Effects of long-term application of various organic amendments on soil particulate organic matter storage and chemical stabilisation of vertisol soil

Current understanding of the effects of long-term application of various organic amendments on soil particulate organic matter (POM) storage and chemical stabilisation remains limited. Therefore, we collected soil samples from the soil profile (0–100?cm) under six treatments in a 31-year long-term fertilisation experiment: no fertiliser (CK), mineral fertilisers (NPK), mineral fertilisers plus 3.8 or 7.5?t?ha^?1?year^?1 (fresh base) the amount of wheat straw (1/2SNPK and SNPK) and mineral fertilisers plus swine or cattle manure (PMNPK and CMNPK). Long-term incorporation of wheat straw and livestock manure amendments significantly (p?<?0.05) increased crop yield and sustainable yield index, and POM storage compared with CK and NPK treatments. The mole ratios of H/C in the POM under organic amendment treatments significantly (p?<?0.05) decreased by 13.8% and 37.1%, respectively, compared with the NPK treatment. Similarly, solid state NMR spectroscopy showed that the O–alkyl carbon content of POM was greatly decreased, whereas aromatic carbon contents and alkyl to O–alkyl carbon ratios were substantially increased under PMNPK and CMNPK treatments. In conclusion, we recommend long-term livestock manure application as a preferred strategy for enhancing POM quantity and quality (chemical stability), and crop yield of vertisol soil in northern China.     

The Yields and Carbon and Nitrogen Balances in the Polyfactorial Field Experiments

The polyfactorial long-term field experiments have been founded in 1979 in several experimental stations located in different soil and climatic conditions, representing a climate and pedosequence of arable soils in the Czech Republic. Four of these experiments exist till the present time. Essentially, the same experimental design that includes different fertilisation with farmyard manure and/or with mineral fertilisers (N, P, K), liming and stand density, each in five levels with four replications, have been applied for all these experiments. Practically, the same eight year crop rotations were applied during the first and second rotations. A conventional tillage has been applied. Organic carbon and nitrogen contents in soil, dry matter of the main and second products, nitrogen uptake by the main and second products and carbon and nitrogen balances have been evaluated in six selected variants of organic and mineral fertilisation over the time period 1996 to 2000.     

The results of an NPK-fertilisation trial of long-term crop rotation on carbonate-rich soil in Estonia

ABSTRACT

Soil is an element of crop cultivation that demands consistent fertilisation to compensate for the nutrients that are removed by the harvest. Changes in soil because of prolonged fertilisation can only be estimated by long-term field trials. Experiments in long-term field trial site Kuusiku (since 1965) include crop rotation of potato, late harvest barley, early harvest barley undersown with forage grasses (red clover?+?timothy), 1-year forage grasses, 2-year forage grasses, and winter rye. Various combinations of mineral and organic fertilisers were used to investigate the yield, soil humus, phosphorus, and potassium content (available and total) of the top- and subsoil. Fertilisation improved the yield of different crops by 1.3–2.6 times; meteorological conditions caused the yield to vary up to 6.4 times. The concentration of humus decreased 0.2% when not using inorganic and organic fertilisers; use of fertilisers increased the concentration of humus by 0.2–0.6%. The humus-rich subsoil (3.5% humus) contained less available phosphorus than humus-poor subsoil (humus 3.0%), which had 29 and 63?mg P_DL kg^?1, respectively. Grasses in crop rotation enriched the soil with organic matter and reduced the excess of nutrients remaining from previous fertilisation, thereby decreasing nutrient leakage and eutrophication of bodies of water.     

Seed coating with inocula of arbuscular mycorrhizal fungi and plant growth promoting rhizobacteria for nutritional enhancement of maize under different fertilisation regimes

Arbuscular mycorrhizal (AM) fungi and plant growth-promoting rhizobacteria, responsible for enhancing plant nutrition, vigour and growth, may be used to reduce dosages of chemical fertilisers. Technologies that allow an economically viable and efficient application of these beneficial microbes in large scale agriculture must be studied. Seed coating is a potential delivery system for efficiently introducing minor amounts of bioinoculants. Despite the dramatic reduction on inoculum dose per plant, inoculation of AM fungi via seed coating was as effective as conventional soil inoculation. Fertilisation and inoculation had a significant impact on maize shoots nutrient concentrations. Different fertilisation regimes did not influence mycorrhizal colonisation. Plants without fertilisation and singly inoculated with R. irregularis showed shoot nutrient concentration increments of 110, 93, 88 and 175% for nitrogen, phosphorus, potassium and zinc, respectively, comparing with non-inoculated controls. Plants singly inoculated with P. fluorescens via seed coating under full fertilisation, presented enhancements of 100, 75 and 141% for magnesium, zinc and manganese, respectively, comparing with non-inoculated controls. Seed coating is a promising tool for delivering microbial inoculants into the soil, while promoting sustainable production of maize. This technology is particularly pertinent in low input agriculture, with potential environmental profits and food quality improvements.     

