scholarly journals Response of Gross Mineralization and Nitrification Rates to Banana Cultivation Sites Converted from Natural Forest in Subtropical China

Land ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 376
Author(s):  
Xinghua Qin ◽  
Cheng Yang ◽  
Lin Yang ◽  
Erdeng Ma ◽  
Lei Meng ◽  
...  

Evaluations of gross mineralization (MNorg) and nitrification (ONH4) can be used to evaluate the supply capacity of inorganic N, which is crucial in determining appropriate N fertilizer application. However, the relevant research for banana plantations to date is limited. In this study, natural forest and banana plantations with different cultivation ages (3, 7, 10, and 22 y) were chosen in a subtropical region, and the 15N dilution technique was used to determine the gross MNorg and ONH4 rates. The objective was to evaluate the effect of the conversion of natural forests to banana plantations on inorganic N supply capacity (MNorg + ONH4) and other relevant factors. Compared to other natural forests in tropical and subtropical regions reported on by previous studies, the natural forest in this study was characterized by a relatively low MNorg rate and a high ONH4 rate in the soil, resulting in the presence of inorganic N dominated by nitrate. Compared to the natural forest, 3 y banana cultivation increased the MNorg and ONH4 rates and inorganic N availability in the soil, but these rates were significantly reduced with prolonged banana cultivation. Furthermore, the mean residence times of ammonium and nitrate were shorter in the 3 y than in the 7, 10, and 22 y banana plantations, indicating a reduced turnover of ammonium and nitrate in soil subjected to long-term banana cultivation. In addition, the conversion of natural forest to banana plantation reduced the soil organic carbon (SOC), total N and calcium concentrations, as well as water holding capacity (WHC), cation exchangeable capacity (CEC), and pH, more obviously in soils subjected to long-term banana cultivation. The MNorg and ONH4 rates were significantly and positively related to the SOC and TN concentrations, as well as the WHC and CEC, suggesting that the decline in soil quality after long-term banana cultivation could significantly inhibit MNorg and ONH4 rates, thus reducing inorganic N supply and turnover. Increasing the amount of soil organic matter may be an effective measure for stimulating N cycling for long-term banana cultivation.

Forests ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 1282
Author(s):  
Zhijie Shan ◽  
Zhe Yin ◽  
Hui Yang ◽  
Changqing Zuo ◽  
Tongbin Zhu

Determination of rates of mineralization of organic nitrogen (N) into ammonium-N (NH4+-N) and nitrification of NH4+-N into nitrate-N (NO3−-N) could be used to evaluate inorganic N supply capacity, which, in turn, could guide N fertilizer application practices in crop cultivation systems. However, little information is available on the change of mineralization and nitrification in soils under fruit cultivation systems converted from forestlands in karst regions. In a 15N-tracing study, inorganic N supply capacity in forest soils and three typical fruit crop soils under long-term cultivation was investigated, in addition to factors influencing the supply, in calcareous soils in the karst regions in southwestern China. Long-term fruit crop cultivation decreased soil organic carbon (SOC), total N, and calcium concentrations, cation exchange capacity (CEC), water holding capacity (WHC), pH, and sand content, significantly, but increased clay content. Compared to that of forests, long-term fruit crop cultivation significantly decreased mineralization and nitrification rates to 0.61–1.34 mg N kg−1 d−1 and 1.95–5.07 mg N kg−1 d−1, respectively, from 2.85–6.49 mg N kg−1 d−1 and 8.17–15.5 mg N kg−1 d−1, respectively, but greatly increased the mean residence times of NH4+-N and NO3−-N. The results indicate that long-term fruit crop cultivation could decrease soil inorganic N supply capacity and turnover in karst regions. Both mineralization and nitrification rates were significantly and positively correlated with SOC and total N concentrations, CEC, and WHC, but negatively correlated with clay content, suggesting that decreased soil organic matter and increased clay content were responsible for the decline in mineralization and nitrification rates in soils under long-term cultivation of fruit crops. The results of the present study highlight the importance of rational organic fertilizer application in accelerating soil inorganic N supply and turnover under long-term cultivation of fruit crops in karst regions.


Geoderma ◽  
2021 ◽  
Vol 381 ◽  
pp. 114754 ◽  
Author(s):  
Farzaneh Garousi ◽  
Zhijie Shan ◽  
Kang Ni ◽  
Hui Yang ◽  
Jun Shan ◽  
...  

