scholarly journals Effects of Planting Density on Soil Bulk Density, pH and Nutrients of Unthinned Chinese Fir Mature Stands in South Subtropical Region of China

Forests ◽  
2019 ◽  
Vol 10 (4) ◽  
pp. 351
Author(s):  
Aiguo Duan ◽  
Jie Lei ◽  
Xiaoyan Hu ◽  
Jianguo Zhang ◽  
Hailun Du ◽  
...  
Keyword(s):  
Organic Matter ◽  
Bulk Density ◽  
Soil Depth ◽  
Soil Nutrient ◽  
Chinese Fir ◽  
Planting Density ◽  
Total N ◽  
Nutrient Contents ◽  
Exchangeable Ca ◽  
Soil Nutrient Contents

Chinese fir (Cunninghamia lanceolata (Lamb.) Hook) is a fast-growing evergreen conifer with high-quality timber and is an important reforestation and commercial tree species in southern China. Planting density affects the productivity of Chinese fir plantations. To study the effect of five different planting densities and soil depth on soil nutrient contents of a mature C. lanceolata plantation, the soil nutrient contents (soil depths 0–100 cm) of 36-year-old mature Chinese fir plantations under five different planting densities denoted A (1667 trees·ha−1), B (3333 trees·ha−1), C (5000 trees·ha−1), D (6667 trees·ha−1), and E (10,000 trees·ha−1) were measured in Pingxiang county, Guangxi province, China. Samples were collected from the soil surface down to a one meter depth from each of 45 soil profiles, and soil samples were obtained at 10 different soil depths of 0–10, 10–20, 20–30, 30–40, 40–50, 50–60, 60–70, 70–80, 80–90, and 90–100 cm. Twelve soil physical and chemical indicators were analyzed. The results showed that: (1) as planting density increased, the organic matter, organic carbon, total N and P, available N, effective Fe, and bulk density decreased. Soil pH, total K, and effective K increased with increasing planting density. Planting density did not significantly influence the exchangeable Ca and Mg. (2) Soil organic matter; organic carbon; total N and P; effective N, P, and K; exchangeable Ca and Mg; effective Fe content; and bulk density decreased with increasing soil depth. This pattern was particularly evident in the top 30 cm of the soil. (3) Excessively high planting density is not beneficial to the long-term maintenance of soil fertility in Chinese fir plantations, and the planting density of Chinese fir plantations should be maintained below 3333 stems·ha−1 (density A or B) to maintain soil fertility while ensuring high yields.

scholarly journals Short-term effects of thinning on the development and communities of understory vegetation of Chinese fir plantations in Southeastern China

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e8536 ◽  
Author(s):  
Xuelei Xu ◽  
Xinjie Wang ◽  
Yang Hu ◽  
Ping Wang ◽  
Sajjad Saeed ◽  
...  
Keyword(s):  
Environmental Factors ◽  
Community Composition ◽  
Sustainable Management ◽  
Soil Nutrient ◽  
Chinese Fir ◽  
Understory Vegetation ◽  
Southeastern China ◽  
Nutrient Contents ◽  
Thinning Intensity ◽  
Soil Nutrient Contents

Background High-density conditions are global issues that threaten the sustainable management of plantations throughout the world. Monocultures and untimely management practices have identically resulted in the simplex of community structures, decreases in biodiversity, and long-term productivity losses in plantations China. The most popular measure which is commonly used to address these issues is thinning, which potentially results in increases in the development of understory plants in plantations. However, there is limited information currently available regarding the community composition of understory vegetation and the associated environmental factors, which has limited the sustainable management of China’s fir plantation ecosystems. Method In the present study, a thinning experiment was implemented which included a control check (CK: no thinning), as well as low intensity thinning (LIT: 20%), moderate intensity thinning (MIT: 33%), and high intensity thinning (HIT: 50%) in Chinese fir plantations located in the Southeastern China. During the investigation process, the understory vegetation examined three years after thinning measures were completed, in order to analyze the impacts of different thinning intensities on the growth and community composition of the understory plants. At the same time, the associated environmental factors in the fir plantations were also investigated. Results The species richness, total coverage, and biomass of the understory vegetation were observed to be apparently increased with increasing thinning intensity. In addition, it was found that the thinning measures had prominently influenced the soil nutrients. The community compositions of the understory vegetation were significantly different among the four thinning intensity levels, especially between the CK and the HIT. Furthermore, the development of the understory vegetation was found to be significantly correlated with the soil nutrient contents, and the community compositions of the understory vegetation were prominently driven by the tree densities, slope positions, and soil nutrient contents.

