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通过田间定位试验,研究了石灰(L)、钙镁磷肥(G)、泥炭(P)、猪粪(M)、石灰 泥炭(L P)、石灰 猪粪(L M)、钙镁磷肥 泥炭(G P)、钙镁磷肥 猪粪(G M)等改良材料对新罗区特钢厂附近的重金属污染田的长期改良效应.结果表明:大部分处理可提高土壤的pH值、有机质含量,降低了土壤的有效锌含量,石灰 泥炭、钙镁磷肥 泥炭的改良效果要优于单施有机、中性化改良剂和其它处理,和对照相比,有效锌含量和糙米锌含量最高分别降低了59.2%、36.2%. 相似文献
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兔粪是一种高效优质的有机肥,含氮、磷、钾的成分较其它畜粪高。喷施兔粪液能促进水稻对氮、磷、钾肥料的吸收,保持叶色青绿,防止早衰,增加结实 相似文献
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试验工程师经常要测量环境试验箱内的湿度含量.由于许多产品受到湿度影响,所以这一测量和温度同等重要.什么是湿度?湿度是存在于空气或其它气体中的水.通常,我们根据达尔顿分压规律测量这一气体的分蒸气压.湿度是较难测量的一种参数.以下章节将介绍几种最普通的测量方法. 相似文献
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泥炭沼泽不仅蕴藏有丰富的泥炭,而且还是重要的土地资源。多数泥炭沼泽受人类活动影响很小,是一些稀有动植物生活、繁衍的良好场所;因此,它在自然生态平衡中占有重要地位。如能全面掌握其特性,便可克服其不利于人类经济活动的方面,变不利为有利。世界上许多国家和地区都极其重视泥炭沼泽的开发与保护。一、泥炭沼泽的特性 相似文献
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一、概述若尔盖高原泥炭沼泽分布区位于青藏高原东部边缘,范围包括四川的若尔盖、红原、阿坝及甘肃省玛曲县的大部,地理坐标为北纬32°40′~34°10′,东经101°45′~103°20′之间。据现有资料估算,全区沼泽草地总面积6377.8km~2,其中有泥炭资源分布的沼泽面积达4135.6km~2,已初步评价出大型泥炭地100余处,泥炭厚度一般均在2m以上,最厚可达10m多,泥炭远景储量约在 相似文献
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J. Spångberg P.-A. HanssonP. Tidåker H. Jönsson 《Resources, Conservation and Recycling》2011,55(11):1078-1086
Animal by-products (ABP) are rich in nutrients and energy. This LCA study assessed and compared the environmental impact of using meat meal as fertilizer with that of using chemical fertilizer. In one system the nutrient content of ABP Category 2 was recovered and used as a meat meal fertilizer on arable land, replacing chemical fertilizers. In the other system a chemical fertilizer was used and the energy content of the ABP material recovered. The functional unit consisted of one kg of harvested spring wheat and treatment of 0.59 kg of ABP Category 2. The system for nutrient recovery and chemical fertilizer replacement had lower emissions of greenhouse gases and acidification than the energy recovery system, but had higher total use of energy and eutrophying emissions. Overall, the results of the study greatly depended on the fuels replaced. 相似文献
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化肥不合理施用带来的农业面源污染问题亟待治理,实践表明,绿色、高效、环保、优质的新型肥料是促进化肥减施增效的有效途径。本文以新型肥料为例,通过对肥料生产企业的实地调研,从肥料生产环节识别化肥减施增效工作推进中存在的问题。新型肥料在生产环节面临供给成本高、需求不足的困境,其主要原因是:新型肥料生产工序复杂,环保设施增加成本;按照国家产业目录,企业性质统一划分为化工企业,发展受到严重制约;新型肥料品种层出不穷,标准落后不匹配;新型肥料产品推广服务成本高。另外,政府低价招标有机肥,弊病丛生,扰乱正常市场秩序,降低企业生产优质新型肥料的积极性。为此本文建议,一方面应降低新型肥料生产和流通成本,另一方面应加强新型肥料宣传推广。 相似文献
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四川省农业生产环境因素-化肥施用状况宏观分析 总被引:3,自引:1,他引:2
本文首次提出“区域化肥施用负荷”、“化肥施用相对生产力”、“化肥施用相对适宜度”等概念及研究方法,用于四川省化肥施用状况宏观分析。四川全省化肥施用量F=228.86kg/hm^2,全省21个市州中自贡、攀枝花、德阳、绵阳、遂宁、眉山、雅安和巴中等8个市F〉250kg/hm^2,其中攀枝花市达到457kg/hm^2;全省5个农业区中,成都平原区F值最高,达285.63kg/hm^2。四川省化肥施用负荷H=4704kg/km^2,自贡、德阳、遂宁、内江等4市H值是全省H值4倍以上,自贡、遂宁2市甚至达5倍以上;成都平原区、盆地丘陵区H值分别是17491kg/km^2和16309kg/km^2,远远高于其他地区。全省化肥施用相对生产力R=20.26kg,攀枝花市R=12.11kg,是全省最低的;盆地丘陵区R=20.16kg,其余地区R值均高于全省的。全省近10年平均化肥施用相对适宜度T=3.19作为评价基准,攀枝花市T=5.22,是全省最高的,属化肥施用高度过量;各农业区中,盆地丘陵区T=3.47,盆周山地区T=3.28,属化肥施用轻度过量,其余地区基本适宜。 相似文献
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Matthew P. Miller Paul D. Capel Ana María García Scott W. Ator 《Journal of the American Water Resources Association》2020,56(1):100-112
In response to concerns regarding the health of streams and receiving waters, the United States Environmental Protection Agency established a total maximum daily load for nitrogen in the Chesapeake Bay watershed for which practices must be in place by 2025 resulting in an expected 25% reduction in load from 2009 levels. The response of total nitrogen (TN) loads delivered to the Bay to nine source reduction and land use change scenarios was estimated using a Spatially Referenced Regression on Watershed Attributes model. The largest predicted reduction in TN load delivered to the Bay was associated with a scenario in which the mass of TN as fertilizer applied to agricultural lands was decreased. A 25% decrease in the mass of TN applied as fertilizer resulted in a predicted reduction in TN loading to the Bay of 11.3%, which was 2.5–5 times greater than the reductions predicted by other scenarios. Eliminating fertilizer application to all agricultural land in the watershed resulted in a predicted reduction in TN load to the Bay of 45%. It was estimated that an approximate 25% reduction in TN loading to the Bay could be achieved by eliminating fertilizer applied to the 7% of subwatersheds contributing the greatest fertilizer‐sourced TN loads to the Bay. These results indicate that management strategies aimed at decreasing loading from a small number of subwatersheds may be effective for reducing TN loads to the Bay, and similar analyses are possible in other watersheds. 相似文献