2004 ◽  
Vol 34 (2) ◽  
pp. 303-309 ◽  
Author(s):  
Timo Kuuluvainen ◽  
Raija Laiho

Forest floor microhabitat diversity was studied in old Pinus sylvestris L. dominated forest sites in two regions within the middle boreal vegetation zone in Fennoscandia: in 50 managed forest sites in the Häme region in southwestern Finland and in 45 natural or old selectively logged forest sites in the Kuhmo–Viena region in northeastern Finland and northwestern Russia. The forests in the Häme region are characterized by a long history of forest utilization, while the forests in the Kuhmo–Viena region can be regarded as natural or near natural. The managed forest sites in Häme had significantly lower forest floor microhabitat diversity compared with natural and near-natural forests. Microhabitats that were significantly more scarce in managed versus natural and near-natural forest sites included humps, depressions, decayed wood, and vicinity of decayed wood. On the other hand, even ground was significantly more abundant in managed forest compared with natural and near-natural forest. Microhabitat availability was also reflected in the occurrence of tree saplings growing in different microhabitats. The results suggest that long-term forest utilization has decreased forest floor microhabitat diversity. This has occurred because of a decreased amount of fallen deadwood and, possibly, lack of soil disturbances because of fewer uprootings caused by falling trees.


2011 ◽  
Vol 20 (7) ◽  
pp. 856 ◽  
Author(s):  
A. Couto-Vázquez ◽  
S. García-Marco ◽  
S. J. González-Prieto

The effects of fire and firefighting chemicals on soil properties and the soil–plant system were evaluated 5 years after treatment application. Unburnt soils were compared with burnt soils treated with water alone (BS) or with foaming agent (BS+Fo), Firesorb polymer (BS+Fi), or ammonium polyphosphate (BS+Ap). Soils (0–2 cm depth) and foliar material (Ulex micranthus, Pterospartum tridentatum, Erica umbellata and Pinus pinaster) were analysed for total C, total N, δ15N, nutrients (soil-available; plant total), pH and inorganic-N (soils) and vegetation cover and height. No long-term effects of firefighting chemicals on soil properties were found except for pH (BS+Fo > BS+Ap), inorganic-N and P (BS+Ap > other treatments). BS+Ap plants usually showed higher values of δ15N, N, P and Na, but less K. Soil coverage by Pterospartum and Ulex was higher in BS+Ap than in other treatments, whereas the opposite was observed for Erica; shrubs were always taller in BS+Ap. After 3 years of growth, the size of pine seedlings followed the order BS+Ap > unburnt soil > other treatments. Foliar N and P, scrub regeneration and growth of pines showed the long-term fertilising effect of ammonium polyphosphate, although the second highest pine mortality was found in the BS+Ap treatment. The foaming agent did not affect vegetation cover, and Firesorb had no noticeable effect on shrubs but the highest pine mortality.


BMJ Open ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. e048172
Author(s):  
Marie Fly Lindholt ◽  
Frederik Jørgensen ◽  
Alexander Bor ◽  
Michael Bang Petersen

ObjectivesThe management of the COVID-19 pandemic hinges on the approval of safe and effective vaccines but, equally importantly, on high vaccine acceptance among people. To facilitate vaccine acceptance via effective health communication, it is key to understand levels of vaccine scepticism and the demographic, psychological and political predictors. To this end, we examine the levels and predictors of acceptance of an approved COVID-19 vaccine.Design, setting and participantsWe examine the levels and predictors of acceptance of an approved COVID-19 vaccine in large online surveys from eight Western democracies that differ in terms of the severity of the pandemic and their response: Denmark, France, Germany, Hungary, Sweden, Italy, UK and USA (total N=18 231). Survey respondents were quota sampled to match the population margins on age, gender and geographical location for each country. The study was conducted from September 2020 to February 2021, allowing us to assess changes in acceptance and predictors as COVID-19 vaccine programmes were rolled out.Outcome measureThe outcome of the study is self-reported acceptance of a COVID-19 vaccine approved and recommended by health authorities.ResultsThe data reveal large variations in vaccine acceptance that ranges from 83% in Denmark to 47% in France and Hungary. Lack of vaccine acceptance is associated with lack of trust in authorities and scientists, conspiratorial thinking and a lack of concern about COVID-19.ConclusionMost national levels of vaccine acceptance fall below estimates of the required threshold for herd immunity. The results emphasise the long-term importance of building trust in preparations for health emergencies such as the current pandemic. For health communication, the results emphasise the importance of focusing on personal consequences of infections and debunking of myths to guide communication strategies.


1999 ◽  
Vol 10 (6) ◽  
pp. 815-824 ◽  
Author(s):  
Kiyoshi Umeki ◽  
Kihachiro Kikuzawa

2012 ◽  
Vol 12 (5) ◽  
pp. 1789-1797 ◽  
Author(s):  
R. Gómez-Beas ◽  
A. Moñino ◽  
M. J. Polo

Abstract. In compliance with the development of the Water Framework Directive, there is a need for an integrated management of water resources, which involves the elaboration of reservoir management models. These models should include the operational and technical aspects which allow us to forecast an optimal management in the short term, besides the factors that may affect the volume of water stored in the medium and long term. The climate fluctuations of the water cycle that affect the reservoir watershed should be considered, as well as the social and economic aspects of the area. This paper shows the development of a management model for Rules reservoir (southern Spain), through which the water supply is regulated based on set criteria, in a sustainable way with existing commitments downstream, with the supply capacity being well established depending on demand, and the probability of failure when the operating requirements are not fulfilled. The results obtained allowed us: to find out the reservoir response at different time scales, to introduce an uncertainty analysis and to demonstrate the potential of the methodology proposed here as a tool for decision making.


