scholarly journals Using Different Regression Tree Algorithms to Predict Soil Organic Matter with Digital Color Parameters in Soil Profile Wall

2021 ◽  
Vol 7 (2) ◽  
pp. 326-336
Author(s):  
Gafur GÖZÜKARA ◽  
Yasin ALTAY
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Soil Profile ◽  
Regression Tree ◽  
Color Parameters ◽  
Tree Algorithms

scholarly journals The Use of Radiocarbon to Measure the Effects of Earthworms On Soil Development

Radiocarbon ◽  
1980 ◽  
Vol 22 (3) ◽  
pp. 892-896 ◽  
Author(s):  
J D Stout ◽  
K M Goh
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Soil Profile ◽  
Mineral Soil ◽  
Soil Development ◽  
Plant Debris ◽  
Grassland Soils ◽  
Fresh Plant

Δ14C and δ13C values for organic matter in forest and grassland soils, in the presence or absence of earthworms, indicate that it should be possible to quantify the effects of earthworms on soil organic matter by this means. Without earthworms, both in forest and grassland soils, plant debris tends to accumulate on the surface of the mineral soil and little organic matter is incorporated into or is translocated down the soil profile. Where earthworms are present, there is much more marked incorporation of fresh plant debris in the mineral soil. This is shown especially by the pulse of ‘bomb’ carbon and also by the δ13C values.

Traffic and tillage effects on wheat production on the Loess Plateau of China: 1. Crop yield and SOM

Soil Research ◽  
2008 ◽  
Vol 46 (8) ◽  
pp. 645 ◽  
Author(s):  
Hao Chen ◽  
Yuhua Bai ◽  
Qingjie Wang ◽  
Fu Chen ◽  
Hongwen Li ◽  
...  
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Field Experiment ◽  
Loess Plateau ◽  
Crop Yield ◽  
Soil Profile ◽  
Conventional Tillage ◽  
Zero Tillage ◽  
The Loess Plateau ◽  
Controlled Traffic

Challenges for dryland farming on the Loess Plateau of China are continuous nutrient loss, low soil organic matter and crop yield, and soil degradation. Controlled traffic, combined with zero or minimum tillage and residue cover, has been proposed to improve soil structure and crop yield. From 1998 to 2006, we conducted a field experiment comparing soil organic matter and wheat productivity between controlled traffic and conventional tillage farming systems. The field experiment was conducted using 2 controlled traffic treatments (zero tillage with residue cover and no compaction, shallow tillage with residue cover and no compaction) and a conventional tillage treatment. Results showed that controlled traffic treatments significantly increased soil organic matter and microbial biomass in the 0–0.30 m soil profile. Controlled traffic with zero tillage significantly increased total N in the 0–0.05 m soil profile. The mean yield over 8 years of controlled traffic treatments was >10% greater than that of conventional tillage. Controlled traffic farming appears to be a solution to the cropping problems faced on the Loess Plateau of China.

Soil abiotic factors associated with Meloidogyne spp. and Pratylenchus spp. populations in sugarcane

Nematology ◽  
2020 ◽  
pp. 1-13
Author(s):  
Marissônia de A. Noronha ◽  
Marcelo F. Fernandes ◽  
Maria de Fatima S. Muniz ◽  
Elvira Maria R. Pedrosa ◽  
Mayara C. Assunção ◽  
...  
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Root Zone ◽  
Abiotic Factors ◽  
Regression Tree ◽  
Parasitic Nematodes ◽  
Population Densities ◽  
Multivariate Regression Tree ◽  
Soil Variables ◽  
Meloidogyne Spp

