scholarly journals Organic matter and soil structure in the Everglades Agricultural Area

2013 ◽  
Author(s):  
Alan L. Wright ◽  
Edward A. Hanlon



EDIS ◽  
2019 ◽  
Vol 2019 (1) ◽  
Author(s):  
James Mabry McCray

Potassium is a primary plant nutrient that is required in large amounts by sugarcane. About 74% of the 400,000 acres of Florida sugarcane is grown on organic soils in the Everglades Agricultural Area. Potassium is not a component of organic matter and virgin Histosols contain very low concentrations of K, so release of K through mineralization of organic matter in these soils is not an adequate K source for plant growth. This 7-page document presents revised potassium fertilizer recommendations for sugarcane grown on Florida organic soils along with supporting information. Written by J. Mabry McCray, and published by the UF/IFAS Agronomy Department, February 2019.  http://edis.ifas.ufl.edu/ag428



EDIS ◽  
2009 ◽  
Vol 2009 (4) ◽  
Author(s):  
Alan L. Wright ◽  
Edward A. Hanlon

SL-285, a 5-page illustrated fact sheet by Alan L. Wright and Edward A. Hanlon, recommends for growers, managers, and researchers the new and simple Loss-On-Ignition (LOI) test for determining the organic matter content of soils. Includes additional sources of information. Published by the UF Department of Soil and Water Sciences, April 2009. SL 285/SS498: Measuring Organic Matter in Everglades Wetlands and the Everglades Agricultural Area (ufl.edu)



1986 ◽  
Vol 66 (2) ◽  
pp. 273-285 ◽  
Author(s):  
J. F. DORMAAR ◽  
C. W. LINDWALL ◽  
G. C. KOZUB

A field was artificially eroded by levelling in 1957 and then continuously cropped to barley for 7 yr. Subsequently, a wheat-fallow experiment was conducted from 1965 to 1979 to determine the effects of four fertilizer treatments and green manure (yellow sweet clover) on restoring the productivity to soil that had been "eroded" to various depths. After 22 yr and 14 crops, the productivity of the land from which soil was removed has been improved but not fully restored. Although green manuring with yellow sweet clover improved soil structure, wheat yields were not improved because of competition for soil moisture and poorer in-crop weed control in this part of the rotation. The addition of 45 kg N plus 90 kg P2O5 per hectare in each crop year to sites from which 8–10, 10–20, or 46 + cm of soil had been removed resulted in yield increases of 18, 46, and 70%, respectively, over the unfertilized check of each treatment; the average yields were 104, 91, and 70%, respectively, of the undisturbed, unfertilized (check) treatment. On "erosion" treatments where only 8–10 cm of soil were removed, 45 kg N plus 22 kg P2O5 per hectare were sufficient to restore the productivity. Precipitation apparently had a greater effect than fertilizer application on wheat yields. The loss of organic matter and associated soil structure characteristics seemed to be critical factors contributing to yield losses associated with soil erosion. These results show that it is more practical to use management practices that prevent soil erosion than to adopt the practices required to restore eroded soil. Key words: Soil erosion, topsoil loss, water-stable aggregates, soil organic matter, green manure, precipitation



EDIS ◽  
2007 ◽  
Vol 2007 (17) ◽  
Author(s):  
Orlando A. Diaz ◽  
Timothy A. Lang ◽  
Samira H. Daroub ◽  
Viviana M. Nadal

SL-228-Sp, a 9-page illustrated fact sheet by O.A. Diaz, T.A. Lang, S.H. Daroub, and V.M. Nadal, is the Spanish language version of "SL228/SS448: Best Management Practices in the Everglades Agricultural Area: Controlling Particulate Phosphorus and Canal Sediments." It explains and discusses particulate P and sediment control practices, which serve as important tools in efforts to improve water quality in the basin. This EDIS article is one in a series that attempts to explain in easily understandable terms the implementation methods and rationale behind the main P load reducing BMPs employed on EAA farms. Published by the UF Department of Soil and Water Sciences, August 2007. SL228SP/SS476: Mejores Prácticas de Manejo en el Area Agrícola de los Everglades: Controlando el Fósforo en Partícula y Sedimentos en Canales (ufl.edu) Ask IFAS: Best Management Practices in the Everglades Agricultural Area series (en espanol) (ufl.edu)



2007 ◽  
Vol 28 (3) ◽  
pp. 104 ◽  
Author(s):  
Margaret M Roper ◽  
Vadakattu V S R Gupta

Soils are much more than a porous medium for supporting plant growth. Soils are living, because they contain a wide range of microorganisms including bacteria, fungi, algae, protozoa, nematodes and other fauna including microarthropods, macroarthropods, termites and earthworms. All play a crucial role in the biological function of soils including decomposition of organic matter, nutrient transformations, biological control, development of soil structure to mention a few. Until recently the complexity of life in the soil has been difficult to unravel, but new DNA and biochemical tools are providing insights into its phenotypic and functional diversity and capability, and should drive the development of managements that nurture biodiversity and ecosystem function.



2021 ◽  
Author(s):  
Hans-Jörg Vogel ◽  
Mar­ia Balseiro-Romero ◽  
Philippe C. Baveye ◽  
Alexandra Kravchenko ◽  
Wilfred Otten ◽  
...  

