MORPHOLOGICAL AND MICROMORPHOLOGICAL CHANGES IN THE STRUCTURE OF A RHODIC HAPLUDOX AS A RESULT OF AGRICULTURAL MANAGEMENT

In evaluation of soil quality for agricultural use, soil structure is one of the most important properties, which is influenced not only by climate, biological activity, and management practices but also by mechanical and physico-chemical forces acting in the soil. The purpose of this study was to evaluate the influence of conventional agricultural management on the structure and microstructure of a Latossolo Vermelho distroférrico típico (Rhodic Hapludox) in an experimental area planted to maize. Soil morphology was described using the crop profile method by identifying the distinct structural volumes called Morphologically Homogeneous Units (MHUs). For comparison, we also described a profile in an adjacent area without agricultural use and under natural regrowth referred to as Memory. We took undisturbed samples from the main MHUs so as to form thin sections and blocks of soil for micromorphological and micromorphometrical analyses. Results from the application of the crop profile method showed the occurrence of the following structural types: loose (L), fragmented (F) and continuous (C) in both profiles analyzed. In the Memory soil profile, the fragmented structures were classified as Fptμ∆+tf and Fmt∆μ, whose micromorphology shows an enaulic-porphyric (porous) relative distribution with a great deal of biological activity as indicated by the presence of vughs and channels. Lower down, from 0.20 to 0.35 m, there was a continuous soil volume (sub-type C∆μ), with a subangular block microstructure and an enaulic-porphyric relative distribution, though in this case more compact and with aggregate coalescence and less biological activity. The micromorphometrical study of the soil of the Memory Plot showed the predominance of complex pores in NAM (15.03 %), Fmt∆μ (11.72 %), and Fptμ∆+tf (7.73 %), and rounded pores in C∆μ (8.21 %). In the soil under conventional agricultural management, we observed fragmented structures similar to the Memory Plot from 0.02 to 0.20 m, followed by a volume with a compact continuous structure (C∆μ), without visible porosity and with few roots. In the MHUs under conventional management, reduction in the packing pores (40 %) was observed, mainly in the continuous units (C). The microstructure had well-defined blocks, with the occurrence of planar pores and less evidence of biological activity. In conclusion, the morphological and micromorphological analyses of the soil profiles studied offered complementary information regarding soil structural quality, especially concerning the changes in pore types as result of mechanical stress undergone by the soil.

BIOCHAR: PYROGENIC CARBON FOR AGRICULTURAL USE - A CRITICAL REVIEW

Biochar (carbonized biomass for agricultural use) has been used worldwide as soil amendment and is a technology of particular interest for Brazil, since its "inspiration" is from the historical Terra Preta de Índios(Amazon Dark Earth), and also because Brazil is the world's largest charcoal producer, generating enormous residue quantities in form of fine charcoal and due to the availability of different residual biomasses, mainly from agroindustry (e.g., sugar-cane bagasse; wood and paper-mill wastes; residues from biofuel industries; sewage sludge etc), that can be used for biochar production, making Brazil a key actor in the international scenario in terms of biochar research and utilization). In the last decade, numerous studies on biochar have been carried out and now a vast literature, and excellent reviews, are available. The objective of this paper is therefore to deliver a critical review with some highlights on biochar research, rather than an exhaustive bibliographic review. To this end, some key points considered critical and relevant were selected and the pertinent literature "condensed", with a view to guide future research, rather than analyze trends of the past.

Greenhouse Gas and Nitrogen Fertilizer Scenarios for U.S. Agriculture and Global Biofuels, June 2011

This analysis uses the 2011 FAPRI-CARD (Food and Agricultural Policy Research Institute–Center for Agricultural and Rural Development) baseline to evaluate the impact of four alternative scenarios on U.S. and world agricultural markets, as well as on world fertilizer use and world agricultural greenhouse gas emissions. A key assumption in the 2011 baseline is that ethanol support policies disappear in 2012. The baseline also assumes that existing biofuel mandates remain in place and are binding. Two of the scenarios are adverse supply shocks, the first being a 10% increase in the price of nitrogen fertilizer in the United States, and the second, a reversion of cropland into forestland. The third scenario examines how lower energy prices would impact world agriculture. The fourth scenario reintroduces biofuel tax credits and duties. Given that the baseline excludes these policies, the fourth scenario is an attempt to understand the impact of these policies under the market conditions that prevail in early 2011. A key to understanding the results of this fourth scenario is that in the absence of tax credits and duties, the mandate drives biofuel use. Therefore, when the tax credits and duties are reintroduced, the impacts are relatively small. In general, the results show that the entire international commodity market system is remarkably robust with respect to policy changes in one country or in one sector. The policy implication is that domestic policy changes implemented by a large agricultural producer like the United States can have fairly significant impacts on the aggregate world commodity markets. A second point that emerges from the results is that the law of unintended consequences is at work in world agriculture. For example, a U.S. nitrogen tax that might presumably be motivated for environmental benefit results in an increase in world greenhouse gas emissions. A similar situation occurs in the afforestation scenario in which crop production shifts from high-yielding land in the United States to low-yielding land and probably native vegetation in the rest of the world, resulting in an unintended increase in global greenhouse gas emissions.

