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1.
Effect of phosphate rock,coal combustion by-product,lime, and cellulose on ryegrass in an acidic soil 总被引:1,自引:0,他引:1
Remediation of soil acidity is crucial for increasing crop production and improving environmental quality of acid infertile soils. Soil incubation and greenhouse pot experiments were carried out to examine the interactions between phosphate rock (PR), coal combustion by-product (BP), dolomitic lime (L), and cellulose (C) in an acidic soil and their effects on ryegrass (Lolium perenne L. cv Linn) growth. BP and PR application increased plant P content and dry matter yield (DMY) of shoots and roots by improving soil Ca availability and reducing Al toxicity. Application of BP at low rates (5 to 10 g BP kg-1) with PR appeared to decrease both plant P content and DMY compared to PR application alone. The reduced DMY is due to an increased Al concentration in soil solution as a result of displacement of sorbed Al by Ca of BP. Increases in DMY were obtained by addition of lime along with PR and BP at low rates or by increasing BP application rates above 15 g kg-1. This improved plant response was likely related to alleviation of Al toxicity by CaCO3 contained in the BP. In addition to raising the pH to an acceptable level for plant growth, the dolomitic lime supplied needed Mg for plants, thereby maintaining a good balance between available Ca and Mg for plants in the BP- and PR-amended soils. The addition of cellulose to the BP- and PR-amended soils reduced water-soluble Al and increased DMY. Plant growth increased PR dissolution by 2.4 to 243% in a soil with low available P. Use of BP at moderate rates with PR and dolomitic lime appears to be the best combination in increasing crop yields on infertile acidic soils. 相似文献
2.
Pot experiments were conducted to assess the lime and phosphorus requirements ofLeucaena leucocephala (LAM.) De Wit grown on three acid soils (Ultisols) from southeastern Nigeria. Liming and phosphorus application significantly enhanced growth ofL. leucocephala. Ammakama soil showed best effect to phosphorus application, while acidity problems were more pronounced on Onne and Isienu soils. High lime rate (2000 ppm) reduced plant growth in Isienu soil probably due to nutrient imbalance. Potassium, manganese and zinc levels in the plants were reduced with increasing lime rates. On Onne and Isienu soils plant tops correlated better with total acidity and extractable Al+3 level than with soil pH-H2O. 相似文献
3.
Grain yield, dry-matter production, and susceptibility to grain discoloration syndrome of upland rice (Oryza sativa L.) in relation to nutrient supplies were studied in Ultisols in Nigeria's humid tropics. Nutrients identified as necessary to produce high dry matter were N, K, Mg, and Si. Among these nutrients, Mg and Si were found to be involved in the protection of rice plants against grain discoloration and their application increased the grain yield of 3 varieties by an average of 34%. 相似文献
4.
Effects of soil macrofauna, micro-environment and mulch quantity were investigated on an acid Ultisol in a high-rainfall area in S.E. Nigeria, using litterbags or littertubes with leaves from the trees of an alley cropping system with t Flemingia congesta or t Dactyladenia barteri as hedgerow species.There was no effect of mulch quantity on the rate of decomposition. Soil macrofauna contributed to between 30 and 40% of mulch decomposition over the period of approximately 50% of disappearance of the original material. The faunal effect became apparent after a longer incubation period (>20 weeks) with the slower decomposing t Dactyladenia than with the t Flemingia mulch (immediate effect). This is presumably related to t Dactyladenia's higher lignin content (40% compared to 22% for t Flemingia). The t Flemingia mulch decomposed faster in alley cropping with t Dactyladenia hedgerow than with t Flemingia hedgerow, irrespective of faunal access, suggesting a microclimate efffect on decomposition. There were no marked changes in chemical composition of the mulches with decomposition period, except for a rapid decrease of K content in both mulches and a rapid increase in lignin content of the t Flemingia mulch within the first 10 days of decomposition, which indicates that early decomposition affected the relatively easily degradable compounds. 相似文献
5.