Quantification of the carbon and nitrogen cycles in long‐term field experiments in Prague

The oldest still existing long‐term field experiments in Czech Republic were founded in 1955. In Prague Ruzyné, there are five of nine experiments founded by ?karda. Data of two of these experiments (Block III and Block B) were used to evaluate the carbon and nitrogen cycles in time period 1966–1997. These two experiments have a similar design. They differ in the crop rotation. Four variants of organic and mineral fertilisation, receiving similar doses of fertilisers, have been selected. The same was calculated for the same time period for a mini‐plot bare fallow field experiment founded in 1958 by Novák.

The results of these experiments conducted in one locality (the same soil and climatic conditions) show the effect of the cultivated crops on the carbon and nitrogen cycles (comparing bare fallow experiment with the cropped ones), the effect of organic and mineral fertilisation (among all experiments), and the effect of crop rotation (comparing Block III to Block B) on these cycles.     

作物土传病害防控的健康微生物群落构建原理与实践

植物-土壤反馈效应及农田生产特点决定了农田土壤生产力的不可持续性,因而必须采用适当的措施方可保持地力常新。施用化肥解决了农田土壤的养分贫化问题,极大地提高了作物产量,但激发了土传病原生物的活性,作物土传病频发成为制约集约化农业可持续发展的瓶颈问题。现有的研究成果表明,地上生物多样性与土壤微生物多样性紧密联系,植物提供的有机物质是连接二者的物质基础。单一作物种植的集约化农业提供给土壤微生物可利用的有机物质来源单一,导致土壤微生物多样性下降,削弱对土传病原生物致病性的抑制作用。本文提出,在作物生长过程中添加土壤有益微生物偏好利用的有机物质,激活土壤有益微生物,可能是维持集约化农业土壤生物健康,抑制作物土传病的有效途径。为此,有必要开展各种土壤微生物偏好利用的有机物质以及作物生长过程中如何施用有机物质的方法。     

开发更高效的生物炭肥料提高辣椒产量和质量

Utilization of biochar at high application rates can increase soil C and crop yields, decrease greenhouse gas emissions and reduce nutrient run-off from soils. However, the high application rate of 10 t ha-1may not return a profit to the farmer due to the high cost of biochar. In this study biochar was modified through pre-treating the biomass and post-treating with phosphoric acid, minerals and different chemical fertilisers to study the effects of two new enhanced biochar fertilisers on the yield and quality of green pepper in a field experiment with 5 fertilisation treatments and 3 replications. The two new biochar fertilisers significantly(P 0.05) increased the yield of green pepper(11.33–11.47 t ha-1), compared with the conventional chemical fertiliser(9.72 t ha-1). The biochar fertiliser treatments improved the vitamin C content of green pepper from 236.99 to 278.28 mg kg-1, and also significantly(P 0.05) reduced the nitrate content from 132.32 to 101.92 mg kg-1, compared with chemical fertiliser. This study indicated that, compared to the use of conventional chemical fertiliser, all of the biochar fertiliser treatments could significantly improve the yield and quality of green pepper.     

Developed microbial biofilms can restore deteriorated conventional agricultural soils

Nitrogen fixing bacteria play a key role in the growth and persistence of effective microbial communities in the soil by supplying N through biological nitrogen fixation (BNF). In the long run, chemical inputs, particularly N fertilisers are known to adversely affect N₂ fixers and hence maintenance of soil fertility and crop productivity. This study examined the effect of developed microbial biofilms with N₂ fixers on restoration of soils deteriorated by conventional agricultural practices in tea cultivation. Just reducing recommended chemical fertiliser use by 50% significantly increased soil microbial biomass and BNF, and decreased soil NO₃⁻ and pest infestation. The lower chemical fertiliser addition coupled with the biofilm-based biofertilisers known as biofilmed biofertilisers (BFBFs) further increased BNF significantly. The combined application significantly increased soil organic C by ca. 20%, and reduced leaf transpiration by ca. 40%. It also supported plant growth, rhizoremediation and soil moisture conservation in comparison to the 100% chemical fertilisation. Those improved performances were observed to be proportional to the increased density of soil bacteria, and have several agronomic and environmental implications. It is apparent from this study that replenishing the depleted soil microbial communities by applying such biofertilisers is likely to be beneficial in agroecosystems with chemical N fertiliser use, if they are to be sustained for crop production.     

