Dynamics of physical and chemical properties of soil after agricultural abandonment in a karst region in Southwest China

Author(s):  
Ke Wang ◽  
Zhigang Wang ◽  
Jiale Wang ◽  
Jianming Li ◽  
Bei Sun ◽  
...  

<p>Rocky desertification induced by severe deforestation has caused the water loss and soil erosion in karst regions in southeast China, limiting local social and economic developments. To prevent further rocky desertification, the farmland which had obtained by deforestation were abandoned for recovery. As soil quality improved by agriculture abandonment should be examined, it is necessary to investigate the dynamics of physical and chemical properties of soil in different ages after abandonment. In this study, 38 investigation sites were selected for soil sampling on the slopes in Longtan trough valley in Youyang County, Chongqing Municipality, China. The dominant plant species of the investigation sites were also noted during soil sampling. The sites were divided into seven age classes according to their abandonment time. Dynamics of water content, bulk density, pH, and concentration of available potassium, available phosphorus, available nitrogen, total nitrogen and organic matters were examined. It suggests that soil quality might be deteriorated right after abandonment and then improved from around 20 years after abandonment. Deterioration of soil quality may be induced by lack of plant coverage and exposure of rock outcrops which may accelerate water loss and swelling and shrinkage cycles of soil. After the formation of plant communities and litter layer above the ground, soil quality was then apparently improved. These findings can provide a potential guideline for recovery management in karst regions in southwest of China.</p>

2011 ◽  
Vol 3 (5) ◽  
pp. 37-42
Author(s):  
Renata Mikalauskienė ◽  
Donatas Butkus ◽  
Ingrida Pliopaitė Bataitienė

The present article describes changes in specific activities and fluctuations in the ratio of natural 40K and artificial 137Cs radionuclides in soil samples taken from different places of Lithuanian territory. The samples of soil have been selected from the districts polluted after the accident in Chernobyl nuclear plant performing nuclear testing operations. The study has established the main physical and chemical properties of soil samples and their impact on the concentration of 40K activities. 137Cs/40K specific activities in soil have been observed under the dry weight of the sample that varied from 0.0034 to 0.0240. The results of the study could be used for establishing and estimating 137Csand 40K transfer in the system “soil-plant”. Santrauka Straipsnyje nagrinėjama gamtinės (40K) ir dirbtinės (137Cs) kilmės radionuklidų savitųjų aktyvumų ir jų santykio kaita skirtinguose Lietuvos teritorijos dirvožemiuose. Dirvožemio mėginiai parinkti iš vietovių, kurios buvo labiau užterštos po Černobylio atominės elektrinės avarijos ir buvusių branduolinių bandymų. Tyrimo metu nustatytos pagrindinės fizinės cheminės dirvožemio savybės ir jų poveikis 40K aktyvumų koncentracijai. 137Csir 40K savitieji aktyvumai dirvožemyje tirti esant sausam mėginio svoriui. 137Cs savitieji aktyvumai sausame dirvožemyje svyravo nuo 1,1±1,0 iki 14,3±0,9 Bq/kg, o 40K savitieji aktyvumai – nuo 326±29 iki 740±15 Bq/kg. 137Csir 40K savitųjų aktyvumų santykis skirtingų vietovių dirvožemiuose kito nuo 0,0034 iki 0,0240 Bq/kg. Tyrimo rezultatai gali būti panaudoti, nustatant ir įvertinant 137Csir 40K pernašą sistemoje dirvožemis–augalai.


2012 ◽  
Vol 36 (4) ◽  
pp. 1299-1310 ◽  
Author(s):  
Carolina Tirloni ◽  
Antonio Carlos Tadeu Vitorino ◽  
Anderson Cristian Bergamin ◽  
Luiz Carlos Ferreira de Souza

Crop-livestock integration represents an interesting alternative of soil management, especially in regions where the maintenance of cover crops in no-tillage systems is difficult. The objective of this study was to evaluate soil physical and chemical properties, based on the hypothesis that a well-managed crop-livestock integration system improves the soil quality and stabilizes the system. The experiment was set up in a completely randomized design, with five replications. The treatments were arranged in a 6 x 4 factorial design, to assess five crop rotation systems in crop-livestock integration, and native forest as reference of soil undisturbed by agriculture, in four layers (0.0-0.05; 0.05-0.10; 0.10-0.15 and 0.15-0.20 m). The crop rotation systems in crop-livestock integration promoted changes in soil physical and chemical properties and the effects of the different systems were mainly detected in the surface layer. The crops in integrated crop-livestock systems allowed the maintenance of soil carbon at levels equal to those of the native forest, proving the efficiency of these systems in terms of soil conservation. The systems influenced the environmental stability positively; the soil quality indicator mineral-associated organic matter was best related to aggregate stability.


2019 ◽  
Vol 11 (12) ◽  
pp. 3369 ◽  
Author(s):  
Shuyue Feng ◽  
Hui Wen ◽  
Shimin Ni ◽  
Junguang Wang ◽  
Chongfa Cai

In the subtropical hilly areas of China, a collapsing gully, a particular type of permanent gully, poses a great threat to the productivity and sustainability of the local ecological and agricultural systems. However, few studies have been performed regarding the effects of collapsing gully erosion on soil degradation. The aim of this study was to evaluate the effects of collapsing gully erosion on soil-quality-related physical and chemical properties. The collapsing gullies that were severely affected by erosion processes were considered at three stages (initial, active and stable stages) and corresponding soil samples were collected to analyze the spatial variation of the soil physical and chemical quality at each stage. The changes in the properties were assumed to be considerable in the regions affected by the erosion process compared with those unaffected by this process. Soil physical properties were more susceptible than soil nutrients to collapsing gully erosion in different spatial locations. The soil quality index (SQI) system consists of total nitrogen (TN), total phosphorus (TP), pH, capillary porosity (CP), sand content (SA), soil cohesion (SC) and root density (RD). Collapsing gully erosion was found to affect the soil physical and chemical properties by progressively reducing the SQI. The mean SQI value was the lowest in the active stage of the collapsing gully, with a higher soil degradation. For the different spatial positions in the collapsing gullies, the scour channel showed the lowest SQI value. The limiting indicators varied in the different stages or spatial sites in the collapsing gullies.


Sign in / Sign up

Export Citation Format

Share Document