Effects of arbuscular mycorrhizal inoculation and phosphorus supply on the growth and nutrient uptake of Kandelia obovata (Sheue,Liu & Yong) seedlings in autoclaved soil

This study evaluated the interactive effect of arbuscular mycorrhizal fungi (AMF) inoculation and exogenous phosphorus supply on soil phosphotases, plant growth, and nutrient uptake of Kandelia obovata (Sheue, Liu & Yong). We aimed to explore the ecophysiological function of AMF in mangrove wetland ecosystems, and to clarify the possible survival mechanism of mangrove species against nutrient deficiency. K. obovata seedlings with or without AMF inoculation (mixed mangrove AMF), were cultivated for six months in autoclaved sediment medium which was supplemented with KH₂PO₄ (0, 15, 30, 60, 120 mg kg−¹). Then the plant growth, nitrogen and phosphorus content, root vitality, AMF colonization and soil phosphatase activity were analyzed. The inoculated AMF successfully infected K. obovata roots, developed intercellular hyphae, arbuscular (Arum-type), and vesicle structures. Arbuscular mycorrhizal fungi colonization ranged from 9.04 to 24.48%, with the highest value observed under 30 and 60 mg kg⁻¹ P treatments. Soil P supply, in the form of KH₂PO₄, significantly promoted the height and biomass of K. obovata, enhanced root vitality and P uptake, while partially inhibiting soil acid (ACP) and alkaline phosphotase (ALP) activities. Without enhancing plant height, the biomass, root vitality and P uptake were further increased when inoculated with AMF, and the reduction on ACP and ALP activities were alleviated. Phosphorus supply resulted in the decrease of leaf N–P ratio in K. obovata, and AMF inoculation strengthened the reduction, thus alleviating P limitation in plant growth. Arbuscular mycorrhizal fungi inoculation and adequate P supply (30 mg kg⁻¹ KH₂PO₄) enhanced root vitality, maintained soil ACP and ALP activities, increased plant N and P uptake, and resulted in greater biomass of K. obovata. Mutualistic symbiosis with AMF could explain the survival strategies of mangrove plants under a stressed environment (waterlogging and nutrient limitation) from a new perspective.     

Long-term tillage and cropping effects on microbiological properties associated with aggregation in a semi-arid soil

Little is known about the long-term tillage and cropping management effects on the microbiologically derived factors that influence macroaggregates in semi-arid soil. We tested the hypothesis that differences in macro-aggregation are due to changes in soil structure related to management treatment-induced microbiological changes. In an experiment, microbiological factors consisting of aggregate stability, glomalin, russuloid basidiomycete fungi, uronic acids, total organic C (TOC), and total N (TN) were quantified in macroaggregate-size classes ranging from 4.75 to 0.25 mm, collected at 0–5 cm depth for the following treatments: (1) 12th year of fallow phase after 11 years of conventional- and no-tilled spring wheat-fallow (CTF and NTF), (2) 12th year of lentil phase after 11 years of conventional- and no-tilled spring wheat-lentil (CTL and NTL), (3) 12 years no-tilled continuous spring wheat (NTCW), and (4) 16 years uncultivated pasture (P) used as a baseline treatment. Immunoreactive easily extractable glomalin concentration was five to six times greater under P, NTCW, or NTL in the 2.00–1.00- and 1.00–0.50-mm macroaggregate-size classes than the other treatments and these results corroborated well with the results from aggregate stability assays. Russuloid basidiomycetes were highest in all NTCW macroaggregate-size classes, suggesting that annual input of lignin-containing wheat residues may influence the growth and survival of these fungi. Uronic acid amounts were highest in P but did not differ among the other treatments. In all macroaggregate-size classes, TOC content was greater in NTCW compared to CTF, and TN was about three times higher in NTL than NTF or CTF. In conclusion, 12 years of NTCW management in semi-arid soil has resulted in higher macroaggregate stability, glomalin concentration, russuloid basidiomycete populations, and TOC in macroaggregates compared to alternate-year fallow. Lentil can be used to replace fallow in dryland wheat rotation under no-till to enhance TN content and improve soil macro-aggregation.     

