scholarly journals Nutrient Availability for Lactuca sativa Cultivated in an Amended Peatland: An Ionic Exchange Study

Nitrogen ◽  
2022 ◽  
Vol 3 (1) ◽  
pp. 26-42
Author(s):  
Jacynthe Dessureault-Rompré ◽  
Alexis Gloutney ◽  
Jean Caron

Few conservation strategies have been applied to cultivated peatland. This field study over one growth cycle of Lactuca sativa examined the effect of plant-based, high-C/N-ratio amendments in a real farming situation on peatland. Plant Root Simulator (PRS®) probes were used directly in the field to assess the impacts of incorporating Miscanthus x giganteus straw and Salix miyabeana chips on nutrient availability for lettuce. The results showed that lettuce yield decreased by 35% in the miscanthus straw treatment and by 14% in the willow chip treatment. In addition, the nitrogen flux rate was severely reduced during crop growth (75% reduction) and the plant N uptake index was much lower in the amended treatments than in the control. The phosphorus supply rate was also significantly lower (24% reduction) in the willow treatment. The influence of sampling zone was significant as well, with most macro-nutrients being depleted in the root zone and most micro-nutrients being mobilized. Additional work is needed to optimize the proposed conservation strategy and investigate the effects of consecutive years of soil amendment on different vegetable crops and in different types of cultivated peatlands to confirm and generalize the findings of this study. Future field studies should also explore the long-term carbon dynamics under plant-based, high-C/N-ratio amendments to determine if they can offset annual C losses.

2002 ◽  
Vol 12 (2) ◽  
pp. 250-256 ◽  
Author(s):  
Hudson Minshew ◽  
John Selker ◽  
Delbert Hemphill ◽  
Richard P. Dick

Predicting leaching of residual soil nitrate-nitrogen (NO3-N) in wet climates is important for reducing risks of groundwater contamination and conserving soil N. The goal of this research was to determine the potential to use easily measurable or readily available soilclimatic-plant data that could be put into simple computer models and used to predict NO3 leaching under various management systems. Two computer programs were compared for their potential to predict monthly NO3-N leaching losses in western Oregon vegetable systems with or without cover crops. The models were a statistical multiple linear regression (MLR) model and the commercially available Nitrate Leaching and Economical Analysis Package model (NLEAP 1.13). The best MLR model found using stepwise regression to predict annual leachate NO3-N had four independent variables (log transformed fall soil NO3-N, leachate volume, summer crop N uptake, and N fertilizer rate) (P < 0.001, R2 = 0.57). Comparisons were made between NLEAP and field data for mass of NO3-N leached between the months of September and May from 1992 to 1997. Predictions with NLEAP showed greater correlation to observed data during high-rainfall years compared to dry or averagerainfall years. The model was found to be sensitive to yield estimates, but vegetation management choices were limiting for vegetable crops and for systems that included a cover crop.


Author(s):  
Chang-Soo Kim ◽  
S. Sathyan ◽  
D.M. Porterfield
Keyword(s):  

2010 ◽  
Vol 34 (4) ◽  
pp. 699-711 ◽  
Author(s):  
Alexandre Schiavetti ◽  
Haydee Torres de Oliveira ◽  
Alene da Silva Lins ◽  
Pablo Santana Santos

Brazil was the first country in Latin America to establish and regulate this type of reserve, and there are currently more than 700 Private Nature Heritage Reserves (RPPN in Portuguese) officially recognized by either federal or state environmental agencies. Together, these RPPN protect more than a half million hectares of land in the country. The coastal forests in the southern part of Bahia State extend 100 to 200 km inland, gradually changing in physiognomy as they occupy the dryer inland areas. The coastal forest has been subjected to intense deforestation, and currently occupies less than 10% of its original area. For this work the creation processes of the RPPN were consulted to obtain the data creation time, size of property, the condition of the remaining forest, succession chain and the last paid tax. After that, interviews with the owners were made to confirm this data. Sixteen RPPN have been established in this region until 2005. Their sizes vary from 4.7 to 800 ha. Ten of these RPPN are located within state or federal conservation areas or their buffer zones. In spite of the numerous national and international conservation strategies and environmental policies focused on the region, the present situation of the cocoa zone is threatening the conservation of the region's natural resources. The establishment of private reserves in the cocoa region could conceivably improve these conservation efforts. This type of reserve can be established under a uniform system supported by federal legislation, and could count on private organizations.