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Limited information exists on specific urban lawn care practices in the United States. We conducted a door-to-door lawn care survey in five North Carolina communities to determine suburban fertilizer, pesticide, and water use. These communities, Cary, Goldsboro, Kinston, New Bern, and Greenville, are mostly located within the Neuse River basin, a nutrient-sensitive water resource. Residents in Cary used lawn care companies more than twice as frequently as residents in the other communities (43 compared with 20%). Cary had the smallest mean lawn size (445 m2), while the largest was in Goldsboro (1899 m2). Tall fescue [Festuca arundinacea Schreb.] was the predominant grass type in Cary (99%), and centipedegrass [Eremochloa ophiuroides (Munro) Hack.] or centipedegrass mixtures were the predominant grass types in Greenville and New Bern. Kinston had the lowest fertilizer usage with only 54% of the residents using fertilizer; Cary had the highest rate of 83%. The average N fertilizer rate applied to the lawns was dissimilar ranging from 24 to 151 kg N ha(-1). Analysis of variance results for fertilizer rates and household income indicated a significant difference (P < 0.05) in application rate between high- and medium-income levels and the low-income level. Cary, Goldsboro, and Greenville had approximately the same number of fertilizer applications per year (1.5), whereas the average number of fertilizer applications per year in New Bern was 3.0. Most household residents (53%) used instructions on the bag and either grass type and/or lawn area to guide them on fertilizer application rates. 相似文献
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Development of a phosphorus index for pastures fertilized with poultry litter--factors affecting phosphorus runoff 总被引:1,自引:0,他引:1
DeLaune PB Moore PA Carman DK Sharpley AN Haggard BE Daniel TC 《Journal of environmental quality》2004,33(6):2183-2191
Currently, several state and federal agencies are proposing upper limits on soil test phosphorus (P), above which animal manures cannot be applied, based on the assumption that high P concentrations in runoff are due to high soil test P. Recent studies show that other factors are more indicative of P concentrations in runoff from areas where manure is being applied. The original P index was developed as an alternative P management tool incorporating factors affecting both the source and transport of P. The objective of this research was to evaluate the effects of multiple variables on P concentrations in runoff water and to construct a P source component of a P index for pastures that incorporates these effects. The evaluated variables were: (i) soil test P, (ii) soluble P in poultry litter, (iii) P in poultry diets, (iv) fertilizer type, and (v) poultry litter application rate. Field studies with simulated rainfall showed that P runoff was affected by the amount of soluble P applied in the fertilizer source. Before manure applications, soil test P was directly related to soluble P concentrations in runoff water. However, soil test P had little effect on P runoff after animal manure was applied. Unlike most other P indices, weighting factors of the P source components in the P index for pastures are based on results from runoff studies conducted under various management scenarios. As a result, weighting factors for the P source potential variables are well justified. A modification of the P index using scientific data should strengthen the ability of the P index concept to evaluate locations and management alternatives for P losses. 相似文献
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Nitrogen, tillage, and crop rotation effects on nitrous oxide emissions from irrigated cropping systems 总被引:5,自引:0,他引:5