土样制备和保存方法对亚热带土壤反硝化的影响

比较了两种土样制备和保存方法对厌氧培养1周内土壤反硝化及矿化的动态影响。试验结果表明,强烈风干后并经长期存放过的土样显著促进了NO3--N浓度降低速率和N2O排放速率的提高,其反硝化速率和矿化速率分别较稍微风干后无存放时间(即立即开始培养试验)的土样提高了47.3%和31.0%。强烈风干土有机C矿化作用的增强以及易矿化有效态C含量的提高是促进反硝化作用增强的主要原因。风干程度和存放时间对反硝化的促进程度取决于其对有机质矿化影响的相对大小,对有机质矿化的影响越大,反硝化强度增加的幅度也越大。由试验结果可推测,利用风干土的实验室培养方法测定得到的土壤反硝化势可能会过高估计田间原位测定的反硝化势。     

Ramifications of crop residue loading for soil microbial community composition,activity and nutrient supply

Variable results have been reported on the effects of crop residue loads on soil microbial properties. We investigated changes in soil bacterial composition, β-glucosidase enzyme activity and nutrient bioavailability in response to wheat residue loading. The treatments included three levels of above-ground wheat residues (removed, retained or supplemented), with or without fertilizer N. Bacteroidetes, Firmicutes and Verrucomicrobia (the first two are copiotrophs) were less abundant where residues were removed than where residues were retained or supplemented, but the reverse was true for Actinobacteria, Cyanobacteria, Chloroflexi and Nitrospirae (all oligotrophs, although some Actinobacteria can be copiotrophic). Actinobacteria were also less abundant where fertilizer N was applied, and the abundances of their genera (including Arthrobacter and Mycobacterium) increased where residues were removed, confirming that they were oligotrophic in this study. β-diversity showed similar differences in the bacterial community structures because of residue management, but α-diversity was not affected by residue management or N fertilizer. β-glucosidase enzyme activities increased as C inputs increased with residue manipulation and N fertilizer. The enzyme activities increased with increasing residue loading in the 0–15 cm soil depth, but decreased with soil depth. Soil K supply increased with increasing residue loading, but nitrate-N supply was highest with residue retention. These results demonstrate remarkable resilience of soil microbial functioning under a wide range of crop residue inputs, without adverse effects on enzyme activity attributable to inorganic N fertilizer. The increasing β-glucosidase activity with increasing residue loading probably explains why crop residue return does not always increase soil C stocks.     

A rhizobial biofilm with nitrogenase activity alters nutrient availability in a soil

This study investigates the role played by a Bradyrhizobium japonicum SEMIA 5019-Penicillium spp. biofilm in terms of soil fertility, when it is free-living in a soil. The biofilm increased N and P mineralizations of the soil and showed a high nitrogenase activity even under a very high NO₃⁻ concentration in the soil, compared to its member microbes. It maintained a low SO₄²⁻ concentration in the soil, which was conducive to the high nitrogenase activity. The application of this microbial association as a biofilmed inoculum is important for sustaining soil fertility as well as survival of such rhizobia in the soil in the absence of their hosts. Further studies are needed to evaluate the performance of the biofilm in terms of soil fertility in the ecosystems.     

湖北潮土区不同轮作制度下土壤养分平衡状况与评价

通过连续5年定点调查和取样分析,研究了湖北省2个潮土区域农田土壤养分平衡状况,并用允许养分平衡盈亏率进行了评价.结果表明:①在几种主要轮作制中,所有作物的K肥施用量及施用比例均明显比N肥低,但几乎所有作物的K素吸收量均明显高于N素吸收量,早、晚稻吸收P、K的比例明显高于其它作物.②不同轮作制中土壤养分平衡状况表现为N素有不同程度的盈余、P素基本平衡、K素总是亏缺的,且水田K素亏缺量明显高于早地.在此基础上,作者提出"减N稳P增K"和以一个轮作周期为单位进行统筹施肥的养分平衡调控措施,以实现作物生产的高产稳产和土壤养分平衡的良性循环.     