营养元素循环和农业的持续发展

我国2000多年的历史证明:农业可以持续发展,从农业外部投入物质和能量,是现代化农业生产力突破性进展的重要特征。单靠化肥引起许多土壤问题,关系到人类健康,生产使用有机肥料是一项重要的社会产业,保证营养元素合理循环是农业生产持续发展的根本问题。     

长期施肥对农田土壤氮素关键转化过程的影响

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。     

我国的农业和土壤保持

 我国2000多年的农业史表明:通过循环利用有机肥,可以使粮食生产持续发展,保持并逐渐改善土地生产力。非农肥料的最高效投入方式可以增加粮食产量。但在一些地区,出现农民只偏好化肥的趋势。长期使用化肥会导致土壤问题,也会给粮食质量和人类健康带来不利影响,有机肥的使用应当引起特别关注,以改善土壤性状、发展可持续农业。人类创造农业,农业养育人类,为使资源环境进入正确的循环轨道,人类是自然的一个组成部分,而不是自然的敌人。通过对湖南省南部山区红壤的长期试验,表明天然植被恢复对于水土保持极为重要,在阴山北部的观测数据也得到同样的结论。     

Stocktake study of current fertilisation recommendations across Europe and discussion towards a more harmonised approach

The European Commission has set targets for a reduction in nutrient losses by at least 50% and a reduction in fertiliser use by at least 20% by 2030 while ensuring no deterioration in soil fertility. Within the mandate of the European Joint Programme EJP Soil ‘Towards climate-smart sustainable management of agricultural soils’, the objective of this study was to assess current fertilisation practices across Europe and discuss the potential for harmonisation of fertilisation methodologies as a strategy to reduce nutrient loss and overall fertiliser use. A stocktake study of current methods of delivering fertilisation advice took place across 23 European countries. The stocktake was in the form of a questionnaire, comprising 46 questions. Information was gathered on a large range of factors, including soil analysis methods, along with soil, crop and climatic factors taken into consideration within fertilisation calculations. The questionnaire was completed by experts, who are involved in compiling fertilisation recommendations within their country. Substantial differences exist in the content, format and delivery of fertilisation guidelines across Europe. The barriers, constraints and potential benefits of a harmonised approach to fertilisation across Europe are discussed. The general consensus from all participating countries was that harmonisation of fertilisation guidelines should be increased, but it was unclear in what format this could be achieved. Shared learning in the delivery and format of fertilisation guidelines and mechanisms to adhere to environmental legislation were viewed as being beneficial. However, it would be very difficult, if not impossible, to harmonise all soil test data and fertilisation methodologies at EU level due to diverse soil types and agro-ecosystem influences. Nevertheless, increased future collaboration, especially between neighbouring countries within the same environmental zone, was seen as potentially very beneficial. This study is unique in providing current detail on fertilisation practices across European countries in a side-by-side comparison. The gathered data can provide a baseline for the development of scientifically based EU policy targets for nutrient loss and soil fertility evaluation.     

Improving mineral nitrogen control by combining catch crops,fertilisation, and straw management in a clay loam soil

This experiment was conducted on a clay loam Cambisol and set out to determine the effects of combining catch crops, variable fertilisation levels, and straw management on the productivity of a spring barley-catch crop agrosystem, on the enrichment of soil with organic matter and nitrogen (N), and on soil mineral N control. Research was carried out in a spring barley (Hordeum vulgare L.) crop without catch crops, with undersown red clover (Trifolium pratense L.), and with post-crop white mustard (Sinapis alba L.). The barley was unfertilised, fertilised at moderate rates or at high rates. Straw was managed by either removing it from the field or chopping and spreading it. The quantity of organic matter and N incorporated into the soil depended on the fertilisation level of the barley crop. Soil mineral N stocks in the spring were reduced when straw was used together with red clover. When white mustard mass was incorporated alone in the autumn during ploughing, soil mineral N was reduced in the spring; however, when it was incorporated with straw, the effect was the opposite. Soil mineral N content is controllable when organic matter components are combined according to their decomposition rates, masses, and incorporation times.     

The response of properties of soil cropped with shell beans and treated with disinfectant and fertiliser during the plant growing season

Disinfectants and fertilisers exert strong impact on soil processes by affecting the structure and the activity of the soil microbial community. Most relevant studies examined these impacts independently, under laboratory conditions and without crop cover. In this study, we have monitored the response of soil chemical, microbial, and biochemical properties to disinfectant and fertiliser treatments in field plots cultivated with beans. The measured properties comprised microbial C and N, asparaginase, gultaminase, urease, and acid phosphomonoesterase activities and contents of organic N, organic C, inorganic N, and inorganic P. We ran four different treatments using different combinations of chemical (metham sodium) and biological disinfectant (a mixture of neem cake and essential oils) and fertilisers (NPK 8-16-24 and cow manure) in plots cultivated with shell beans, while the control soil was neither treated nor cropped with beans. The data were expressed as percentage (%RC) in relation to the control values. The disinfectant and fertiliser treatments had less impact on soil properties compared to bean crop growth (except for microbial C and N, and content of organic C). In comparison to the control, higher activities of urease and asparaginase and content of inorganic N were recorded in bean cropped plots at the stage of seedlings (June), while higher activities of acid phosphomonoesterase and glutaminase and content of organic N were recorded at the stage of plant flowering (August). In October, the values of all properties were higher in the control plots compared to the treated plots. The joint effect of disinfectants x fertilisers affected the response of content of organic C and N and extractable P and glutaminase activity. The %RC of the properties exhibited more negative values in plots treated with chemical disinfectant and chemical fertiliser than in the other treatments. We suggested that the response of soil properties to disinfectants and fertilisers were influenced by the growth of P. vulgaris.     

