Background and aims We studied the effect of different biochar (BC) application rates on soil properties, crop growth dynamics and yield on a fertile sandy clay loam in boreal conditions. Methods In ...a three-year field experiment conducted in Finland, the field was divided into three sub-experiments with a split-plot experimental design, one for each crop: wheat (Triticum aestivum), turnip rape (Brassica rapa), and faba bean (Vicia faba). The main plot factor was BC rate (0, 5 and 101 DM ha⁻¹) and the sub-plot factor was the N-P-K fertiliser rate. Soil physico-chemical properties as well as plant development, yield components and quality were investigated. Results BC addition did not significantly affect the soil chemical composition other than the increased C and initially increased K contents. Increased soil moisture content was associated with BC application, especially at the end of the growing seasons. BC decreased the N content of turnip rape and wheat biomass in 2010, thus possibly indicating an initial N immobilisation. In dry years, the seed number per plant was significantly higher in faba bean and turnip rape when grown with BC, possibly due to compensation for decreased plant density and relieved water deficit. However, the grain yields and N uptake with BC addition were not significantly different from the control in any year. Conclusions Even though BC application to a fertile sandy clay loam in a boreal climate might have relieved transient water deficit and thereby supported yield formation of crops, it did not improve the yield or N uptake.
Full text
Available for:
BFBNIB, DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NMLJ, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Natural organic biomass burning creates black carbon which forms a considerable proportion of the soil's organic carbon. Due to black carbon's aromatic structure it is recalcitrant and has the ...potential for long-term carbon sequestration in soil. Soils within the Amazon-basin contain numerous sites where the ‘dark earth of the Indians' (Terra preta de Indio, or Amazonian Dark Earths (ADE)) exist and are composed of variable quantities of highly stable organic black carbon waste (‘biochar'). The apparent high agronomic fertility of these sites, relative to tropical soils in general, has attracted interest. Biochars can be produced by ‘baking' organic matter under low oxygen (‘pyrolysis'). The quantities of key mineral elements within these biochars can be directly related to the levels of these components in the feedstock prior to burning. Their incorporation in soils influences soil structure, texture, porosity, particle size distribution and density. The molecular structure of biochars shows a high degree of chemical and microbial stability. A key physical feature of most biochars is their highly porous structure and large surface area. This structure can provide refugia for beneficial soil micro-organisms such as mycorrhizae and bacteria, and influences the binding of important nutritive cations and anions. This binding can enhance the availability of macro-nutrients such as N and P. Other biochar soil changes include alkalisation of soil pH and increases in electrical conductivity (EC) and cation exchange capacity (CEC). Ammonium leaching has been shown to be reduced, along with N₂O soil emissions. There may also be reductions in soil mechanical impedance. Terra preta soils contain a higher number of ‘operational taxonomic units' and have highly distinctive microbial communities relative to neighbouring soils. The potential importance of biochar soil incorporation on mycorrhizal fungi has also been noted with biochar providing a physical niche devoid of fungal grazers. Improvements in soil field capacity have been recorded upon biochar additions. Evidence shows that bioavailability and plant uptake of key nutrients increases in response to biochar application, particularly when in the presence of added nutrients. Depending on the quantity of biochar added to soil significant improvements in plant productivity have been achieved, but these reports derive predominantly from studies in the tropics. As yet there is limited critical analysis of possible agricultural impacts of biochar application in temperate regions, nor on the likelihood of utilising such soils as long-term sites for carbon sequestration. This review aims to determine the extent to which inferences of experience mostly from tropical regions could be extrapolated to temperate soils and to suggest areas requiring study.
Full text
Available for:
BFBNIB, DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NMLJ, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Abstract
Soil phosphorus (P) loss from agricultural systems will limit food and feed production in the future. Here, we combine spatially distributed global soil erosion estimates (only considering ...sheet and rill erosion by water) with spatially distributed global P content for cropland soils to assess global soil P loss. The world’s soils are currently being depleted in P in spite of high chemical fertilizer input. Africa (not being able to afford the high costs of chemical fertilizer) as well as South America (due to non-efficient organic P management) and Eastern Europe (for a combination of the two previous reasons) have the highest P depletion rates. In a future world, with an assumed absolute shortage of mineral P fertilizer, agricultural soils worldwide will be depleted by between 4–19 kg ha
−1
yr
−1
, with average losses of P due to erosion by water contributing over 50% of total P losses.
AIMS: Hotspots of enzyme activity in soil strongly depend on carbon inputs such as rhizodeposits and root detritus. In this study, we compare the effect of living and dead Lupinus polyphyllus L. ...roots on the small-scale distribution of cellulase, chitinase and phosphatase activity in soil. METHODS: Soil zymography, a novel in situ method, was used to analyze extracellular cellulase, chitinase and phosphatase activity in the presence of i. living L. polyphyllus roots prior to shoot cutting and ii. dead/dying roots 10, 20 and 30 days after shoot cutting. RESULTS: After shoot cutting, cellulase and chitinase activities increased and were highest at the root tips. The areas of high cellulase and phosphatase activity extend up to 55 mm away from the root. Moreover, we observed microhotspots of cellulose, chitinase, and phosphatase activity up to 60 mm away from the next living root. The number and activity of microhotspots of chitinase activity was maximal 10 days after shoot cutting. CONCLUSIONS: The study showed that young root detritus stimulates enzyme activities stronger than living roots. Soil zymography allowed identification of microhotspots of enzyme activity up to several cm away from living and dying roots, which most likely were caused by arbuscular mycorrhizal fungi.