The short-term effects of cessation of fertiliser applications,liming, and grazing on microbial biomass and activity in a reseeded upland grassland soil

A field study was conducted to determine the influence of a short-term (2 year) cessation of fertiliser applications, liming, and sheep-grazing on microbial biomass and activity in a reseeded upland grassland soil. The cessation of fertiliser applications (N and NPK) on a limed and grazed grassland had no effect on microbial biomass measurements, enzyme activities, or respiration. Withholding fertiliser and lime from a grazed grassland resulted in significant reductions in both microbial biomass C (P<0.05) and dehydrogenase activity (P<0.05) by approximately 18 and 21%, respectively. The removal of fertiliser applications, liming, and grazing resulted in even greater reductions in microbial biomass C (44%, P<0.001) and dehydrogenase activity (31%, P<0.001), and significant reductions in microbial biomass N (P<0.005), urease activity (P<0.05), phosphatase activity (P<0.001), and basal respiration (P<0.05). The abundance of culturable bacteria and fungi and the soil ATP content were unaffected by changes in grassland managements. With the cessation of liming soil pH fell from 5.4 to 4.7, and the removal of grazing resulted in a further reduction to pH 4.5. A significant negative linear relationship (r ²=0.97; P<0.01) was found between increasing soil acidity and dehydrogenase activity. Possible mechanisms influencing these changes are discussed.     

传统耕作和覆盖作物管理方式下半干旱区葡萄园表层土壤性质影响降水后碳氧化物排放

In semiarid regions of the Mediterranean basin, a rainfall event can induce a respiratory pulse that releases a large amount of soil carbon dioxide(CO_2) into the atmosphere; this pulse can significantly contribute to the annual ecosystem carbon(C) balance.The impacts of conventional tillage and two different cover crops, resident vegetation and Bromus catharticus L., on soil CO_2 efflux were evaluated in a Vitis vinifera L. vineyard in La Rioja, Spain. Soil CO_2 efflux, gravimetric water content, and temperature were monitored at a depth of 0–5 cm after rainfall precipitation events approximately every 10 d in the period from May 17 to July 27, 2012,during which the cover crops had withered. Additionally, on June 10, 2012, soil organic C, microbial biomass C, and β-glucosidase activity were determined at soil depths of 0–2.5, 2.5–5, 5–15, and 15–25 cm. The results show that pulses of soil CO_2 were related to the increase in soil water content following precipitation events. Compared to the conventional tillage treatment, both cover crop treatments had higher soil CO_2 efflux after precipitation events. Both cover crop treatments had higher soil organic C, microbial biomass C, and β-glucosidase activity at the soil surface(0–2.5 cm) than the conventional tillage treatment. Each pulse of CO_2 was related to the surface soil properties. Thus, this study suggests that the enhancement of soil organic C and microbiological properties at the soil surface under cover crops may increase soil CO_2 efflux relative to conventional tillage immediately after precipitation events during the dry season.     

Bt-transgenic rice straw affects the culturable microbiota and dehydrogenase and phosphatase activities in a flooded paddy soil

