水NH_4~+-N和NO_3~--N质量浓度,有效减少无机氮素径流流失风险.TN、NH_4~+-N、NO_3~--N径流流失量分别介于16.24~18.09、1.76~2.22、0.76~1.38 kg·hm~(-2).与单施控释肥相比,各处理TN、NH_4~+-N、NO_3~--N径流流失均有不同程度削减.生物炭配施控释肥和稳定性肥显著削减了氮素径流流失,有效降低区域稻田氮素面源污染风险. 相似文献
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H.Y. Guo J.G. Zhu X.R. Wang Z.H. Wu Z. Zhang 《Environmental geochemistry and health》2004,26(2):209-219
The agricultural non-point source pollution by nitrogen (N) and phosphorus (P) loss from typical paddy soil (whitish soil, Bai Tu in Chinese) in the Taihu Lake region was investigated through a case study. Results shown that the net load of nutrients from white soil is 34.1 kg ha–1 for total nitrogen (TN), distributed as 19.4 kg ha–1, in the rice season and 14.7 kg ha–1in the wheat season, and for total phosphorus (TP) 1.75 kg ha–1, distributed as 1.16 kg ha–1 in the rice season and 0.58 kg ha–1 in the wheat season. The major chemical species of N loss is different in the two seasons. NH4-N is main the form in the rice season (53% of TN). NO3-N is the main form in wheat season (46% of TN). Particle-P is the main form in both seasons, (about 56% of TP). The nutrient loss varied with time of the year. The main loss of nutrients happened in the 10 days after planting, 64% of TN and 42% of TP loss, respectively. Rainfall and fertilizer application are the key factors which influence nitrogen and phosphorus loss from arable land, especially rainfall events shortly after fertilizer application. So it is very important to improve the field management of the nutrients and water during the early days of planting. 相似文献
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259.
Scenarios of animal waste production and fertilizer use and associated ammonia emission for the developing countries 总被引:1,自引:0,他引:1
A.F. Bouwman K.W. Van Der Hoek 《Atmospheric environment (Oxford, England : 1994)》1997,31(24):4095-4102
Livestock production and the use of synthetic fertilizer are responsible for about half of the global emission of NH3. Depending on the animal category between 10 and 36% of the N in animal excreta is lost as NH3. The current annual NH3 emission in developing countries of 15 million ton N accounts for of the global emission from animal excreta. In addition, 7.2 million tons NH3N of synthetic N fertilizers are lost as NH3 in developing countries. This is 80% of the global NH3 emission from synthetic fertilizer's use. Along with human population increase and economic growth, livestock production in developing countries may even increase by a factor of 3 between now and 2025. The net result of rapid increase of livestock production combined with higher efficiency is an increase in NH3 emissions of only 60% from 15 to 24 million tons NH3N between 1990 and 2025 in developing countries. Livestock production is an important consumer of feedstuffs, mainly cereals, thereby inducing additional demand for synthetic fertilizers. Despite the projected major increase of synthetic fertilizer use from 42 to 106 million ton N between 1990 and 2025, the NH3 loss in developing countries may decrease if a shift towards other fertilizer types, that are less vulnerable to NH3 volatilization, is realized. According to the scenario, the total emission of NH3 associated with food production in developing countries will increase from 22 to 30 million ton N yr−1 between 1990 and 2025. Although the NH3 emission increases more slowly than food production, in particular, animal production may show geographic concentration in certain regions, which may lead to high local emission densities and associated environmental problems. 相似文献
260.
Regional monitoring of lead and cadmium contamination in a tropical grazing land site,Thailand 总被引:1,自引:0,他引:1
Parkpian P Leong ST Laortanakul P Thunthaisong N 《Environmental monitoring and assessment》2003,85(2):157-173
An investigation was carried out to monitor Pb and Cd contamination in grazing land located near a highway. Environmental media at different distances fromhighway (soil, grass, water, cow's forage, fertilizer,manure and milk samples) were collected from three samplinglocations. Soil and grass were characterized by high metalmobility (soil with Pb: 5.25±0.71–14.59±1.17 mgkg-1, dry mass and Cd: 0.038–0.33±0.04 mg kg-1, dry mass and grass with Pb: 0.76±0.05–6.62±0.18 mg kg-1, dry mass and Cd: 0.17±0.01–0.73±0.09 mg kg-1, dry mass). One-way analysis of variane (ANOVA) was applied to find out the correlation between metal (total and bioavailable) concentrationsin the soil and the distance from roadside. In most cases, the finding showed that plants growing nearer to the highway are usually exposed to more heavy metal accumulations than those awayfrom the highway. In addition, a correlation was established between plant available metal concentrations and plant metaluptake concentrations.Analysis of fertilizer and manure showed considerable amountof metals (fertilizer with Pb: 1.53±0.06 mg kg-1 andCd: 0.038 mg kg-1 and manure with Pb: 2.55–3.34 mgkg-1 and Cd: 0.14–0.31 mg kg-1). Long termsimultaneous application of fertilizer and manure on thecommercial farm showed higher metal accumulation in the soiland plants than those of co-operative farm Considerableconcentrations of metals (Pb: 1.60–2.94 mg kg-1 andCd: 0.025–0.19 mg kg-1) were observed in fodder. The finding clearly demonstrated that there are seasonalvariation in total daily metal intake by individual cow (Pb:109.37 mg day-1 (dry), 273.47 mg day-1 (rainy) andCd: 2.02 mg day-1 (dry), 19.62 mg day-1 (rainy)).The provisional tolerable weekly intake of heavy metals incows is 390 g Pb and 28 g Cd per kg bodyweight in the rainy season and 156 g Pb and 2 gCd per kg body weight in the dry season. The levels of metals (Pb: 0.014 mg L-1 and Cd: not detectable) and bio-transferfactor (10-5–10-4) in raw milk were found to be well below the Codex Alimentarius Commissions Draft (1997). Ouranalysis revealed that improvements on farm management give significant reduction in elevated levels of Pb and Cdin soil and plants, and however leads to minimize the amountof Pb and Cd in consumed milk. 相似文献