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1.
The uniformity, low cost and ease of application associated with inorganic fertilizers have diminished the use of organic nutrient sources. Concern for food safety, the environment and the need to dispose of animal and municipal wastes have focused attention on organic sources of N such as animal-derived amendments, green manures, and crop rotations. Managing organic N sources to provide sufficient N for crop growth requires knowledge of C and N decomposition over several years, particularly where manure and compost are applied. We report a comparison of compost and chemical fertilizer, use of a corn-corn-soybean-wheat rotation compared to continuous corn and the use of cover crops. Nitrogen (150 d) and C incubations (317 d) were conducted to determine the effect of cropping system and nutrient management on: N mineralization potential (NMP), the mineralizable organic N pool (No), the mean residence time (MRT) of No, C mineralization (Cmin), and soil organic carbon (SOC) pool sizes and fluxes. Compost applications over 6 y increased the resistant pool of C by 30% and the slow pool of C by 10%. The compost treatment contained 14% greater soil organic C than the fertilizer management. Nitrogen was limiting on all compost treatments with the exception of first year corn following wheat fallow and clover cover crop. The clover cover crop and wheat-fallow increased inorganic N in both nutrient managements. We recommend that growers adjust their N fertilizer recommendation to reflect the quantity and timing of N mineralized from organic N sources and the N immobilization that can be associated with compost or other residue applications. Proper management of nutrients from compost, cover crops and rotations can maintain soil fertility and increase C sequestration. 相似文献
2.
M. Deurer D. Grinev I. Young B. E. Clothier K. Müller 《European Journal of Soil Science》2009,60(6):945-955
We analysed the long‐term effect of the addition of organic carbon (C) on the macropore structure of topsoils. For this purpose we compared the top 50 mm in the tree rows of an organic apple orchard with those in an adjacent conventional orchard with the same soil type, texture and previous land‐use history in New Zealand. After 12 years the topsoils of the organic orchard had 32% more soil organic carbon (SOC) sequestered than those of the conventional, integrated orchard because of regular compost applications and grass coverage. We quantified the macropore structure (macropores = pores > 0.3 mm) of nine undisturbed soil columns (43 mm long, 20 × 17 mm in the plane) within each orchard using 3D X‐ray computed tomography. The macroporosity (7.5 ± 2.1%) of the organic orchard soil was significantly greater than that of the integrated orchard (2.4 ± 0.5%). The mean macropore radius was similar in the organic and integrated systems, with 0.41 ± 0.02 mm and 0.39 ± 0.01 mm, respectively. The connectivity of macropores tended to be greater in the organic than in the integrated system, but this was not statistically significant. The pronounced soil C management in the organic orchard increased both the formation of macropores by roots and a larger fresh weight of anecic earthworms, and the stabilization of the macropore structure was increased by a larger aggregate stability and microbial biomass compared with those of the integrated orchard. We simulated the diffusion through the measured pore structures of segments of the soil columns. The segments had the length of the mean aggregate size of the soils. The relative diffusion coefficients at this aggregate scale were significantly greater in the organic (0.024 ± 0.0009) than in the integrated (0.0056 ± 0.008) orchard. In a regression analysis with both the porosity and connectivity of macropores as significant variables, 76% of the variability of the relative diffusion coefficients was explained in the integrated, and, with the porosity as the only significant factor, 71% of the variability in the organic orchard. We hypothesize that a greater relative diffusion coefficient at the aggregate scale would reduce nitrous oxide (N2O) production and emission in a wet soil and suggest that soil C management combats climate change directly by sequestering C and indirectly in the form of a reduction of N2O emissions, by creating more macropores. 相似文献
3.
