scholarly journals Effect of ecological and conventional managements on soil enzymatic activities in coffee agroecosystems

2018 ◽  
Vol 48 (4) ◽  
pp. 420-428
Author(s):  
Johana Juliet Caballero Vanegas ◽  
Karen Bibiana Mejía Zambrano ◽  
Lizeth Manuela Avellaneda-Torres
Keyword(s):  
Sustainable Management ◽  
Climatic Variability ◽  
Agricultural Practices ◽  
Enzymatic Activities ◽  
Acid And Alkaline Phosphatase ◽  
Dry Seasons ◽  
Synthetic Fertilizers ◽  
Coffee Agroecosystems ◽  
Alkaline And Acid Phosphatase

ABSTRACT Understanding the impacts of agricultural practices on soil quality indicators, such as enzymatic activities, is of great importance, in order to advance in their diagnosis and sustainable management. This study aimed to evaluate the effect of ecological and conventional agricultural managements on enzymatic activities of a soil under coffee agroecosystems. The enzymatic activities were associated with the biogeochemical cycles of nitrogen (urease and protease), phosphorus (acid and alkaline phosphatase) and carbon (β-glucosidase), during the rainy and dry seasons. Physical-chemical soil proprieties were also assessed and related to resilience scores linked to the climatic variability reported for the areas under study. The activities of urease, alkaline and acid phosphatase and ß-glucosidase were statistically higher in ecological agroecosystems than in conventional ones. This may be attributed to the greater application of organic waste in the ecological environment, as well as to the absence of pesticides and synthetic fertilizers, which allow better conditions for the microbial activity. The resilience scores to the climate variability that showed the highest correlations with the assessed enzymatic activities were: the farmers' knowledge on soil microorganisms, non-use of pesticides and synthetic fertilizers and non-dependence on external supplies. It was concluded that the enzymatic activities are modified by the management systems, being specifically favored by the ecological management. This agroecosystem, in the long term, ensures an efficient use of the soil resources, with a lower degradation and contamination.

Long-term impacts of agricultural practices and climatic variability on carbon storage in a permanent pasture

2011 ◽  
Vol 17 (12) ◽  
pp. 3534-3545 ◽  
Author(s):  
Katja Klumpp ◽  
Tiphaine Tallec ◽  
Noëlle Guix ◽  
Jean-François Soussana
Keyword(s):  
Carbon Storage ◽  
Climatic Variability ◽  
Agricultural Practices ◽  
Permanent Pasture

scholarly journals Hydrological processing of salinity and nitrate in the Salinas Valley agricultural watershed

2021 ◽  
Vol 193 (S1) ◽  
Author(s):  
Prudentia Zikalala ◽  
Isaya Kisekka ◽  
Mark Grismer
Keyword(s):  
Chemical Weathering ◽  
Climatic Variability ◽  
Agricultural Practices ◽  
Regime Shifts ◽  
Agricultural Watershed ◽  
Solute Flux ◽  
Positive Trend ◽  
Grab Sampling ◽  
Salinas River

AbstractRegime shifts of major salinity constituents (Ca, Mg, Na, K, SO4, Cl, HCO3, and NO3) in the lower Salinas River, an agricultural ecosystem, can have major impacts on ecosystem services central to continued agricultural production in the region. Regime shifts are large, persistent, and often abrupt changes in the structure and dynamics of social-ecological systems that occur when there is a reorganization of the dominant feedbacks in the system. Monitoring information on changes in the system state, controlling variables, and feedbacks is a crucial contributor to applying sustainability and ecosystem resilience at an operational level. To better understand the factors driving salinization of the lower Salinas River on the central coast of California, we examined a 27-year record of concentrations of major salinity constituents in the river. Although limited in providing an understanding of solute flux behavior during storm events, long-term “grab sampling” datasets with accompanying stream discharges can be used to estimate the actual history of concentrations and fluxes. We developed new concentration–discharge relationships to evaluate the dynamics of chemical weathering, hydrological processes, and agricultural practices in the watershed. Examinations of long-term records of surface water and groundwater salinity are required to provide both understanding and perspective towards managing salinity in arid and semi-arid regions while also enabling determination of the influence of external climatic variability and internal drivers in the system. We found that rock weathering is the main source of Ca, Mg, Na, HCO3, and SO4 in the river that further enables ion exchange between Ca, Mg, and Na. River concentrations of K, NO3, and Cl were associated with human activities while agricultural practices were the major source of K and NO3. A more direct anthropogenic positive trend in NO3 that has persisted since the mid-1990s is associated with the lag or memory effects of field cropping and use of flood irrigation. Event to inter-year scale patterns in the lower Salinas River salinity are further controlled by antecedent hydrologic conditions. This study underscores the importance of obtaining long-term monitoring records towards understanding watershed changes-of-state and time constants on the range of driving processes.