2020 ◽  
Vol 12 (3) ◽  
pp. 1062 ◽  
Author(s):  
Francis Azumah Chimsah ◽  
Liqun Cai ◽  
Jun Wu ◽  
Renzhi Zhang

Sustainable food production has long been a priority for mankind and this is being challenged by limited arable land, challenged landscapes, and higher human population growth. China started conservation farming around the 1950’s. However, main Conservation Tillage (CT) research started in 1992. Using a systematic meta-analysis approach, this review aims at examining China’s approach to CT and to characterize the main outcomes of long-term CT research across northern China. Data from organizations in charge of CT research in China showed an improvement in crop yield of at least 4% under double cropping systems and 6% under single cropping systems in dry areas of northern China. Furthermore, long-term CT practices were reported to have improved soil physical properties (soil structure, bulk density, pore size, and aggregate stability), soil nutrient levels, and reduction in greenhouse gas emission. Other benefits include significant increase in income levels and protection of the environment. Limitations to CT practice highlighted in this study include occasional reduction in crop yields during initial years of cropping, significant reduction in total N of soils, increase in N2O emission, and the need for customized machinery for its implementation. Outcomes of CT practice are ecologically and economically beneficial though its limitations are worth cogitating.


2020 ◽  
Author(s):  
Christian Zúñiga-Méndez ◽  
Victor Meza-Picado ◽  
Sebastian Ugalde-Alfaro ◽  
Jhonny Méndez-Gamboa

Abstract Background: Part of the success of forest conservation programs is due to the economic sustainability they can provide to owners of forest resources, and how these management mechanisms can be used within an increasingly aggressive productive landscape matrix. However, there are currently no precise or up-to-date data on the economic relationships between land uses and their respective productive activities. This study designed a model to evaluate the opportunity cost of natural forest management, taking as a reference the primary productive activities that take place within the Arenal-Huetar Norte Conservation Area, in Costa Rica. Methods: Profitability data from 24 sites in natural forests with a forest management plan approved by the State Forest Administration was used, as well as geographic and productive information on alternative land uses. Results: Based on these data, an opportunity cost map was generated which shows a marked segregation of the forests into two main areas: a) a high-opportunity cost area, located south of the study area; and b) a medium-low opportunity cost area, to the center-north of the study area. Conclusions: It is concluded that ideal areas for timber harvesting are currently restricted to places far from the market, and with low opportunity costs (ranging between ≤ $0 ha -1 year -1 and $500 ha -1 year -1 ).


2021 ◽  
Vol 6 (3) ◽  
pp. 67328
Author(s):  
Nur Apriatun Nafisah ◽  
R.C.Hidayat Soesilohadi

Petungkriyono forest is a tropical rainforest with high biodiversity. The increasing tourism activities in Petungkriyono lead to land conversion. Dragonfly (order Odonata) is a good bioindicator for aquatic and terrestrial. This study aimed to compare the community structure of Odonata in natural forests and tourist sites. The method of collecting imago Odonata was done by direct searching, samples were captured using sweep netting. The results showed that the dragonflies found in all locations consisted of the same family, 2 families (Gomphidae and Libellulidae) from the suborder Anisoptera and 6 families (Calopterygidae, Chlorocyphidae, Coenagrionidae, Euphaidae Platycnemididae, and Platystictidae) from the suborder Zygoptera. The total species of dragonflies found in Sokokembang were 15 species with a total of 293 individuals, Tirta Muncar 13 species of 287 individuals, Karanggondang 17 species of 276 individuals, and Curug Lawe 14 species of 242 individuals. The highest relative abundance of individuals was in the natural forest of Sokokembang is Drepanosticta spatulifera (26.28%) and in Karanggondang Vestalis luctuosa (24.64%), while in the tourist forests of Tirta Muncar and Curug Lawe were Euphaea variegata (34.84% and 28.51 %). The structure of the Odonata community is based on the Shannon-Wiener diversity index in the natural forests of Sokokembang (2.18) and Karanggondang (2.21) at the tourist sites of Tirta Muncar (1.84) and Curug Lawe (2.11). The results showed that the structure of the Odonata community based on the level of the diversity index value, evenness index, and dominance index in natural forests and tourist sites in Petungkriyono forest was not significantly different. 


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