ABSTRACT: This had a wide variety of links. I chose this one for now. The possibility of calculating useful microbial community diversity indices from environmental polar lipid fatty acid and 16S rDNA PCR-DGGE data was investigated. First, the behavior of the species richness, Shannon's, and Simpson's diversity indices were determined on polar lipid fatty acid profiles of 115 pure cultures, communities constructed from those profiles with different numbers of species, and constructed communities with different distributions of species. Differences in the species richness of these artificial communities was detected by all three diversity indices, but they were insensitive to the evenness of the distribution of species. Second, data from a field experiment with substrate addition to soil was used to compare the methods developed for lipid- and DNA-based diversity indices. Very good agreement was found between indices calculated from environmental polar lipid fatty acid profiles and denaturing gradient gel electrophoresis profiles from matched samples (Pearson's correlation coefficient r=0.95-0.96). A method for data pre-treatment for diversity calculations is described.
ABSTRACT: Reforestation with different types of plants can affect soil biochemical activity and microbial community structure. However, little is known about the mechanism by which reforestation affects soil microbial community. We investigated soil microbial communities and biochemical properties in moso bamboo and Japanese cedar plantations in central Taiwan, which were established through reforestation of a natural hardwood forest. Soil microbial biomass carbon (Cmic) and nitrogen (Nmic) were lower in two reforested plantations than in natural hardwood forest. The conversion of natural hardwood forest to cedar and bamboo plantations, however, increased soil Cmic/Corg and Nmic/Ntot ratios and decreased soil metabolic quotient (respiration per unit of microbial biomass). Most soil enzymatic activities decreased after the shift from natural hardwood forest to reforested plantations. The abundance of total phospholipid fatty acids (PLFA), bacteria and gram-positive bacteria was lower in bamboo and cedar plantations than in natural hardwood forest. However, ratios of soil gram-positive to gram-negative bacteria and cyclopropane fatty acids to monoenoic precursor fatty acids, which are considered indicators of physiological stress, were lower in the reforested plantations as compared to the natural hardwood forest. These results suggest that the microbial community is less physiologically stressed in the bamboo and cedar plantations soils, though it still had a smaller biomass. Principal component analysis of soil PLFA content showed that the natural forest separated from bamboo and cedar plantations. Similarly, denaturing gradient gel electrophoresis analysis revealed changes in bacterial and fungal community structures after the reforestation. Our results suggest that the reforestation with bamboo and cedar in the strongly acidic natural forest drove the microbial community structure to favor gram-negative bacteria, possibly due to an increase in nutrient availability after the forest conversion.
ABSTRACT: This review covers the current and emerging analytical methods used in laboratory, field, landscape and regional contexts for measuring soil organic carbon (SOC) sequestration in agricultural soil. Soil depth plays an important role in estimating SOC sequestration. Selecting appropriate sampling design, depth of soil, use of proper analytical methods and base line selection are prerequisites for estimating accurately the soil carbon stocks. Traditional methods of wet digestion and dry combustion (DC) are extensively used for routine laboratory analysis; the latter is considered to be the “gold standard” and superior to the former for routine laboratory analysis. Recent spectroscopic techniques can measure SOC stocks in laboratory and in-situ even up to a deeper depth. Aerial spectroscopy using multispectral and/or hyperspectral sensors located on aircraft, unmanned aerial vehicles (UAVs) or satellite platforms can measure surface soil organic carbon. Although these techniques' current precision is low, the next generation hyperspectral sensor with improved signal noise ratio will further improve the accuracy of prediction. At the ecosystem level, carbon balance can be estimated directly using the eddy-covariance approach and indirectly by employing agricultural life cycle analysis (LCA). These methods have tremendous potential for estimating SOC. Irrespective of old or new approaches, depending on the resources and research needed, they occupy a unique place in soil carbon and climate research. This paper highlights the overview, potential limitations of various scale-dependent techniques for measuring SOC sequestration in agricultural soil.