Effects of Long Term Application of Organic and Mineral Fertilizers on Soil Enzymes

2018 ◽  
Vol 69 (10) ◽  
pp. 2608-1612 ◽  
Author(s):  
Alina Dora Samuel ◽  
Simona Bungau ◽  
Delia Mirela Tit ◽  
Carmen Elena Melinte (Frunzulica) ◽  
Lavinia Purza ◽  
...  
Keyword(s):  
Biological Activity ◽  
Soil Quality ◽  
Soil Enzymes ◽  
Farmyard Manure ◽  
Enzymatic Activities ◽  
Mineral Fertilizers ◽  
Soil Biology ◽  
Soil Biological Activity ◽  
Organic And Mineral Fertilizers

Long term productivity and conservation of soils is critical for sustaining agricultural ecosystems. The specific objective of the work reported was to determine the effects of long term application of organic and mineral fertilizers on soil enzyme activity as an index of soil biology and biochemistry. Three key soil enzymes involved in intracellular metabolism of microorganisms and two soil enzymes involved in phosphorus metabolism were selected. Actual and potential dehydrogenase, catalase, acid and alkaline phosphatase activities were determined in the 0-20 cm layer of an eroded soil submitted to a complex fertilization experiment. Results showed that addition of mineral fertilizers to organic (green manure and farmyard manure) fertilizers led to a significant increase in each activity because of increased plant biomass production which upon incorporation stimulates soil biological activity. The enzymatic indicators of soil quality calculated from the values of enzymatic activities depending on the kind of fertilizers showed that by the determination of enzymatic activities valuable information can be obtained regarding fertility status of soils. A weak positive correlation between enzymatic indicators of soil quality and maize yield was established. The yield data demonstrate the superiority of farmyard manure which provided greater stability in crop production. Substantial improvement in soil biological activity due to application of organic fertilizers with mineral fertilizers contribute in maintaining the productivity and soil health.

scholarly journals Sustaining Rice Production through Biofertilization with N2-Fixing Cyanobacteria

2021 ◽  
Vol 11 (10) ◽  
pp. 4628
Author(s):  
Macarena Iniesta-Pallarés ◽  
Consolación Álvarez ◽  
Francisco M. Gordillo-Cantón ◽  
Carmen Ramírez-Moncayo ◽  
Pilar Alves-Martínez ◽  
...  
Keyword(s):  
Agricultural Practices ◽  
Vital Role ◽  
Rice Production ◽  
Point Of View ◽  
Paddy Fields ◽  
Nitrogen Fertilizers ◽  
Trophic Chain ◽  
Agricultural Practice ◽  
Biotechnological Potential

Current agricultural productivity depends on an exogenous nutrient supply to crops. This is of special relevance in cereal production, a fundamental part of the trophic chain that plays a vital role in the human diet. However, our agricultural practices entail highly detrimental side-effects from an environmental point of view. Long-term nitrogen fertilization in croplands results in degradation of soil, water, and air quality, producing eutrophication and subsequently contributing to global warming. In accordance with this, there is a biotechnological interest in using nitrogen-fixing microorganisms to enhance crop growth without adding chemically synthesized nitrogen fertilizers. This is particularly beneficial in paddy fields, where about 60% of the synthetic fertilizer that has been applied is dissolved in the water and washed away. In these agricultural systems, N2-fixing cyanobacteria show a promising biotechnological potential as biofertilizers, improving soil fertility while reducing the environmental impact of the agricultural practice. In the current study, Andalusian paddy fields have been explored to isolate N2-fixing cyanobacteria. These endogenous microorganisms have been subsequently re-introduced in a field trial in order to enhance rice production. Our results provide valuable insights regarding the use of an alternative natural source of nitrogen for rice production.

scholarly journals Bacterial Communities and Enzymatic Activities in Sediments of Long-Term Fish and Crab Aquaculture Ponds

2021 ◽  
Vol 9 (3) ◽  
pp. 501
Author(s):  
Zhimin Zhang ◽  
Qinghui Deng ◽  
Lingling Wan ◽  
Xiuyun Cao ◽  
Yiyong Zhou ◽  
...  
Keyword(s):  
Bacterial Communities ◽  
Enzymatic Activities ◽  
Nutrient Concentrations ◽  
Biological Processes ◽  
Farming Practices ◽  
Mitten Crab ◽  
Aquaculture Ponds ◽  
Pond Sediments ◽  
Sediment Ph