Full text
Available for:
BFBNIB, DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NMLJ, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Rising global temperature, pollution load, and energy crises are serious problems, recently facing the world. Scientists around the world are ambitious to find eco-friendly and cost-effective routes ...for resolving these problems. Biochar has emerged as an agent for environmental remediation and has proven to be the effective sorbent to inorganic and organic pollutants in water and soil. Endowed with unique attributes such as porous structure, larger specific surface area (SSA), abundant surface functional groups, better cation exchange capacity (CEC), strong adsorption capacity, high environmental stability, embedded minerals, and micronutrients, biochar is presented as a promising material for environmental management, reduction in greenhouse gases (GHGs) emissions, soil management, and soil fertility enhancement. Therefore, the current review covers the influence of key factors (pyrolysis temperature, retention time, gas flow rate, and reactor design) on the production yield and property of biochar. Furthermore, this review emphasizes the diverse application of biochar such as waste management, construction material, adsorptive removal of petroleum and oil from aqueous media, immobilization of contaminants, carbon sequestration, and their role in climate change mitigation, soil conditioner, along with opportunities and challenges. Finally, this review discusses the evaluation of biochar standardization by different international agencies and their economic perspective.
Display omitted
•Biochar characteristics are correlated with feedstock and pyrolysis conditions.•Biochar-mediated mitigation of gaseous pollutants from the soil is reviewed.•Biochar addition to contaminated soil immobilizes heavy metals.•Biochar acts as soil conditioner and improves soil productivity.•The environmental management with biochar is economical and viable.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ
•ISFM treatments increased long-term grain yields by 1.4–8.7 times in Sahel.•Cereal-legume rotation had higher average yields compared to the continuous cropping.•Manure addition at 40,000 kg ha−1 ...prevented fertilizer induced acidification.•Microbially-derived N moieties increased with organic inputs as indicated by XANES.•Manure addition at 40,000 kg ha−1 led to the increase in soil C, N and P levels.
Joint application of mineral and organic fertilizers and incorporation of legumes into cropping systems, known as integrated soil fertility management (ISFM), has improved short-term crop productivity in sub-Saharan Africa. Little research exists, however, on the effectiveness of long-term ISFM in improving soil quality and productivity. This study determined the long-term effects of different ISFM treatments on soil chemical properties and OM dynamics up to 20 cm soil depth at a long-term research site at Saria, Burkina Faso. The ISFM treatments applied from 1960 to 2008 included broadcasted fertilizer (100 kg ha−1 14-23-14 (NPK) with 50 kg ha−1 urea; and NPK with an additional 50 kg ha−1 urea and 50 kg ha−1 KCl) supplemented with crop residue retention, and with manure application at 5000 or 40000 kg ha−1. In addition, continuous cropping of Sorghum bicolor (sorghum) was compared to yearly rotation between sorghum and Vigna unguiculata (cowpea). The large manure rate (40,000 kg ha−1) supplement was most effective in buffering fertilizer-application-induced pH decline and increasing grain yield, soil carbon (C), nitrogen (N), and phosphorus (P) concentrations (p < 0.05). Manure application also enhanced the microbial cycling and retention of C and N microbial byproducts compared to other fertilizer treatments, as indicated by C and N X-ray Absorption Near Edge Structure (XANES) spectroscopies. Legume-cereal cropping led to increased abundance of C and N functional groups indicative of reduced OM breakdown compared to the continuous cropping system. Supplemental application of manure with mineral fertilizers under mixed cereal-legume cropping was found to be most effective in improving long-term soil fertility and crop productivity in the Sahel.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ
Background Nitrogen (N) is one of the key mineral nutrients for plants and its availability has a major impact on their growth and development. Most often N resources are limiting and plants have ...evolved various strategies to modulate their root uptake capacity to compensate for both spatial and temporal changes in N availability in soil. The main N sources for terrestrial plants in soils of temperate regions are in decreasing order of abundance, nitrate, ammonium and amino acids. N uptake systems combine, for these different N forms, high-and low-affinity transporters belonging to multige families. Expression and activity of most uptake systems are regulated locally by the concentration of their substrate, and by a systemic feedback control exerted by whole-plant signals of N status, giving rise to a complex combinatory network. Besides modulation of the capacity of transport systems, plants are also able to modulate their growth and development to maintain N homeostasis. In particular, root system architecture is highly plastic and its changes can greatly impact N acquisition from soil. Scope In this review, we aim at detailing recent advances in the identification of molecular mechanisms responsible for physiological and developmental responses of root N acquisition to changes in N availability. These mechanisms are now unravelled at an increasing rate, especially in the model plant Arabidopsis thaliana L. Within the past decade, most root membrane transport proteins that determine N acquisition have been identified. More recently, molecular regulators in nitrate or ammonium sensing and signalling have been isolated, revealing common regulatory genes for transport system and root development, as well as a strong connection between N and hormone signalling pathways. Conclusion Deciphering the complexity of the regulatory networks that control N uptake, metabolism and plant development will help understanding adaptation of plants to sub-optimal N availability and fluctuating environments. It will also provide solutions for addressing the major issues of pollution and economical costs related to N fertilizer use that threaten agricultural and ecological sustainability.