Jean-Michel Harmand Hector Ávila Etienne Dambrine Ute Skiba Sergio de Miguel Reina Vanessa Renderos Robert Oliver Francisco Jiménez John Beer 《Biogeochemistry》2007,85(2):125-139
Nitrogen fertilization is a key factor for coffee production but creates a risk of water contamination through nitrate (NO3−) leaching in heavily fertilized plantations under high rainfall. The inclusion of fast growing timber trees in these coffee
plantations may increase total biomass and reduce nutrient leaching. Potential controls of N loss were measured in an unshaded
coffee (Coffea arabica L.) plot and in an adjacent coffee plot shaded with the timber species Eucalyptus deglupta Blume (110 trees ha−1), established on an Acrisol that received 180 kg N ha−1 as ammonium-nitrate and 2,700 mm yr−1 rainfall. Results of the one year study showed that these trees had little effect on the N budget although some N fluxes
were modified. Soil N mineralization and nitrification rates in the 0–20 cm soil layer were similar in both systems (≈280 kg N ha−1 yr−1). N export in coffee harvest (2002) was 34 and 25 kg N ha−1 yr−1 in unshaded and shaded coffee, and N accumulation in permanent biomass and litter was 25 and 45 kg N ha−1 yr−1, respectively. The losses in surface runoff (≈0.8 kg mineral N ha−1 yr−1) and N2O emissions (1.9 kg N ha−1 yr−1) were low in both cases. Lysimeters located at 60, 120, and 200 cm depths in shaded coffee, detected average concentrations
of 12.9, 6.1 and 1.2 mg NO3−-N l−1, respectively. Drainage was slightly reduced in the coffee-timber plantation. NO3− leaching at 200 cm depth was about 27 ± 10 and 16 ± 7 kg N ha−1 yr−1 in unshaded and shaded coffee, respectively. In both plots, very low NO3− concentrations in soil solution at 200 cm depth (and in groundwater) were apparently due to NO3− adsorption in the subsoil but the duration of this process is not presently known. In these conventional coffee plantations,
fertilization and agroforestry practices must be refined to match plant needs and limit potential NO3− contamination of subsoil and shallow soil water. 相似文献
6.
完全氨氧化菌(comammox Nitrospira)的发现对硝化微生物的研究提出了新的挑战。大量研究表明完全氨氧化菌在陆地生态系统中广泛分布,但其在农田土壤中的分布规律及其对长期施用粪肥的响应尚不清楚。研究了长期施用猪粪对农田红壤完全氨氧化菌、氨氧化古菌(AOA)和氨氧化细菌(AOB)功能基因(amoA)丰度的影响,及其与土壤净硝化速率的关系。结果表明:与不施肥的对照处理相比,猪粪施用显著提高土壤有机质和养分含量,且随着猪粪的施用量增加而增加。同时,施用中量和高量猪粪显著提升土壤净硝化速率,增幅分别达到317%和416%。所有处理中,完全氨氧化菌丰度以进化枝A为主,进化枝B丰度极低,大多为非特异性扩增产物,但进化枝A的amoA丰度均低于氨氧化古菌和氨氧化细菌。长期施用高量猪粪显著提升进化枝A的amoA基因丰度,表明存在喜好富营养环境的完全氨氧化菌,而有效磷是最主要的影响因子。相关性分析表明,进化枝A的amoA丰度与净硝化速率呈显著正相关(P<0.01),而氨氧化古菌和氨氧化细菌则没有,表明进化枝A可能在长期施用粪肥的农田红壤硝化过程中发挥重要功能。综上所述,长期施用粪肥显著提高... 相似文献
7.
Badejo MA Espindola JA Guerra JG De Aquino AM Correa ME 《Experimental & applied acarology》2002,27(4):283-296
Oribatid mite densities in the topsoil and their activity at the soil surface were monitored under three species of perennial
legume cover crops namely, Arachis pintoi, Macroptilium atropupureum and Pueraria phaseoloides, grass (Panicum maximum) and bare plots on three occasions in 1998 and 1999 in a derived savanna zone in Brazil. Both densities and activity at the
soil surface were higher in the early but cool dry season in April 1998 than in the early wet but warm season in November
1998 and 1999. Three taxonomic groups of macropyline oribatid mites, namely Nothrus, Archegozetes and Masthermannia as well as a brachypyline taxon, Scheloribates were suggested as possible indicators of effect of legumes on soil biota because their populations increased under the legumes
and/or their residues. Nothrus in particular increased in abundance more than any other taxon in the presence of residues of A. pintoi. Each legume supported a unique oribatid mite community in terms of species composition and relative abundance. The large
numbers of Archegozetes trapped from all the legume and grass plots in April and November 1998 were also attributed to highly conducive conditions
provided by the vegetation cover and their residues. The results suggest that the oribatid mite community of the study area
was numerically stable as the peak populations of different species were not synchronized. Many taxonomic groups of pycnonotic
brachypyline mites were absent. Legume cover crops, especially A. pintoi, and their residues have potential in restoring oribatid mite populations to precultivation levels.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
8.