ABSTRACT: Bamboo species have been promoted for utility in both biomass and pulp production because of their high productivity. However, some bamboo species are known to be problematic invaders. Our goal was to use a weed risk assessment (WRA) tool to evaluate and compare invasion risk of non-native running and clumping bamboo species, many of which are under consideration as paper pulp and bioenergy crops in the continental United States. WRAs were conducted for 18 running and 29 clumping bamboo species using a version of the Australian WRA modified for the U.S. We tested for differences in scores and the number of questions answered for clumping and running species, the relationship between the WRA score and the number of questions answered, and the questions that differentiated low and high-risk species. Overall, we found that running bamboo species present a significantly higher invasion risk than clumping species. Only one running bamboo species (Chimonobambusa tumidissinoda) was identified as low risk and one clumping species (Bambusa bambos) was high risk for invasion. History of invasiveness elsewhere, the ability to form dense thickets, and unintentional dispersal of viable rhizome pieces were associated with significantly greater predicted risk. Commercial applications of bamboo should focus on the use of low invasion risk clumping bamboo species to reduce the risk of escape and colonization of nearby natural areas. Further, bamboo-specific best management practices (BMPs) should be implemented to reduce the probability of invasion for species used in commercial production. NOTE: • Is an integrated asset in Dreamland production • Bamboo biomass carbon storage is comparable to the Woody biomass of trees • Biomass and carbon storage in bamboo is permanent as a sink • Bamboo has high carbon sequestration rate and a large geographical distribution • Woody bamboo provide ample opportunity for carbon farming in carbon trading Therefore once an equitable appropriate and managed carbon commodity Trading is created this becomes another Revenue asset for the Dreamland operation.
ABSTRACT: Research on identifying cost-effective managed ecosystems that can substantially remove atmospheric carbon-dioxide (CO2) while providing essential societal benefits has gained momentum since the Kyoto Protocol of 1997. Carbon farming allows farmers and investors to generate tradable carbon offsets from farmlands and forestry projects through carbon trading. Carbon trading is pertinent to climate negotiations by decelerating the climate change phenomenon. Thus, the objective of this article is to describe the potential of woody bamboos in biomass carbon storage and as an option for carbon farming and carbon trading. Bamboo is an important agroforestry and forest plant managed and used by the rural communities in several countries of the Asia-Pacific region for generating diverse economic and socio-environmental needs. Mean carbon storage and sequestration rate in woody bamboos range from 30–121 Mg ha−1 and 6–13 Mg ha−1 yr−1, respectively. Bamboo has vigorous growth, with completion of the growth cycle between 120 and 150 days. Because of its rapid biomass accumulation and effective fixation of CO2, it has a high carbon sequestration capacity. Over and above the high biomass carbon storage, bamboo also has a high net primary productivity (12–26 Mg ha−1 yr−1) even with regular selective harvesting, thus making it a standing carbon stock and a living ecosystem that continues to grow. Despite its high potential in carbon storage and sequestration and its important role in livelihood of millions of rural poor’s worldwide, prospects of bamboo ecosystems in CDM (Clean Development Mechanism) and REDD (Reduced Emission from Deforestation and Forest Degradation) schemes remain to be explored. Thus, there is an urgent need to recognize ecosystem services that woody bamboo provides for well-being of rural communities and nature conservancy. Present synthesis suggests that bamboo offers tremendous opportunity for carbon farming and carbon trading.
ABSTRACT: Using an in vitro bioreactor system in which the arbuscular mycorrhizal (AM) fungus Glomus intraradices was grown in a soil devoid of detectable living microbes, we could show that the mycelium of this fungus contributed to the maintenance of water-stable soil aggregates and increased soil water repellency, as measured by water drop penetration time. This is to our knowledge the first demonstration of a causal link between AM fungal growth and water repellency of soil aggregates. Our results also place AM fungal contributions to soil aggregation on a firm mechanistic footing by showing that hyphae are sufficient to produce effects, in the absence of other soil biota, which have always been included in previous studies.
ABSTRACT: Understanding the contributions of soil microorganisms to soil stabilization at the molecular level will lead to ways to enhance inputs for sustainable agricultural systems. Recent discoveries of copious production of glycoprotein (glomalin) by arbuscular mycorrhizal (AM) fungi and the apparent recalcitrance of this material in soils led to the comparison between concentration of glomalin and aggregate stability. Stability was measured on air-dried aggregates rewetted by capillary action and then subjected to wet sieving for 10 min. Thirty-seven samples from four geographic areas of the U.S. and one area of Scotland were tested. The monoclonal antibody used to discover glomalin on AM hyphae was employed to assess immunoreactive glomalin on aggregate surfaces by immunofluorescence and in extracts from aggregates by enzyme-linked immunosorbent assay (ELISA). Immunofluorescence was observed on at least some surfaces of aggregates from all soils examined, but was most evident on aggregates with high glomalin concentrations. Easily extractable glomalin (EEG) was solubilized by 20 mM citrate, pH 7.0 at 121 °C for 30 min, and total glomalin (TG) was solubilized with 50 mM citrate, pH 8.0 at 121 °C for 90 to 450 min. Some soils required up to seven sequential extractions to remove all of the glomalin. Aggregate stability was linearly correlated (p < 0.001) with all measures of glomalin (mg/g of aggregates) in these soils. The best predictor of aggregate stability (AS) was immunoreactive easily extractable glomalin (IREEG) according to the following relationship: AS = 42.7 +61.30 x log10 IREEG (r2 = 0.86; p <0.001, n = 37).