Liming in Agricultural Production Models with and Without the Adoption of Crop-Livestock Integration

ABSTRACT Perennial forage crops used in crop-livestock integration (CLI) are able to accumulate large amounts of straw on the soil surface in no-tillage system (NTS). In addition, they can potentially produce large amounts of soluble organic compounds that help improving the efficiency of liming in the subsurface, which favors root growth, thus reducing the risks of loss in yield during dry spells and the harmful effects of “overliming”. The aim of this study was to test the effects of liming on two models of agricultural production, with and without crop-livestock integration, for 2 years. Thus, an experiment was conducted in a Latossolo Vermelho (Oxisol) with a very clayey texture located in an agricultural area under the NTS in Bandeirantes, PR, Brazil. Liming was performed to increase base saturation (V) to 65, 75, and 90 % while one plot per block was maintained without the application of lime (control). A randomized block experimental design was adopted arranged in split-plots and four plots/block, with four replications. The soil properties evaluated were: pH in CaCl2, soil organic matter (SOM), Ca, Mg, K, Al, and P. The effects of liming were observed to a greater depth and for a long period through mobilization of ions in the soil, leading to a reduction in SOM and Al concentration and an increase in pH and the levels of Ca and Mg. In the first crop year, adoption of CLI led to an increase in the levels of K and Mg and a reduction in the levels of SOM; however, in the second crop year, the rate of decline of SOM decreased compared to the decline observed in the first crop year, and the level of K increased, whereas that of P decreased. The extent of the effects of liming in terms of depth and improvement in the root environment from the treatments were observed only partially from the changes observed in the chemical properties studied.

Audit report on America’s Agricultural Industrial Heritage Landscape, Inc., d/b/a Silos and Smokestacks National Heritage Area, in Waterloo, Iowa for the years ended December 31, 2011 and 2010

Audit report on America’s Agricultural Industrial Heritage Landscape, Inc., d/b/a Silos and Smokestacks National Heritage Area, in Waterloo, Iowa for the years ended December 31, 2011 and 2010

Uniform-price assignment markets

Uniform-price assignment games are introduced as those assignment markets with the core reduced to a segment. In these games, for all active agents, competitive prices are uniform although products may be non-homogeneous. A characterization in terms of the assignment matrix is given. The only assignment markets where all submarkets are uniform are the Bohm-Bawerk horse markets. We prove that for uniform-price assignment games the kernel, or set of symmetrically-pairwise bargained allocations, either coincides with the core or reduces to the nucleolus

Audit report on the Muscatine Agricultural Learning Center for the year ended December 31, 2011 and the six months ended December 31, 2010

Audit report on the Muscatine Agricultural Learning Center for the year ended December 31, 2011 and the six months ended December 31, 2010

Audit report on the Iowa Agricultural Development Authority for the year ended June 30, 2012

Audit report on the Iowa Agricultural Development Authority for the year ended June 30, 2012

Price transmission and market power analysis in the Spanish seafood market chain

[cat] Espanya és un dels principals mercats de productes pesquers d’Europa i del món. El consum de productes pesquers ha estat tradicionalment molt important a Espanya, el 2005 es varen consumir 36,7 kg per persona (MAPA, diversos anys). Malgrat això, el mercat i cóm interactuen els diversos nivells de la cadena de comercialització han gaudit de poca atenció. En aquest estudi, utilitzant dades setmanals, s’analitza per als dotze principals productes pesquers, l’elasticitat en la transmissió de preus al llarg de la cadena de comercialització a Espanya (llotja, mercat central i detallista). Finalment s’investiga la presència d’assimetria en la transmissió de preus entre aquests nivells de mercat. Els resultats obtinguts tenen importants implicacions a l’hora d’analitzar la demanda, poder de mercat i marges al llarg del mercat per als productes pesquers.

Drug price differentials caused by de-listing and price cap policies

This paper analyses the behaviour of pharmaceutical companies that face the threat of having their drugs excluded from reimbursement and the markets characterised also by price caps. We conclude that price elasticity of demand and cost differentials cause the price discounts which drug firms offer to health care organisations. Additionally, we conclude that price cap regulations affect the time path of prices, resulting in higher prices for new products and lower prices for old products.

Monetary integration and the cost of borrowing

With the beginning of the European Monetary Union (EMU), euro-area sovereign securities¿ adjusted spreads over Germany (corrected from the foreign exchange risk) experienced an increase that caused a lower than expected decline in borrowing costs. The objective of this paper is to study what explains that rising. In particular, if it took place a change in the price assigned by markets to domestic (credit risk and/or market liquidity) or to international risk factors. The empirical evidence supports the idea that a change in the market value of liquidity occurred with the EMU. International and default risk play a smaller role

Factor shares, the price markup, and the elasticity of substitution between capital and labor

[spa] La participación del trabajo en la renta nacional es constante bajo los supuestos de una función de producción Cobb-Douglas y competencia perfecta. En este artículo se relajan estos supuestos y se investiga si el comportamiento no constante de la participación del trabajo en la renta nacional se explica por (i) una elasticidad de sustitución entre capital y trabajo no unitaria y (ii) competencia no perfecta en el mercado de producto. Nos centramos en España y los U.S. y estimamos una función de producción con elasticidad de sustitución constante y competencia imperfecta en el mercado de producto. El grado de competencia imperfecta se mide a través del cálculo del price markup basado en laaproximación dual. Mostramos que la elasticidad de sustitución es mayor que uno en España y menor que uno en los US. También mostramos que el price markup aleja la elasticidad de sustitución de uno, lo aumenta en España, lo reduce en los U.S. Estos resultados se utilizan para explicar la senda decreciente de la participación del trabajo en la renta nacional, común a ambas economías, y sus contrastadas sendas de capital.

Audit report on America’s Agricultural Industrial Heritage Landscape, Inc., d/b/a Silos and Smokestacks National Heritage Area and Silos and Smokestacks Natural Heritage Area Foundation in Waterloo, Iowa for the years ended December 31, 2012 and 2011

Audit report on America’s Agricultural Industrial Heritage Landscape, Inc., d/b/a Silos and Smokestacks National Heritage Area and Silos and Smokestacks Natural Heritage Area Foundation in Waterloo, Iowa for the years ended December 31, 2012 and 2011