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  • Open access
  • 26 Reads
How good are vegetation indices to assess water status and biochemical parameters in olive tree?

As the water is an increasingly scarce resource, the adoption of deficit irrigation (DI) strategies has become essential to optimize its use in agriculture. To implement DI, it is important to monitor the leaf water status during crop development by indicators such as Relative Water Content (RWC) and Leaf Water Potential (LWP) to optimize the crop production. However, these methods are destructive and time-consuming. Many relationships between spectral data from remote sensing observations and various biophysical and physiological crops parameters have been proposed, in which, Vegetation Indices (VIs) are widely used. This study aims to evaluate the relationship between VIs with leaf water status (RWC, LWP) and biochemical parameters, in a drip irrigated olive orchard (cv. Cobrançosa), located in the Northeast of Portugal (Alfândega da Fé). Five irrigation strategies were studied: full irrigated (FI), that received a volume of water equivalent to satisfy crop water needs, FI120 irrigated with 20% more than FI, two sustained deficit irrigation (SDI60 and SDI30) and farmer-managed irrigation (FMI). A list of 20 VIs was calculated and correlated with RWC, LWP and biochemical parameters. Although no good correlations were found between VIs and total polyphenols, a good agreement were found between: Photochemical Reflectance Index (PRI) and ortho-diphenols (R2=0.64); Green Normalized Difference Vegetation Index (GNDVI) and proline (R2=0.74); Normalized Difference Greenness Vegetation Index (NDGI) and glucose (R2=0.95); Transformed Chlorophyll Absorption Reflectance Index (TCARI) and LWP (R2=0.71); TCARI divided by Optimized Soil Adjusted Index (OSAVI) and RWC (R2=0.77). Thus, VIs appears as a useful tool to evaluate leaf water status and biochemical parameters from olive trees.

  • Open access
  • 14 Reads
Effect of differently matured compost produced from willow (Salix viminalis L.) on growth and development of lettuce (Lactuca sativa L.)

Soil amendments produced from peats, brown coals, and composts produced from segregated biodegradable waste or biomass from fallow lands can increase soil fertility and improve soil productivity. Due to the demand for alternative horticultural substrates in last years, the concept of compost production based on the willow biomass Salix viminalis L. has emerged1).
The aim of the study was to determine the possibility of using willow biomass composts as a substrate component in horticulture. The objects of the research were composts produced from willow chips (A), willow mixed with hay (B) and willow mixed with hay and mineral nitrogen (Nmin) fertilizer (C). Composting was carried out in a pile under aerobic conditions. To determine the biological activity and fertilizing value of the composts, a pot experiment was conducted to test the germination and growth of lettuce (Lactuca sativa L.) seedlings. Compost from various stages of maturity was added to the mineral soil in a dose of 200 t/ha respectively. Pot with mineral soil was the control object. Vegetation experiment lasted for 40 days and was conducted with lettuce seedlings. Lettuce yield was determined as well as basic properties of the compost variants used in the researches.
There were observed a significant increase in pH, total content of nitrogen, phosphorus, and a decrease in TOC in the composts with the addition of hay and Nmin. Results of the experiment showed that the highest yield was obtained from the pots with the mixture of willow, hay and Nmin. It was also observed that the test plants grew and developed better on substrates contained mature composts, compare to unmatured ones.
Based on the obtained results it can be concluded that the addition of hay and Nmin significantly increased fertilizing value of the investigated composts.