ABSTRACT: Arbuscular mycorrhizal fungi (AMF) proliferate in soils and are known to affect soil structure. Although their contribution to structure is extensively investigated, the consequences of those processes for soil water extractability and transport has, so far, gained surprisingly little attention. Therefore we asked, whether AMF can affect water retention and unsaturated hydraulic conductivity under exclusion of root ingrowth , in order to minimize plant driven effects. We carried out experiments with tomato inoculated with Rhizoglomus irregulare in a soil substrate with sand and vermiculite that created variation in colonization by mixed pots with wild type (WT) plants and mycorrhiza resistant (RMC) mutants. Sampling cores were introduced and used to assess substrate moisture retention dynamics and modeling of substrate water retention and hydraulic conductivity. AMF reduced the saturated water content and total porosity, but maintained air filled porosity in soil spheres that excluded root ingrowth. The water content between field capacity and the permanent wilting point (6-1500 kPa) was only reduced in mycorrhizal substrates that contained at least one RMC mutant. Plant available water contents correlated positively with soil protein contents. Soil protein contents were highest in pots that possessed the strongest hyphal colonization, but not significantly affected. Substrate conductivity increased up to 50 % in colonized substrates in the physiologically important water potential range between 6 and 10 kPa. The improvements in hydraulic conductivity are restricted to substrates where at least one WT plant was available for the fungus, indicating a necessity of a functional symbiosis for this effect. We conclude that functional mycorrhiza alleviates the resistance to water movement through the substrate in substrate areas outside of the root zone.
ABSTRACT: Earthworms play an important role in ecosystems and act as a soil engineers changing the physico-chemical properties of soil. Eco-friendly methods for the extraction of earthworms are needed to assess earthworm abundance, biomass and their diversity. In this study, a comparison was made to find out the most effective chemical expellants for the extraction of earthworms in different concentrations of Formalin, Allyl isothiocyanate (AITC) (0.25, 0.50, 0.75 and 1.0 g/l), Allium cepa solution (50, 100, 150 and 200 g/l) and distilled water as a control. Three species of earthworms from the family Megascolecidae have been extracted belonging to two ecological groups: the endogeic species Metaphire posthuma as well as the anecic species Lampito mauritti and Amynthas morissi. The number of extracted individuals across all species and age classes was significantly affected by the type of vermifuge. A. cepa solution was more efficient than Formalin and AITC for extraction of worms and it is also similarly efficient for extracting adult worms and juveniles. Only for the number of extracted juveniles and individuals of A. morissi the effects of formalin and AITC were not significantly different (p > 0.05), in all other cases AITC was more efficient than formalin. It was found that A. cepa solution expelled 66.15% and 53.30% more numbers of earthworms than AITC and formalin respectively. We conclude that A. cepa extraction solution is a suitable and eco-friendly alternative to AITC and formalin for sampling of endogeic and anecic earthworms.
ABSTRACT: I can't find any links with that title. Here's what I did find that might be of use.
ABSTRACT: The importance of the inherent resistance of soil to erosional processes, or soil erodibility, is generally recognized in hillslope and fluvial geomorphology, but the full implications of the dynamic soil properties that affect erodibility are seldom considered. In Canada, a wide spectrum of soils and erosional processes has stimulated much research related to soil erodibility. This paper aims to place this work in an international framework of research on water erosion processes, and to identify critical emerging research questions. It focuses particularly on experimental research on rill and interrill erosion using simulated rainfall and recently developed techniques that provide data at appropriate temporal and spatial scales, essential for event-based soil erosion prediction. Results show that many components of erosional response, such as partitioning between rill and interrill or surface and subsurface processes, threshold hydraulic conditions for rill incision, rill network configuration and hillslope sediment delivery, are strongly affected by spatially variable and temporally dynamic soil properties. This agrees with other recent studies, but contrasts markedly with long-held concepts of soil credibility as an essentially constant property for any soil type. Properties that determine erodibility, such as soil aggregation and shear strength, are strongly affected by climatic factors such as rainfall distribution and frost action, and show systematic seasonal variation. They can also change significantly over much shorter time scales with subtle variations in soil water conditions, organic composition, microbiological activity, age-hardening and the structural effect of applied stresses. Property changes between and during rainstorms can dramatically affect the incidence and intensity of rill and interrill erosion and, therefore, both short and long-term hillslope erosional response. Similar property changes, linked to climatic conditions, may also significantly influence the stability and resilience of plant species and vegetation systems. Full understanding of such changes is essential if current event-based soil erosion models such as WEPP and EUROSEM are to attain their full potential predictive precision. The complexity of the interacting processes involved may, however, ultimately make stochastic modelling more effective than physically based modelling in predicting hillslope response to erodibility dynamics.