Summary Meloidogyne spp. and Pratylenchus spp. are the most damaging plant-parasitic nematodes to sugarcane and the knowledge of soil characteristics that influence the occurrence of these pathogens can be useful in their management. With the objective to investigate the relationships between soil variables and populations of Meloidogyne spp. and Pratylenchus spp. in sugarcane fields, root-zone soil and root samples were collected from 20 farms located in 16 municipalities in Alagoas state, Brazil. The multivariate regression tree technique was used to model the population density’s response variables for Meloidogyne spp. and Pratylenchus spp. in the root-zone soil and the roots according to sugarcane cultivars, soil organic matter, and soil chemical and physical variables. The results showed the existence of associations between soil factors, sugarcane cultivars and populations of nematodes. Root samples from soils with K > 37.79 mmolc dm−3, Al < 5.93 mmolc dm−3 and sugarcane ‘RB92579’, ‘SP753046’, ‘SP813250’ and ‘SP921631’ showed the lowest Pratylenchus spp. population densities. However, the lowest densities in the root-zone were found in soils with sum of bases > 1.91 mmolc dm−3, Ca:Mg ratio < 1:2 and soil organic matter < 10.7 g dm−3. The lowest population densities of Meloidogyne spp. in roots were associated with sugarcane ‘RB92579’, ‘RB93509’, ‘RB98710’, ‘SP791011’ and ‘SP921631’ and soil aggregate mean diam. > 0.48 mm, while root-zone densities were minimum in soils with P > 28.59 mg dm−3. This information should support further studies to investigate the effect of each variable on populations of Pratylenchus and Meloidogyne.

Demonstration of spatial heterogeneity in the organic matter of de-ashed humin samples by solid-state 13C CPMAS NMR

1992 ◽  
Vol 72 (1) ◽  
pp. 13-19 ◽  
Author(s):  
C. M. Preston ◽  
R. H. Newman
Keyword(s):  
Organic Matter ◽  
Solid State ◽  
Soil Organic Matter ◽  
Forest Soil ◽  
Soil Profile ◽  
Spin Diffusion ◽  
Nmr Relaxation ◽  
13C Cpmas Nmr ◽  
Novel Approach ◽  
Methylene Groups

A variant of solid-state 13C CPMAS NMR demonstrated the presence of carbon in spatially distinct domains within three de-ashed samples of humin from a forest soil profile under Douglas-fir near Victoria, British Columbia. Differences in 1H T1 values indicated incomplete spin diffusion in the solid state and separation of organic matter in domains with dimensions of tens of nanometres or more. These relaxation differences were used to separate subspectra of carbons associated with the slower- and faster-relaxing protons. The former were dominated by methylene chains, while the latter contained more aromatic and O-alkyl carbon. Most of the organic matter appears to remain associated with iron even after extensive de-ashing with HCl/HF, but the aromatic and carbohydrate structures appear to be more closely associated with iron than methylene groups in long chains. This NMR technique offers a novel approach to probing the structure of insoluble soil organic matter. Key words: Humin, CPMAS NMR, relaxation, iron, forest soil, Brunisol

Soil organic matter and aggregates affected by wildfire in a Pinus halepensis forest in a Mediterranean environment

2002 ◽  
Vol 11 (2) ◽  
pp. 107 ◽  
Author(s):  
J. Mataix-Solera ◽  
I. Gómez ◽  
J. Navarro-Pedreño ◽  
C. Guerrero ◽  
R. Moral
Keyword(s):  
Electron Microscopy ◽  
Organic Matter ◽  
Soil Organic Matter ◽  
Forest Fire ◽  
Soil Profile ◽  
Soil Structure ◽  
Organic Matter Content ◽  
Matter Content ◽  
Crown Fire ◽  
Surface Fire

Three Mediterranean soils located in the north of the Province of Alicante (Spain) were studied for a year after a forest fire. The percentage of water-stable aggregates (between 0.2 and 4 mm) and organic matter content were measured. Microaggregates (< 0.2 mm) were observed using electron microscopy. The results showed the importance of type of forest fire on soil organic matter and aggregates. Soil structure was more affected by surface fire (which affects mainly brushwood and soil surface) than crown fire (which burns the tops of trees and some brushwood). Accumulation of organic matter from burnt trees and brushwood in areas affected by crown fire and alterations in organic matter content through the soil profile were observed. Surface forest fire affected soil structure more negatively than crown fire as observed using electron microscopy. Soils affected by surface fire may be more easily eroded and recovery of vegetation may be delayed because of effects on soil structure. Organic matter content through the soil profile comparing burnt and adjacent unburnt soil could be used to determine the type of fire.

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