Direct and Residual Effects of Fly Ash-Based Integrated Fertilization on Rice (Oryza sativa L.) and Rapeseed (Brassica camprestris L.)

Integrated effects of fly ash (FA), farmyard manure (FYM), and chemical fertilizers recommended dose of fertilizer (RDF) on the performance of rice (Oryza sativa L.) and their residual effect on rapeseed (Brassica camprestris L. vartoria) were studied for two years in loamy acidic inceptisol of Assam, India.

The FA was generated from a bituminous and lignite coal-based captive thermal power plant of Hindustan Paper Corporation Ltd (HPCL), Assam. Rice yields were higher when FA, FYM, and RDF were used collectively vis-à-vis sole application of RDF reflected also in rapeseed under residual effect . FA effect on mean rice equivalent yield of the rice–rapeseed system was the highest (24.4%) under integrated application. Nickel (Ni) and cadmium (Cd) contents in rice decreased with increasing FA, while arsenic (As) was just the opposite. Integration of FA, FYM, and RDF was effective in lowering Ni, Cd, and As in rice compared to 100% RDF alone or together with FA. The residual effect on rapeseed was similar for Ni and As while the Cd content increased. Blending of FA, FYM, and RDF also positively altered the residual soil pH, organic carbon (C), and nitrogen, phosphorus, and potassium (NPK). Thus, FA can be an integral component of integrated plant nutrition system (IPNS) in augmenting crop yield and residual benefits in loamy acid inceptisol.     

Cadmium in upland forests after vitality fertilization with wood ash—a summary of soil microbiological studies into the potential risk of cadmium release

The use of wood ash in forestry has been questioned because of the potential risk associated with its cadmium (Cd) content (1–30 mg kg^–1). In agriculture, wood ash is only allowed for use as a fertilizer when its Cd content is below 3 mg kg^–1. This restriction has not been applied to forest soils and there is a lack of knowledge about the potentially harmful effects of the Cd in wood ash on forest ecosystems. This paper summarizes our recent studies on the microbial communities of boreal coniferous forest humus exposed to Cd-containing wood ash treatment. The main objectives of our studies were to test if the Cd in wood ash has the potential to affect the humus layer microflora of coniferous upland forests and if it has the potential to enter the human food chain. These objectives were tested both in laboratory and field experiments with ash and ash spiked with Cd (in laboratory 400 or 1,000 mg Cd kg^–1 as CdO or CdCl₂; in field 400 mg Cd kg^–1 as CdO). In one study the dissolution of ash was accelerated by irrigating it with simulated acid rain (SAR). Wood ash increased humus layer pH and microbial activities (respiration or thymidine incorporation rates) and changed its microfloral community structure (Biolog, PLFA, 16S or 18S rDNA PCR-DGGE) in both laboratory and field experiments. Spiking ash with Cd induced no further changes in the above-mentioned variables compared to ash alone. The Cd added with wood ash did not become bioavailable as detected with a bacterial biosensor Bacillus subtilis BR151(pTOO24). The form and level of Cd added in the ash had no further effect on the microbiological variables studied. Irrigation of ash with SAR did not increase the amount of bioavailable Cd, although the dissolution rate of the ash was increased. The concentration of Cd in soil water and in the berries of Vaccinium uliginosum and V. vitis-idaea, and the amount of humus bioavailable Cd did not increase with applied ash or ash spiked with Cd although the ash spiked with Cd increased the amount of humus total and extractable Cd in the 4-year field study. Only the ash spiked with Cd and not the unspiked normal wood ash resulted in significantly higher Cd concentrations in the mushroom Lactarius rufus and a slight increase in the berries of Empetrum nigrum (first year only). In conclusion, the Cd in wood ash did not become bioavailable and harmful to forest soil microbes, or leach into the humus layer even when treated with simulated acid rain. It is thus safe to use wood ash as a fertilizer in forests. However, since wood ash adds Cd to the environment, it is recommended that the same sites should not be fertilized with wood ash more than once. The effects of wood ash (3 t ha^–1) on forest soil humus layer microbes are long-term, lasting at least 20 years, and probably longer if higher application dose and/or hardened ash is used.     

毛竹叶片灰分含量及热值月动态变化规律研究

在福建省永春县,对毛竹(Phyllostachys pubescens)叶片的灰分含量、干重热值、去灰分热值月动态变化规律进行研究。结果表明:①毛竹成熟叶、老叶的灰分含量月变化趋势相似,毛竹成熟叶、老叶的灰分含量在秋季的10月至翌年春季的3月灰分含量较高,而春夏季相对较低;毛竹成熟叶的灰分含量在7.56%～15.91%之间,老叶的灰分含量在7.46%～16.67%,老叶的灰分含量显著高于成熟叶(P=0.0199)。②毛竹成熟叶、老叶的干重热值月变化趋势相似;成熟叶的干重热值在18.166～20.923 kJ.g-1之间,老叶的干重热值在18.581～20.249 kJ.g-1,老叶的干重热值与成熟叶接近;成熟叶的干重热值与灰分含量相关性不显著,老叶的干重热值与灰分含量具有显著的线性负相关。③毛竹成熟叶、老叶的去灰分热值月变化趋势相似;成熟叶的去灰分热值在20.061～22.962 kJ.g-1之间,平均为(21.670±0.720)kJ.g-1;老叶的去灰分热值在20.793～23.053 kJ.g-1之间,平均为(21.779±0.584)kJ.g-1;成熟叶的去灰分热值与老叶接近。     