ABSTRACT: Mycorrhizal fungi associated with plant roots may contribute to carbon sequestration in soils.
ABSTRACT: Soil health, and the closely related terms of soil quality and fertility, is considered as one of the most important characteristics of soil ecosystems. The integrated approach to soil health assumes that soil is a living system and soil health results from the interaction between different processes and properties, with a strong effect on the activity of soil microbiota. All soils can be described using physical, chemical, and biological properties, but adaptation to environmental changes, driven by the processes of natural selection, are unique to the latter one. This mini review focuses on fungal biodiversity and its role in the health of managed soils as well as on the current methods used in soil mycobiome identification and utilization next generation sequencing (NGS) approaches. The authors separately focus on agriculture and horticulture as well as grassland and forest ecosystems. Moreover, this mini review describes the effect of land-use on the biodiversity and succession of fungi. In conclusion, the authors recommend a shift from cataloging fungal species in different soil ecosystems toward a more global analysis based on functions and interactions between organisms.
ABSTRACT: Biodiversity is responsible for the provision of many ecosystem services; human well-being is based on these services, and consequently on biodiversity. In soil, earthworms represent the largest component of the animal biomass and are commonly termed ‘ecosystem engineers’. This review considers the contribution of earthworms to ecosystem services through pedogenesis, development of soil structure, water regulation, nutrient cycling, primary production, climate regulation, pollution remediation and cultural services. Although there has been much research into the role of earthworms in soil ecology, this review demonstrates substantial gaps in our knowledge related in particular to difficulties in identifying the effects of species, land use and climate. The review aims to assist people involved in all aspects of land management, including conservation, agriculture, mining or other industries, to obtain a broad knowledge of earthworms and ecosystem services.
ABSTRACT: The purpose of this paper is to evaluate the possibility of using the diffusion equation for raindrop erosion modelling. We wanted in particular to know if such a model could provide accurate interpolations of microrelief between two known dates. In a theoretical section, we show that the assumption that soil particles follow parabolic trajectories when splashed by raindrop impacts leads to a diffusion equation. This equation suggests a linear relation between Δz, the variation of height between two dates, and the Laplacian ∇2z (∇2z=∂2z/∂x2+∂2z/∂y2). This relation is confirmed by data from a simulated rainfall experiment carried out in the sandy soils of the Senegalese groundnut belt. Four square plots of side 4 m each were used. They were hoed with a traditional horse-drawn three-tined hoe. Three rains of 70 mm h−1 lasting 30 min each were applied. An automated relief meter designed and constructed by the authors was used to measure the distribution of heights for every 5 cm before the first rain, and after the first and the third rains. The mean correlation coefficient of the model was 62% for the first rain and 46% for the next two rains. Besides raindrop erosion, compaction occurred during the first rain. Adding a crude description of compaction enhanced the mean of the correlation coefficients of the model up to 70% for the first rain. Furthermore, the coefficient of variation of the four adjusted total diffusion lessens from 10 to 6%. The simulated surfaces were smoother than the real ones, which was an expected result, but the surface storage capacity was overestimated. The latter result illustrates the role of runoff in shaping the flow paths it follows and, consequently, in lessening the surface storage capacity. The main conclusion is that the diffusion equation provides a promising frame for further development of models simulating microrelief evolution during rainfall. Another conclusion is that these models should integrate existing routines for runoff erosion at small scale in order to simulate surfaces with realistic hydraulic properties.
ABSTRACT: Raindrop-impact-induced erosion is initiated when detachment of soil particles from the surface of the soil results from an expenditure of raindrop energy. Once detachment by raindrop impact has taken place, particles are transported away from the site of the impact by one or more of the following transport processes: drop splash, raindrop-induced flow transport, or transport by flow without stimulation by drop impact. These transport processes exhibit varying efficiencies. Particles that fall back to the surface as a result of gravity produce a layer of pre-detached particles that provides a degree of protection against the detachment of particles from the underlying soil. This, in turn, influences the erodibility of the eroding surface. Good understanding of rainfall erosion processes is necessary if the results of erosion experiments are to be properly interpreted. Current process-based erosion prediction models do not deal with the issue of temporal variations in erodibility during a rainfall event or variabilities in erodibility associated with spatial changes in dominance of the transport processes that follow detachment by drop impact. Although more complex erosion models may deal with issues like this, their complexity and high data requirement may make them unsuitable for use as general prediction tools. Copyright © 2005 John Wiley & Sons, Ltd.