<p>Soil structure, lately referred to as the ''architecture'' is a key to explain and understand all soil functions. The development of sophisticated imaging techniques over the last decades has led to significant progress in the description of this architecture and in particular of the geometry of the hierarchically-branched pore space in which transport of water, gases, solutes and particles occurs and where myriads of organisms live. Moreover, there are sophisticated tools available today to also visualize the spatial structure of the solid phase including mineral grains and organic matter. Hence, we do have access to virtually all components of soil architecture.</p><p>Unfortunately, it has so far proven very challenging to study the dynamics of soil architecture over time, which is of critical importance for soil as habitat and the turnover of organic matter. Several largely conflicting theories have been proposed to account for this dynamics, especially the formation of aggregates. We review these theories, and we propose a conceptual approach to reconcile them based on a consistent interpretation of experimental observations and by integrating known physical and biogeochemical processes. A key conclusion is that rather than concentrating on aggregate formation in the sense of how particles and organic matter reorganize to form aggregates as distinct functional units we should focus on biophysical processes that produce a porous, heterogeneous organo-mineral soil matrix that breaks into fragments of different size and stability when exposed to mechanical stress.  The unified vision we propose for soil architecture and the mechanisms that determine its temporal evolution, should pave the way towards a better understanding of soil processes and functions.</p>



2009 ◽  
Vol 13 (8) ◽  
pp. 1485-1502 ◽  
Author(s):  
L. W. de Jonge ◽  
P. Moldrup ◽  
P. Schjønning

Abstract. Soil functions and their impact on health, economy, and the environment are evident at the macro scale but determined at the micro scale, based on interactions between soil micro-architecture and the transport and transformation processes occurring in the soil infrastructure comprising pore and particle networks and at their interfaces. Soil structure formation and its resilience to disturbance are highly dynamic features affected by management (energy input), moisture (matric potential), and solids composition and complexation (organic matter and clay interactions). In this paper we review and put into perspective preliminary results of the newly started research program "Soil-it-is" on functional soil architecture. To identify and quantify biophysical constraints on soil structure changes and resilience, we claim that new approaches are needed to better interpret processes and parameters measured at the bulk soil scale and their links to the seemingly chaotic soil inner space behavior at the micro scale. As a first step, we revisit the soil matrix (solids phase) and pore system (water and air phases), constituting the complementary and interactive networks of soil infrastructure. For a field-pair with contrasting soil management, we suggest new ways of data analysis on measured soil-gas transport parameters at different moisture conditions to evaluate controls of soil matrix and pore network formation. Results imply that some soils form sponge-like pore networks (mostly healthy soils in terms of agricultural and environmental functions), while other soils form pipe-like structures (agriculturally poorly functioning soils), with the difference related to both complexation of organic matter and degradation of soil structure. The recently presented Dexter et al. (2008) threshold (ratio of clay to organic carbon of 10 kg kg−1) is found to be a promising constraint for a soil's ability to maintain or regenerate functional structure. Next, we show the Dexter et al. (2008) threshold may also apply to hydrological and physical-chemical interface phenomena including soil-water repellency and sorption of volatile organic vapors (gas-water-solids interfaces) as well as polycyclic aromatic hydrocarbons (water-solids interfaces). However, data for differently-managed soils imply that energy input, soil-moisture status, and vegetation (quality of eluded organic matter) may be equally important constraints together with the complexation and degradation of organic carbon in deciding functional soil architecture and interface processes. Finally, we envision a road map to soil inner space where we search for the main controls of particle and pore network changes and structure build-up and resilience at each crossroad of biophysical parameters, where, for example, complexation between organic matter and clay, and moisture-induced changes from hydrophilic to hydrophobic surface conditions can play a role. We hypothesize that each crossroad (e.g. between organic carbon/clay ratio and matric potential) may control how soil self-organization will manifest itself at a given time as affected by gradients in energy and moisture from soil use and climate. The road map may serve as inspiration for renewed and multi-disciplinary focus on functional soil architecture.



2018 ◽  
Vol 13 (No. 3) ◽  
pp. 140-149 ◽  
Author(s):  
Šimanský Vladimír ◽  
Lukáč Martin

Soil structure is a key determinant of many soil environmental processes and is essential for supporting terrestrial ecosystem productivity. Management of arable soils plays a significant role in forming and maintaining their structure. Between 1994 and 2011, we studied the influence of soil tillage and fertilisation regimes on the stability of soil structure of loamy Haplic Luvisol in a replicated long-term field experiment in the Dolná Malanta locality (Slovakia). Soil samples were repeatedly collected from plots exposed to the following treatments: conventional tillage (CT) and minimum tillage (MT) combined with conventional (NPK) and crop residue-enhanced fertilisation (CR+NPK). MT resulted in an increase of critical soil organic matter content (St) by 7% in comparison with CT. Addition of crop residues and NPK fertilisers significantly increased St values (by 7%) in comparison with NPK-only treatments. Soil tillage and fertilisation did not have any significant impact on other parameters of soil structure such as dry sieving mean weight diameters (MWD), mean weight diameter of water-stable aggregates (MWD<sub>WSA</sub>), vulnerability coefficient (Kv), stability index of water-stable aggregates (Sw), index of crusting (Ic), contents of water-stable macro- (WSA<sub>ma</sub>) and micro-aggregates (WSA<sub>mi</sub>). Ic was correlated with organic matter content in all combinations of treatments. Surprisingly, humus quality did not interact with soil management practices to affect soil structure parameters. Higher sums of base cations, CEC and base saturation (Bs) were linked to higher Sw values, however higher values of hydrolytic acidity (Ha) resulted in lower aggregate stability in CT treatments. Higher content of K<sup>+</sup> was responsible for higher values of MWD<sub>WSA </sub>and MWD in CT. In MT, contents of Ca<sup>2+</sup>, Mg<sup>2+ </sup>and Na<sup>+</sup> were significantly correlated with contents of WSA<sub>mi </sub>and WSA<sub>ma</sub>. Higher contents of Na<sup>+</sup> negatively affected St values and positive correlations were detected between Ca<sup>2+</sup>, Mg<sup>2+ </sup>and Na<sup>+</sup> and Ic in NPK treatments.



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