The content of soil organic matter (SOM) can be considered as an important factor for evaluating soil fertility, crop yields, and environmental effects. Sensitive measurements for the assessment of quantitative changes in SOM shortly after the conversion of the management practice would be helpful to understand the SOM‐transformation cycle in more detail. Changes in SOM are reflected in modifications of total organic‐carbon (TOC) and total organic‐nitrogen (TON) contents. They are initially detectable in the readily decomposable fraction. We used hot water–extractable carbon (HWC) and nitrogen (HWN) as measurement of labile pools of SOM and aimed to quantify changes in contents of these C and N fractions in a sandy soil already few years after changing management strategy. In this context, we examined the impact of the conversion of a succession fallow (F) to organic (O) and intensive (I) agriculture on TOC, total N (TN), HWC, and HWN. The conversion of succession fallow to cultivated land resulted in a significant decrease of TOC, TN, and HWC at 0–10 cm soil depth. On average, TOC decreased approx. 0.70 g C kg–1 (approx. 9% of initial TOC), TN decreased approx. 0.13 g N kg–1 (approx. 17% of initial TN), and HWC decreased approx. 0.05 g C kg–1 (approx. 12% of initial HWC) within 3 years. Relatively rapid changes in TOC and TN contents indicated comparatively high proportions of decomposable C and N. These were reflected in comparable high HWC (ranging from 0.37 to 0.59 g C kg–1 at 0–30 cm soil depth) and HWN (ranging from 0.04 to 0.10 g N kg–1 at 0–30 cm) contents. These high contents as well as the high HWC : TOC and organic hot water–extractable N (HWNorg) : TN ratios (both between 5% and 7%) implied that the soil investigated has a high ability to provide short‐term available organic C and N compounds. Long‐lasting applications of high quantities of organic fertilizer in the past and high quantities of rhizodepositions were assumed as reasons for the high capability of soil to provide short‐term to medium‐term available C and N. Changes in the HWN content due to the fertilization or crop rotation were mainly based on changes in its inorganic part. This ranged between 10% and 30% of HWN. By discriminant function analysis, it could be shown that the HWN represents a suitably sensitive measurement for the determination of management‐specific impacts in terms of the N, but also of the C cycle. In combination with other C and particularly with other N parameters, the HWN allowed a statistically significant separation of comparable sites varying in management practice already 2 years after the conversion of the management system. 相似文献
4.
The capability of organic wastes to release available N in soil varies largely, depending on their source and form of production, or rather on their composition and biodegradability. Our purpose was to predict mineralization rates of different materials using their analyses joined with a simulation model, and to evaluate the influence of soil type and application rate of the organic materials on N and C transformations in soil. Four organic materials, sewage sludge (SS), sewage sludge compost (SSC), cattle manure compost (CMC), hen and cattle manure compost (HCMC), were applied to two soils at rates of 2 and/or 4%. The soils were incubated aerobically for 168 days at 30°C, during which CO2 evolution rates and mineral-N concentrations were measured periodically. Hot water extractable C and N of all organic amendments correlated well with short term C and N mineralization, except HCMC that immobilized N although its soluble N content was large. NCSOIL, a computer model that simulates C and N cycling in soil with organic amendments, predicted well C and N mineralization of SS, SSC and CMC when considered as three-pool materials that decomposed at specific rates of 0.4, 0.024 and 10?4 d?1, using hot water soluble C and N as the labile pool. N immobilization by HCMC could be simulated only if the distribution of N between the labile and resistant pools was derived by optimization of NCSOIL, while hot water soluble C was labile. Laboratory methods to determine an intermediate pool or components that contribute to immobilization are required for improving the predictions of C and N mineralization from organic amendments. 相似文献
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6.
有机物循环对红壤稻田土壤有机碳和热水可提取碳的影响 总被引:1,自引:0,他引:1
利用长期定位试验研究了有机物循环对红壤稻田土壤有机碳(SOC)和热水可提取碳(HWC)的影响。研究包括4种施肥处理:CK(无肥),C(有机物循环),NPK和NPK+C。结果表明,有机物循环显著提高了SOC和HWC的含量(P<0.05)。在4种处理中,NPK+C处理的SOC和HWC含量均为最大值。SOC随时间呈线性增加(R2>0.7);然而,HWC则是先下降,后缓慢上升或趋于稳定,变化趋势以一元二次线性拟合更好(R2>0.7)。与化肥NPK相比,有机物循环对SOC和HWC变化趋势的影响更大,它明显加快了SOC的积累速率,减缓了HWC的下降速率。与SOC相比,HWC与土壤养分更相关,它可能更好地反映了土壤养分的供应能力。 相似文献
7.
