凯里地区白云质砂石山主要植被类型调查

根据凯里地区白云质砂石山植被调查,对其生态环境、分布规律、植物组成、植被类型进行分析研究,为白云质砂石山植被恢复提供理论依据。     

Evaluation of Dolomite Phosphate Rock–N‐Viro Soil Mixtures for Growth of a Horticultural Crop in an Acidic Sandy Soil

Abstract

Most agricultural soils in the Indian River area, South Florida, are sandy with minimal holding capacity for moisture and nutrients. Phosphorus (P) leaching from these soils has been suspected of contributing to the eutrophication of surface waters in this region. Dolomite phosphate rock (DPR) and N‐viro soil are promising amendments to increase crop production and reduce P loss from sandy soils. Soil incubation and greenhouse pot experiments were conducted to examine the effects of Florida DPR–N‐viro soil mixtures on the growth of a horticultural crop in an acidic sandy soil and to generate information for developing a desired formula of soil amendments. Dolomite phosphate rock and N–viro soil application increased soil pH, electrical conductivity (EC), extractable P, calcium (Ca), and magnesium (Mg). N–viro soil had greater effect on soil pH, organic matter content, and microbial biomass than the DPR. Comparatively higher nitrification rates were found in the N–viro soil treatment than the DPR treatment. A systematic decrease in soil‐extractable P was found with increasing proportions of N‐viro soil from the combined amendments. Greenhouse study demonstrated that the application of DPR and N‐viro soil significantly improved dry‐matter yield and increased plant P, Ca, and Mg concentrations of radish (Raphanus sativus L.). Based on dry‐matter yield and plant N uptake, the combined amendments that contained 30% or 20% of DPR materials appear to be optimal but remain to be confirmed by field trials.     

皖南烟区白云石粉对酸性植烟土壤的改良研究

采用盆栽与室内分析的方法,研究了不同粒径与用量的白云石粉对植烟土壤的酸性改良效应。结果表明:白云石粉越细、用量越高,改良越快,效果越明显,持续时间越短;白云石粉应在烟苗移栽前30天左右使用;若土壤pH的调整目标值为1个单位或施用量为1 500 kg/hm2时,粒径为250μm的白云石粉较为经济;土壤交换性铝含量较土壤pH更能反映烟草植株生长情况,其临界指标为0.30~0.45 cmol/kg,高于此临界值,应施用白云石粉进行调酸。     

黔东南州白云质砂石山10个树种造林试验初析

通过对构树等10个树种在白云质砂石山上进行造林对比试验,结果显示10个树种间的造林成活率、年生长量均存在极显著差异,表明白云质砂石山造林成功的关键技术之一是树种选择,根据本试验各树种的造林成活率与年生长量的综合表现,初步认为构树、南酸枣、侧柏、乌桕、女贞可作为白云质砂石山的造林树种,优良适宜树种的确定有待于进行更多树种参加的多个立地造林试验及其至林分郁闭年份以上的观测结果。     

Dissolved organic carbon (doc) and dissolved organic nitrogen (don) content of an arenosol as affected by liming in a pot experiment

The effect of liming materials was investigated on the dissolved organic carbon (DOC) and dissolved organic nitrogen (DON) content of the soil in a pot experiment on an acidic soil using oat (Avena sativa L. ) as an indicator plant. Soil samples were taken three times during the growing season. The lime rates applied were 0, 1, 2, 3 g calcite/pot and 0.92, 1.84, 2.76 g dolomite/pot, respectively. Due to an increase in soil pH and microbial activity the DOC concentration significantly increased with increasing lime doses at all three samplings. An exponential relationship was found between soil pH and DOC concentration: y v = v 0.3733e 0.7893x , r v = v 0.903***. Lime had a significant effect on DON concentration at the first sampling, while for the remainder of the growing period no further significant increases were found. This could be explained by the fact that the biodegradability of DOC and DON differs under conditions of the experiment, resulting in a decrease in the N content of the dissolved organic matter, while the amount of DOM and DOC increased with increasing pH. Because of the above mentioned facts the DOC/DON ratio increased significantly with liming. There were no significant changes in the dissolved organic carbon content of the soil during the 15-week growing period, while DON concentration decreased significantly. It can be explained by the initial addition of N fertilizer, which increased the DON quantity at the first sampling in the soil.     

Utilization of Large-Sized Dolomite By-Product Particles and Losses of Cations from Acidic Soil

To investigate the possibilities of utilization of dolomite large size fractions (dropouts) and their effect on plants a five-year experiment was set in 2015. A fertilization value of large fractions (5–7 and 7–10 mm) of dolomite in two doses was studied. The biomass yield of crops in dolomite dropout treatment was around 90% from the treatment using dolomite flour (control). Losses of bases from the soil treated with high doses of dropouts did not exceed the migration losses of the treatment with dolomite flour. Dynamics of dolomite flour dissolution in the soil was empirically modeled. The data prove that high doses of the large-sized dolomite fractions act similarly to standard dolomite flour and have more persistent effects on soil and plants.     

酸性红黄壤施用白云石对小麦生长及产量的影响

针对皖南酸性红黄壤的酸和瘠特点 ,采用田间试验方法研究了白云石对皖南酸性红黄壤的改土效果。结果表明 :皖南酸性红黄壤上施用白云石能改善小麦生长发育状况 ,显著提高小麦的产量。白云石施用量以 110 0～ 16 0 0kg/hm2 为宜     

Effects on stream water chemistry and forest vitality after whole-catchment application of dolomite to a forest ecosystem in southern Norway

An acidified, 0.8 km² coniferous-forested catchment was limed with 3 t ha⁻¹ of coarse-grained dolomite powder in September 1994. The liming resulted in an immediate change in runoff water chemistry relative to the stream of an adjacent reference catchment. pH, calcium, magnesium and acid neutralising capacity (ANC) increased and inorganic Al decreased after liming. Potential favourable water quality for sensitive organisms remained relatively constant over the post-liming period (7 years), and model simulations indicate that adequate water quality may last for an additional 40–50 years. NO₃ concentrations showed no significant change due to liming. A significant increasing trend in TOC was attributed to liming. Concentrations of Cd, Co, Fe, Mn, Ni and Zn were lower in the limed stream than in the reference stream during a period of 3 years after liming, whereas concentrations of As, Cu, and Pb were not significantly different. Steep slopes, thin soils, high amounts of precipitation and thus dominance of surface and subsurface flow in this catchment may explain the rapid response in runoff. During the first 6 years after liming there have been no significant effects on tree growth and vitality (crown density and crown colour). This experiment shows that liming of forested catchments may be a viable method to obtain long-term improvement in water quality and potential positive effects for acid-sensitive aquatic organisms.     

施用白云石粉对黄红壤 酸度和油菜产量的影响

田间试验结果表明,酸性黄红壤上施用白云石粉显著降低了土壤交互性铝含量和提高了土壤pH值,其 降酸作用与白云石粉用量呈正相关。适当施用白云石粉能够极显著提高油菜产量。白云石粉用量在1 600kg/hm2 时,油菜达到最高产量2 518kg/hm2。此外,施用白云石粉改善了土壤的养分状况,提高了油菜植株的养分含量和 养分吸收量。     

施肥条件下白云石粉对菜地土壤氮素转化的影响

采用室内培养的方法,研究施肥条件下添加白云石粉对菜地土壤氮素形态转化的影响,结果表明：土壤铵态氮含量呈先增加后减少的趋势,而硝态氮含量呈逐步增加的趋势;随着白云石粉用量的增加,土壤铵态氮含量减少而硝态氮含量增加.