Agricultural practices for crop residue transformation into soil organic matter in cold humid temperate agroecosystems.

2018 ◽  
Vol 13 (060) ◽  
Author(s):  
Tian Tian
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Crop Residue ◽  
Agricultural Practices

scholarly journals Glomalin – an interesting protein part of the soil organic matter

2020 ◽  
Vol 15 (No. 2) ◽  
pp. 67-74 ◽  
Author(s):  
Vítězslav Vlček ◽  
Miroslav Pohanka
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Arbuscular Mycorrhiza ◽  
Mycorrhizal Fungi ◽  
Biological Diversity ◽  
Agricultural Practices ◽  
Arbuscular Mycorrhizal ◽  
Fulvic Acids ◽  
Soil Parameters ◽  
Citrate Buffer

The negative effects of the current agricultural practices include erosion, acidification, loss of soil organic matter (dehumification), loss of soil structure, soil contamination by risky elements, reduction of biological diversity and land use for non-agricultural purposes. All these effects are a huge risk to the further development of soil quality from an agronomic point of view and its resilience to projected climate change. Organic matter has a crucial role in it. Relatively significant correlations with the quality or the health of soil parameters and the soil organic matter or some fraction of the soil organic matter have been found. In particular, Ctot, Cox, humic and fulvic acids, the C/N ratio, and glomalin. Our work was focused on glomalin, a glycoprotein produced by the hyphae and spores of arbuscular mycorrhizal fungi (AMF), which we classify as Glomeromycota. Arbuscular mycorrhiza, and its molecular pathways, is not a well understood phenomenon. It appears that many proteins are involved in the arbuscular mycorrhiza from which glomalin is probably one of the most significant. This protein is also responsible for the unique chemical and physical properties of soils and has an ecological and economical relevance in this sense and it is a real product of the mycorrhiza. Glomalin is very resistant to destruction (recalcitrant) and difficult to dissolve in water. Its extraction requires specific conditions: high temperature (121°C) and a citrate buffer with a neutral or alkaline pH. Due to these properties, glomalin (or its fractions) are very stable compounds that protect the soil aggregate surface. In this review, the actual literature has been researched and the importance of glomalin is discussed.  

Effect of Organic Amendments on the Evolution of Soil Organic Matter in Soils Stressed by Intensive Agricultural Practices

2013 ◽  
Vol 17 (24) ◽  
pp. 2998-3005 ◽  
Author(s):  
Riccardo Scotti ◽  
Pellegrino Conte ◽  
Anne Berns ◽  
Giuseppe Alonzo ◽  
Maria Rao
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Organic Amendments ◽  
Agricultural Practices

Integrating principles of nitrogen dynamics in a method to estimate leachable nitrogen under agricultural systems

2006 ◽  
Vol 53 (2) ◽  
pp. 289-301 ◽  
Author(s):  
M. Burkart ◽  
D. James ◽  
M. Liebman ◽  
E. van Ouwerkerk
Keyword(s):  
Organic Matter ◽  
Surface Water ◽  
Soil Organic Matter ◽  
Nitrogen Mineralization ◽  
Crop Residue ◽  
Nitrogen Flow ◽  
Soil N ◽  
Agricultural Systems ◽  
Nitrate N ◽  
Agricultural Regions

Surplus nitrogen (N) in ground and surface water is of concern in intensive agricultural regions. Surplus N leaches during lengthy periods where annual crop systems are used in temperate regions. This paper presents a model to estimate the surplus N available for leaching to ground water beneath agricultural systems and applies the model to watersheds in an intensive maize and soybean production system. The model utilizes commonly available georeferenced data on soils, crops, and livestock, making it applicable to watersheds in many regions. The model links stocks of N in soil, crops, livestock, fertilizer and the atmosphere. Nitrogen flow centers on exchange between the soil N stocks. Nitrogen mineralization rates are defined for three soil organic matter pools, crop residue, and manure based on carbon:N ratios. Nitrogen exports from the system are harvested crops, livestock and losses to the atmosphere. Application of the model in 26 Iowa watersheds finds surpluses of 18 to 43 kg-N/ha. Surpluses exceeded measured annual nitrate-N loads in regional streams by amounts equivalent to denitrification rates in groundwater. Deficits in soil N were sufficiently small to suggest that the system is in equilibrium with soils of the region.

Susceptibility of Groundwater to Pesticide and Nitrate Contamination in Predisposed Areas of Southwestern Ontario

1995 ◽  
Vol 30 (3) ◽  
pp. 443-468 ◽  
Author(s):  
Wray Lampman
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Crop Rotation ◽  
Agricultural Land ◽  
Monitoring Program ◽  
Agricultural Practices ◽  
Crop Rotations ◽  
Pesticide Contamination ◽  
The Impact

Abstract Agricultural practices today employ a vast array of chemicals in large volumes in order to improve both the quantity and quality of our agricultural products. While it has long been recognized that runoff from agricultural land has the potential to degrade surface water quality, only recently has attention been focused on the effect of agricultural usage on groundwater. In order to study the effects of pesticides and nitrate usage on the quality of groundwater, in 1985 the Ontario Ministry of Environment and Energy began operating a groundwater monitoring program in southwestern Ontario. Data generated from this program, which utilized sample data collected from both wells and piezometers, indicate that in areas of heavy pesticide and nitrate usage, shallow groundwater is continuously testing positive for nitrate and a variety of pesticides. Factors which influence the number of positive incidents for pesticides are directly related to the persistence of the chemical, its method of application, and the amounts utilized. Soil types and depth to groundwater, although influencing the time of detection, do not govern the number of detection events. Changes in agricultural practices are also monitored to see if pesticide reduction, a variation in the method of application, crop rotations and an increase in soil organic matter could influence the levels of pesticide It was found that when chemicals of a low persistence were applied post emergent at the minimum recommended rate, pesticides were not detected in the groundwater. Crop rotations were also effective in reducing the level of pesticides in groundwater. Tillage practices and increases in soil organic matter were also effective in reducing pesticide contamination. It was found that when chemicals of a low persistence were applied post emergent at the minimum recommended rate, pesticides were not detected in the groundwater. Crop rotation and reduction in nitrate loadings were found to be the only effective methods to reduce nitrate loading to groundwater. It was also found that elevated levels of potassium and/or nitrate in groundwater serve as a reliable indicator of the groundwater susceptibility to pesticide contamination. Remedial action to alleviate the impact of pesticides and nitrates in groundwater must focus on the chemical usage patterns employed on the farm site and an overall reduction of the quantities of pesticides and nitrates utilized. These patterns must incorporate a well-designed program of crop rotation with the proper utilization of these chemicals on site.

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