The steadily increasing utilization of bio‐waste compost in German viticulture requires a more detailed investigation of nitrogen (N) mineralization parameters for mature bio‐waste compost applied to vineyard soils. N mineralization kinetics were described with two superposing exponential equations. Long‐term aerobic laboratory incubation experiments of 12 soil‐compost substrates revealed that 5±2.8% of its total N content could be released from a rapidly decomposable fraction (half‐life period t50 = 41 d at 15°C) and another 60±2.9% from a slower decomposable fraction (t50 = 490 d). The remaining proportion (35%) is considered not to be released in the medium term. The obtained potentially mineralizable nitrogen of 65% of total compost N significantly differs from current fertilizer recommendations, which were adopted from calculations for agricultural conditions. For fertilizer recommendations in viticulture, we recommend the consideration of a higher N‐mineralization potential for organic fertilizers. 相似文献
8.
Improved predictive relationships between compost maturity and nitrogen (N) availability are needed. A total of 13 compost samples were collected from a single windrow over a 91 d period. Compost stability and maturity were assessed using both standard chemical analyses (total C and N, mineral N, total volatile solids) and other methods (CO2 evolution, commercial maturity kits, and neutral detergent fiber, and lignin). Compost N and carbon (C) were evaluated during a 130 d aerobic incubation in a sandy loam soil after each compost was applied at 200 mg total kg?1 soil. The effect of compost maturity on plant growth was evaluated by growing two ryegrass (Lolium perenne L.) crops and one barley (Hordeum vulgare L.) crop in succession in compost-amended soil under greenhouse conditions. Potential phytotoxicity from compost was assessed by growing tomato (Lypersicum esculentum L.) seedlings in compost-amended soil. Regression and correlation analyses were used to evaluate the relationship between compost maturity parameters, the rate and extent of net N and C mineralization, plant yield and N uptake, and phytotoxicity. Commonly used maturity parameters like total C, total N, and C:N ratio were poorly correlated with the rate and extent of mineralization, and with plant growth parameters. The N mineralization rate during the first 48 d of aerobic incubation was strongly correlated (r= ?0.82 to ?0.86) to compost fiber and lignin concentration, and to the Maturity Index (r=0.85). Trends in C mineralization were similar. There were few differences in C mineralization between composts after 48 d of aerobic incubation in soil. Ryegrass harvested 35 and 70 d after compost application was not strongly affected by compost maturity, and relatively immature composts were phytotoxic to tomato seedlings. Methods of characterizing compost maturity and stability that more realistically reflect the composting process are better predictors of N release and potential plant inhibition after incorporation into soil. 相似文献
9.
Using pre-established trial sites on allophanic soils, we investigated the impacts of long to medium-term pastoral management practices, such as fertilisation and grazing intensity, on a range of soil biological and biochemical properties; hot water-extractable C (HWC), water-soluble C (WSC), hot-water extractable total carbohydrates, microbial biomass-C and N and mineralisable N. These properties were examined for their usefulness as soil quality indicators responding to changes in the rhizosphere caused by management practices. Adjacent cropping, market garden and native bush sites located on similar soil types were included to determine the changes in soil biological and biochemical properties resulting from changes in land use. The seasonal variability of HWC and its relationship with other labile fractions of soil organic matter was also examined.Microbial biomass-C, mineralisable N and extractable total carbohydrates showed promise in differentiating treatment and land use effects. However, HWC was one of the most sensitive and consistent indicators examined at 52 different sites. The impact of different land uses on the amounts of HWC in the same soil type was far greater than that was observed for the soil organic carbon. The average values of HWC for soil under different land use were: native (4000 μg C g−1 soil), sheep/beef pastures (3400), dairy pastures (3000), cropping (1000) and market gardening soils (850). HWC was also sensitive to differences within an ecosystem, e.g. effects of grazing intensities and effects of N or P fertilisers on pastures. The sheep and beef/cattle grazed pastures always had higher amounts of HWC than the intensively grazed dairy pastures. Nitrogen fertiliser application (200 and 400 kg N ha−1 yr−1) over the previous 5 yr had significant (P<0.001) negative impacts on HWC and other soil microbial properties. In contrast, long-term application of P fertilisers had a significant (P<0.001) positive effect on the HWC levels in pastoral soils. In the case of long-term P trials, HWC increased even though no increase in the total soil carbon pool was detected.HWC was positively correlated with soil microbial biomass-C (R2=0.84), microbial nitrogen (R2=0.72), mineralisable N (R2=0.86), and total carbohydrates (R2=0.88). All these correlations were significant at P<0.001 level of significance. The HWC was also positively correlated with WSC and total organic C. However, these correlations were poorer than those found for other soil parameters. Most of these measurements have been actively promoted as key indicators of soil quality. Given the strong correlations between HWC and other biochemical measurements, HWC could be used as an integrated measure of soil quality. When HWC is extracted, other pools of labile nutrients are also extracted along with C. Therefore it is suggested that decline in HWC would also indicate a decline in other labile organic pools of nutrients such as nitrogen, sulphur and phosphorus. About 40-50% of the C in the HWC extract was present as carbohydrates. 相似文献
10.