Biogeomorphological influence of the Hawaiian silversword (Argyroxiphium sandwicense DC.) on soil erosion in Haleakala (Maui,Hawai'i)

Soils were examined at 2505 m elevation in Haleakala's crater (Maui, Hawai?i) beneath 50 adult Hawaiian silversword plants (Argyroxiphium sandwicense DC.); mean canopy diameter was 42.0 cm. Exposed volcanic Inceptisols (Andic Humitropepts) seem significantly eroded beyond the dense rosette crowns, but remain unaffected below plants. Rosettes are perched on isolated basal soil mounds or pedestals 27–121 mm high (mean: 77.5 mm). Geomorphic field response of soils below rosettes and adjacent (∼ 100 cm apart) bare soils differs. Infiltration rates are higher under plants (mean: 158.7 mm/min) than in exposed control soils (60.0 mm/min). Soils below silverswords also show greater shear strength (146.1 g/cm²) and compressibility (2.795 kg/cm²) than unprotected soils (36.1 g/cm², and 0.108 kg/cm², respectively). Soil in the plant mounds contains more organic matter; this has influenced other pedological properties, which also differ substantially between sampling positions. Substrate under plants has a porosity ∼ 53% higher than exposed soil, while bulk density is 62% higher in soil outside the plant crown. The observed microtopographic differences are ascribed to greater soil erosion by rainsplash and runoff outside the silversword canopy. The dense rosette crown effectively intercepts raindrops; soils beneath plants also have a high surface cohesiveness provided by a dense network of fine plant rootlets and partially decomposed organic material. Higher runoff rates occur on the less permeable substrate beyond rosettes, which is affected by soil crusting.     

绒毛白蜡插条不定根的发生及其影响因素

分别以绒毛白蜡1年生苗干和3年生苗干作材料，研究了插条不定根的解剖学特征和形态特征，以及影响不定根发生的因素。结果表明：绒毛白蜡插条不定根起源于形成层周围，内与木质部连接，向外穿过皮层而延伸。不定根在插条上呈散生状态，插条下切口处，形成的不定根较多，但无典型的愈伤组织生根现象，光照、插壤和不同的激素处理都影响不定根的发生。     

粉煤灰改良砂姜黑土对小麦生长发育的影响

采用大田与盆栽的方法 ,研究了粉煤灰改良砂姜黑土对小麦生长发育的影响 .结果表明 ,粉煤灰改良砂姜黑土能促进小麦根系的生长、幼穗分化和分蘖的消长 ,提高了分蘖质量、小穗可孕率和产量 .粉煤灰搀和量以 2 4× 10 4 kg·hm-2 的效果为好 .     

Fenton氧化-粉煤灰处理造纸废水的研究

采用Fenton氧化和粉煤灰吸附两级工艺,研究其对造纸厂废水处理的效果。结果表明,在pH值为3,H2O2投加量为2.5mL/L,FeSO4投加量为150mg/L时,Fenton氧化对废水COD的去除率达86%,色度去除率达90%。粉煤灰的投加量为300g/L,吸附时间为3h,COD的去除率可达68%。     

粉煤灰改良砂姜黑土对冬小麦田生态因子的影响

1997年—1999年通过桶栽试验研究了粉煤灰改良砂姜黑土对冬小麦田生态因子的影响。结果表明，粉煤灰施入砂姜黑土降低了土壤的容重、比重及土壤的粘粒含量，增加了土壤的总孔隙度、毛管孔隙度和土壤饱和导水率。并分别得出土壤容重、比重、毛管孔隙度和饱和导水率与粉煤灰用量的模拟方程。同时，也对土壤温度、土壤含水量及土壤微生物数量在整个生育时期的变化动态进行了研究。     

改性粉煤灰混凝剂HYL处理印染废水的研究

以改性粉煤灰 HYL为混凝剂 ,按 3.5 0～ 4 .0 0 g· L-1的投加量 ,常温下沉降反应 1h,就可使 CODcr为 85 0 mg· L-1印染废水中的 CODcr降到 170 mg· L-1以下 ,色度降到 4以下 ,达到国家行业排放标准。为印染废水的处理探索出了一条新路。     

高铝粉煤灰蒸压制品强度的研究

利用X射线衍射、扫描电镜、红外光谱对高铝粉煤灰进行了分析,在不同蒸压制度下通过未反应CH量的测定、结合水量的测定、冷热盐酸中溶出量的变化以及XRD、SEM等方法对该粉煤灰的蒸压性能进行了研究。结果表明,该粉煤灰的主要矿物组成为刚玉、莫来石、赤铁矿和少量玻璃相,不含二氧化硅。在不同蒸压制度下,该粉煤灰石灰蒸压试样中水化产物主要为C-S-H(I)和水石榴石,水石榴石的量较多,蒸压试样的强度很低,其原因与粉煤灰中可参与反应的硅的量少有关。