ABSTRACT: Soil erosionfrom row sideslopes can result in contour failure and reducethe soil conservation capacity of contourridges. Understanding soil erosion processes on row sideslopes and their effects will improveour understandingof soil erosion in contour ridge systems. This knowledge will provide guidance for improving the use of contourridges. In this study, 32 rainfall simulation experiments were conducted in order to analyze the effects of twodifferent microtopography indices (row grade and ﬁeld slope), two ridge geometry indices (ridge heightand ridge width), and rainfall intensity on erosion of sandy brown soil with two replications.Based on the runoff and sediment yield time series, which was monitored over 1 min intervals, the soil erosionprocess was classiﬁed into periods of interrill or rill erosion. The runoff values for the two periods accountedfor approximately 44.2% and 55.8% of the entire runoff value, respectively. Sediment was mainly generatedfrom rill erosion (87.2%). However, interrill erosion occurred most of the time (72.3%). During the interrillerosion period, the ridge width and rainfall intensity signiﬁcantly and positively affected the amount of runoff(contributions of 33.1 and 28.7%, respectively) and sediment yield per min (14.8 and 17.0%, respectively).Ridge height signiﬁcantly and positively affected the runoff per min but not the sediment yield per min. Incontrast,ﬁeld slope negatively affected runoff per min, which indicated that the runoff during the interrill periodwas mainly affected by the ridge geometry, while the sediment yield per min was mainly affected by themicrotopography relief. During the rill erosion period, the ridge height signiﬁcantly and negatively affectedthe runoff per min because the increasing ridge height prolonged the duration of this period and enhancedinﬁltration, and the row grade signiﬁcantly and positively affected the sediment yield per min, which resultedfrom decreasing soil cohesiveness with increasing row grade. The entire runoff and sediment yield per minduring the experiment were inﬂuenced by the same factors that inﬂuenced the interrill and rill erosion periods,respectively. Interactions between the different factors, especially between ridge height, row grade, and rainfallintensity, play an important role during the erosion process by increasing runoff and sediment yield per min.Therefore, reducing the ﬁeld slope and using high ridges may reduce contour failure during rainfall events.
ABSTRACT: One of the methods for testing splash (the first phase of water erosion) may be an analysis of photos taken using so-called high-speed cameras. The aim of this study was to determine the reproducibility of measurements using a single drop splash of simulated precipitation. The height from which the drops fell resulted in a splash of 1.5 m. Tests were carried out using two types of soil: Eutric Cambisol (loamy silt) and Orthic Luvisol (sandy loam); three initial pressure heads were applied equal to 16 kPa, 3.1 kPa, and 0.1 kPa. Images for one, five, and 10 drops were recorded at a rate of 2000 frames per second. It was found that (i) the dispersion of soil caused by the striking of the 1st drop was significantly different from the splash impact caused by subsequent drops; (ii) with every drop, the splash phenomenon proceeded more reproducibly, that is, the number of particles of soil and/or water that splashed were increasingly close to each other; (iii) the number of particles that were detached during the splash were strongly correlated with its surface area; and (iv) the higher the water film was on the surface the smaller the width of the crown was.
ABSTRACT: We described the vegetation of two alluvial swamp forest stands along Durham Creek in Beaufort County, North Carolina, USA in relation to elevation, hydrologic, and edaphic gradients. Over 3,000 surveyed elevations of individual plant microsites were used in conjunction with 26 years of stream gage data to examine individual species responses to annual and growing season flooding frequencies. Direct gradient analyses combined with plot ordinations derived from detrended correspondence analysis and canonical correspondence analysis suggested that differences in vegetation between the stands were primarily the result of variations in elevation, growing season flooding frequency, percent base saturation, exchangeable acidity, and soil physical properties. Although the stands were less than 4.5 km apart and without significant intermediate tributaries, growing season flooding frequency and duration were magnified in the lowest elevations of the downstream stand. An elevation difference of as little as 10 cm resulted in a 20% difference in the frequency of surface flooding during the growing season. Species distributions were significantly correlated with depth to mottling (r2=0.75), flooding frequency (r2=−0.57), elevation (r2=0.70), and several soil chemical properties. The two stands had very similar annual surface flooding regimes, but subtle differences in growing season flooding frequency, soil characteristics, and disturbance history have apparently resulted in dissimilar plant community composition and structure. These results suggest that the lack of quantitative data on vegetation-environment interactions occurring at the microtopographic scale (10−1 m) in alluvial swamp forests makes precise prediction, planning, or design of created or restored wetland composition and function a formidable challenge.