河北省果园氮素投入特点及其土壤氮素负荷分析 总被引:19,自引:1,他引:18
以河北省果园土壤地力调查、农户调查和统计数据为基础,采用氮盈余法从果树种类和区域角度分析了果园生产体系中的氮素输入输出特点及氮养分盈余状况。结果表明,河北果园平均化肥氮投入量为438.0 kg/hm2,主要品种为尿素和复合肥,有机肥氮为181.6 kg/hm2,以畜禽粪为主,其中禽粪占25.5%。京津东部区和冀中、南平原区的果园氮素投入、盈余量较高;葡萄园和桃园的氮素投入水平较高;果园氮素施用与养分盈余量之间存在极显著的正相关,过量施用氮肥是氮盈余量很高的主要原因。随着氮盈余量增加,果园土壤全氮呈增加趋势,而土壤C/N均呈下降趋势,氮素盈余对土壤全氮的影响大于对土壤有机质的影响。 相似文献
11.
长期有机肥与化肥配施对渭北旱塬苹果园水分生产力和土壤有机碳含量影响的定量模拟 总被引:2,自引:0,他引:2
12.
To calculate the correct nitrogen fertilizer rate for crops and the possibility of using municipal solid waste (MSW) compost
as an organic amendment, nitrogen mineralization rates were studied by laboratory incubation and field measurements in a soil
in central Spain. Nitrogen mineralization rates were studied in a 250-day laboratory soil incubation with two treatments:
with and without compost, incubated at 28°C and a moisture content of 70% of field capacity. Three phases are described: (1)
no increase in the mineral nitrogen content, (2) a linear increase in the mineral N fraction and, finally, (3) a linear, parallel
increase in both mineral N and easily mineralizable organic N fractions. Incubation data were fitted to three different equations.
The exponential model proposed by Stanford and Smith (1972) was selected to predict field N mineralization rates. The field
experiment was performed using a crop of maize with three treatments: compost applied in February (before sowing), compost
applied during sowing and a control (without compost application): sampling was carried out over 14 months. Soil water content
was measured periodically. Soil with compost applied in February showed 1.9 and 1.4 times more available nitrogen than soil
without compost and compost at sowing, respectively, for the month of maximum accumulation. These results suggest that compost
amendments must be applied before sowing. Compost applications were shown to supply the available nitrogen for spring crops.
A simulation model showed satisfactory agreement with field data, after correction for soil temperature and water content.
Received: 22 July 1996 相似文献
13.
Jie Liu Hardy Schulz Susanne Brandl Herbert Miehtke Bernd Huwe Bruno Glaser 《植物养料与土壤学杂志》2012,175(5):698-707
Crop growth in sandy soils is usually limited by plant‐available nutrients and water contents. This study was conducted to determine whether these limiting factors could be improved through applications of compost and biochar. For this purpose, a maize (Zea mays L.) field trial was established at 1 ha area of a Dystric Cambisol in Brandenburg, NE Germany. Five treatments (control, compost, and three biochar‐compost mixtures with constant compost amount (32.5 Mg ha–1) and increasing biochar amount, ranging from 5–20 Mg ha–1) were compared. Analyses comprised total organic C (TOC), total N (TN), plant‐available nutrients, and volumetric soil water content for 4 months under field conditions during the growing season 2009. In addition, soil water‐retention characteristics were analyzed on undisturbed soil columns in the laboratory. Total organic‐C content could be increased by a factor of 2.5 from 0.8 to 2% (p < 0.01) at the highest biochar‐compost level compared with control while TN content only slightly increased. Plant‐available Ca, K, P, and Na contents increased by a factor of 2.2, 2.5, 1.2, and 2.8, respectively. With compost addition, the soil pH value significantly increased by up to 0.6 (p < 0.05) and plant‐available soil water retention increased by a factor of 2. Our results clearly demonstrated a synergistic positive effect of compost and biochar mixtures on soil organic‐matter content, nutrients levels, and water‐storage capacity of a sandy soil under field conditions. 相似文献
14.