There have been few investigations of the possible effects of genetically engineered plants on the microbiota and enzyme activities in flooded soil. We studied the influence of the transgenic rice KeMingDao (KMD) straw on the culturable microbiota and enzymatic activities in a flooded paddy soil under laboratory conditions. KMD contained a synthetic cry1Ab gene from Bacillus thuringiensis under the control of a maize ubiquitin promoter and linked in tandem with the gusA and hpt genes. The results showed that there were only some occasional significant differences (P<0.05) in the number of Colony forming units of aerobic bacteria, actinomycetes and fungi and in the number of anaerobic fermentative bacteria, denitrifying bacteria, hydrogen-producing acetogenic bacteria, and methanogenic bacteria between the paddy soil amended with Bt-transgenic rice straw and with the non-Bt parental rice straw during the early stages of incubation. From d14 to d84 there were significant increases (P<0.05) in soil dehydrogenase and soil neutral phosphatase activity in soils amended with rice straw compared to soil without added straw. The dehydrogenase activity was significantly greatly (almost 1.95-fold) in soil amended with Bt-transgenic straw from d7 to d14 but from d21 to d49 there was significantly greater activity (about 1.47-fold) in the soil amended with non-Bt-straw. There were no apparent differences between the activity of soil neutral phosphatase in the soils to which non-Bt-straw and Bt-straw had been added. However, both soils to which rice straws were added demonstrated significant differences in the number of microorganisms except for aerobic bacteria and enzymatic activities with respect to the control soil throughout the incubation. The above results indicated that the Bt-straw from KMD transgenic rice is not toxic to a variety of culturable microorganisms in the studied flooded paddy soil.     

Water balance simulation of a dryland soil during fallow under conventional and conservation tillage in semiarid Aragon, Northeast Spain

In Central Aragon, winter cereal is sown in the autumn (November–December), commonly after a 16–18 months fallow period aimed at conserving soil water. This paper uses the Simple Soil–Plant–Atmosphere Transfer (SiSPAT) model, in conjunction with field data, to study the effect of long fallowing on the soil water balance under three tillage management systems (conventional tillage, CT; reduced tillage, RT; and no-tillage, NT). This was on the assumption that soil properties would remain unchanged during the entire fallow season. Once the model was validated with data obtained before primary tillage implementation, the differences between simulated and observed soil water losses for the CT and RT treatments could be interpreted as the direct effect of the soil tillage system. The model was calibrated and validated in a long-term tillage experiment using data from three contrasting long-fallow seasons over the period 1999–2002, where special attention was paid to predicting soil hydraulic properties in the pre-tillage conditions. The capacity of the model to simulate the soil water balance and its components over long fallowing was demonstrated. Both the fallow rainfall pattern and the tillage management system affected the soil water budget and components predicted by the model. The model predicted that about 81% of fallow seasonal rainfall is lost by evaporation in long-fallow periods with both a dry autumn in the first year of fallow and a rainfall above normal in spring. Whereas, when the fallow season is characterised by a wet autumn during the first year of fallow the model predicted a decrease in soil water evaporation and an increase in water storage and deep drainage components. In this case, the predicted water lost by evaporation was higher under NT (64%) than under RT (56%) and CT (44%). The comparison between measured and simulated soil water loss showed that the practice of tillage decreased soil water conservation in the short term. The long-term analysis of the soil water balance showed that, in fallow periods with a wet autumn during the first year of fallow, the soil water loss measured under CT and RT was moderately greater than that predicted by the model.     

长期平衡施肥对潮土微生物活性和玉米养分吸收的影响

利用中国科学院封丘农业生态实验站农田生态系统养分平衡长期定位试验地,研究氮磷钾平衡施肥(NPK)与缺素施肥(NK、PK、NP)对土壤微生物生物量、酶活性、呼吸强度以及玉米养分吸收的影响。结果发现,与不施肥对照(CK)相比,NPK处理玉米根系与茎叶生物量、籽粒产量以及植株氮磷钾吸收量均大幅提高,NP处理次之,PK与NK处理则无显著影响;同一处理玉米茎叶与根系养分含量接近,而籽粒的全氮和全磷含量较高、全钾含量偏低;与NPK处理相比,缺施氮、磷或钾肥均直接导致玉米植株相应养分的明显亏缺或其他养分的过量富集,但在根系、茎叶和籽粒部位的累积情况存在一定差异。与CK相比,所有施加磷肥的处理(NPK、NP、PK)土壤微生物生物量(碳、氮、磷)、脱氢酶、转化酶、脲酶与碱性磷酸酶活性以及土壤微生物代谢活性和土壤基础呼吸强度均显著升高(p<0.05),土壤微生物代谢熵则显著下降(p<0.05),而缺施磷肥的NK处理除显著提高脲酶活性外(p<0.05),对其他指标均无显著影响。结果表明,氮磷钾平衡施肥在促进土壤微生物繁育和保育微生物代谢活性以及促进作物生长和保证养分吸收等方面显得非常重要,而缺素施肥中以缺施磷肥的不利影响最为突出。     