Summary We studied the effect of liming on the rates of mineralization and nitrification in a coarse-textured kaolinitic Ultisol.
Soil samples were taken from field plots which received lime rates from 0 to 4mt/ha three years prior to the study. The pH
of the soil samples varied from 4.2 to 6.1.
Ammonification of soil organic N and added urea source proceeded readily and was not affected by lime rate. Nitrification
occurred in both limed and unlimed soils but the rate of nitrification depended upon the rate of lime application. Soil pH,
exchangeable Ca and exchangeable A1 were significantly correlated with the amount of NO3-N accumulated at the end of the 65 days incubation period.
Nitrification of NH4-N from ammonium sulfate was absent in soils receiving lower rates of lime which gave pH values ranging from 4.2 to 4.8. Added
ammonium source was nitrified readily after a 3-week delay period in the soil (pH 6.1) which received a higher rate of lime
(4 mt/ha). 相似文献
9.
Summary The differential response of six cowpea (Vigna unguiculata (L.) Walp) cultivars to liming was assessed in a greenhouse trial using an Ultisol (Typic Paleudult) from southeastern Nigeria. Lime rates from 0 to 5.0 t/ha were applied to give a range of soil pH, determined in 11 soil/water from 4.25 to about 7.0. Without liming, relative dry matter yields of tops ranged between 46.6 and 76.8 percent. Significant yield responses to the first lime increment (0.5 t/ha) were observed particularly in the less tolerant cultivars and maximum yields were generally obtained with application of 1.6 to 2.5 t/ha lime.Among the six cultivars, TVu 4557 and Ife Brown were most tolerant, Vita-1 and Vita-3 were moderately tolerant, and TVu 1977-OD and TVu 4552 were least tolerant to soil acidity. The latter two cultivars were the most poorly nodulated when grown in the unlimed soil. The first lime increment enabled excellent nodulation to be achieved in all cultivars. Nitrogen analyses on tops confirmed the visual symptoms of nitrogen deficiency in two cultivars (Vita-1, TVu 1977-OD) grown in the unlimed soil. Analysis of data on chemical composition of plant tops and chemical soil characteristics gave indications that aluminium toxicity is the major growth limiting factor for cowpeas in this soil.This study, albeit with a limited range of cowpea germplasm clearly indicates that cowpea possesses considerable potential as a grain legume on strongly acid soils (pH<5.0), even in circumstances where lime is not available. Low rates of lime (0.5 t/ha or less) will greatly expand the available choice of cultivars. 相似文献
10.
Effect of rock phosphate on soil properties and apparent phosphorus recovery in acid soil of Sumatra
M. Utomo 《Plant and Soil》1995,171(1):199-202
The effects of rock phosphate (RP) on soil properties and apparent P recovery of corn in acid soil of Sumatra were investigated. The soil was dominated by kaolinitic minerals, very acid and low in extractable phosphorus. The experiment was conducted in two steps: incubation and greenhouse. The treatments were rock phosphate and triple superphosphate (TSP) at 0, 200, 400 and 600 µg P g-1 for the incubation experiment, and at 0, 50, 100, 150 and 200 µg P g-1 for greenhouse experiment In the incubation experiment, rock phosphate reduced exchangeable Al and increased pHH2O better than TSP, and supplied Bray-1 extractable P as much as did TSP. In the greenhouse experiment, apparent P recovery values of rock phosphate were very close to those of TSP and the values tended to decrease at higher rates of P. Although corn yields of the rock phosphate treatment were lower than TSP, its relative agronomic effectiveness was quite high. 相似文献