《Communications in Soil Science and Plant Analysis》2012,43(11-12):1964-1982
Mineralization of soil organic carbon (C) plays a key role in supplying nutrient elements essential to plant growth. Changes of C mineralization of mixed stands of Chinese fir and Michelia macclurei (a broadleaf tree), pure M. macclurei stands, and pure Chinese fir (Cunninghamia lanceolata) stands established in 1983 after clear‐felling of a first‐generation Chinese fir forest were analyzed in Huitong, Hunan Province, China, and compared with those of a stand of native secondary evergreen broadleaf forest (NBF). The results showed that NBF soil had the greatest C mineralization. Mixture of Chinese fir and M. macclurei had no effect on total soil organic C in comparison with pure Chinese fir plantation, but significantly increased C mineralization from soils was detected in this study. This positive influence on C mineralization could be explained by the increase of soil labile C pools and soil microbial biomass and activity. From the analysis of C mineralization, soil microbial properties, and labile organic C, mixtures of broadleaf and Chinese fir can be considered to be an effective sustainable management model for a Chinese fir plantation. Given strong correlations with microbiological and biochemical characteristics of soils and an easier process of determination, hot water extraction, hot water–extractable C (HWC) could be used as an integrated measure of forest soil quality in mid‐subtropics. 相似文献
15.
The application of manure compost is an effective way to increase soybean [Glycine max (L.) Merr.] yield and nitrogen (N) fertility in drained paddy fields. We investigated changes in soil N mineralization during soybean cultivation using reaction kinetics analysis to determine the contribution of increased N mineralization after manure compost application (at a rate of 0 to 6?kg?m?2) on N accumulation and seed yield of soybean under drained paddy field conditions. The seed yield and N accumulation decreased markedly in the second and third year of the experiment, but soil N mineralization increased in both years. No decrease in soil N mineralization occurred even after two soybean crops. Soil N availability was not the main cause of decreased soybean yield in the second and third years. The differences in plant aboveground N content between plots with and without manure compost was similar to the increase in N mineralization caused by manure compost application in the second and third years. The application of 6?kg?m?2 of manure compost increased the amount of ureide-N and nitrate-N in soybean in the third year. Our results suggest that manure compost application increases soil N mineralization and soybean N2 fixation, resulting in increased N accumulation and seed yield. However, the soybean yield remained less than 300?g?m?2 in the second and third years (i.e., below the yield in the first year) at all levels of manure compost application due to the remarkable decrease of N accumulation in the second and the third crops. 相似文献
16.
This study aims to elucidate the significance of compost and soil characteristics for the biological activity of compost‐amended soils. Two agricultural soils (Ap horizon, loamy arable Orthic Luvisol and Ah horizon, sandy meadow Dystric Cambisol) and a humus‐free sandy mineral substrate were amended with two biowaste composts of different maturity in a controlled microcosm system for 18 months at 5 °C and 14 °C, respectively. Compost application increased the organic matter mineralization, the Cmic : Corg ratio, and the metabolic quotients significantly in all treatments. The total amount of Corg mineralized ranged from < 1 % (control plots) to 20 % (compost amended Dystric Cambisol). Incubation at 14 °C resulted in 2.7‐ to 4‐fold higher cumulative Corg mineralization compared to 5 °C. The Cmic : Corg ratios of the compost‐amended plots declined rapidly during the first 6 months and reached a similar range as the control plots at the end of the experiment. This effect may identify the compost‐derived microbial biomass as an easily degradable C source. Decreasing mineralization rates and metabolic quotients indicated a shift from a compost‐derived to a soil‐adapted microbial community. The Corg mineralization of the compost amended soils was mainly regulated by the compost maturity and the soil texture (higher activity in the sandy textured soils). The pattern of biological activity in the compost‐amended mineral substrate did not differ markedly from that of the compost‐amended agricultural soils, showing that the turnover of compost‐derived organic matter dominated the overall decay process in each soil. However, a priming effect occurring for the Dystric Cambisol indicated, that the effect of compost application may be soil specific. 相似文献
17.