Physical extent,frequency, and intensity of phosphatase activity varies on soil profiles across a Douglas-fir chronosequence

In forest soils, the availability of phosphate is largely dependent on phosphatase activity. We used soil imprinting to compare in situ activity and fine-scale distribution of phosphatase on soil profiles located across forest chronosequences of four age classes young (5–6 yrs), canopy closure (24–30 yrs), stem exclusion (61–71 yrs), and older (90–103 yrs) of mixed Douglas-fir/paper birch stands regenerated after fire or clearcutting in southern interior British Columbia, Canada. Chromatography paper treated with a mixture of substrate and colorimetric reagent was applied directly to vertical soil surfaces, accessed through root windows. Stands older than 61 years had both the highest level of in situ phosphatase activity and larger, more intense regions of activity. Bray-extractable phosphorus was negatively related to imprintable phosphatase activity. We compared the changes in phosphatase activity with differences in the ectomycorrhizal fungal (EMF) community that had been documented previously in the same stands. Of 84 ectomycorrhizal fungi found on roots in at least two of the stand-age classes, eight taxa were positively correlated and one taxon (Rhizopogon vinicolor/vesiculosus) negatively correlated with high phosphatase activity. The frequency of three taxa appeared to be positively correlated with larger areas of activity on the soil profiles. By using an imprinting approach, this study was able to demonstrate, for the first time, that in situ phosphatase activity and physical attributes of that activity (i.e., number, size, and relative rates of each area of activity) were related to concentrations of soil nutrients and with the frequency of individual ectomycorrhizal fungi.     

Recent yield results and trends over time with conservation tillage on morainic loam soil in southeast Norway

Abstract

Results for 1998–2004 are reported from four long-term (25–28 years) tillage trials, comparing conventional autumn ploughing with reduced tillage, normally spring harrowing only. Plant residues were retained during the period studied. The weather was somewhat wetter than the 1961–1990 normal. Results with reduced tillage were mostly similar to those seen in earlier trial periods. In Trial 1, mean grain yield was 95% with spring harrowing only versus autumn ploughing, 96% when harrowing in autumn was performed as well and 97% when the soil was ploughed every third year. In Trial 2 positive crop rotation effects were found both with and without ploughing, and reduced tillage gave 5% lower grain yield also in this trial. In Trial 3, tillage system did not affect yields of cereals grown in rotation with potatoes, but reduced tillage gave 12% lower potato yield than ploughing. Little difference in response to N fertilizer was found. In Trial 4, reduced tillage on large-scale (0.7 ha) plots gave 11% lower grain yields than annual ploughing, partly due to shallow sowing depth. No long-term trend in yield responses to tillage was discernible in any trial, and between-year variability was similar with both ploughing and reduced tillage. Percentage yields with reduced tillage relative to annual ploughing correlated positively with rainfall in May and with mean air temperature in August. It is concluded that the reduced tillage systems studied are sustainable in terms of productivity, relative to labour, machinery and energy inputs. Likely benefits of such systems include higher levels of organic matter and aggregate stability in surface soil horizons, but a disadvantage is the need for frequent herbicide use to control perennial weeds.     