2018 ◽  
Vol 22 (10) ◽  
pp. 5427-5444 ◽  
Author(s):  
Benjamin Mary ◽  
Luca Peruzzo ◽  
Jacopo Boaga ◽  
Myriam Schmutz ◽  
Yuxin Wu ◽  
...  

Abstract. The investigation of plant roots is inherently difficult and often neglected. Being out of sight, roots are often out of mind. Nevertheless, roots play a key role in the exchange of mass and energy between soil and the atmosphere, in addition to the many practical applications in agriculture. In this paper, we propose a method for roots imaging based on the joint use of two electrical noninvasive methods: electrical resistivity tomography (ERT) and mise-à-la-masse (MALM). The approach is based on the key assumption that the plant root system acts as an electrically conductive body, so that injecting electrical current into the plant stem will ultimately result in the injection of current into the subsoil through the root system, and particularly through the root terminations via hair roots. Evidence from field data, showing that voltage distribution is very different whether current is injected into the tree stem or in the ground, strongly supports this hypothesis. The proposed procedure involves a stepwise inversion of both ERT and MALM data that ultimately leads to the identification of electrical resistivity (ER) distribution and of the current injection root distribution in the three-dimensional soil space. This, in turn, is a proxy to the active (hair) root density in the ground. We tested the proposed procedure on synthetic data and, more importantly, on field data collected in a vineyard, where the estimated depth of the root zone proved to be in agreement with literature on similar crops. The proposed noninvasive approach is a step forward towards a better quantification of root structure and functioning.


2018 ◽  
Vol 8 (3) ◽  
pp. 1
Author(s):  
Dickson Adom

Biodiversity management in Ghana has been largely driven by scientific conservation models. The time-tested and useful traditional conservation ethos in the Ghanaian cultural and artistic elements such as festivals, proverbs, cosmological belief systems and taboos are often watered down by conservationists in biodiversity conservation schemes. This is due to conservationists’ lack of clear-cut guidelines on how to effectively utilize the traditional knowledge systems in complementing the scientific conservation models they are well versed. The developed traditional biodiversity strategy was based on the findings from a robust phenomenological study conducted among purposively and randomly sampled key stakeholders in biodiversity management in the Ashanti Region of Ghana. The document aims at offering comprehensive information and guidelines to conservationists on effective ways of implementing traditional knowledge systems in biodiversity conservation issues in Ghana. It ultimately aims at filling the dearth in traditional knowledge systems that have been an age-long problem for the conservation ministries and agencies in Ghana. The informative directions in the developed traditional biodiversity strategy would offer another lens to addressing conservation issues in Ghana while acting as a viable complement to the scientific models. This would ultimately maximize and enrich the conservation strategies for managing Ghana’s biodiversity.


2017 ◽  
Vol 9 (1) ◽  
pp. 55-59
Author(s):  
Dilpreet Talwar ◽  
Kulbir Singh ◽  
Jagdish Singh

Biofertilizers improves the soil microbial content, Soil nutrient status and nutrient uptake by plant. In an experiment, fifteen treatments comprised of various combinations of biofertilizers, organic manures and chemical fertilizers were compared to access the impact of different sources of nutrient on performance of onion. The highest soil organic carbon (0.40%) was observed in the treatments T12 (Farm Yard Manure (FYM) @ 20 t/ha) and T11 (FYM myctes count (29.9 X 104) was recorded in T11 (FYM @ 20 t/ha + Azotobacter + VAM) treatment while highest fungal @ 20 t/ha + Azotobacter + Vesicular-Arbuscular Mycorrhizae (VAM)). Highest bacterial (24.5 X 106) and actino-count (17.5 X 103) was observed in T3 (Azospirillium+ Recommended dose of NPK) treatment. At the time of harvesting, available nitrogen (N), available phosphorus (P) and available potassium (K) were higher in treatment T3 (Azospirillium + Recommended dose of NPK), T9 (Azotobacter+ VAM + Recommended dose of NPK) and T13 (Poultry treatment (162.6 Kg ha-1) as compared to all other treatments except T1 and T9 treatments while P uptake (13.6 Kg ha-Manure @ 5t/ha) treatments respectively than that in other treatments. Azospirillum and Azotobacter application along with recommended dose of N, P and K improved the fertility status of soil. The N uptake was significantly higher in T3 treatments. The present study highlights the need of use of biofertilizers along with organic and inorganic 1) was significantly higher in T9 treatment than that in other treatments except T1, T3, T5 and T7 treatments. The K uptake was significantly higher in T3 treatment (126.9 Kg ha-1) as compare to all other treatments except T1 and T9 manures/fertilizer to enhance the nutrient availability and improve soil health.