scholarly journals Conversion of Secondary Forests into Chestnut Forests Affects Soil Nutrients in Anji County, China

2019 ◽  
Vol 11 (8) ◽  
pp. 2373 ◽  
Author(s):  
Shiyong Sun ◽  
Zebo Li ◽  
Rongjia Wang ◽  
Jianfeng Zhang ◽  
Chunxia Pan ◽  
...  
Keyword(s):  
Soil Nutrients ◽  
Water Conservation ◽  
Secondary Forest ◽  
Soil Depth ◽  
Soil Nutrient ◽  
Vegetation Coverage ◽  
Secondary Forests ◽  
Nutrient Contents ◽  
Particle Form ◽  
Soil Nutrient Contents

The maintenance of drinking water safety is a major environmental issue. It is necessary to strengthen environmental protection in water source areas and establish good vegetation coverage. This study examined the effects of secondary forests transformation on chestnut forests on soil nutrient changes in the Fuji Reservoir, Anji County, Zhejiang province, China. Plots were set up in a chestnut plantation and a nearby secondary forest to measure the nutrient contents of soil samples that were collected from different soil depths. Differences of soil nutrient content from the two stands were significant at 0–20 cm soil depth. There were no significant differences in the contents of total phosphorus and total potassium between the two forests; however, the available phosphorus content in chestnut stands was 2.73 mg/kg higher than in secondary forests. Overall, the soil nutrient contents under chestnut stands were lower than those under secondary forests. Some of the soil surface is exposed due to the low diversity of the chestnut forest. The soil nutrients in the chestnut forest are usually carried and transferred in soil particle form and they become dissolved in the runoff during rainfall and lost, which explains the lower soil nutrient contents in the chestnut forest than the secondary forest. Therefore, for economic forests, such as chestnut forests, measures should be taken to protect understory vegetation and enhance soil and water conservation capacity, which is conducive to retaining soil nutrients.

Predicting soil nutrient contents using Landsat OLI satellite images in rain-fed agricultural lands, northwest of Iran

2021 ◽  
Vol 193 (9) ◽  
Author(s):  
Naser Miran ◽  
Mir Hassan Rasouli Sadaghiani ◽  
Vali Feiziasl ◽  
Ebrahim Sepehr ◽  
Mehdi Rahmati ◽  
...  
Keyword(s):  
Satellite Images ◽  
Soil Nutrient ◽  
Agricultural Lands ◽  
Nutrient Contents ◽  
Northwest Of Iran ◽  
Soil Nutrient Contents

The Application of GIS Techniques in Soil Testing and Fertilizer Recommendations: Part II the Distribution of Soil Nutrients in Hainan, China

2012 ◽  
Vol 610-613 ◽  
pp. 3697-3701
Author(s):  
Zhi Yuan Wei ◽  
Deng Feng Wang ◽  
Zhi Ping Qi
Keyword(s):  
Spatial Analysis ◽  
Soil Nutrients ◽  
Arable Land ◽  
Soil Nutrient ◽  
Hainan Island ◽  
Nutrient Elements ◽  
Available N ◽  
Nutrient Contents ◽  
Fertilizer Recommendations ◽  
Soil Nutrient Contents

The research on the distribution of soil nutrient contents in arable land regionally is the basis for the proper fertilization. The study, taking Hainan Island as the study area, analyzes the distribution and variation of soil nutrient contents in arable land spatially and temporally by applying GIS spatial analysis. As the study shows, from the 1980s to the year of 2005, the TN, TP, TK, and Available N contents in soil of arable land have declined to certain degree, while Available P and Available K kept increasing. Generally, the soil nutrients have declined in quality during last two decades but remain in a mediate level. Spatial analysis can reflect the distribution characteristics of the regional soil nutrient elements in an objective manner.