We evaluated the effects of irrigated crop management practices on nitrous oxide (N(2)O) emissions from soil. Emissions were monitored from several irrigated cropping systems receiving N fertilizer rates ranging from 0 to 246 kg N ha(-1) during the 2005 and 2006 growing seasons. Cropping systems included conventional-till (CT) continuous corn (Zea mays L.), no-till (NT) continuous corn, NT corn-dry bean (Phaseolus vulgaris L.) (NT-CDb), and NT corn-barley (Hordeum distichon L.) (NT-CB). In 2005, half the N was subsurface band applied as urea-ammonium nitrate (UAN) at planting to all corn plots, with the rest of the N applied surface broadcast as a polymer-coated urea (PCU) in mid-June. The entire N rate was applied as UAN at barley and dry bean planting in the NT-CB and NT-CDb plots in 2005. All plots were in corn in 2006, with PCU being applied at half the N rate at corn emergence and a second N application as dry urea in mid-June followed by irrigation, both banded on the soil surface in the corn row. Nitrous oxide fluxes were measured during the growing season using static, vented chambers (1-3 times wk(-1)) and a gas chromatograph analyzer. Linear increases in N(2)O emissions were observed with increasing N-fertilizer rate, but emission amounts varied with growing season. Growing season N(2)O emissions were greater from the NT-CDb system during the corn phase of the rotation than from the other cropping systems. Crop rotation and N rate had more effect than tillage system on N(2)O emissions. Nitrous oxide emissions from N application ranged from 0.30 to 0.75% of N applied. Spikes in N(2)O emissions after N fertilizer application were greater with UAN and urea than with PCU fertilizer. The PCU showed potential for reducing N(2)O emissions from irrigated cropping systems. 相似文献
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The primary goal of the paper is to show the validity of investing capital in fertilizer–mining companies, both from a market return perspective for individual or institutional investors, or from a hedging standpoint for insurance companies and other economic actors exposed to inflation risk and high agricultural commodity prices. After providing some elements on the fertilizer market and describing the joint dynamics of corn, wheat and fertilizer prices over the last decade, we analyze an exhaustive sample of listed fertilizer producing companies over the years January 2004–December 2012. We show that their shares generated quite good returns over the whole period and extremely high ones during the years January 2004–December 2007, both in absolute terms and compared to their betas. We also exhibit that these returns display higher sensitivities to major agricultural indexes than to the World Bank Fertilizer Index, making the hedging argument quite compelling. 相似文献
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Maize (Zea mays L.) production in the smallholder farming areas of Zimbabwe is based on both organic and mineral nutrient sources. A study was conducted to determine the effect of composted cattle manure, mineral N fertilizer, and their combinations on NO3 concentrations in leachate leaving the root zone and to establish N fertilization rates that minimize leaching. Maize was grown for three seasons (1996-1997, 1997-1998, and 1998-1999) in field lysimeters repacked with a coarse-grained sandy soil (Typic Kandiustalf). Leachate volumes ranged from 480 to 509 mm yr(-1) (1395 mm rainfall) in 1996-1997, 296 to 335 mm yr(-1) (840 mm rainfall) in 1997-1998, and 606 to 635 mm yr(-1) (1387 mm rainfall) in 1998-1999. Mineral N fertilizer, especially the high rate (120 kg N ha(-1)), and manure plus mineral N fertilizer combinations resulted in high NO3 leachate concentrations (up to 34 mg N L(-1)) and NO3 losses (up to 56 kg N ha(-1) yr(-1)) in 1996-1997, which represent both environmental and economic concerns. Although the leaching losses were relatively small in the other seasons, they are still of great significance in African smallholder farming where fertilizer is unaffordable for most farmers. Nitrate leaching from sole manure treatments was relatively low (average of less than 20 kg N ha(-1) yr(-1)), whereas the crop uptake efficiency of mineral N fertilizer was enhanced by up to 26% when manure and mineral N fertilizer were applied in combination. The low manure (12.5 Mg ha(-1)) plus 60 kg N ha(-1) fertilizer treatment was best in terms of maintaining dry matter yield and minimizing N leaching losses. 相似文献