施肥对设施土壤及作物生育的影响研究进展

该文综述了施肥措施对设施土壤及作物品质、产量的影响，指出有机肥与无机肥合理配施对土壤的可持续性利用的重要性，而过量施肥(有机肥或化肥)或偏施氮肥均导致土壤、植物养分平衡失调，作物产量和品质下降。     

中红外光谱法测定土壤碳的研究进展

土壤碳不仅是影响土壤肥力和农业可持续发展的重要因子,也对减缓温室效应有重要意义。因此,土壤碳分析是农业、环境等学科领域的重要研究内容。传统化学分析方法存在测定效率低、实时性差、有污染等缺点,无法满足现代绿色农业快速测定土壤碳的需求。近年来,中红外光谱（mid-infrared spectroscopy, MIR）技术以其操作简便、重现性好、测试速度快、样品用量少、绿色环保和适合批量样品测定的特点,逐渐成为获取土壤碳信息的有效方法。本文简要介绍了中红外光谱分析基本原理,重点论述了该技术在预测土壤碳方面的国内外研究进展及影响因素,并对MIR技术在我国土壤碳定量研究方面的应用前景进行了展望。目前,MIR技术已成功应用于土壤总碳、有机碳、无机碳、炭、水溶性有机碳、微生物量碳、生物量碳、颗粒有机碳、矿物结合有机碳、惰性有机碳等土壤碳组分的预测,为土壤碳分析提供了快速无损的测定手段,也为绿色农业和精准农业的发展提供了先进的技术支撑。     

施肥对设施土壤及作物生育的影响研究进展

该文综述了施肥措施对设施土壤及作物品质、产量的影响,指出有机肥与无机肥合理配施对土壤的可持续性利用的重要性,而过量施肥(有机肥或化肥)或偏施氮肥均导致土壤、植物养分平衡失调,作物产量和品质下降。     

Long-term phosphorus fertilisation increased the diversity of the total bacterial community and the phoD phosphorus mineraliser group in pasture soils

Fertilisers, especially nitrogen (N) and phosphorus (P) supplies, are frequently used in agricultural soil management to attain high crop yields. However, the intensive application of these chemical inputs can decrease the quality of agricultural soils and increase the probability of environmental pollution. In this study, the impact of P fertilisation on the diversity of the soil bacterial community was assessed. For this, a culture-independent approach targeting 16 rRNA and phoD genes was used on DNA extracted from pasture soils subjected to three different P fertilisation regimes for a long-term (42 years). As alkaline phosphomonoesterase (ALP) is necessary for mineralisation of organic P, an inverse relationship between the level of potential ALP activity and soil available P was expected. Indeed, a lower ALP activity was observed in soil subjected to higher chemical P fertiliser input. Analysis of the prevalence of three divergent families of ALP (PhoA, PhoD and PhoX) in metagenomic datasets revealed that PhoD is the most frequent ALP in soil samples and was selected as the most representative ALP possessed by the soil bacterial communities. Diversity of the phoD phosphorus mineraliser group, as well as the total bacterial community, was both increased in response to long-term P fertilisation. Specifically, phosphorus fertilisation decreased the relative abundance of certain taxa, including Acidobacteria and Pseudomonas fluorescens. In conclusion, this study shows that P fertilisation affects the microbial diversity of soil ecosystems, which might potentially modulate the soil biogeochemical cycle.     

生物炭及炭基硝酸铵肥料对土壤化学性质及作物产量的影响

为了促进生物炭研究和农用,采用盆栽试验研究了两种生物炭基氮肥及相应生物炭对土壤部分化学性质、养分状况及作物产量的影响。试验结果表明：施用生物炭基氮肥可显著提高土壤有机碳含量,提高土壤pH值、阳离子交换量、土壤速效磷、速效钾和矿质态氮含量,增强土壤保肥能力,促进作物增产。生物炭对土壤化学性质和养分状况虽有一定改善作用,但作物增产效应不明显甚至减产。因此,将生物炭与肥料复合制成生物炭基肥料不但可以保持生物炭改良土壤的功能,还可促进作物生长和增产,有利于生物炭农用效益的提升。