The chemical and physical stability soil organic carbon in the top 1 m of the soil profile under different land uses in the UK

2020 ◽  
Author(s):  
Dedy Antony ◽  
Jo Clark ◽  
Chris Collins ◽  
Tom Sizmur
Keyword(s):  
Land Use ◽  
Organic Matter ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Soil Profile ◽  
Soil Depth ◽  
Physical Stability ◽  
Silty Clay ◽  
Land Uses ◽  
Total N

<p>Soils are the largest terrestrial pool of organic carbon and it is now known that as much as 50% of soil organic carbon (SOC) can be stored below 30 cm. Therefore, knowledge of the mechanisms by which soil organic carbon is stabilised at depth and how land use affects this is important.</p><p>This study aimed to characterise topsoil and subsoil SOC and other soil properties under different land uses to determine the SOC stabilisation mechanisms and the degree to which SOC is vulnerable to decomposition. Samples were collected under three different land uses: arable, grassland and deciduous woodland on a silty-clay loam soil and analysed for TOC, pH, C/N ratio and texture down the first one metre of the soil profile. Soil organic matter (SOM) physical fractionation and the extent of fresh mineral surfaces were also analysed to elucidate SOM stabilisation processes.</p><p>Results showed that soil texture was similar among land uses and tended to become more fine down the soil profile, but pH did not significantly change with soil depth. Total C, total N and C/N ratio decreased down the soil profile and were affected by land use in the order woodland > grassland > arable. SOM fractionation revealed that the free particulate organic matter (fPOM) fraction was significantly greater in both the topsoil and subsoil under woodland than under grassland or arable. The mineral associated OC (MinOC) fraction was proportionally greater in the subsoil compared to topsoil under all land uses: arable > grassland > woodland. Clay, Fe and Mn availability play a significant role (R<sup>2</sup>=0.87) in organic carbon storage in the top 1 m of the soil profile.</p><p>It is evidently clear from the findings that land use change has a significant effect on the dynamics of the SOC pool at depth, related to litter inputs to the system.</p>

Effect of density of Tephrosia candida stands on soil characteristics

2016 ◽  
Author(s):  
Zhiyang Lie ◽  
Zhuomin Wang ◽  
Li Xue
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Ph Value ◽  
Soil Nutrient ◽  
Stand Density ◽  
Nutrient Content ◽  
Total N ◽  
One Year ◽  
Tephrosia Candida ◽  
Total P

With one-year-old Tephrosia candida trees as experimental material, influence of stand density on soil nutrient content and enzyme activity was studied. The results showed that density had little influenced on pH value in 2, 4 and 8 trees m2 stands. The contents of soil organic matter, effective nitrogen and effective phosphorus significantly increased in 2 trees m2 stands. The contents of soil organic matter and effective nitrogen significantly increased, whereas total N, total P, total K, effective N, effective P and effective K significantly decreased in 4 trees/m2 stand. Soil organic matter and nutrients except for total P significantly decreased in 8 trees m2 stand. Among the three density stands, the activities of urease, catalase and phosphatase were the lowest in 8 trees m2 stand.

scholarly journals Integrated Nutrient Management of an Acid Paddy Soil in Karang Tanjung Village, Padang Ratu, Central Lampung

2017 ◽  
Vol 22 (2) ◽  
pp. 97-106
Author(s):  
Antonius Kasno ◽  
Irawan Irawan ◽  
Husnain Husnain ◽  
Sri Rochayati
Keyword(s):  
Organic Matter ◽  
Nutrient Management ◽  
Soil Nutrient ◽  
Nutrient Status ◽  
Inorganic Fertilizer ◽  
Soil Nutrient Status ◽  
Inorganic Fertilizers ◽  
Total N ◽  
Organic C ◽  
Set Up