长期施肥对农田土壤氮素关键转化过程的影响 总被引:32,自引:0,他引:32
当前,如何合理施肥、提高作物产量、维持土壤肥力、并兼顾生态环境效应是农业研究的主要挑战之一。本文综述了长期施肥对农田土壤氮素关键转化过程的影响,主要从土壤氮转化过程的初级转化速率角度综述肥料(有机肥和化学氮肥)对土壤氮素关键转化过程的影响。土壤氮素矿化-同化循环是自然界氮循环过程中两个至关重要的环节,是决定土壤供氮能力的重要因素。总体而言,长期施用氮肥,尤其是有机肥能显著提高初级矿化-同化周转速率;长期施肥可以刺激自养硝化作用,且有机肥的刺激作用更明显;施用化学氮肥和有机肥均能提高反硝化速率,且有机肥的刺激作用高于化学氮肥。有机肥一直被提倡和实践用来改善土壤肥力和提高土壤固碳能力,无论是单施有机肥还是有机-无机配施,均能有效地减轻硝酸盐污染,改善土壤肥力并提高作物产量。但是有机肥的施用并不是多多益善,有机肥过多施用也会增加氮损失的风险。因此,本文综述了长期施肥对农田土壤氮素关键转化过程初级转化速率的影响,讨论了各个氮转化过程之间的联系,以期增强人们对长期施肥措施影响农田土壤氮素循环的理解,并为合理施用氮肥、提高氮肥利用率、减少与氮相关的环境污染提供理论依据。 相似文献
18.
Total, mobile, and easily available C and N fractions, microbial biomass, and enzyme activities in a sandy soil under pine (Pinus sylvestris L.) and black locust (Robinia pseudoacacia L.) stands were investigated in a field study near Riesa, NE Germany. Samples of the organic layers (Oi and Oe‐Oa) and the mineral soil (0–5, 5–10, 10–20, and 10–30 cm) were taken in fall 1999 and analyzed for their contents of organic C and total N, hot‐water‐extractable organic C and N (HWC and HWN), KCl‐extractable organic C and N (Corg(KCl) and Norg(KCl)), NH ‐N and NO ‐N, microbial‐biomass C and N, and activities of β‐glucosidase and L‐asparaginase. With exception of the HWC, all investigated C and N pools showed a clear response to tilling, which was most pronounced in the Oi horizon. Compared to soils under pine, those under black locust had higher contents of medium‐ and short‐term available C (HWC, Corg(KCl)) and N (HWN, Norg(KCl)), mineral N (NH ‐N, NO ‐N), microbial‐biomass C and N, and enzyme activities in the uppermost horizons of the soil. The strong depth gradient found for all studied parameters was most pronounced in soils under black locust. Microbial‐biomass C and N and enzyme activities were closely related to the amounts of readily mineralizable organic C (HWC and Corg(KCl)). However, the presented results implicate a faster C and N turnover in the top‐soil layers under black locust caused by higher N‐input rates by symbiotic N2 fixation. 相似文献
19.
20.
广西红壤果园土壤肥力退化研究 总被引:5,自引:2,他引:5
根据广西第2次土壤普查资料,对广西柑桔、荔枝、龙眼和芒果4种果园土壤肥力状况进行调查。结果表明:广西红壤果园土壤环境恶化,主要表现在果园土壤普遍酸化,柑桔、荔枝、龙眼和芒果4种果园土壤pH分别下降了0.95、0.70,0.89和0.64个单位;有机质减少,其中芒果园和柑桔园下降较多,降幅分别达50.63%和22.45%;有效阳离子交换量(ECEC)下降,柑桔园下降43.64%,而芒果园和龙眼园也有30.77%和27.27%的降幅;容重增加,比第2次普查时增加14%~39%。受施肥投入影响, N、P、K养分在柑桔、荔枝和龙眼园上有增加的趋势,而芒果园在全N、速效P、速效K方面则有较大的下降。利用数理统计软件SPSS对果园土壤环境和养分因素进行综合分析显示,柑桔、龙眼和芒果园均表现出退化,其中芒果园退化最为严重,而荔枝园由于施肥投入较多而使土壤肥力有一定进化。 相似文献