2020 ◽  
Author(s):  
Jing Yan ◽  
Nathaniel A. Bogie ◽  
Teamrat Ghezzehei

Abstract. Most plants derive their water and nutrient needs from soils, where the resources are often scarce, patchy, and ephemeral. In natural environments, it is not uncommon for plant roots to encounter mismatched patches of water-rich and nutrient-rich regions. Such an uneven distribution of resources necessitates plants to rely on strategies that allow them to explore and acquire nutrients from relatively dry patches. We conducted a laboratory study to provide a mechanistic understanding of the biophysical factors that enable this adaptation. We grew plants in split-root pots that permitted precisely controlled spatial distributions of resources. The results demonstrated that spatial mismatch of water and nutrient availability does not cost plant productivity compared to matched distributions. Specifically, we showed that nutrient uptake is not reduced by overall soil dryness, provided that the whole plant has access to sufficient water elsewhere in the root zone. Essential strategies include extensive root proliferation towards nutrient-rich dry soil patches that allows rapid nutrient capture from brief pulses. Using high-frequency water potential measurements, we also observed nocturnal water release by roots that inhabit dry and nutrient-rich soil patches. Soil water potential gradient is the primary driver of this transfer of water from wet to dry soil parts of the root zone, which is commonly known as hydraulic redistribution (HR). The occurrence of HR prevents the soil drying from approaching the permanent wilting point, and thus supports root functions and enhance nutrient availability. Our results indicate that roots facilitate HR by increasing root-hair density and length and deposition of organic coatings that alter water retention. Therefore, we conclude that biologically-controlled root adaptation involves multiple strategies that compensate for nutrient acquisition under mismatched resource distributions. Based on our findings, we proposed a nature-inspired nutrient management strategy for significantly curtailing water pollution from intensive agricultural systems.


2002 ◽  
Vol 127 (6) ◽  
pp. 1013-1017 ◽  
Author(s):  
Carmen Feller ◽  
Matthias Fink

To reduce nitrogen (N) losses from vegetable fields, fertilizer recommendations should be adjusted according to the large range in yield and thus in N uptake of vegetable crops. Therefore, a model was used to predict total N uptake based on expected yield. The model has been validated successfully in a series of studies for Brussels sprouts (Brassica oleracea L. var. gemmifera), white cabbage (Brassica oleracea L. var. capitata) and kohlrabi (Brassica oleracea L. var. gongylodes). The objective of this study was to validate the model for table beet (Beta vulgaris L. var. conditiva), a crop with a considerable variability in N uptake, which is caused by a large potential range of selecting sowing dates, plant densities and cultivars. Field experiments were carried out over two years. Fifty-five combinations of N fertilizer levels, plant densities, cultivars and sowing dates were tested. Plants were sampled at 2- or 3-week intervals, and fresh matter, dry matter and N content of leaves and roots were measured. Crop specific model parameters for table beets were determined from independent data. The model wverestimated N uptake for N-limiting conditions, but for optimally fertilized table beets measured and estimated N uptake showed a close correlation (R2 = 0.93) when total yield was used as an input parameter for the model. Although the error of estimation (35 kg·ha-1) was considerable, studies with other vegetable crops using the model found the error even higher if other tools, such as look-up tables, were used for predicting N uptake.


2020 ◽  
Vol 8 (2) ◽  
pp. 131-138
Author(s):  
Muhammad Yousaf Ali

The biggest responsibility of agriculture department is to produce food and cloth for huge population using the resource getting limited day by day. Water scarcity is most threatening among these limiting factors. New techniques are being developed day by day to utilize the water efficiently. Application of water only in the plant root zone will be one of the water saving technique to grow crops. This will control the losses due to evaporation and leaching. Irrigation to soil does not control the climate variables and precipitation cannot be substituted to irrigation. Sprinkler irrigation could be one of the way to utilize the water efficiently by in time application and reducing the losses of leaching and evaporation along with amelioration of micro climate of the crop. Canals and tube well water is conventionally given to crop through flood irrigation. These fields are in direct threat of evaporation and leaching resulting in excess water losses and damaging the soil quality. The study was designed taking cotton as experimental crop to calculate comparisons in plant growth parameters and yields along with water saving ability of different irrigation system. Maximum yield was obtained from sprinkler irrigation and water was saved under drip irrigation system.


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