Aquaculture is among the most important and fastest growing agriculture sectors worldwide; however, it generates environmental impacts by introducing nutrient accumulations in ponds, which are possibly different and further result in complex biological processes in the sediments based on diverse farming practices. In this study, we investigated the effects of long-term farming practices of representative aquatic animals dominated by grass carp (GC, Ctenopharyngodon idella) or Chinese mitten crab (CMC, Eriocheir sinensis) on the bacterial community and enzyme activity of sediments from more than 15 years of aquaculture ponds, and the differences associated with sediment properties were explored in the two farming practices. Compared to CMC ponds, GC ponds had lower contents of TC, TN, and TP in sediments, and similar trends for sediment pH and moisture content. Sediment bacterial communities were significantly different between GC and CMC ponds, with higher bacterial richness and diversity in GC ponds. The bacterial communities among the pond sediments were closely associated with sediment pH, TC, and TN. Additionally, the results showed profoundly lower activities of β-1,4-glucosidase, leucine aminopeptidase, and phosphatase in the sediments of GC ponds than CMC ponds. Pearson’s correlation analysis further revealed strong positive correlations between the hydrolytic enzyme activities and nutrient concentrations among the aquaculture ponds, indicating microbial enzyme regulation response to sediment nutrient dynamics. Our study herein reveals that farming practices of fish and crab differently affect bacterial communities and enzymatic activities in pond sediments, suggesting nutrient-driven sediment biological processes in aquaculture ponds for different farming practices.

Agrodeforestation and the loss of agrobiodiversity in the Pacific Islands: a call for conservation

2014 ◽  
Vol 20 (2) ◽  
pp. 180 ◽  
Author(s):  
Randolph Thaman
Keyword(s):  
Biodiversity Conservation ◽  
Sustainable Management ◽  
Pacific Islands ◽  
Agricultural Land ◽  
Ecosystem Goods And Services ◽  
Livelihood Security ◽  
Goods And Services ◽  
The Pacific ◽  
Aichi Biodiversity Targets

Our ability to conserve biodiversity and to adapt to climate, environmental and economic change in the Pacific Islands will be greatly dependent on the conservation, restoration and enrichment of biodiversity within traditional multispecies agricultural land use systems. “Agrobiodiversity” is the most well-known, culturally-useful and accessible biodiversity on most islands and constitutes the most important foundation for ecosystem goods and services that support food, health, energy and livelihood security. This rich Pacific agrobiodiversity heritage, including associated ethnobiodiversity is highly threatened and deserves more prominence in mainstream conservation initiatives as a foundation for long-term sustainability. Such action is in line with Aichi Biodiversity Targets 7 and 13 which set goals for sustainable management of agriculture, fisheries and forestry, and the maintenance of genetic diversity as critical for successful biodiversity conservation globally. It is also supported by the findings of the Japan Satoyama-Satoumi Assessment, which stresses the critical importance of biodiversity conservation and ecosystem services provided by traditional agricultural and village landscapes.

Rising ecosystem water demand exacerbates the lengthening of tropical dry seasons

2021 ◽  
Author(s):  
Hao Xu ◽  
Xu Lian ◽  
Ingrid Slette ◽  
Hui Yang ◽  
Yuan Zhang ◽  
...  
Keyword(s):  
Water Demand ◽  
Potential Evapotranspiration ◽  
Central Africa ◽  
Dry Season ◽  
Land Area ◽  
Key Factor ◽  
Dry Seasons ◽  
The Tropics ◽  
Factor Governing

Abstract The timing and length of the dry season is a key factor governing ecosystem productivity and the carbon cycle of the tropics. Mounting evidence has suggested a lengthening of the dry season with ongoing climate change. However, this conclusion is largely based on changes in precipitation (P) compared to its long-term average (P ̅) and lacks consideration of the simultaneous changes in ecosystem water demand (measured by potential evapotranspiration, Ep, or actual evapotranspiration, E). Using several long-term (1979-2018) observational datasets, we compared changes in tropical dry season length (DSL) and timing (dry season arrival, DSA, and dry season end, DSE) among three common metrics used to define the dry season: P < P ̅, P < Ep, and P < E. We found that all three definitions show that dry seasons have lengthened in much of the tropics since 1979. Among the three definitions, P < E estimates the largest fraction (49.0%) of tropical land area likely experiencing longer dry seasons, followed by P < Ep (41.4%) and P < P ̅ (34.4%). The largest differences in multi-year mean DSL (> 120 days) among the three definitions occurred in the most arid and the most humid regions of the tropics. All definitions and datasets consistently showed longer dry seasons in southern Amazon (due to delayed DSE) and central Africa (due to both earlier DSA and delayed DSE). However, definitions that account for changing water demand estimated longer DSL extension over those two regions. These results indicate that warming-enhanced evapotranspiration exacerbates dry season lengthening and ecosystem water deficit. Thus, it is necessity to account for the evolving water demand of tropical ecosystems when characterizing changes in seasonal dry periods and ecosystem water deficits in an increasingly warmer and drier climate.

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