ABSTRACT: Although both above ground and below ground components of vegetation act together in reducing soil erosion, mainly the above ground component has received attention in past research. The aim of this study was to evaluate the contribution of roots in soil erosion control and the effect of root density in soil erodibility and soil physical properties. Perennial ryegrass (Lolium perenne L. Hugo) was grown in soil pans, and laboratory rainfall simulation experiments were conducted after 4, 8, 12 weeks of their growth with seeding density of 50 kg haj1, after 4 weeks for seeding density of 100 kg haj1, and on a control. The experiments with ryegrass were done in the presence of complete plants and after clipping off the shoots. Roots of ryegrass grew rapidly, attaining densities of 0.614 kg mj2 and 2.280 kg mj2 in 4 and 12 weeks, respectively. With increasing root density, splash and wash decreased exponentially. There was positive correlation between soil shear strength and root density, but no influence of roots on bulk density and saturated hydraulic conductivity was observed.
ABSTRACT: Litter decomposition is an important component of the global carbon budget. Due to the strong climatic control of litter decomposition, climate change may significantly affect this pathway. This review quantifies the climatic influences on litter decomposition rates, both directly and indirectly through effects on litter chemistry. To this end, I analysed first-year leaf litter decomposition data from 44 locations, ranging from cool temperate sites to humid tropical sites. Actual evapotranspiration (AET) was used as an index for the climatic control on decomposition. As litter chemistry parameters I included N and P concentrations, C/N and C/P ratios, lignin concentrations, and lignin/N and lignin/P ratios. At a global scale, climate (expressed as AET) is the best predictor for the decomposition constants (k-values) of the litter, whereas litter chemistry parameters have much lower predictive values. Path analysis showed that the control of AET on litter decomposability is partly mediated through an in
ABSTRACT: Compaction can be a problem in some no-till (NT) soils, but accumulation of soil organic C (SOC) with time may reduce the soil's susceptibility to compaction. Relationships between SOC and soil maximum bulk density (BD(max)), equivalent to maximum soil compactibility, have not been well documented, particularly in NT systems. We assessed near-surface BD(max) using the Proctor test under long-term (>19 yr) moldboard plow (MP), conventional tillage (CT), reduced tillage (RT), and NT conditions in the central Great Plains and determined its relationships with SOC, particle size distribution, and Atterberg consistency limits. The experiments were located on silt loam soils at Hays and Tribune, KS, and loam soils at Akron, CO, and Sidney, NE. The near-surface BD(max) of the MP soil was higher than that of the NT soil by 13% at Sidney, while the near-surface BD(max) of the CT was higher than that of the NT soil by about 6% at Akron, Hays, and Tribune. Critical water content (CWC) for BD(max) in the NT soil was higher than in the CT and MP soils except at Tribune. The BD(max) decreased with increase in CWC (r = -0.91). The soil liquid limit was higher for NT than for MP by 82% at Sidney, and it was higher than for CT by 14, 9, and 31% at Akron, Hays, and Tribune, respectively. The SOC concentration in NT soil was higher than in MP by 60% at Akron and 76% at Sidney, and it was higher than in CT soil by 82% at Hays. The BD(max) decreased (r = –0.64) and the CWC increased (r = 0.60) with an increase in SOC concentration. Across all soils, SOC concentration was a sensitive predictor of BD(max) and CWC. This regional study showed that NT management-induced increase in SOC improves the soil's ability to resist compaction.
ABSTRACT: Soil bulk density is a dynamic property that varies with the soil structural conditions. The relationships between some soil physical and chemical properties such as, clay content (C), silt content (Si), sand content (S), very fine sand content (Vfs) and organic matter content (OMC) with soil bulk density (ρb) were studied using path analysis on 77 surface soil samples (0-20 cm). Soil bulk density showed positive relationships with S and Vfs and negative relationships with Si, C and OMC. It was determined that the direct effects of some soil properties on ρb were in the following order; S>C>Si>OMC>Vfs. On the other hand, the indirect effects of soil particle size distribution varied among soil bulk densities. The indirect effects of the soil particle size distribution generally occured through sand content. Sand content was the most effective soil property that affected bulk density in soils.