长期秸秆还田提升稻麦轮作系统土壤供钾容量和强度

[目的]农作物秸秆中含有丰富的钾素,秸秆还田不仅为植物生长提供钾素,还可以补充农田土壤钾库容.本研究利用动力学模型,评估长期秸秆还田对土壤供钾能力的影响.[方法]基于稻麦轮作制长期秸秆还田定位试验,设置4个处理:秸秆不还田、不施肥(CK);不施肥、每季秸秆还田量为6000 kg/hm2(RS);施化肥、秸秆不还田(NP...     

Long-term effects of tillage and fallow-frequency on soil quality attributes in a clay soil in semiarid southwestern saskatchewan

Reduced tillage management is being adopted at an accelerated rate on the Canadian prairies. This may influence soil quality and productivity. A study conducted on a clay soil (Udic Haplustert) in southwestern Saskatchewan, Canada, to determine the effects of fallow frequency [fallow-wheat (F-W) vs. continuous wheat (Cont W)] and tillage [no-tillage (NT) vs. conventional (CT) or minimum tillage (MT)] on yields of spring wheat (Triticum aestivum L.), was sampled after 3, 7 and 11 years to assess changes in selected soil quality attributes. Tillage had no effect on amount of crop residues returned to the land, but the tilled systems had significantly (P<0.05) lower total organic C and N in the 0–7.5 cm soil depth, though not in the 7.5–15 cm depth. Further, these differences were observed after only 3 years and persisted for the entire 11 years of the study. For example, in the 0–7.5 cm depth, organic C in F-W (MT) after 3 years was 10 480 kg ha⁻¹ and in F-W (NT) 13 380 kg ha⁻¹, while in Cont W (CT) and Cont W (NT) corresponding values were 11 310 and 13 400 kg ha⁻¹, respectively. After 11 years, values for F-W (MT) and F-W (NT) were 11 440 and 14 960 kg ha⁻¹, respectively, and for Cont W (CT) and Cont W (NT), 12 970 and 16 140 kg ha⁻¹, respectively. In contrast to total organic matter, two of the more labile soil quality attributes [i.e., C mineralization (C_min) and N mineralization (N_min)] did not respond to fallow frequency until after 7 years and only in the 0–7.5 cm depth. Microbial biomass (MB) and the ratio of C_min to MB [specific respiratory activity (SRA)], two attributes also regarded as labile, were not influenced by the treatments even after 11 years. After 11 years, only C_min and N_min among the labile soil quality attributes responded to the treatments. Surprisingly, the labile attributes were no more sensitive to the treatments than was total organic C or N. More research is required to determine why responses in this soil differed from those reported elsewhere.     

The influence of 12 years of tillage and crop rotation on total and labile organic carbon in a sandy loam soil

Information on which management practices can enhance soil organic matter (SOM) content and quality can be useful for developing sustainable crop production systems. We tested the influence of 12 years of no-till (NT) versus conventional tillage (CT), and four crop sequences on the organic C pools of a Grey Luvisolic sandy loam soil in northwestern Alberta, Canada. The crop sequences were: continuous wheat (Triticum aestivum L.), field pea (Pisum sativum L.)–wheat–canola (Brassica rapa L.)–wheat, red clover (Trifolium pratense L.) green manure–wheat–canola–wheat/red clover and fallow–wheat–canola–wheat. Soil samples from 1992, when the study was initiated, and 1996, 2000 and 2004 were analyzed for total organic C (TOC), the light fraction (LF) and its C content, and water-soluble and mineralizable C. Total organic C in the top 15 cm of soil was higher in the red clover rotation than either the pea or fallow rotation by 1996. The tillage effect became significant only in 2004 with NT having a higher TOC than CT. The LF dry matter (DM) increased from 6.9 g kg⁻¹ soil in 1992 to a range of 10–13 g kg⁻¹ in 2000 and 2004. It was higher under NT than CT in 2 of 3 years and in the red clover rotation than the pea or fallow rotation in 1 of 3 years. The LF C content exhibited a similar trend as LF DM. The water-soluble and mineralizable C pools were not affected by tillage but decreased with time. Among crop rotations, the red clover rotation tended to result in higher levels of hot water-soluble and mineralizable C. It is concluded that tillage had a greater influence than crop rotation on the LF DM and LF C (as indicators of C storage), whereas the converse effect applied to mineralizable C and, to a lesser degree, hot water-soluble C (as indicators of SOM quality).     