Balanced fertilization is the key factor to improve the efficiency and effectiveness of fertilization.The dosage of inorganic fertilizers applied can be determined based on the nutrient status of P, K and rice productivity. The research aims to improve balance fertilization that combines inorganic fertilizers, which is set up based on soil nutrient status, and organic fertilizers. The research was conducted in Karang Tanjung Village, Padang Ratu District, Central Lampung, in the dry season of 2009 until 2012. An experimental plot of one hectare was set up in the farmer’s paddy fields. Generally, the plot for every treatment was owned by two or more farmers. The treatments consisted of the dose of fertilizer applications for lowland rice, namely (1) dose of fertilizers based on farmer practice, (2) dose of fertilizers proposed by Petrokimia, (3) 75% of fertilizer dose that was set up based on soil analysis plus straw compost, and (4) 75% of inorganic fertilizer combined with manure and biofertilizer. At the fourth growing season, each plot was applied with 100% inorganic fertilizer (NPK fertilizer). The results showed that the limiting factor of the soil used in the current study is the content of organic-C, N, K, and CEC. The compost of rice straw used as organic matter in the current study contains higher organic-C and total-N in comparison to manure. Organic matter application in the form of straw compost or manure can reduce 25% of NPK application, while the production of rice remains high. Fertilization on paddy soils based on soil nutrient status can improve fertilization efficiency. Rice production in the treatment of 100% NPK is similar to that in the fertilization treatments based on farmer practice and Petrokima rate. Keywords: Nutrient management, acid soil, fertilization efficiency

scholarly journals Structural changes and degradation of Red Latosols under different management systems for 20 years

2014 ◽  
Vol 38 (4) ◽  
pp. 1293-1303 ◽  
Author(s):  
João Tavares Filho ◽  
Thadeu Rodrigues de Melo ◽  
Wesley Machado ◽  
Bruno Vieira Maciel
Keyword(s):  
Organic Matter ◽  
Bulk Density ◽  
Crop Rotation ◽  
Structural Changes ◽  
Soil Depth ◽  
Conventional Tillage ◽  
No Tillage ◽  
Reference Area ◽  
Perennial Crop ◽  
Structural Units

Soils are the foundation of terrestrial ecosystems and their role in food production is fundamental, although physical degradation has been observed in recent years, caused by different cultural practices that modify structures and consequently the functioning of soils. The objective of this study was to evaluate possible structural changes and degradation in an Oxisol under different managements for 20 years: no-tillage cultivation with and without crop rotation, perennial crop and conventional tillage, plus a forested area (reference). Initially, the crop profile was described and subsequently, 10 samples per management system and forest soil were collected to quantify soil organic matter, flocculation degree, bulk density, and macroporosity. The results indicated structural changes down to a soil depth of 50 cm, with predominance of structural units ∆μ (intermediate compaction level) under perennial crop and no-tillage crop rotation, and of structural units ∆ (compacted) under conventional tillage and no-tillage. The soil was increasingly degraded in the increasing order: forest => no-tillage crop rotation => perennial crop => no-tillage without crop rotation => conventional tillage. In all managements, the values of organic matter and macroporosity were always below and bulk density always above those of the reference area (forest) and, under no-tillage crop rotation and perennial crop, the flocculation degree was proportionally equal to that of the reference area.

scholarly journals Decomposition characteristics of long-established Salix psammophila sand barriers in an arid area, Northwestern China

BioResources ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. 5947-5963
Author(s):  
Ruidong Wang ◽  
Xia Yang ◽  
Yong Gao ◽  
Xiaohong Dang ◽  
Yumei Liang ◽  
...  
Keyword(s):  
Nutrient Release ◽  
Soil Nutrient ◽  
Decomposition Process ◽  
Northwestern China ◽  
Barrier Material ◽  
Nutrient Contents ◽  
Arid Northwestern China ◽  
Decomposition Time ◽  
Soil Nutrient Contents

Salix psammophila has been extensively used as a sand barrier material for various desertification control applications. Elucidating the long-term decomposition characteristics and nutrient cycling process of this sand barrier in desert environments is of great importance. In this study, which was conducted for 1 to 9 years, changes in the mass loss percentage and the residual percentage in the decomposition process were explored of S. psammophila sand barriers in arid Northwestern China. In addition, the S. psammophila analysis nutrient elements release rule and its influence on soil properties were evaluated. The results showed that the decomposition process of S. psammophila sand barriers exhibited a “slow-fast” trend. After decomposition time for 9 years, mass decreased remarkably, and the residual percentage was 33.6%. Further, the nutrient release characteristics differed. C, P, and K were in the release state, whereas N was in the enrichment state. The decomposition percentage of the sand barriers was significantly correlated with N, P, K, C/N, C/P, and N/P (p < 0.05). The soil nutrient contents of C, P, and K contents increased 3.43, 2.23, and 2.08 g/kg compared to the initial values, respectively. The soil nutrient contents of N contents decreased 0.19 g/kg.

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