ABSTRACT: Scientists have recently discovered a new mechanism determining how carbon is stored in soils that could improve the climate resilience of cropping systems and also reduce their carbon footprints.
ABSTRACT: Existing Soil Organic Carbon (SOC) models contain several pools having different Mean Residence Times (MRTs) that each correspond to the average reactivity of the carbon compounds they contain. However, this approach does not consider the formation of soil aggregates and the fact that SOC is actively involved in this process. Some species thereby become physically protected and their decay rates are delayed. We wish to propose a new approach to SOC modelling that takes soil aggregation into account. A new model, named Struc-C, is being implemented following this approach.
ABSTRACT: Soil contains approximately 2344 Gt (1 gigaton = 1 billion tonnes) of organic carbon globally and is the largest terrestrial pool of organic carbon. Small changes in the soil organic carbon stock could result in significant impacts on the atmospheric carbon concentration. The fluxes of soil organic carbon vary in response to a host of potential environmental and anthropogenic driving factors. Scientists worldwide are contemplating questions such as: ‘What is the average net change in soil organic carbon due to environmental conditions or management practices?’, ‘How can soil organic carbon sequestration be enhanced to achieve some mitigation of atmospheric carbon dioxide?’ and ‘Will this secure soil quality?’. These questions are far reaching, because maintaining and improving the world’s soil
ABSTRACT: Moreover, overall soil porosity may be altered by the addition of biochar due to the interaction between biochar particles and soil aggregates (Curaqueo et al., 2014).
ABSTRACT: Methods used 1,400 years ago could boost water availability during Lima's dry season, according to new research.
ABSTRACT: The coastal region of Peru has one of the world’s least reliable water supplies, which dwindles dramatically during its dry season, meaning Lima especially struggles to supply water to its growing population. However, scientists believe that an existing Pre-Incan water flow system engineered just for this problem could help Peru to better manage its water. They believe that this system, which is 1400 years old, used in conjunction with modern methods, could help to create a stable and sustainable water supply for cities such as Lima.
ABSTRACT: As planetary boundaries are rapidly being approached, humanity has little room for additional expansion and conventional intensification of agriculture, while a growing world population further spreads the food gap. Ample evidence exists that improved on-farm water management can close water-related yield gaps to a considerable degree, but its global significance remains unclear. In this modeling study we investigate systematically to what extent integrated crop water management might contribute to closing the global food gap, constrained by the assumption that pressure on water resources and land does not increase. Using a process-based bio-/agrosphere model, we simulate the yield-increasing potential of elevated irrigation water productivity (including irrigation expansion with thus saved water) and optimized use of in situ precipitation water (alleviated soil evaporation, enhanced infiltration, water harvesting for supplemental irrigation) under current and projected future climate (from 20 climate models, with and without beneficial CO2 effects). Results show that irrigation efficiency improvements can save substantial amounts of water in many river basins (globally 48% of non-productive water consumption in an 'ambitious' scenario), and if rerouted to irrigate neighboring rainfed systems, can boost kcal production significantly (26% global increase). Low-tech solutions for small-scale farmers on water-limited croplands show the potential to increase rainfed yields to a similar extent. In combination, the ambitious yet achievable integrated water management strategies explored in this study could increase global production by 41% and close the water-related yield gap by 62%. Unabated climate change will have adverse effects on crop yields in many regions, but improvements in water management as analyzed here can buffer such effects to a significant degree.
ABSTRACT: A need to increase agricultural production across the world for food security appears to be at odds with the urgency to reduce agriculture's negative environmental impacts. We suggest that a cause of this dichotomy is loss of diversity within agricultural systems at field, farm and landscape scales. To increase diversity, local integration of cropping with livestock systems is suggested, which would allow (i) better regulation of biogeochemical cycles and decreased environmental fluxes to the atmosphere and hydrosphere through spatial and temporal interactions among different land-use systems; (ii) a more diversified and structured landscape mosaic that would favor diverse habitats and trophic networks; and (iii) greater flexibility of the whole system to cope with potential socio-economic and climate change induced hazards and crises. The fundamental role of grasslands on the reduction of environmental fluxes to the atmosphere and hydrosphere operates through the coupling of C and N cycles within vegetation, soil organic matter and soil microbial biomass. Therefore, close association of grassland systems with cropping systems should help mitigate negative environmental impacts resulting from intensification of cropping systems and improve the quality of grasslands through periodic renovations. However, much research is needed on designing appropriate spatial and temporal interactions between these systems using contemporary technologies to achieve the greatest benefits in different agro-ecological regions. We postulate that development of modern integrated crop-livestock systems to increase food production at farm and regional levels could be achieved, while improving many ecosystem services. Integrated crop-livestock systems, therefore, could be a key form of ecological intensification needed for achieving future food security and environmental sustainability.