Microbial populations,enzyme activities and nitrogen-phosphorus-potassium enrichment in earthworm casts and in the surrounding soil of a pineapple plantation

Summary Total populations of bacteria and fungi, dehydrogenase activity (as a measure of total potential microbial activity), and urease and phosphatase activities were determined in earthworm casts and surrounding laterite soils planted to pineapple. The casts contained higher microbial populations and enzyme activities than the soil. Except for fungal populations, statistically significant (P = 0.05) increases were found in all other parameters. Microbial populations and enzyme activities showed similar temporal trends with higher values in spring and summer and lower values in winter. The earthworm casts contained higher amounts of N, P, K and organic C than the soil (P = 0.05). Selective feeding by earthworms on organically rich substrates, which break down during passage through the gut, is likely to be responsible for the higher microbial populations and greater enzyme activity in the casts.     

等氮配施有机肥对喀斯特峰丛洼地农田作物产量与养分平衡的影响

基于自2006年在广西喀斯特峰丛洼地区开展的长期玉米/大豆套作定位施肥试验,选择2010—2014年监测数据,探讨等氮量投入条件下,不同比例有机肥替代无机氮肥对喀斯特峰丛洼地玉米/大豆套作系统作物产量及土壤养分的影响,为喀斯特峰丛洼地农田作物高效施肥及提高土壤肥力提供理论依据。试验选取4个处理:对照(不施肥,CK)、平衡施用化肥(NPK)、有机粪肥替代30%化肥氮(C7M3,按氮素计算,不足30%的PK用无机肥补充,肥料总量与NPK处理相同,有机粪肥为牛粪,下同)、有机粪肥替代60%化肥氮(C4M6,按氮素计算,不足60%的PK用无机肥补充),每个处理4次重复。于2010年、2012年、2014年大豆收获后采集土壤样品,测定土壤养分状况。结果表明:1)施肥处理土壤有机质、全氮、速效磷及速效钾含量均高于CK处理,其中C4M6处理有机质含量显著高于NPK处理(P0.05),全氮、速效磷和速效钾含量随着有机粪肥施用量的增加而增加。2)长期不同施肥处理玉米和大豆产量分别是不施肥处理的4.15~4.36倍、2.47~2.58倍。不同施肥处理的增产效果为C4M6NPKC7M3,但施肥处理间差异不显著(P0.05)。3)长期不施肥CK处理玉米产量随着试验年限推移呈下降趋势,降幅为5.45 g·m~(-2)·a~(-1),大豆产量却表现出增加趋势,增幅为1.50 g·m~(-2)·a~(-1)。长期施肥处理中,玉米和大豆产量总体呈增加趋势。4)施肥处理中,玉米季表现为钾素亏缺(NPK处理除外),大豆季表现为氮素亏缺。综合两季作物,只有C4M6钾素表现亏缺,亏缺量为7.9 kg·hm~(-2)。磷素在各施肥处理中盈余量较大,分别为81.2 kg·hm~(-2)(NPK)、83.4 kg·hm~(-2)(C7M3)和74.8 kg·hm~(-2)(C4M6)。综上,在喀斯特峰丛洼地玉米/大豆套作制度下,基于作物产量及土壤养分表观平衡特征提出有机粪肥可以代替部分化肥施用,在玉米季适当"减氮、稳磷和增钾",大豆季"稳氮、减磷和减钾"的施肥措施。