1)Copyright on the bases of application to the Polish Patent Office No. P.435103

  • Open access
  • 38 Reads

LCA of soybean supply chain produced in state of Pará, located on Brazilian amazon biome

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Recently, Brazil turned the biggest soybean producer and exporter of the world. The state of Pará, located in the Brazilian amazon biome, was turned one of last agricultural frontier of the country, which increased positively the soybean cultivation along it is territory. However, it is necessary to know the associated environmental impacts along the supply chain. Thus, we are applying the life cycle assessment (LCA) methodology using openLCA software in two producing regions: northeast pole (Paragominas) and south pole (Redenção). Based on the cradle to grave scope, the Recipe Midpoint (H) and Intergovernmental Panel on Climate Change (IPCC) method of environmental impacts categories were used. To calculate the land use change (LUC), we used the BRLUC regionalized model (v1.3). The obtained results showed that LUC were the main responsible for the global warming potential (GWP) along all soybean supply chain, especially when the land occupied with tropical forest was changed for soybean growth. Despite the largest distance between origin and destiny (road + railway = 1306 km), the soybean produced in south pole (Redenção) is better shipped through the TEGRAM port of São Luis – Maranhão due to the use of multimodal platforms (lorry + train), allowing a more efficient logistical performance (greater loads of grains transported and less environmental impacts). The soybean produced in northeast pole (Paragominas) is better shipped through the ports around Barcarena – Pará due to the shortest distance by road (average 350 km) and hence less environment impacts.

  • Open access
  • 16 Reads
Infiltration and Salt Leaching Effects due to Sandy Particles Adding on Heavy Saline-Alkali Topsoil, in Hetao Irrigation District

Introduction: Soil salinization restricts the Hetao Irrigation District (China) agriculture, affecting about 64% of total cultivated land. A common local practice to deal with this problem is to improve the topsoil by adding wind sand.This study deals with this problem, based on laboratory work, analysing its effects on soil infiltration and salt leaching

Material and Methods: Ulat Front Banner site samples of a silty loam saline soil were used, 40cm deep, with 21 g/kg of salinity. Wind sand was use to add in 30cm soil toplayer. The infiltration tests carried out on plastic columns with 9cm diameter and 45cm high, being loaded by soil mixed with aeolian sandy, with 2% to 30% ratio, supplied by a constant hydraulic head. The 30-40cm layer had unchanged soil. To determine the salt leaching in the soil column, soil samples were taken during 15 days to soil salinity measurement.

Results: It was observed an increase of the infiltration rate, from 1.1mm/h to 7.4mm/h (6.6 times more), in responde to the adding of 30% of sandy particles; also that the effect on salt leaching was significant, being observed on top 15 cm layer, after 7 days of infiltration, the salt relative decrease of 25%, 42%, and 55%, relatively to the treatments with 14%, 20% and 30% of sandy particles added, respectively.

Conclusions: The practice of adding sandy particles in the 30cm topsoil has a significant impact on soil infiltration and deep percolation salt leaching. A ratio of 30% of sand allowed an increase of 6.6 times of the infiltration rate, that in turn allowed a decrease about 50% of the soil salinity after one week of infiltration. This results are encouraging and appeal for field studies to assess the impact of field-scale drainage system, and the effects of this soil melioration on agronomical aspects.

  • Open access
  • 20 Reads
Evaluation of harvesting driving modes from environmental point of view

Numerous automatic technological processes control systems that are implemented in the modern agriculture equipment. Automation facilitates technological processes and allows to increase the technical potential such as shorter time of the technological process, more efficient use of the fertilizer, plant protection products and saves fuel. Machinery performance data collected and stored via Telemetry platform can be sent to customer’s computer for overview and decision- making for the following years. However, a significant quantity of data is not automatically processed by the Telemetry platform. Usually, the final decisions by customers are based on their experience. Farmers want to be sure that the equipment they use will not only depend on the technological process, but also reduce the negative impact on the environment.

The aim of this study is to analyze the combine harvester data collected in Telemetry platform during harvesting at manual and auto-steering mode. The study compares the influence of combine harvester steering modes on GHG emissions and diesel fuel consumption using the Life Cycle Assessment (LCA) modules.

The results show that global warming emission, using automatic steering mode, was reduced by 4.79% as compared to the manual driving mode. The diesel fuel consumption at automatic steering mode was reduced by 22.02% compared to the manual driving. The working time analysis has shown a more rational and more accurate technological operation during linear steering mode. In summary, the analysis of the structure work process provides detailed information that can increase the overall productivity of the machine and optimize the work process.

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