ABSTRACT: Water resources worldwide are under severe stress from increasing climate variability and human pressures. In the tropical Andes, pre-Inca cultures developed nature-based water harvesting technologies to manage drought risks under natural climatic extremes. While these technologies have gained renewed attention as a potential strategy to increase water security, limited scientific evidence exists about their potential hydrological contributions at catchment scale. Here, we evaluate a 1,400-year-old indigenous infiltration enhancement system that diverts water from headwater streams onto mountain slopes during the wet season to enhance the yield and longevity of downslope natural springs. Infiltrated water is retained for an average of 45 d before resurfacing, confirming the system’s ability to contribute to dry-season flows. We estimate that upscaling the system to the source-water areas of the city of Lima can potentially delay 99 × 106 m3 yr−1 of streamflow and increase dry-season flows by 7.5% on average, which may provide a critical complement to conventional engineering solutions for water security.
UN FAO: how many harvests are left?
No word about how they arrived at this important number, but it did acknowledge that fertile (my word) soil is increasingly scarce.
The National Association of State Departments of Agriculture (NASDA) enhances American food and agricultural communities through policy, partnerships and public engagement.
(2) ACTIVITIES.—The activities for which covered entities may provide technical assistance or conduct verification of processes under the Program are current and future activities that prevent, reduce, or mitigate greenhouse gas emissions or sequester carbon, which may include—
*** (A) land or soil carbon sequestration;
(B) emissions reductions derived from fuel choice or reduced fuel use;
(C) livestock emissions reductions, including emissions reductions achieved through—
(i) feeds, feed additives, and the use of byproducts as feed sources; or
(ii) manure management practices;
(D) on-farm energy generation;
(E) energy feedstock production;
(F) fertilizer or nutrient use emissions reductions;
*** (G) reforestation;
(H) forest management, including improving harvesting practices and thinning diseased trees;
*** (I) prevention of the conversion of forests, grasslands, and wetlands;
*** (J) restoration of wetlands or grasslands;
*** (K) grassland management, including prescribed grazing;
* I’ve excluded (L) because conservation is not the goal of Dreamland. The Climate Smart Act will pay people/corporations to do nothing with their land.
(L) current practices associated with private land conservation programs administered by the Secretary; and
(M) such other activities, or combinations of activities, that the Secretary, in consultation with the Advisory Council, determines to be appropriate.
On this note, Pilot Projects and Climate-Smart Production Practices from the USDA Climate Smart Partnerships website could fund Dreamland:
"For the purposes of this funding opportunity, a climate-smart commodity is defined as an agricultural commodity that is produced using farming, ranching or forestry practices that reduce greenhouse gas emissions or sequester carbon.Partnerships for Climate-Smart Commodities pilot projects must focus on the on-farm, on-ranch, or forest production of climate-smart commodities and associated reductions of greenhouse gas (GHG) emissions and/or carbon sequestration.
Highly competitive projects will include agricultural and forestry practices or combinations of practices, and/or practice enhancements that provide GHG benefits and/or carbon sequestration, including but not limited to:
Low-till or no-till
Nutrient management (Dreamland style, meaning Nbs)
Enhanced efficiency fertilizers
Feed management to reduce enteric emissions (cow farts is still a thing)
Buffers, wetland and grassland management, and tree planting on working lands
Agroforestry and afforestation on working lands (One cannot just wave a wand and expect Nature to supply the fungi needed)
Afforestation/reforestation and sustainable forest management (sustainable means consumption up to the point of no return)
Planting for high carbon sequestration rate
Maintaining and improving forest soil quality (yes, by doing to it).
Increase on-site carbon storage through forest stand management (ditto).
Alternate wetting and drying on rice fields
Climate-smart pasture practices, such as prescribed grazing or legume interseeding
Soil amendments, like biochar"
Q: the aspects of this bill and its assertions. Why is this bad, misleading piece of legislation?
A: It’s a carbon credit market that incentivizes agricultural status quo which will lead to food shortages as more and more grain croplands are unable to meet market quotas.
How can we integrate with their opposition to create evidence basis for the People’s Farm Bill?
I honestly don't understand this because "evidence basis" to me is Dreamland's proven concept.