Full text
Available for:
BFBNIB, DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NMLJ, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Serious soil erosion has resulted in widespread land degradation in the Loess Plateau of China. In the past two decades, great efforts have been made to restore degraded soil such as reconverting ...croplands into forestlands or grasslands. A comparison of soil qualities of different revegetation types has important implications in soil reclamation. Our study investigated the effect of different revegetation types on the physicochemical and microbial soil properties in the Loess Plateau, with the aim of determining which revegetation type has the best capacity for soil recovery. The vegetation types included two shrublands (Caragana korshinskii and Hippophae rhamnoides), two grasslands (Astragalus adsurgens and Panicum virgatum), and two species from croplands that were abandoned for natural recovery (Artemisia capillaries and Heteropappus altaicus). Among the plants studied, H. altaicus and A. capillaries had the highest values of soil organic C, total N, total P, available N, available P, moisture content, microbial biomass C (MBC), substrate-induced respiration, saccharase, urease, catalase, and peroxidase. Soil sampled from the A. adsurgens plot had the highest bulk density and microbial biomass N, and soil from the H. rhamnoides plot had the highest metabolic quotient (basal respiration/MBC). The soil quality index, which was obtained based on the available N, metabolic quotient, MBC, urease, polyphenol oxidase, and bulk density, shows that the abandoned cropland for natural recovery had the highest soil quality, followed by grassland, and then shrubland. Vegetation types affect the physicochemical and microbial properties of soils in arid climatic conditions. Abandoned cropland for natural recovery has the best capacity for improving soil quality in the Loess Plateau among all studied revegetation types. Our study suggests that in the Loess Plateau, natural recovery is the best choice for soil revegetation of sloping croplands.
Full text
Available for:
BFBNIB, DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NMLJ, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
▶ Comparison between long-term no-till and conventional tillage in North China Plain. ▶ No-till increases soil fertility such as C, N and P. ▶ No-till improves soil porosity and macro-aggregates, and ...decreases bulk density. ▶ Wheat and maize yields increase in no-till system due to improved soil properties.
Soil deterioration and the accompanying decline in crop yields are the main factors limiting the further development of agriculture in North China Plain. The long-term effects of no tillage (NT) and conventional tillage (CT) on soil properties and crop yields were investigated in annual double cropping system of winter wheat–summer maize in the Gaocheng in Hebei, North China Plain over a 11-year period (1998–2009). Long-term NT significantly (
P
<
0.05) increased soil organic matter, available N and P in the top 10
cm by 16.1%, 31.0% and 29.6% as compared to CT treatment. Mean percentage of macro-aggregates (>0.25
mm, +8.1%) and macroporosity (>60
μm, +43.3%) was also enhanced statistically (
P
<
0.05) in the 0–30
cm soil layer. Winter wheat and summer maize yields tended to be 3.5% and 1.4% higher under NT than under CT, particularly in the dry years, suggesting that the change in soil physical properties, soil fertility and moisture has provided a better environment for crop development. These improvements in soil properties and yields are of considerable importance for the degraded soils in semiarid North China Plain, as well as for food security, sustainable agriculture and carbon storage in the annual double cropping areas of China.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Biochar is a promising novel material for managing phosphorus (P), a nutrient often limiting for primary production but can also be a pollutant, in the environment. Reducing P input to the ...environment and finding cost-effective approaches to remediate P contamination are major challenges in P management. There is currently no review that systematically summarizes biochar effects on soil P availability and its P removal potential from water systems. In this paper, we comprehensively reviewed biochar effects on soil P availability and P removal from water systems and discussed the mechanisms involved. Biochar affects soil P cycling by altering P chemical forms, changing soil P sorption and desorption capacities, and influencing microbial population size, enzyme activities, mycorrhizal associations and microbial production of metal-chelating organic acids. The porous structure, high specific surface area, and metal oxide and surface functional groups make biochars effective materials for removing P from eutrophic water via ligand exchange, cation bridge, and P precipitation. Because soil and biochar properties are widely variable, the effect of biochar on the fate of P in soil and water systems is inconsistent among different studies. Knowledge gaps in the economic practicability of large-scale biochar application, the longevity of biochar benefits, and the potential ecological risks of biochar application should be addressed in future research.
Display omitted
•Biochar is a novel/designed adsorbent for phosphorus in soil and water (Ps-w).•Biochar nutrients release and its specific surface area affect Ps-w availability.•Feedstock type and pyrolysis condition play a key role affecting Ps-w dynamics.•Solution and biochar properties determine P removal efficiency from wastewater.•Novel modification methods enhance biochar P sorption capacity.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
PDF
